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