src/librustc_codegen_llvm/intrinsic.rs

   1 #![allow(non_upper_case_globals)]
   2
   3 use crate::attributes;
   4 use crate::llvm;
   5 use crate::llvm_util;
   6 use crate::abi::{Abi, FnType, LlvmType, PassMode};
   7 use crate::context::CodegenCx;
   8 use crate::type_::Type;
   9 use crate::type_of::LayoutLlvmExt;
  10 use crate::builder::Builder;
  11 use crate::value::Value;
  12 use crate::va_arg::emit_va_arg;
  13 use rustc_codegen_ssa::MemFlags;
  14 use rustc_codegen_ssa::mir::place::PlaceRef;
  15 use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue};
  16 use rustc_codegen_ssa::glue;
  17 use rustc_codegen_ssa::base::{to_immediate, wants_msvc_seh, compare_simd_types};
  18 use rustc::ty::{self, Ty};
  19 use rustc::ty::layout::{self, LayoutOf, HasTyCtxt, Primitive};
  20 use rustc_codegen_ssa::common::{IntPredicate, TypeKind};
  21 use rustc::hir;
  22 use syntax::ast::{self, FloatTy};
  23
  24 use rustc_codegen_ssa::traits::*;
  25
  26 use rustc::session::Session;
  27 use syntax_pos::Span;
  28
  29 use std::cmp::Ordering;
  30 use std::{iter, i128, u128};
  31
  32 fn get_simple_intrinsic(cx: &CodegenCx<'ll, '_>, name: &str) -> Option<&'ll Value> {
  33     let llvm_name = match name {
  34         "sqrtf32" => "llvm.sqrt.f32",
  35         "sqrtf64" => "llvm.sqrt.f64",
  36         "powif32" => "llvm.powi.f32",
  37         "powif64" => "llvm.powi.f64",
  38         "sinf32" => "llvm.sin.f32",
  39         "sinf64" => "llvm.sin.f64",
  40         "cosf32" => "llvm.cos.f32",
  41         "cosf64" => "llvm.cos.f64",
  42         "powf32" => "llvm.pow.f32",
  43         "powf64" => "llvm.pow.f64",
  44         "expf32" => "llvm.exp.f32",
  45         "expf64" => "llvm.exp.f64",
  46         "exp2f32" => "llvm.exp2.f32",
  47         "exp2f64" => "llvm.exp2.f64",
  48         "logf32" => "llvm.log.f32",
  49         "logf64" => "llvm.log.f64",
  50         "log10f32" => "llvm.log10.f32",
  51         "log10f64" => "llvm.log10.f64",
  52         "log2f32" => "llvm.log2.f32",
  53         "log2f64" => "llvm.log2.f64",
  54         "fmaf32" => "llvm.fma.f32",
  55         "fmaf64" => "llvm.fma.f64",
  56         "fabsf32" => "llvm.fabs.f32",
  57         "fabsf64" => "llvm.fabs.f64",
  58         "minnumf32" => "llvm.minnum.f32",
  59         "minnumf64" => "llvm.minnum.f64",
  60         "maxnumf32" => "llvm.maxnum.f32",
  61         "maxnumf64" => "llvm.maxnum.f64",
  62         "copysignf32" => "llvm.copysign.f32",
  63         "copysignf64" => "llvm.copysign.f64",
  64         "floorf32" => "llvm.floor.f32",
  65         "floorf64" => "llvm.floor.f64",
  66         "ceilf32" => "llvm.ceil.f32",
  67         "ceilf64" => "llvm.ceil.f64",
  68         "truncf32" => "llvm.trunc.f32",
  69         "truncf64" => "llvm.trunc.f64",
  70         "rintf32" => "llvm.rint.f32",
  71         "rintf64" => "llvm.rint.f64",
  72         "nearbyintf32" => "llvm.nearbyint.f32",
  73         "nearbyintf64" => "llvm.nearbyint.f64",
  74         "roundf32" => "llvm.round.f32",
  75         "roundf64" => "llvm.round.f64",
  76         "assume" => "llvm.assume",
  77         "abort" => "llvm.trap",
  78         _ => return None
  79     };
  80     Some(cx.get_intrinsic(&llvm_name))
  81 }
  82
  83 impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
  84     fn codegen_intrinsic_call(
  85         &mut self,
  86         callee_ty: Ty<'tcx>,
  87         fn_ty: &FnType<'tcx, Ty<'tcx>>,
  88         args: &[OperandRef<'tcx, &'ll Value>],
  89         llresult: &'ll Value,
  90         span: Span,
  91     ) {
  92         let tcx = self.tcx;
  93
  94         let (def_id, substs) = match callee_ty.sty {
  95             ty::FnDef(def_id, substs) => (def_id, substs),
  96             _ => bug!("expected fn item type, found {}", callee_ty)
  97         };
  98
  99         let sig = callee_ty.fn_sig(tcx);
 100         let sig = tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
 101         let arg_tys = sig.inputs();
 102         let ret_ty = sig.output();
 103         let name = &*tcx.item_name(def_id).as_str();
 104
 105         let llret_ty = self.layout_of(ret_ty).llvm_type(self);
 106         let result = PlaceRef::new_sized(llresult, fn_ty.ret.layout, fn_ty.ret.layout.align.abi);
 107
 108         let simple = get_simple_intrinsic(self, name);
 109         let llval = match name {
 110             _ if simple.is_some() => {
 111                 self.call(simple.unwrap(),
 112                         &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(),
 113                         None)
 114             }
 115             "unreachable" => {
 116                 return;
 117             },
 118             "likely" => {
 119                 let expect = self.get_intrinsic(&("llvm.expect.i1"));
 120                 self.call(expect, &[args[0].immediate(), self.const_bool(true)], None)
 121             }
 122             "unlikely" => {
 123                 let expect = self.get_intrinsic(&("llvm.expect.i1"));
 124                 self.call(expect, &[args[0].immediate(), self.const_bool(false)], None)
 125             }
 126             "try" => {
 127                 try_intrinsic(self,
 128                               args[0].immediate(),
 129                               args[1].immediate(),
 130                               args[2].immediate(),
 131                               llresult);
 132                 return;
 133             }
 134             "breakpoint" => {
 135                 let llfn = self.get_intrinsic(&("llvm.debugtrap"));
 136                 self.call(llfn, &[], None)
 137             }
 138             "size_of" => {
 139                 let tp_ty = substs.type_at(0);
 140                 self.const_usize(self.size_of(tp_ty).bytes())
 141             }
 142             "va_start" => {
 143                 self.va_start(args[0].immediate())
 144             }
 145             "va_end" => {
 146                 self.va_end(args[0].immediate())
 147             }
 148             "va_copy" => {
 149                 let va_list = match (tcx.lang_items().va_list(), &result.layout.ty.sty) {
 150                     (Some(did), ty::Adt(def, _)) if def.did == did => args[0].immediate(),
 151                     (Some(_), _)  => self.load(args[0].immediate(),
 152                                                tcx.data_layout.pointer_align.abi),
 153                     (None, _) => bug!("`va_list` language item must be defined")
 154                 };
 155                 let intrinsic = self.cx().get_intrinsic(&("llvm.va_copy"));
 156                 self.call(intrinsic, &[llresult, va_list], None);
 157                 return;
 158             }
 159             "va_arg" => {
 160                 match fn_ty.ret.layout.abi {
 161                     layout::Abi::Scalar(ref scalar) => {
 162                         match scalar.value {
 163                             Primitive::Int(..) => {
 164                                 if self.cx().size_of(ret_ty).bytes() < 4 {
 165                                     // va_arg should not be called on a integer type
 166                                     // less than 4 bytes in length. If it is, promote
 167                                     // the integer to a `i32` and truncate the result
 168                                     // back to the smaller type.
 169                                     let promoted_result = emit_va_arg(self, args[0],
 170                                                                       tcx.types.i32);
 171                                     self.trunc(promoted_result, llret_ty)
 172                                 } else {
 173                                     emit_va_arg(self, args[0], ret_ty)
 174                                 }
 175                             }
 176                             Primitive::Float(FloatTy::F64) |
 177                             Primitive::Pointer => {
 178                                 emit_va_arg(self, args[0], ret_ty)
 179                             }
 180                             // `va_arg` should never be used with the return type f32.
 181                             Primitive::Float(FloatTy::F32) => {
 182                                 bug!("the va_arg intrinsic does not work with `f32`")
 183                             }
 184                         }
 185                     }
 186                     _ => {
 187                         bug!("the va_arg intrinsic does not work with non-scalar types")
 188                     }
 189                 }
 190             }
 191             "size_of_val" => {
 192                 let tp_ty = substs.type_at(0);
 193                 if let OperandValue::Pair(_, meta) = args[0].val {
 194                     let (llsize, _) = glue::size_and_align_of_dst(self, tp_ty, Some(meta));
 195                     llsize
 196                 } else {
 197                     self.const_usize(self.size_of(tp_ty).bytes())
 198                 }
 199             }
 200             "min_align_of" => {
 201                 let tp_ty = substs.type_at(0);
 202                 self.const_usize(self.align_of(tp_ty).bytes())
 203             }
 204             "min_align_of_val" => {
 205                 let tp_ty = substs.type_at(0);
 206                 if let OperandValue::Pair(_, meta) = args[0].val {
 207                     let (_, llalign) = glue::size_and_align_of_dst(self, tp_ty, Some(meta));
 208                     llalign
 209                 } else {
 210                     self.const_usize(self.align_of(tp_ty).bytes())
 211                 }
 212             }
 213             "pref_align_of" => {
 214                 let tp_ty = substs.type_at(0);
 215                 self.const_usize(self.layout_of(tp_ty).align.pref.bytes())
 216             }
 217             "type_name" => {
 218                 let tp_ty = substs.type_at(0);
 219                 let ty_name = self.tcx.type_name(tp_ty);
 220                 OperandRef::from_const(self, ty_name).immediate_or_packed_pair(self)
 221             }
 222             "type_id" => {
 223                 self.const_u64(self.tcx.type_id_hash(substs.type_at(0)))
 224             }
 225             "init" => {
 226                 let ty = substs.type_at(0);
 227                 if !self.layout_of(ty).is_zst() {
 228                     // Just zero out the stack slot.
 229                     // If we store a zero constant, LLVM will drown in vreg allocation for large
 230                     // data structures, and the generated code will be awful. (A telltale sign of
 231                     // this is large quantities of `mov [byte ptr foo],0` in the generated code.)
 232                     memset_intrinsic(
 233                         self,
 234                         false,
 235                         ty,
 236                         llresult,
 237                         self.const_u8(0),
 238                         self.const_usize(1)
 239                     );
 240                 }
 241                 return;
 242             }
 243             // Effectively no-ops
 244             "uninit" | "forget" => {
 245                 return;
 246             }
 247             "needs_drop" => {
 248                 let tp_ty = substs.type_at(0);
 249
 250                 self.const_bool(self.type_needs_drop(tp_ty))
 251             }
 252             "offset" => {
 253                 let ptr = args[0].immediate();
 254                 let offset = args[1].immediate();
 255                 self.inbounds_gep(ptr, &[offset])
 256             }
 257             "arith_offset" => {
 258                 let ptr = args[0].immediate();
 259                 let offset = args[1].immediate();
 260                 self.gep(ptr, &[offset])
 261             }
 262
 263             "copy_nonoverlapping" => {
 264                 copy_intrinsic(self, false, false, substs.type_at(0),
 265                                args[1].immediate(), args[0].immediate(), args[2].immediate());
 266                 return;
 267             }
 268             "copy" => {
 269                 copy_intrinsic(self, true, false, substs.type_at(0),
 270                                args[1].immediate(), args[0].immediate(), args[2].immediate());
 271                 return;
 272             }
 273             "write_bytes" => {
 274                 memset_intrinsic(self, false, substs.type_at(0),
 275                                  args[0].immediate(), args[1].immediate(), args[2].immediate());
 276                 return;
 277             }
 278
 279             "volatile_copy_nonoverlapping_memory" => {
 280                 copy_intrinsic(self, false, true, substs.type_at(0),
 281                                args[0].immediate(), args[1].immediate(), args[2].immediate());
 282                 return;
 283             }
 284             "volatile_copy_memory" => {
 285                 copy_intrinsic(self, true, true, substs.type_at(0),
 286                                args[0].immediate(), args[1].immediate(), args[2].immediate());
 287                 return;
 288             }
 289             "volatile_set_memory" => {
 290                 memset_intrinsic(self, true, substs.type_at(0),
 291                                  args[0].immediate(), args[1].immediate(), args[2].immediate());
 292                 return;
 293             }
 294             "volatile_load" | "unaligned_volatile_load" => {
 295                 let tp_ty = substs.type_at(0);
 296                 let mut ptr = args[0].immediate();
 297                 if let PassMode::Cast(ty) = fn_ty.ret.mode {
 298                     ptr = self.pointercast(ptr, self.type_ptr_to(ty.llvm_type(self)));
 299                 }
 300                 let load = self.volatile_load(ptr);
 301                 let align = if name == "unaligned_volatile_load" {
 302                     1
 303                 } else {
 304                     self.align_of(tp_ty).bytes() as u32
 305                 };
 306                 unsafe {
 307                     llvm::LLVMSetAlignment(load, align);
 308                 }
 309                 to_immediate(self, load, self.layout_of(tp_ty))
 310             },
 311             "volatile_store" => {
 312                 let dst = args[0].deref(self.cx());
 313                 args[1].val.volatile_store(self, dst);
 314                 return;
 315             },
 316             "unaligned_volatile_store" => {
 317                 let dst = args[0].deref(self.cx());
 318                 args[1].val.unaligned_volatile_store(self, dst);
 319                 return;
 320             },
 321             "prefetch_read_data" | "prefetch_write_data" |
 322             "prefetch_read_instruction" | "prefetch_write_instruction" => {
 323                 let expect = self.get_intrinsic(&("llvm.prefetch"));
 324                 let (rw, cache_type) = match name {
 325                     "prefetch_read_data" => (0, 1),
 326                     "prefetch_write_data" => (1, 1),
 327                     "prefetch_read_instruction" => (0, 0),
 328                     "prefetch_write_instruction" => (1, 0),
 329                     _ => bug!()
 330                 };
 331                 self.call(expect, &[
 332                     args[0].immediate(),
 333                     self.const_i32(rw),
 334                     args[1].immediate(),
 335                     self.const_i32(cache_type)
 336                 ], None)
 337             },
 338             "ctlz" | "ctlz_nonzero" | "cttz" | "cttz_nonzero" | "ctpop" | "bswap" |
 339             "bitreverse" | "add_with_overflow" | "sub_with_overflow" |
 340             "mul_with_overflow" | "overflowing_add" | "overflowing_sub" | "overflowing_mul" |
 341             "unchecked_div" | "unchecked_rem" | "unchecked_shl" | "unchecked_shr" |
 342             "unchecked_add" | "unchecked_sub" | "unchecked_mul" | "exact_div" |
 343             "rotate_left" | "rotate_right" | "saturating_add" | "saturating_sub" => {
 344                 let ty = arg_tys[0];
 345                 match int_type_width_signed(ty, self) {
 346                     Some((width, signed)) =>
 347                         match name {
 348                             "ctlz" | "cttz" => {
 349                                 let y = self.const_bool(false);
 350                                 let llfn = self.get_intrinsic(
 351                                     &format!("llvm.{}.i{}", name, width),
 352                                 );
 353                                 self.call(llfn, &[args[0].immediate(), y], None)
 354                             }
 355                             "ctlz_nonzero" | "cttz_nonzero" => {
 356                                 let y = self.const_bool(true);
 357                                 let llvm_name = &format!("llvm.{}.i{}", &name[..4], width);
 358                                 let llfn = self.get_intrinsic(llvm_name);
 359                                 self.call(llfn, &[args[0].immediate(), y], None)
 360                             }
 361                             "ctpop" => self.call(
 362                                 self.get_intrinsic(&format!("llvm.ctpop.i{}", width)),
 363                                 &[args[0].immediate()],
 364                                 None
 365                             ),
 366                             "bswap" => {
 367                                 if width == 8 {
 368                                     args[0].immediate() // byte swap a u8/i8 is just a no-op
 369                                 } else {
 370                                     self.call(
 371                                         self.get_intrinsic(
 372                                             &format!("llvm.bswap.i{}", width),
 373                                         ),
 374                                         &[args[0].immediate()],
 375                                         None,
 376                                     )
 377                                 }
 378                             }
 379                             "bitreverse" => {
 380                                 self.call(
 381                                     self.get_intrinsic(
 382                                         &format!("llvm.bitreverse.i{}", width),
 383                                     ),
 384                                     &[args[0].immediate()],
 385                                     None,
 386                                 )
 387                             }
 388                             "add_with_overflow" | "sub_with_overflow" | "mul_with_overflow" => {
 389                                 let intrinsic = format!("llvm.{}{}.with.overflow.i{}",
 390                                                         if signed { 's' } else { 'u' },
 391                                                         &name[..3], width);
 392                                 let llfn = self.get_intrinsic(&intrinsic);
 393
 394                                 // Convert `i1` to a `bool`, and write it to the out parameter
 395                                 let pair = self.call(llfn, &[
 396                                     args[0].immediate(),
 397                                     args[1].immediate()
 398                                 ], None);
 399                                 let val = self.extract_value(pair, 0);
 400                                 let overflow = self.extract_value(pair, 1);
 401                                 let overflow = self.zext(overflow, self.type_bool());
 402
 403                                 let dest = result.project_field(self, 0);
 404                                 self.store(val, dest.llval, dest.align);
 405                                 let dest = result.project_field(self, 1);
 406                                 self.store(overflow, dest.llval, dest.align);
 407
 408                                 return;
 409                             },
 410                             "overflowing_add" => self.add(args[0].immediate(), args[1].immediate()),
 411                             "overflowing_sub" => self.sub(args[0].immediate(), args[1].immediate()),
 412                             "overflowing_mul" => self.mul(args[0].immediate(), args[1].immediate()),
 413                             "exact_div" =>
 414                                 if signed {
 415                                     self.exactsdiv(args[0].immediate(), args[1].immediate())
 416                                 } else {
 417                                     self.exactudiv(args[0].immediate(), args[1].immediate())
 418                                 },
 419                             "unchecked_div" =>
 420                                 if signed {
 421                                     self.sdiv(args[0].immediate(), args[1].immediate())
 422                                 } else {
 423                                     self.udiv(args[0].immediate(), args[1].immediate())
 424                                 },
 425                             "unchecked_rem" =>
 426                                 if signed {
 427                                     self.srem(args[0].immediate(), args[1].immediate())
 428                                 } else {
 429                                     self.urem(args[0].immediate(), args[1].immediate())
 430                                 },
 431                             "unchecked_shl" => self.shl(args[0].immediate(), args[1].immediate()),
 432                             "unchecked_shr" =>
 433                                 if signed {
 434                                     self.ashr(args[0].immediate(), args[1].immediate())
 435                                 } else {
 436                                     self.lshr(args[0].immediate(), args[1].immediate())
 437                                 },
 438                             "unchecked_add" => {
 439                                 if signed {
 440                                     self.unchecked_sadd(args[0].immediate(), args[1].immediate())
 441                                 } else {
 442                                     self.unchecked_uadd(args[0].immediate(), args[1].immediate())
 443                                 }
 444                             },
 445                             "unchecked_sub" => {
 446                                 if signed {
 447                                     self.unchecked_ssub(args[0].immediate(), args[1].immediate())
 448                                 } else {
 449                                     self.unchecked_usub(args[0].immediate(), args[1].immediate())
 450                                 }
 451                             },
 452                             "unchecked_mul" => {
 453                                 if signed {
 454                                     self.unchecked_smul(args[0].immediate(), args[1].immediate())
 455                                 } else {
 456                                     self.unchecked_umul(args[0].immediate(), args[1].immediate())
 457                                 }
 458                             },
 459                             "rotate_left" | "rotate_right" => {
 460                                 let is_left = name == "rotate_left";
 461                                 let val = args[0].immediate();
 462                                 let raw_shift = args[1].immediate();
 463                                 if llvm_util::get_major_version() >= 7 {
 464                                     // rotate = funnel shift with first two args the same
 465                                     let llvm_name = &format!("llvm.fsh{}.i{}",
 466                                                             if is_left { 'l' } else { 'r' }, width);
 467                                     let llfn = self.get_intrinsic(llvm_name);
 468                                     self.call(llfn, &[val, val, raw_shift], None)
 469                                 } else {
 470                                     // rotate_left: (X << (S % BW)) | (X >> ((BW - S) % BW))
 471                                     // rotate_right: (X << ((BW - S) % BW)) | (X >> (S % BW))
 472                                     let width = self.const_uint(
 473                                         self.type_ix(width),
 474                                         width,
 475                                     );
 476                                     let shift = self.urem(raw_shift, width);
 477                                     let width_minus_raw_shift = self.sub(width, raw_shift);
 478                                     let inv_shift = self.urem(width_minus_raw_shift, width);
 479                                     let shift1 = self.shl(
 480                                         val,
 481                                         if is_left { shift } else { inv_shift },
 482                                     );
 483                                     let shift2 = self.lshr(
 484                                         val,
 485                                         if !is_left { shift } else { inv_shift },
 486                                     );
 487                                     self.or(shift1, shift2)
 488                                 }
 489                             },
 490                             "saturating_add" | "saturating_sub" => {
 491                                 let is_add = name == "saturating_add";
 492                                 let lhs = args[0].immediate();
 493                                 let rhs = args[1].immediate();
 494                                 if llvm_util::get_major_version() >= 8 {
 495                                     let llvm_name = &format!("llvm.{}{}.sat.i{}",
 496                                                              if signed { 's' } else { 'u' },
 497                                                              if is_add { "add" } else { "sub" },
 498                                                              width);
 499                                     let llfn = self.get_intrinsic(llvm_name);
 500                                     self.call(llfn, &[lhs, rhs], None)
 501                                 } else {
 502                                     let llvm_name = &format!("llvm.{}{}.with.overflow.i{}",
 503                                                              if signed { 's' } else { 'u' },
 504                                                              if is_add { "add" } else { "sub" },
 505                                                              width);
 506                                     let llfn = self.get_intrinsic(llvm_name);
 507                                     let pair = self.call(llfn, &[lhs, rhs], None);
 508                                     let val = self.extract_value(pair, 0);
 509                                     let overflow = self.extract_value(pair, 1);
 510                                     let llty = self.type_ix(width);
 511
 512                                     let limit = if signed {
 513                                         let limit_lo = self.const_uint_big(
 514                                             llty, (i128::MIN >> (128 - width)) as u128);
 515                                         let limit_hi = self.const_uint_big(
 516                                             llty, (i128::MAX >> (128 - width)) as u128);
 517                                         let neg = self.icmp(
 518                                             IntPredicate::IntSLT, val, self.const_uint(llty, 0));
 519                                         self.select(neg, limit_hi, limit_lo)
 520                                     } else if is_add {
 521                                         self.const_uint_big(llty, u128::MAX >> (128 - width))
 522                                     } else {
 523                                         self.const_uint(llty, 0)
 524                                     };
 525                                     self.select(overflow, limit, val)
 526                                 }
 527                             },
 528                             _ => bug!(),
 529                         },
 530                     None => {
 531                         span_invalid_monomorphization_error(
 532                             tcx.sess, span,
 533                             &format!("invalid monomorphization of `{}` intrinsic: \
 534                                       expected basic integer type, found `{}`", name, ty));
 535                         return;
 536                     }
 537                 }
 538
 539             },
 540             "fadd_fast" | "fsub_fast" | "fmul_fast" | "fdiv_fast" | "frem_fast" => {
 541                 match float_type_width(arg_tys[0]) {
 542                     Some(_width) =>
 543                         match name {
 544                             "fadd_fast" => self.fadd_fast(args[0].immediate(), args[1].immediate()),
 545                             "fsub_fast" => self.fsub_fast(args[0].immediate(), args[1].immediate()),
 546                             "fmul_fast" => self.fmul_fast(args[0].immediate(), args[1].immediate()),
 547                             "fdiv_fast" => self.fdiv_fast(args[0].immediate(), args[1].immediate()),
 548                             "frem_fast" => self.frem_fast(args[0].immediate(), args[1].immediate()),
 549                             _ => bug!(),
 550                         },
 551                     None => {
 552                         span_invalid_monomorphization_error(
 553                             tcx.sess, span,
 554                             &format!("invalid monomorphization of `{}` intrinsic: \
 555                                       expected basic float type, found `{}`", name, arg_tys[0]));
 556                         return;
 557                     }
 558                 }
 559
 560             },
 561
 562             "discriminant_value" => {
 563                 args[0].deref(self.cx()).codegen_get_discr(self, ret_ty)
 564             }
 565
 566             name if name.starts_with("simd_") => {
 567                 match generic_simd_intrinsic(self, name,
 568                                              callee_ty,
 569                                              args,
 570                                              ret_ty, llret_ty,
 571                                              span) {
 572                     Ok(llval) => llval,
 573                     Err(()) => return
 574                 }
 575             }
 576             // This requires that atomic intrinsics follow a specific naming pattern:
 577             // "atomic_<operation>[_<ordering>]", and no ordering means SeqCst
 578             name if name.starts_with("atomic_") => {
 579                 use rustc_codegen_ssa::common::AtomicOrdering::*;
 580                 use rustc_codegen_ssa::common::
 581                     {SynchronizationScope, AtomicRmwBinOp};
 582
 583                 let split: Vec<&str> = name.split('_').collect();
 584
 585                 let is_cxchg = split[1] == "cxchg" || split[1] == "cxchgweak";
 586                 let (order, failorder) = match split.len() {
 587                     2 => (SequentiallyConsistent, SequentiallyConsistent),
 588                     3 => match split[2] {
 589                         "unordered" => (Unordered, Unordered),
 590                         "relaxed" => (Monotonic, Monotonic),
 591                         "acq"     => (Acquire, Acquire),
 592                         "rel"     => (Release, Monotonic),
 593                         "acqrel"  => (AcquireRelease, Acquire),
 594                         "failrelaxed" if is_cxchg =>
 595                             (SequentiallyConsistent, Monotonic),
 596                         "failacq" if is_cxchg =>
 597                             (SequentiallyConsistent, Acquire),
 598                         _ => self.sess().fatal("unknown ordering in atomic intrinsic")
 599                     },
 600                     4 => match (split[2], split[3]) {
 601                         ("acq", "failrelaxed") if is_cxchg =>
 602                             (Acquire, Monotonic),
 603                         ("acqrel", "failrelaxed") if is_cxchg =>
 604                             (AcquireRelease, Monotonic),
 605                         _ => self.sess().fatal("unknown ordering in atomic intrinsic")
 606                     },
 607                     _ => self.sess().fatal("Atomic intrinsic not in correct format"),
 608                 };
 609
 610                 let invalid_monomorphization = |ty| {
 611                     span_invalid_monomorphization_error(tcx.sess, span,
 612                         &format!("invalid monomorphization of `{}` intrinsic: \
 613                                   expected basic integer type, found `{}`", name, ty));
 614                 };
 615
 616                 match split[1] {
 617                     "cxchg" | "cxchgweak" => {
 618                         let ty = substs.type_at(0);
 619                         if int_type_width_signed(ty, self).is_some() {
 620                             let weak = split[1] == "cxchgweak";
 621                             let pair = self.atomic_cmpxchg(
 622                                 args[0].immediate(),
 623                                 args[1].immediate(),
 624                                 args[2].immediate(),
 625                                 order,
 626                                 failorder,
 627                                 weak);
 628                             let val = self.extract_value(pair, 0);
 629                             let success = self.extract_value(pair, 1);
 630                             let success = self.zext(success, self.type_bool());
 631
 632                             let dest = result.project_field(self, 0);
 633                             self.store(val, dest.llval, dest.align);
 634                             let dest = result.project_field(self, 1);
 635                             self.store(success, dest.llval, dest.align);
 636                             return;
 637                         } else {
 638                             return invalid_monomorphization(ty);
 639                         }
 640                     }
 641
 642                     "load" => {
 643                         let ty = substs.type_at(0);
 644                         if int_type_width_signed(ty, self).is_some() {
 645                             let size = self.size_of(ty);
 646                             self.atomic_load(args[0].immediate(), order, size)
 647                         } else {
 648                             return invalid_monomorphization(ty);
 649                         }
 650                     }
 651
 652                     "store" => {
 653                         let ty = substs.type_at(0);
 654                         if int_type_width_signed(ty, self).is_some() {
 655                             let size = self.size_of(ty);
 656                             self.atomic_store(
 657                                 args[1].immediate(),
 658                                 args[0].immediate(),
 659                                 order,
 660                                 size
 661                             );
 662                             return;
 663                         } else {
 664                             return invalid_monomorphization(ty);
 665                         }
 666                     }
 667
 668                     "fence" => {
 669                         self.atomic_fence(order, SynchronizationScope::CrossThread);
 670                         return;
 671                     }
 672
 673                     "singlethreadfence" => {
 674                         self.atomic_fence(order, SynchronizationScope::SingleThread);
 675                         return;
 676                     }
 677
 678                     // These are all AtomicRMW ops
 679                     op => {
 680                         let atom_op = match op {
 681                             "xchg"  => AtomicRmwBinOp::AtomicXchg,
 682                             "xadd"  => AtomicRmwBinOp::AtomicAdd,
 683                             "xsub"  => AtomicRmwBinOp::AtomicSub,
 684                             "and"   => AtomicRmwBinOp::AtomicAnd,
 685                             "nand"  => AtomicRmwBinOp::AtomicNand,
 686                             "or"    => AtomicRmwBinOp::AtomicOr,
 687                             "xor"   => AtomicRmwBinOp::AtomicXor,
 688                             "max"   => AtomicRmwBinOp::AtomicMax,
 689                             "min"   => AtomicRmwBinOp::AtomicMin,
 690                             "umax"  => AtomicRmwBinOp::AtomicUMax,
 691                             "umin"  => AtomicRmwBinOp::AtomicUMin,
 692                             _ => self.sess().fatal("unknown atomic operation")
 693                         };
 694
 695                         let ty = substs.type_at(0);
 696                         if int_type_width_signed(ty, self).is_some() {
 697                             self.atomic_rmw(
 698                                 atom_op,
 699                                 args[0].immediate(),
 700                                 args[1].immediate(),
 701                                 order
 702                             )
 703                         } else {
 704                             return invalid_monomorphization(ty);
 705                         }
 706                     }
 707                 }
 708             }
 709
 710             "nontemporal_store" => {
 711                 let dst = args[0].deref(self.cx());
 712                 args[1].val.nontemporal_store(self, dst);
 713                 return;
 714             }
 715
 716             _ => bug!("unknown intrinsic '{}'", name),
 717         };
 718
 719         if !fn_ty.ret.is_ignore() {
 720             if let PassMode::Cast(ty) = fn_ty.ret.mode {
 721                 let ptr_llty = self.type_ptr_to(ty.llvm_type(self));
 722                 let ptr = self.pointercast(result.llval, ptr_llty);
 723                 self.store(llval, ptr, result.align);
 724             } else {
 725                 OperandRef::from_immediate_or_packed_pair(self, llval, result.layout)
 726                     .val.store(self, result);
 727             }
 728         }
 729     }
 730
 731     fn abort(&mut self) {
 732         let fnname = self.get_intrinsic(&("llvm.trap"));
 733         self.call(fnname, &[], None);
 734     }
 735
 736     fn assume(&mut self, val: Self::Value) {
 737         let assume_intrinsic = self.get_intrinsic("llvm.assume");
 738         self.call(assume_intrinsic, &[val], None);
 739     }
 740
 741     fn expect(&mut self, cond: Self::Value, expected: bool) -> Self::Value {
 742         let expect = self.get_intrinsic(&"llvm.expect.i1");
 743         self.call(expect, &[cond, self.const_bool(expected)], None)
 744     }
 745
 746     fn va_start(&mut self, list: &'ll Value) -> &'ll Value {
 747         let target = &self.cx.tcx.sess.target.target;
 748         let arch = &target.arch;
 749         // A pointer to the architecture specific structure is passed to this
 750         // function. For pointer variants (i686, RISC-V, Windows, etc), we
 751         // should do do nothing, as the address to the pointer is needed. For
 752         // architectures with a architecture specific structure (`Aarch64`,
 753         // `X86_64`, etc), this function should load the structure from the
 754         // address provided.
 755         let va_list = match &**arch {
 756             _ if target.options.is_like_windows => list,
 757             "aarch64" if target.target_os == "ios" => list,
 758             "aarch64" | "x86_64" | "powerpc" =>
 759                 self.load(list, self.tcx().data_layout.pointer_align.abi),
 760             _ => list,
 761         };
 762         let intrinsic = self.cx().get_intrinsic("llvm.va_start");
 763         self.call(intrinsic, &[va_list], None)
 764     }
 765
 766     fn va_end(&mut self, list: &'ll Value) -> &'ll Value {
 767         let target = &self.cx.tcx.sess.target.target;
 768         let arch = &target.arch;
 769         // See the comment in `va_start` for the purpose of the following.
 770         let va_list = match &**arch {
 771             _ if target.options.is_like_windows => list,
 772             "aarch64" if target.target_os == "ios" => list,
 773             "aarch64" | "x86_64" | "powerpc" =>
 774                 self.load(list, self.tcx().data_layout.pointer_align.abi),
 775             _ => list,
 776         };
 777         let intrinsic = self.cx().get_intrinsic("llvm.va_end");
 778         self.call(intrinsic, &[va_list], None)
 779     }
 780 }
 781
 782 fn copy_intrinsic(
 783     bx: &mut Builder<'a, 'll, 'tcx>,
 784     allow_overlap: bool,
 785     volatile: bool,
 786     ty: Ty<'tcx>,
 787     dst: &'ll Value,
 788     src: &'ll Value,
 789     count: &'ll Value,
 790 ) {
 791     let (size, align) = bx.size_and_align_of(ty);
 792     let size = bx.mul(bx.const_usize(size.bytes()), count);
 793     let flags = if volatile {
 794         MemFlags::VOLATILE
 795     } else {
 796         MemFlags::empty()
 797     };
 798     if allow_overlap {
 799         bx.memmove(dst, align, src, align, size, flags);
 800     } else {
 801         bx.memcpy(dst, align, src, align, size, flags);
 802     }
 803 }
 804
 805 fn memset_intrinsic(
 806     bx: &mut Builder<'a, 'll, 'tcx>,
 807     volatile: bool,
 808     ty: Ty<'tcx>,
 809     dst: &'ll Value,
 810     val: &'ll Value,
 811     count: &'ll Value
 812 ) {
 813     let (size, align) = bx.size_and_align_of(ty);
 814     let size = bx.mul(bx.const_usize(size.bytes()), count);
 815     let flags = if volatile {
 816         MemFlags::VOLATILE
 817     } else {
 818         MemFlags::empty()
 819     };
 820     bx.memset(dst, val, size, align, flags);
 821 }
 822
 823 fn try_intrinsic(
 824     bx: &mut Builder<'a, 'll, 'tcx>,
 825     func: &'ll Value,
 826     data: &'ll Value,
 827     local_ptr: &'ll Value,
 828     dest: &'ll Value,
 829 ) {
 830     if bx.sess().no_landing_pads() {
 831         bx.call(func, &[data], None);
 832         let ptr_align = bx.tcx().data_layout.pointer_align.abi;
 833         bx.store(bx.const_null(bx.type_i8p()), dest, ptr_align);
 834     } else if wants_msvc_seh(bx.sess()) {
 835         codegen_msvc_try(bx, func, data, local_ptr, dest);
 836     } else {
 837         codegen_gnu_try(bx, func, data, local_ptr, dest);
 838     }
 839 }
 840
 841 // MSVC's definition of the `rust_try` function.
 842 //
 843 // This implementation uses the new exception handling instructions in LLVM
 844 // which have support in LLVM for SEH on MSVC targets. Although these
 845 // instructions are meant to work for all targets, as of the time of this
 846 // writing, however, LLVM does not recommend the usage of these new instructions
 847 // as the old ones are still more optimized.
 848 fn codegen_msvc_try(
 849     bx: &mut Builder<'a, 'll, 'tcx>,
 850     func: &'ll Value,
 851     data: &'ll Value,
 852     local_ptr: &'ll Value,
 853     dest: &'ll Value,
 854 ) {
 855     let llfn = get_rust_try_fn(bx, &mut |mut bx| {
 856         bx.set_personality_fn(bx.eh_personality());
 857
 858         let mut normal = bx.build_sibling_block("normal");
 859         let mut catchswitch = bx.build_sibling_block("catchswitch");
 860         let mut catchpad = bx.build_sibling_block("catchpad");
 861         let mut caught = bx.build_sibling_block("caught");
 862
 863         let func = llvm::get_param(bx.llfn(), 0);
 864         let data = llvm::get_param(bx.llfn(), 1);
 865         let local_ptr = llvm::get_param(bx.llfn(), 2);
 866
 867         // We're generating an IR snippet that looks like:
 868         //
 869         //   declare i32 @rust_try(%func, %data, %ptr) {
 870         //      %slot = alloca i64*
 871         //      invoke %func(%data) to label %normal unwind label %catchswitch
 872         //
 873         //   normal:
 874         //      ret i32 0
 875         //
 876         //   catchswitch:
 877         //      %cs = catchswitch within none [%catchpad] unwind to caller
 878         //
 879         //   catchpad:
 880         //      %tok = catchpad within %cs [%type_descriptor, 0, %slot]
 881         //      %ptr[0] = %slot[0]
 882         //      %ptr[1] = %slot[1]
 883         //      catchret from %tok to label %caught
 884         //
 885         //   caught:
 886         //      ret i32 1
 887         //   }
 888         //
 889         // This structure follows the basic usage of throw/try/catch in LLVM.
 890         // For example, compile this C++ snippet to see what LLVM generates:
 891         //
 892         //      #include <stdint.h>
 893         //
 894         //      int bar(void (*foo)(void), uint64_t *ret) {
 895         //          try {
 896         //              foo();
 897         //              return 0;
 898         //          } catch(uint64_t a[2]) {
 899         //              ret[0] = a[0];
 900         //              ret[1] = a[1];
 901         //              return 1;
 902         //          }
 903         //      }
 904         //
 905         // More information can be found in libstd's seh.rs implementation.
 906         let i64p = bx.type_ptr_to(bx.type_i64());
 907         let ptr_align = bx.tcx().data_layout.pointer_align.abi;
 908         let slot = bx.alloca(i64p, "slot", ptr_align);
 909         bx.invoke(func, &[data], normal.llbb(), catchswitch.llbb(), None);
 910
 911         normal.ret(bx.const_i32(0));
 912
 913         let cs = catchswitch.catch_switch(None, None, 1);
 914         catchswitch.add_handler(cs, catchpad.llbb());
 915
 916         let tydesc = match bx.tcx().lang_items().msvc_try_filter() {
 917             Some(did) => bx.get_static(did),
 918             None => bug!("msvc_try_filter not defined"),
 919         };
 920         let funclet = catchpad.catch_pad(cs, &[tydesc, bx.const_i32(0), slot]);
 921         let addr = catchpad.load(slot, ptr_align);
 922
 923         let i64_align = bx.tcx().data_layout.i64_align.abi;
 924         let arg1 = catchpad.load(addr, i64_align);
 925         let val1 = bx.const_i32(1);
 926         let gep1 = catchpad.inbounds_gep(addr, &[val1]);
 927         let arg2 = catchpad.load(gep1, i64_align);
 928         let local_ptr = catchpad.bitcast(local_ptr, i64p);
 929         let gep2 = catchpad.inbounds_gep(local_ptr, &[val1]);
 930         catchpad.store(arg1, local_ptr, i64_align);
 931         catchpad.store(arg2, gep2, i64_align);
 932         catchpad.catch_ret(&funclet, caught.llbb());
 933
 934         caught.ret(bx.const_i32(1));
 935     });
 936
 937     // Note that no invoke is used here because by definition this function
 938     // can't panic (that's what it's catching).
 939     let ret = bx.call(llfn, &[func, data, local_ptr], None);
 940     let i32_align = bx.tcx().data_layout.i32_align.abi;
 941     bx.store(ret, dest, i32_align);
 942 }
 943
 944 // Definition of the standard `try` function for Rust using the GNU-like model
 945 // of exceptions (e.g., the normal semantics of LLVM's `landingpad` and `invoke`
 946 // instructions).
 947 //
 948 // This codegen is a little surprising because we always call a shim
 949 // function instead of inlining the call to `invoke` manually here. This is done
 950 // because in LLVM we're only allowed to have one personality per function
 951 // definition. The call to the `try` intrinsic is being inlined into the
 952 // function calling it, and that function may already have other personality
 953 // functions in play. By calling a shim we're guaranteed that our shim will have
 954 // the right personality function.
 955 fn codegen_gnu_try(
 956     bx: &mut Builder<'a, 'll, 'tcx>,
 957     func: &'ll Value,
 958     data: &'ll Value,
 959     local_ptr: &'ll Value,
 960     dest: &'ll Value,
 961 ) {
 962     let llfn = get_rust_try_fn(bx, &mut |mut bx| {
 963         // Codegens the shims described above:
 964         //
 965         //   bx:
 966         //      invoke %func(%args...) normal %normal unwind %catch
 967         //
 968         //   normal:
 969         //      ret 0
 970         //
 971         //   catch:
 972         //      (ptr, _) = landingpad
 973         //      store ptr, %local_ptr
 974         //      ret 1
 975         //
 976         // Note that the `local_ptr` data passed into the `try` intrinsic is
 977         // expected to be `*mut *mut u8` for this to actually work, but that's
 978         // managed by the standard library.
 979
 980         let mut then = bx.build_sibling_block("then");
 981         let mut catch = bx.build_sibling_block("catch");
 982
 983         let func = llvm::get_param(bx.llfn(), 0);
 984         let data = llvm::get_param(bx.llfn(), 1);
 985         let local_ptr = llvm::get_param(bx.llfn(), 2);
 986         bx.invoke(func, &[data], then.llbb(), catch.llbb(), None);
 987         then.ret(bx.const_i32(0));
 988
 989         // Type indicator for the exception being thrown.
 990         //
 991         // The first value in this tuple is a pointer to the exception object
 992         // being thrown.  The second value is a "selector" indicating which of
 993         // the landing pad clauses the exception's type had been matched to.
 994         // rust_try ignores the selector.
 995         let lpad_ty = bx.type_struct(&[bx.type_i8p(), bx.type_i32()], false);
 996         let vals = catch.landing_pad(lpad_ty, bx.eh_personality(), 1);
 997         catch.add_clause(vals, bx.const_null(bx.type_i8p()));
 998         let ptr = catch.extract_value(vals, 0);
 999         let ptr_align = bx.tcx().data_layout.pointer_align.abi;
1000         let bitcast = catch.bitcast(local_ptr, bx.type_ptr_to(bx.type_i8p()));
1001         catch.store(ptr, bitcast, ptr_align);
1002         catch.ret(bx.const_i32(1));
1003     });
1004
1005     // Note that no invoke is used here because by definition this function
1006     // can't panic (that's what it's catching).
1007     let ret = bx.call(llfn, &[func, data, local_ptr], None);
1008     let i32_align = bx.tcx().data_layout.i32_align.abi;
1009     bx.store(ret, dest, i32_align);
1010 }
1011
1012 // Helper function to give a Block to a closure to codegen a shim function.
1013 // This is currently primarily used for the `try` intrinsic functions above.
1014 fn gen_fn<'ll, 'tcx>(
1015     cx: &CodegenCx<'ll, 'tcx>,
1016     name: &str,
1017     inputs: Vec<Ty<'tcx>>,
1018     output: Ty<'tcx>,
1019     codegen: &mut dyn FnMut(Builder<'_, 'll, 'tcx>),
1020 ) -> &'ll Value {
1021     let rust_fn_sig = ty::Binder::bind(cx.tcx.mk_fn_sig(
1022         inputs.into_iter(),
1023         output,
1024         false,
1025         hir::Unsafety::Unsafe,
1026         Abi::Rust
1027     ));
1028     let llfn = cx.define_internal_fn(name, rust_fn_sig);
1029     attributes::from_fn_attrs(cx, llfn, None, rust_fn_sig);
1030     let bx = Builder::new_block(cx, llfn, "entry-block");
1031     codegen(bx);
1032     llfn
1033 }
1034
1035 // Helper function used to get a handle to the `__rust_try` function used to
1036 // catch exceptions.
1037 //
1038 // This function is only generated once and is then cached.
1039 fn get_rust_try_fn<'ll, 'tcx>(
1040     cx: &CodegenCx<'ll, 'tcx>,
1041     codegen: &mut dyn FnMut(Builder<'_, 'll, 'tcx>),
1042 ) -> &'ll Value {
1043     if let Some(llfn) = cx.rust_try_fn.get() {
1044         return llfn;
1045     }
1046
1047     // Define the type up front for the signature of the rust_try function.
1048     let tcx = cx.tcx;
1049     let i8p = tcx.mk_mut_ptr(tcx.types.i8);
1050     let fn_ty = tcx.mk_fn_ptr(ty::Binder::bind(tcx.mk_fn_sig(
1051         iter::once(i8p),
1052         tcx.mk_unit(),
1053         false,
1054         hir::Unsafety::Unsafe,
1055         Abi::Rust
1056     )));
1057     let output = tcx.types.i32;
1058     let rust_try = gen_fn(cx, "__rust_try", vec![fn_ty, i8p, i8p], output, codegen);
1059     cx.rust_try_fn.set(Some(rust_try));
1060     rust_try
1061 }
1062
1063 fn span_invalid_monomorphization_error(a: &Session, b: Span, c: &str) {
1064     span_err!(a, b, E0511, "{}", c);
1065 }
1066
1067 fn generic_simd_intrinsic(
1068     bx: &mut Builder<'a, 'll, 'tcx>,
1069     name: &str,
1070     callee_ty: Ty<'tcx>,
1071     args: &[OperandRef<'tcx, &'ll Value>],
1072     ret_ty: Ty<'tcx>,
1073     llret_ty: &'ll Type,
1074     span: Span
1075 ) -> Result<&'ll Value, ()> {
1076     // macros for error handling:
1077     macro_rules! emit_error {
1078         ($msg: tt) => {
1079             emit_error!($msg, )
1080         };
1081         ($msg: tt, $($fmt: tt)*) => {
1082             span_invalid_monomorphization_error(
1083                 bx.sess(), span,
1084                 &format!(concat!("invalid monomorphization of `{}` intrinsic: ", $msg),
1085                          name, $($fmt)*));
1086         }
1087     }
1088
1089     macro_rules! return_error {
1090         ($($fmt: tt)*) => {
1091             {
1092                 emit_error!($($fmt)*);
1093                 return Err(());
1094             }
1095         }
1096     }
1097
1098     macro_rules! require {
1099         ($cond: expr, $($fmt: tt)*) => {
1100             if !$cond {
1101                 return_error!($($fmt)*);
1102             }
1103         };
1104     }
1105
1106     macro_rules! require_simd {
1107         ($ty: expr, $position: expr) => {
1108             require!($ty.is_simd(), "expected SIMD {} type, found non-SIMD `{}`", $position, $ty)
1109         }
1110     }
1111
1112     let tcx = bx.tcx();
1113     let sig = tcx.normalize_erasing_late_bound_regions(
1114         ty::ParamEnv::reveal_all(),
1115         &callee_ty.fn_sig(tcx),
1116     );
1117     let arg_tys = sig.inputs();
1118
1119     if name == "simd_select_bitmask" {
1120         let in_ty = arg_tys[0];
1121         let m_len = match in_ty.sty {
1122             // Note that this `.unwrap()` crashes for isize/usize, that's sort
1123             // of intentional as there's not currently a use case for that.
1124             ty::Int(i) => i.bit_width().unwrap(),
1125             ty::Uint(i) => i.bit_width().unwrap(),
1126             _ => return_error!("`{}` is not an integral type", in_ty),
1127         };
1128         require_simd!(arg_tys[1], "argument");
1129         let v_len = arg_tys[1].simd_size(tcx);
1130         require!(m_len == v_len,
1131                  "mismatched lengths: mask length `{}` != other vector length `{}`",
1132                  m_len, v_len
1133         );
1134         let i1 = bx.type_i1();
1135         let i1xn = bx.type_vector(i1, m_len as u64);
1136         let m_i1s = bx.bitcast(args[0].immediate(), i1xn);
1137         return Ok(bx.select(m_i1s, args[1].immediate(), args[2].immediate()));
1138     }
1139
1140     // every intrinsic below takes a SIMD vector as its first argument
1141     require_simd!(arg_tys[0], "input");
1142     let in_ty = arg_tys[0];
1143     let in_elem = arg_tys[0].simd_type(tcx);
1144     let in_len = arg_tys[0].simd_size(tcx);
1145
1146     let comparison = match name {
1147         "simd_eq" => Some(hir::BinOpKind::Eq),
1148         "simd_ne" => Some(hir::BinOpKind::Ne),
1149         "simd_lt" => Some(hir::BinOpKind::Lt),
1150         "simd_le" => Some(hir::BinOpKind::Le),
1151         "simd_gt" => Some(hir::BinOpKind::Gt),
1152         "simd_ge" => Some(hir::BinOpKind::Ge),
1153         _ => None
1154     };
1155
1156     if let Some(cmp_op) = comparison {
1157         require_simd!(ret_ty, "return");
1158
1159         let out_len = ret_ty.simd_size(tcx);
1160         require!(in_len == out_len,
1161                  "expected return type with length {} (same as input type `{}`), \
1162                   found `{}` with length {}",
1163                  in_len, in_ty,
1164                  ret_ty, out_len);
1165         require!(bx.type_kind(bx.element_type(llret_ty)) == TypeKind::Integer,
1166                  "expected return type with integer elements, found `{}` with non-integer `{}`",
1167                  ret_ty,
1168                  ret_ty.simd_type(tcx));
1169
1170         return Ok(compare_simd_types(bx,
1171                                      args[0].immediate(),
1172                                      args[1].immediate(),
1173                                      in_elem,
1174                                      llret_ty,
1175                                      cmp_op))
1176     }
1177
1178     if name.starts_with("simd_shuffle") {
1179         let n: usize = name["simd_shuffle".len()..].parse().unwrap_or_else(|_|
1180             span_bug!(span, "bad `simd_shuffle` instruction only caught in codegen?"));
1181
1182         require_simd!(ret_ty, "return");
1183
1184         let out_len = ret_ty.simd_size(tcx);
1185         require!(out_len == n,
1186                  "expected return type of length {}, found `{}` with length {}",
1187                  n, ret_ty, out_len);
1188         require!(in_elem == ret_ty.simd_type(tcx),
1189                  "expected return element type `{}` (element of input `{}`), \
1190                   found `{}` with element type `{}`",
1191                  in_elem, in_ty,
1192                  ret_ty, ret_ty.simd_type(tcx));
1193
1194         let total_len = in_len as u128 * 2;
1195
1196         let vector = args[2].immediate();
1197
1198         let indices: Option<Vec<_>> = (0..n)
1199             .map(|i| {
1200                 let arg_idx = i;
1201                 let val = bx.const_get_elt(vector, i as u64);
1202                 match bx.const_to_opt_u128(val, true) {
1203                     None => {
1204                         emit_error!("shuffle index #{} is not a constant", arg_idx);
1205                         None
1206                     }
1207                     Some(idx) if idx >= total_len => {
1208                         emit_error!("shuffle index #{} is out of bounds (limit {})",
1209                                     arg_idx, total_len);
1210                         None
1211                     }
1212                     Some(idx) => Some(bx.const_i32(idx as i32)),
1213                 }
1214             })
1215             .collect();
1216         let indices = match indices {
1217             Some(i) => i,
1218             None => return Ok(bx.const_null(llret_ty))
1219         };
1220
1221         return Ok(bx.shuffle_vector(args[0].immediate(),
1222                                     args[1].immediate(),
1223                                     bx.const_vector(&indices)))
1224     }
1225
1226     if name == "simd_insert" {
1227         require!(in_elem == arg_tys[2],
1228                  "expected inserted type `{}` (element of input `{}`), found `{}`",
1229                  in_elem, in_ty, arg_tys[2]);
1230         return Ok(bx.insert_element(args[0].immediate(),
1231                                     args[2].immediate(),
1232                                     args[1].immediate()))
1233     }
1234     if name == "simd_extract" {
1235         require!(ret_ty == in_elem,
1236                  "expected return type `{}` (element of input `{}`), found `{}`",
1237                  in_elem, in_ty, ret_ty);
1238         return Ok(bx.extract_element(args[0].immediate(), args[1].immediate()))
1239     }
1240
1241     if name == "simd_select" {
1242         let m_elem_ty = in_elem;
1243         let m_len = in_len;
1244         require_simd!(arg_tys[1], "argument");
1245         let v_len = arg_tys[1].simd_size(tcx);
1246         require!(m_len == v_len,
1247                  "mismatched lengths: mask length `{}` != other vector length `{}`",
1248                  m_len, v_len
1249         );
1250         match m_elem_ty.sty {
1251             ty::Int(_) => {},
1252             _ => return_error!("mask element type is `{}`, expected `i_`", m_elem_ty)
1253         }
1254         // truncate the mask to a vector of i1s
1255         let i1 = bx.type_i1();
1256         let i1xn = bx.type_vector(i1, m_len as u64);
1257         let m_i1s = bx.trunc(args[0].immediate(), i1xn);
1258         return Ok(bx.select(m_i1s, args[1].immediate(), args[2].immediate()));
1259     }
1260
1261     if name == "simd_bitmask" {
1262         // The `fn simd_bitmask(vector) -> unsigned integer` intrinsic takes a
1263         // vector mask and returns an unsigned integer containing the most
1264         // significant bit (MSB) of each lane.
1265         use rustc_target::abi::HasDataLayout;
1266
1267         // If the vector has less than 8 lanes, an u8 is returned with zeroed
1268         // trailing bits.
1269         let expected_int_bits = in_len.max(8);
1270         match ret_ty.sty {
1271            ty::Uint(i) if i.bit_width() == Some(expected_int_bits) => (),
1272             _ => return_error!(
1273                 "bitmask `{}`, expected `u{}`",
1274                 ret_ty, expected_int_bits
1275             ),
1276         }
1277
1278         // Integer vector <i{in_bitwidth} x in_len>:
1279         let (i_xn, in_elem_bitwidth) = match in_elem.sty {
1280             ty::Int(i) => (
1281                 args[0].immediate(),
1282                 i.bit_width().unwrap_or(bx.data_layout().pointer_size.bits() as _)
1283             ),
1284             ty::Uint(i) => (
1285                 args[0].immediate(),
1286                 i.bit_width().unwrap_or(bx.data_layout().pointer_size.bits() as _)
1287             ),
1288             _ => return_error!(
1289                 "vector argument `{}`'s element type `{}`, expected integer element type",
1290                 in_ty, in_elem
1291             ),
1292         };
1293
1294         // Shift the MSB to the right by "in_elem_bitwidth - 1" into the first bit position.
1295         let shift_indices = vec![
1296             bx.cx.const_int(bx.type_ix(in_elem_bitwidth as _), (in_elem_bitwidth - 1) as _); in_len
1297         ];
1298         let i_xn_msb = bx.lshr(i_xn, bx.const_vector(shift_indices.as_slice()));
1299         // Truncate vector to an <i1 x N>
1300         let i1xn = bx.trunc(i_xn_msb, bx.type_vector(bx.type_i1(), in_len as _));
1301         // Bitcast <i1 x N> to iN:
1302         let i_ = bx.bitcast(i1xn, bx.type_ix(in_len as _));
1303         // Zero-extend iN to the bitmask type:
1304         return Ok(bx.zext(i_, bx.type_ix(expected_int_bits as _)));
1305     }
1306
1307     fn simd_simple_float_intrinsic(
1308         name: &str,
1309         in_elem: &::rustc::ty::TyS<'_>,
1310         in_ty: &::rustc::ty::TyS<'_>,
1311         in_len: usize,
1312         bx: &mut Builder<'a, 'll, 'tcx>,
1313         span: Span,
1314         args: &[OperandRef<'tcx, &'ll Value>],
1315     ) -> Result<&'ll Value, ()> {
1316         macro_rules! emit_error {
1317             ($msg: tt) => {
1318                 emit_error!($msg, )
1319             };
1320             ($msg: tt, $($fmt: tt)*) => {
1321                 span_invalid_monomorphization_error(
1322                     bx.sess(), span,
1323                     &format!(concat!("invalid monomorphization of `{}` intrinsic: ", $msg),
1324                              name, $($fmt)*));
1325             }
1326         }
1327         macro_rules! return_error {
1328             ($($fmt: tt)*) => {
1329                 {
1330                     emit_error!($($fmt)*);
1331                     return Err(());
1332                 }
1333             }
1334         }
1335         let ety = match in_elem.sty {
1336             ty::Float(f) if f.bit_width() == 32 => {
1337                 if in_len < 2 || in_len > 16 {
1338                     return_error!(
1339                         "unsupported floating-point vector `{}` with length `{}` \
1340                          out-of-range [2, 16]",
1341                         in_ty, in_len);
1342                 }
1343                 "f32"
1344             },
1345             ty::Float(f) if f.bit_width() == 64 => {
1346                 if in_len < 2 || in_len > 8 {
1347                     return_error!("unsupported floating-point vector `{}` with length `{}` \
1348                                    out-of-range [2, 8]",
1349                                   in_ty, in_len);
1350                 }
1351                 "f64"
1352             },
1353             ty::Float(f) => {
1354                 return_error!("unsupported element type `{}` of floating-point vector `{}`",
1355                               f, in_ty);
1356             },
1357             _ => {
1358                 return_error!("`{}` is not a floating-point type", in_ty);
1359             }
1360         };
1361
1362         let llvm_name = &format!("llvm.{0}.v{1}{2}", name, in_len, ety);
1363         let intrinsic = bx.get_intrinsic(&llvm_name);
1364         let c = bx.call(intrinsic,
1365                         &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(),
1366                         None);
1367         unsafe { llvm::LLVMRustSetHasUnsafeAlgebra(c) };
1368         Ok(c)
1369     }
1370
1371     match name {
1372         "simd_fsqrt" => {
1373             return simd_simple_float_intrinsic("sqrt", in_elem, in_ty, in_len, bx, span, args);
1374         }
1375         "simd_fsin" => {
1376             return simd_simple_float_intrinsic("sin", in_elem, in_ty, in_len, bx, span, args);
1377         }
1378         "simd_fcos" => {
1379             return simd_simple_float_intrinsic("cos", in_elem, in_ty, in_len, bx, span, args);
1380         }
1381         "simd_fabs" => {
1382             return simd_simple_float_intrinsic("fabs", in_elem, in_ty, in_len, bx, span, args);
1383         }
1384         "simd_floor" => {
1385             return simd_simple_float_intrinsic("floor", in_elem, in_ty, in_len, bx, span, args);
1386         }
1387         "simd_ceil" => {
1388             return simd_simple_float_intrinsic("ceil", in_elem, in_ty, in_len, bx, span, args);
1389         }
1390         "simd_fexp" => {
1391             return simd_simple_float_intrinsic("exp", in_elem, in_ty, in_len, bx, span, args);
1392         }
1393         "simd_fexp2" => {
1394             return simd_simple_float_intrinsic("exp2", in_elem, in_ty, in_len, bx, span, args);
1395         }
1396         "simd_flog10" => {
1397             return simd_simple_float_intrinsic("log10", in_elem, in_ty, in_len, bx, span, args);
1398         }
1399         "simd_flog2" => {
1400             return simd_simple_float_intrinsic("log2", in_elem, in_ty, in_len, bx, span, args);
1401         }
1402         "simd_flog" => {
1403             return simd_simple_float_intrinsic("log", in_elem, in_ty, in_len, bx, span, args);
1404         }
1405         "simd_fpowi" => {
1406             return simd_simple_float_intrinsic("powi", in_elem, in_ty, in_len, bx, span, args);
1407         }
1408         "simd_fpow" => {
1409             return simd_simple_float_intrinsic("pow", in_elem, in_ty, in_len, bx, span, args);
1410         }
1411         "simd_fma" => {
1412             return simd_simple_float_intrinsic("fma", in_elem, in_ty, in_len, bx, span, args);
1413         }
1414         _ => { /* fallthrough */ }
1415     }
1416
1417     // FIXME: use:
1418     //  https://github.com/llvm-mirror/llvm/blob/master/include/llvm/IR/Function.h#L182
1419     //  https://github.com/llvm-mirror/llvm/blob/master/include/llvm/IR/Intrinsics.h#L81
1420     fn llvm_vector_str(elem_ty: Ty<'_>, vec_len: usize, no_pointers: usize) -> String {
1421         let p0s: String = "p0".repeat(no_pointers);
1422         match elem_ty.sty {
1423             ty::Int(v) => format!("v{}{}i{}", vec_len, p0s, v.bit_width().unwrap()),
1424             ty::Uint(v) => format!("v{}{}i{}", vec_len, p0s, v.bit_width().unwrap()),
1425             ty::Float(v) => format!("v{}{}f{}", vec_len, p0s, v.bit_width()),
1426             _ => unreachable!(),
1427         }
1428     }
1429
1430     fn llvm_vector_ty(cx: &CodegenCx<'ll, '_>, elem_ty: Ty<'_>, vec_len: usize,
1431                       mut no_pointers: usize) -> &'ll Type {
1432         // FIXME: use cx.layout_of(ty).llvm_type() ?
1433         let mut elem_ty = match elem_ty.sty {
1434             ty::Int(v) => cx.type_int_from_ty( v),
1435             ty::Uint(v) => cx.type_uint_from_ty( v),
1436             ty::Float(v) => cx.type_float_from_ty( v),
1437             _ => unreachable!(),
1438         };
1439         while no_pointers > 0 {
1440             elem_ty = cx.type_ptr_to(elem_ty);
1441             no_pointers -= 1;
1442         }
1443         cx.type_vector(elem_ty, vec_len as u64)
1444     }
1445
1446
1447     if name == "simd_gather" {
1448         // simd_gather(values: <N x T>, pointers: <N x *_ T>,
1449         //             mask: <N x i{M}>) -> <N x T>
1450         // * N: number of elements in the input vectors
1451         // * T: type of the element to load
1452         // * M: any integer width is supported, will be truncated to i1
1453
1454         // All types must be simd vector types
1455         require_simd!(in_ty, "first");
1456         require_simd!(arg_tys[1], "second");
1457         require_simd!(arg_tys[2], "third");
1458         require_simd!(ret_ty, "return");
1459
1460         // Of the same length:
1461         require!(in_len == arg_tys[1].simd_size(tcx),
1462                  "expected {} argument with length {} (same as input type `{}`), \
1463                   found `{}` with length {}", "second", in_len, in_ty, arg_tys[1],
1464                  arg_tys[1].simd_size(tcx));
1465         require!(in_len == arg_tys[2].simd_size(tcx),
1466                  "expected {} argument with length {} (same as input type `{}`), \
1467                   found `{}` with length {}", "third", in_len, in_ty, arg_tys[2],
1468                  arg_tys[2].simd_size(tcx));
1469
1470         // The return type must match the first argument type
1471         require!(ret_ty == in_ty,
1472                  "expected return type `{}`, found `{}`",
1473                  in_ty, ret_ty);
1474
1475         // This counts how many pointers
1476         fn ptr_count(t: Ty<'_>) -> usize {
1477             match t.sty {
1478                 ty::RawPtr(p) => 1 + ptr_count(p.ty),
1479                 _ => 0,
1480             }
1481         }
1482
1483         // Non-ptr type
1484         fn non_ptr(t: Ty<'_>) -> Ty<'_> {
1485             match t.sty {
1486                 ty::RawPtr(p) => non_ptr(p.ty),
1487                 _ => t,
1488             }
1489         }
1490
1491         // The second argument must be a simd vector with an element type that's a pointer
1492         // to the element type of the first argument
1493         let (pointer_count, underlying_ty) = match arg_tys[1].simd_type(tcx).sty {
1494             ty::RawPtr(p) if p.ty == in_elem => (ptr_count(arg_tys[1].simd_type(tcx)),
1495                                                  non_ptr(arg_tys[1].simd_type(tcx))),
1496             _ => {
1497                 require!(false, "expected element type `{}` of second argument `{}` \
1498                                  to be a pointer to the element type `{}` of the first \
1499                                  argument `{}`, found `{}` != `*_ {}`",
1500                          arg_tys[1].simd_type(tcx), arg_tys[1], in_elem, in_ty,
1501                          arg_tys[1].simd_type(tcx), in_elem);
1502                 unreachable!();
1503             }
1504         };
1505         assert!(pointer_count > 0);
1506         assert_eq!(pointer_count - 1, ptr_count(arg_tys[0].simd_type(tcx)));
1507         assert_eq!(underlying_ty, non_ptr(arg_tys[0].simd_type(tcx)));
1508
1509         // The element type of the third argument must be a signed integer type of any width:
1510         match arg_tys[2].simd_type(tcx).sty {
1511             ty::Int(_) => (),
1512             _ => {
1513                 require!(false, "expected element type `{}` of third argument `{}` \
1514                                  to be a signed integer type",
1515                          arg_tys[2].simd_type(tcx), arg_tys[2]);
1516             }
1517         }
1518
1519         // Alignment of T, must be a constant integer value:
1520         let alignment_ty = bx.type_i32();
1521         let alignment = bx.const_i32(bx.align_of(in_elem).bytes() as i32);
1522
1523         // Truncate the mask vector to a vector of i1s:
1524         let (mask, mask_ty) = {
1525             let i1 = bx.type_i1();
1526             let i1xn = bx.type_vector(i1, in_len as u64);
1527             (bx.trunc(args[2].immediate(), i1xn), i1xn)
1528         };
1529
1530         // Type of the vector of pointers:
1531         let llvm_pointer_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count);
1532         let llvm_pointer_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count);
1533
1534         // Type of the vector of elements:
1535         let llvm_elem_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count - 1);
1536         let llvm_elem_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count - 1);
1537
1538         let llvm_intrinsic = format!("llvm.masked.gather.{}.{}",
1539                                      llvm_elem_vec_str, llvm_pointer_vec_str);
1540         let f = bx.declare_cfn(&llvm_intrinsic,
1541                                      bx.type_func(&[
1542                                          llvm_pointer_vec_ty,
1543                                          alignment_ty,
1544                                          mask_ty,
1545                                          llvm_elem_vec_ty], llvm_elem_vec_ty));
1546         llvm::SetUnnamedAddr(f, false);
1547         let v = bx.call(f, &[args[1].immediate(), alignment, mask, args[0].immediate()],
1548                         None);
1549         return Ok(v);
1550     }
1551
1552     if name == "simd_scatter" {
1553         // simd_scatter(values: <N x T>, pointers: <N x *mut T>,
1554         //             mask: <N x i{M}>) -> ()
1555         // * N: number of elements in the input vectors
1556         // * T: type of the element to load
1557         // * M: any integer width is supported, will be truncated to i1
1558
1559         // All types must be simd vector types
1560         require_simd!(in_ty, "first");
1561         require_simd!(arg_tys[1], "second");
1562         require_simd!(arg_tys[2], "third");
1563
1564         // Of the same length:
1565         require!(in_len == arg_tys[1].simd_size(tcx),
1566                  "expected {} argument with length {} (same as input type `{}`), \
1567                   found `{}` with length {}", "second", in_len, in_ty, arg_tys[1],
1568                  arg_tys[1].simd_size(tcx));
1569         require!(in_len == arg_tys[2].simd_size(tcx),
1570                  "expected {} argument with length {} (same as input type `{}`), \
1571                   found `{}` with length {}", "third", in_len, in_ty, arg_tys[2],
1572                  arg_tys[2].simd_size(tcx));
1573
1574         // This counts how many pointers
1575         fn ptr_count(t: Ty<'_>) -> usize {
1576             match t.sty {
1577                 ty::RawPtr(p) => 1 + ptr_count(p.ty),
1578                 _ => 0,
1579             }
1580         }
1581
1582         // Non-ptr type
1583         fn non_ptr(t: Ty<'_>) -> Ty<'_> {
1584             match t.sty {
1585                 ty::RawPtr(p) => non_ptr(p.ty),
1586                 _ => t,
1587             }
1588         }
1589
1590         // The second argument must be a simd vector with an element type that's a pointer
1591         // to the element type of the first argument
1592         let (pointer_count, underlying_ty) = match arg_tys[1].simd_type(tcx).sty {
1593             ty::RawPtr(p) if p.ty == in_elem && p.mutbl == hir::MutMutable
1594                 => (ptr_count(arg_tys[1].simd_type(tcx)),
1595                     non_ptr(arg_tys[1].simd_type(tcx))),
1596             _ => {
1597                 require!(false, "expected element type `{}` of second argument `{}` \
1598                                  to be a pointer to the element type `{}` of the first \
1599                                  argument `{}`, found `{}` != `*mut {}`",
1600                          arg_tys[1].simd_type(tcx), arg_tys[1], in_elem, in_ty,
1601                          arg_tys[1].simd_type(tcx), in_elem);
1602                 unreachable!();
1603             }
1604         };
1605         assert!(pointer_count > 0);
1606         assert_eq!(pointer_count - 1, ptr_count(arg_tys[0].simd_type(tcx)));
1607         assert_eq!(underlying_ty, non_ptr(arg_tys[0].simd_type(tcx)));
1608
1609         // The element type of the third argument must be a signed integer type of any width:
1610         match arg_tys[2].simd_type(tcx).sty {
1611             ty::Int(_) => (),
1612             _ => {
1613                 require!(false, "expected element type `{}` of third argument `{}` \
1614                                  to be a signed integer type",
1615                          arg_tys[2].simd_type(tcx), arg_tys[2]);
1616             }
1617         }
1618
1619         // Alignment of T, must be a constant integer value:
1620         let alignment_ty = bx.type_i32();
1621         let alignment = bx.const_i32(bx.align_of(in_elem).bytes() as i32);
1622
1623         // Truncate the mask vector to a vector of i1s:
1624         let (mask, mask_ty) = {
1625             let i1 = bx.type_i1();
1626             let i1xn = bx.type_vector(i1, in_len as u64);
1627             (bx.trunc(args[2].immediate(), i1xn), i1xn)
1628         };
1629
1630         let ret_t = bx.type_void();
1631
1632         // Type of the vector of pointers:
1633         let llvm_pointer_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count);
1634         let llvm_pointer_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count);
1635
1636         // Type of the vector of elements:
1637         let llvm_elem_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count - 1);
1638         let llvm_elem_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count - 1);
1639
1640         let llvm_intrinsic = format!("llvm.masked.scatter.{}.{}",
1641                                      llvm_elem_vec_str, llvm_pointer_vec_str);
1642         let f = bx.declare_cfn(&llvm_intrinsic,
1643                                      bx.type_func(&[llvm_elem_vec_ty,
1644                                                   llvm_pointer_vec_ty,
1645                                                   alignment_ty,
1646                                                   mask_ty], ret_t));
1647         llvm::SetUnnamedAddr(f, false);
1648         let v = bx.call(f, &[args[0].immediate(), args[1].immediate(), alignment, mask],
1649                         None);
1650         return Ok(v);
1651     }
1652
1653     macro_rules! arith_red {
1654         ($name:tt : $integer_reduce:ident, $float_reduce:ident, $ordered:expr) => {
1655             if name == $name {
1656                 require!(ret_ty == in_elem,
1657                          "expected return type `{}` (element of input `{}`), found `{}`",
1658                          in_elem, in_ty, ret_ty);
1659                 return match in_elem.sty {
1660                     ty::Int(_) | ty::Uint(_) => {
1661                         let r = bx.$integer_reduce(args[0].immediate());
1662                         if $ordered {
1663                             // if overflow occurs, the result is the
1664                             // mathematical result modulo 2^n:
1665                             if name.contains("mul") {
1666                                 Ok(bx.mul(args[1].immediate(), r))
1667                             } else {
1668                                 Ok(bx.add(args[1].immediate(), r))
1669                             }
1670                         } else {
1671                             Ok(bx.$integer_reduce(args[0].immediate()))
1672                         }
1673                     },
1674                     ty::Float(f) => {
1675                         // ordered arithmetic reductions take an accumulator
1676                         let acc = if $ordered {
1677                             let acc = args[1].immediate();
1678                             // FIXME: https://bugs.llvm.org/show_bug.cgi?id=36734
1679                             // * if the accumulator of the fadd isn't 0, incorrect
1680                             //   code is generated
1681                             // * if the accumulator of the fmul isn't 1, incorrect
1682                             //   code is generated
1683                             match bx.const_get_real(acc) {
1684                                 None => return_error!("accumulator of {} is not a constant", $name),
1685                                 Some((v, loses_info)) => {
1686                                     if $name.contains("mul") && v != 1.0_f64 {
1687                                         return_error!("accumulator of {} is not 1.0", $name);
1688                                     } else if $name.contains("add") && v != 0.0_f64 {
1689                                         return_error!("accumulator of {} is not 0.0", $name);
1690                                     } else if loses_info {
1691                                         return_error!("accumulator of {} loses information", $name);
1692                                     }
1693                                 }
1694                             }
1695                             acc
1696                         } else {
1697                             // unordered arithmetic reductions do not:
1698                             match f.bit_width() {
1699                                 32 => bx.const_undef(bx.type_f32()),
1700                                 64 => bx.const_undef(bx.type_f64()),
1701                                 v => {
1702                                     return_error!(r#"
1703 unsupported {} from `{}` with element `{}` of size `{}` to `{}`"#,
1704                                         $name, in_ty, in_elem, v, ret_ty
1705                                     )
1706                                 }
1707                             }
1708                         };
1709                         Ok(bx.$float_reduce(acc, args[0].immediate()))
1710                     }
1711                     _ => {
1712                         return_error!(
1713                             "unsupported {} from `{}` with element `{}` to `{}`",
1714                             $name, in_ty, in_elem, ret_ty
1715                         )
1716                     },
1717                 }
1718             }
1719         }
1720     }
1721
1722     arith_red!("simd_reduce_add_ordered": vector_reduce_add, vector_reduce_fadd_fast, true);
1723     arith_red!("simd_reduce_mul_ordered": vector_reduce_mul, vector_reduce_fmul_fast, true);
1724     arith_red!("simd_reduce_add_unordered": vector_reduce_add, vector_reduce_fadd_fast, false);
1725     arith_red!("simd_reduce_mul_unordered": vector_reduce_mul, vector_reduce_fmul_fast, false);
1726
1727     macro_rules! minmax_red {
1728         ($name:tt: $int_red:ident, $float_red:ident) => {
1729             if name == $name {
1730                 require!(ret_ty == in_elem,
1731                          "expected return type `{}` (element of input `{}`), found `{}`",
1732                          in_elem, in_ty, ret_ty);
1733                 return match in_elem.sty {
1734                     ty::Int(_i) => {
1735                         Ok(bx.$int_red(args[0].immediate(), true))
1736                     },
1737                     ty::Uint(_u) => {
1738                         Ok(bx.$int_red(args[0].immediate(), false))
1739                     },
1740                     ty::Float(_f) => {
1741                         Ok(bx.$float_red(args[0].immediate()))
1742                     }
1743                     _ => {
1744                         return_error!("unsupported {} from `{}` with element `{}` to `{}`",
1745                                       $name, in_ty, in_elem, ret_ty)
1746                     },
1747                 }
1748             }
1749
1750         }
1751     }
1752
1753     minmax_red!("simd_reduce_min": vector_reduce_min, vector_reduce_fmin);
1754     minmax_red!("simd_reduce_max": vector_reduce_max, vector_reduce_fmax);
1755
1756     minmax_red!("simd_reduce_min_nanless": vector_reduce_min, vector_reduce_fmin_fast);
1757     minmax_red!("simd_reduce_max_nanless": vector_reduce_max, vector_reduce_fmax_fast);
1758
1759     macro_rules! bitwise_red {
1760         ($name:tt : $red:ident, $boolean:expr) => {
1761             if name == $name {
1762                 let input = if !$boolean {
1763                     require!(ret_ty == in_elem,
1764                              "expected return type `{}` (element of input `{}`), found `{}`",
1765                              in_elem, in_ty, ret_ty);
1766                     args[0].immediate()
1767                 } else {
1768                     match in_elem.sty {
1769                         ty::Int(_) | ty::Uint(_) => {},
1770                         _ => {
1771                             return_error!("unsupported {} from `{}` with element `{}` to `{}`",
1772                                           $name, in_ty, in_elem, ret_ty)
1773                         }
1774                     }
1775
1776                     // boolean reductions operate on vectors of i1s:
1777                     let i1 = bx.type_i1();
1778                     let i1xn = bx.type_vector(i1, in_len as u64);
1779                     bx.trunc(args[0].immediate(), i1xn)
1780                 };
1781                 return match in_elem.sty {
1782                     ty::Int(_) | ty::Uint(_) => {
1783                         let r = bx.$red(input);
1784                         Ok(
1785                             if !$boolean {
1786                                 r
1787                             } else {
1788                                 bx.zext(r, bx.type_bool())
1789                             }
1790                         )
1791                     },
1792                     _ => {
1793                         return_error!("unsupported {} from `{}` with element `{}` to `{}`",
1794                                       $name, in_ty, in_elem, ret_ty)
1795                     },
1796                 }
1797             }
1798         }
1799     }
1800
1801     bitwise_red!("simd_reduce_and": vector_reduce_and, false);
1802     bitwise_red!("simd_reduce_or": vector_reduce_or, false);
1803     bitwise_red!("simd_reduce_xor": vector_reduce_xor, false);
1804     bitwise_red!("simd_reduce_all": vector_reduce_and, true);
1805     bitwise_red!("simd_reduce_any": vector_reduce_or, true);
1806
1807     if name == "simd_cast" {
1808         require_simd!(ret_ty, "return");
1809         let out_len = ret_ty.simd_size(tcx);
1810         require!(in_len == out_len,
1811                  "expected return type with length {} (same as input type `{}`), \
1812                   found `{}` with length {}",
1813                  in_len, in_ty,
1814                  ret_ty, out_len);
1815         // casting cares about nominal type, not just structural type
1816         let out_elem = ret_ty.simd_type(tcx);
1817
1818         if in_elem == out_elem { return Ok(args[0].immediate()); }
1819
1820         enum Style { Float, Int(/* is signed? */ bool), Unsupported }
1821
1822         let (in_style, in_width) = match in_elem.sty {
1823             // vectors of pointer-sized integers should've been
1824             // disallowed before here, so this unwrap is safe.
1825             ty::Int(i) => (Style::Int(true), i.bit_width().unwrap()),
1826             ty::Uint(u) => (Style::Int(false), u.bit_width().unwrap()),
1827             ty::Float(f) => (Style::Float, f.bit_width()),
1828             _ => (Style::Unsupported, 0)
1829         };
1830         let (out_style, out_width) = match out_elem.sty {
1831             ty::Int(i) => (Style::Int(true), i.bit_width().unwrap()),
1832             ty::Uint(u) => (Style::Int(false), u.bit_width().unwrap()),
1833             ty::Float(f) => (Style::Float, f.bit_width()),
1834             _ => (Style::Unsupported, 0)
1835         };
1836
1837         match (in_style, out_style) {
1838             (Style::Int(in_is_signed), Style::Int(_)) => {
1839                 return Ok(match in_width.cmp(&out_width) {
1840                     Ordering::Greater => bx.trunc(args[0].immediate(), llret_ty),
1841                     Ordering::Equal => args[0].immediate(),
1842                     Ordering::Less => if in_is_signed {
1843                         bx.sext(args[0].immediate(), llret_ty)
1844                     } else {
1845                         bx.zext(args[0].immediate(), llret_ty)
1846                     }
1847                 })
1848             }
1849             (Style::Int(in_is_signed), Style::Float) => {
1850                 return Ok(if in_is_signed {
1851                     bx.sitofp(args[0].immediate(), llret_ty)
1852                 } else {
1853                     bx.uitofp(args[0].immediate(), llret_ty)
1854                 })
1855             }
1856             (Style::Float, Style::Int(out_is_signed)) => {
1857                 return Ok(if out_is_signed {
1858                     bx.fptosi(args[0].immediate(), llret_ty)
1859                 } else {
1860                     bx.fptoui(args[0].immediate(), llret_ty)
1861                 })
1862             }
1863             (Style::Float, Style::Float) => {
1864                 return Ok(match in_width.cmp(&out_width) {
1865                     Ordering::Greater => bx.fptrunc(args[0].immediate(), llret_ty),
1866                     Ordering::Equal => args[0].immediate(),
1867                     Ordering::Less => bx.fpext(args[0].immediate(), llret_ty)
1868                 })
1869             }
1870             _ => {/* Unsupported. Fallthrough. */}
1871         }
1872         require!(false,
1873                  "unsupported cast from `{}` with element `{}` to `{}` with element `{}`",
1874                  in_ty, in_elem,
1875                  ret_ty, out_elem);
1876     }
1877     macro_rules! arith {
1878         ($($name: ident: $($($p: ident),* => $call: ident),*;)*) => {
1879             $(if name == stringify!($name) {
1880                 match in_elem.sty {
1881                     $($(ty::$p(_))|* => {
1882                         return Ok(bx.$call(args[0].immediate(), args[1].immediate()))
1883                     })*
1884                     _ => {},
1885                 }
1886                 require!(false,
1887                          "unsupported operation on `{}` with element `{}`",
1888                          in_ty,
1889                          in_elem)
1890             })*
1891         }
1892     }
1893     arith! {
1894         simd_add: Uint, Int => add, Float => fadd;
1895         simd_sub: Uint, Int => sub, Float => fsub;
1896         simd_mul: Uint, Int => mul, Float => fmul;
1897         simd_div: Uint => udiv, Int => sdiv, Float => fdiv;
1898         simd_rem: Uint => urem, Int => srem, Float => frem;
1899         simd_shl: Uint, Int => shl;
1900         simd_shr: Uint => lshr, Int => ashr;
1901         simd_and: Uint, Int => and;
1902         simd_or: Uint, Int => or;
1903         simd_xor: Uint, Int => xor;
1904         simd_fmax: Float => maxnum;
1905         simd_fmin: Float => minnum;
1906
1907     }
1908
1909     if name == "simd_saturating_add" || name == "simd_saturating_sub" {
1910         let lhs = args[0].immediate();
1911         let rhs = args[1].immediate();
1912         let is_add = name == "simd_saturating_add";
1913         let ptr_bits = bx.tcx().data_layout.pointer_size.bits() as _;
1914         let (signed, elem_width, elem_ty) = match in_elem.sty {
1915             ty::Int(i) =>
1916                 (
1917                     true,
1918                     i.bit_width().unwrap_or(ptr_bits),
1919                     bx.cx.type_int_from_ty(i)
1920                 ),
1921             ty::Uint(i) =>
1922                 (
1923                     false,
1924                     i.bit_width().unwrap_or(ptr_bits),
1925                     bx.cx.type_uint_from_ty(i)
1926                 ),
1927             _ => {
1928                 return_error!(
1929                     "expected element type `{}` of vector type `{}` \
1930                      to be a signed or unsigned integer type",
1931                     arg_tys[0].simd_type(tcx), arg_tys[0]
1932                 );
1933             }
1934         };
1935         let llvm_intrinsic = &format!(
1936             "llvm.{}{}.sat.v{}i{}",
1937             if signed { 's' } else { 'u' },
1938             if is_add { "add" } else { "sub" },
1939             in_len, elem_width
1940         );
1941         let vec_ty = bx.cx.type_vector(elem_ty, in_len as u64);
1942
1943         let f = bx.declare_cfn(
1944             &llvm_intrinsic,
1945             bx.type_func(&[vec_ty, vec_ty], vec_ty)
1946         );
1947         llvm::SetUnnamedAddr(f, false);
1948         let v = bx.call(f, &[lhs, rhs], None);
1949         return Ok(v);
1950     }
1951
1952     span_bug!(span, "unknown SIMD intrinsic");
1953 }
1954
1955 // Returns the width of an int Ty, and if it's signed or not
1956 // Returns None if the type is not an integer
1957 // FIXME: there’s multiple of this functions, investigate using some of the already existing
1958 // stuffs.
1959 fn int_type_width_signed(ty: Ty<'_>, cx: &CodegenCx<'_, '_>) -> Option<(u64, bool)> {
1960     match ty.sty {
1961         ty::Int(t) => Some((match t {
1962             ast::IntTy::Isize => cx.tcx.sess.target.isize_ty.bit_width().unwrap() as u64,
1963             ast::IntTy::I8 => 8,
1964             ast::IntTy::I16 => 16,
1965             ast::IntTy::I32 => 32,
1966             ast::IntTy::I64 => 64,
1967             ast::IntTy::I128 => 128,
1968         }, true)),
1969         ty::Uint(t) => Some((match t {
1970             ast::UintTy::Usize => cx.tcx.sess.target.usize_ty.bit_width().unwrap() as u64,
1971             ast::UintTy::U8 => 8,
1972             ast::UintTy::U16 => 16,
1973             ast::UintTy::U32 => 32,
1974             ast::UintTy::U64 => 64,
1975             ast::UintTy::U128 => 128,
1976         }, false)),
1977         _ => None,
1978     }
1979 }
1980
1981 // Returns the width of a float Ty
1982 // Returns None if the type is not a float
1983 fn float_type_width(ty: Ty<'_>) -> Option<u64> {
1984     match ty.sty {
1985         ty::Float(t) => Some(t.bit_width() as u64),
1986         _ => None,
1987     }
1988 }