src/librustc_codegen_llvm/intrinsic.rs

   1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 #![allow(non_upper_case_globals)]
  12
  13 use attributes;
  14 use intrinsics::{self, Intrinsic};
  15 use llvm::{self, TypeKind};
  16 use llvm_util;
  17 use abi::{Abi, FnType, LlvmType, PassMode};
  18 use mir::place::PlaceRef;
  19 use mir::operand::{OperandRef, OperandValue};
  20 use base::*;
  21 use common::*;
  22 use declare;
  23 use glue;
  24 use type_::Type;
  25 use type_of::LayoutLlvmExt;
  26 use rustc::ty::{self, Ty};
  27 use rustc::ty::layout::LayoutOf;
  28 use rustc::hir;
  29 use syntax::ast;
  30 use syntax::symbol::Symbol;
  31 use builder::Builder;
  32 use value::Value;
  33
  34 use rustc::session::Session;
  35 use syntax_pos::Span;
  36
  37 use std::cmp::Ordering;
  38 use std::iter;
  39
  40 fn get_simple_intrinsic(cx: &CodegenCx<'ll, '_>, name: &str) -> Option<&'ll Value> {
  41     let llvm_name = match name {
  42         "sqrtf32" => "llvm.sqrt.f32",
  43         "sqrtf64" => "llvm.sqrt.f64",
  44         "powif32" => "llvm.powi.f32",
  45         "powif64" => "llvm.powi.f64",
  46         "sinf32" => "llvm.sin.f32",
  47         "sinf64" => "llvm.sin.f64",
  48         "cosf32" => "llvm.cos.f32",
  49         "cosf64" => "llvm.cos.f64",
  50         "powf32" => "llvm.pow.f32",
  51         "powf64" => "llvm.pow.f64",
  52         "expf32" => "llvm.exp.f32",
  53         "expf64" => "llvm.exp.f64",
  54         "exp2f32" => "llvm.exp2.f32",
  55         "exp2f64" => "llvm.exp2.f64",
  56         "logf32" => "llvm.log.f32",
  57         "logf64" => "llvm.log.f64",
  58         "log10f32" => "llvm.log10.f32",
  59         "log10f64" => "llvm.log10.f64",
  60         "log2f32" => "llvm.log2.f32",
  61         "log2f64" => "llvm.log2.f64",
  62         "fmaf32" => "llvm.fma.f32",
  63         "fmaf64" => "llvm.fma.f64",
  64         "fabsf32" => "llvm.fabs.f32",
  65         "fabsf64" => "llvm.fabs.f64",
  66         "copysignf32" => "llvm.copysign.f32",
  67         "copysignf64" => "llvm.copysign.f64",
  68         "floorf32" => "llvm.floor.f32",
  69         "floorf64" => "llvm.floor.f64",
  70         "ceilf32" => "llvm.ceil.f32",
  71         "ceilf64" => "llvm.ceil.f64",
  72         "truncf32" => "llvm.trunc.f32",
  73         "truncf64" => "llvm.trunc.f64",
  74         "rintf32" => "llvm.rint.f32",
  75         "rintf64" => "llvm.rint.f64",
  76         "nearbyintf32" => "llvm.nearbyint.f32",
  77         "nearbyintf64" => "llvm.nearbyint.f64",
  78         "roundf32" => "llvm.round.f32",
  79         "roundf64" => "llvm.round.f64",
  80         "assume" => "llvm.assume",
  81         "abort" => "llvm.trap",
  82         _ => return None
  83     };
  84     Some(cx.get_intrinsic(&llvm_name))
  85 }
  86
  87 /// Remember to add all intrinsics here, in librustc_typeck/check/mod.rs,
  88 /// and in libcore/intrinsics.rs; if you need access to any llvm intrinsics,
  89 /// add them to librustc_codegen_llvm/context.rs
  90 pub fn codegen_intrinsic_call(
  91     bx: &Builder<'a, 'll, 'tcx>,
  92     callee_ty: Ty<'tcx>,
  93     fn_ty: &FnType<'tcx, Ty<'tcx>>,
  94     args: &[OperandRef<'ll, 'tcx>],
  95     llresult: &'ll Value,
  96     span: Span,
  97 ) {
  98     let cx = bx.cx;
  99     let tcx = cx.tcx;
 100
 101     let (def_id, substs) = match callee_ty.sty {
 102         ty::FnDef(def_id, substs) => (def_id, substs),
 103         _ => bug!("expected fn item type, found {}", callee_ty)
 104     };
 105
 106     let sig = callee_ty.fn_sig(tcx);
 107     let sig = tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
 108     let arg_tys = sig.inputs();
 109     let ret_ty = sig.output();
 110     let name = &*tcx.item_name(def_id).as_str();
 111
 112     let llret_ty = cx.layout_of(ret_ty).llvm_type(cx);
 113     let result = PlaceRef::new_sized(llresult, fn_ty.ret.layout, fn_ty.ret.layout.align);
 114
 115     let simple = get_simple_intrinsic(cx, name);
 116     let llval = match name {
 117         _ if simple.is_some() => {
 118             bx.call(simple.unwrap(),
 119                     &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(),
 120                     None)
 121         }
 122         "unreachable" => {
 123             return;
 124         },
 125         "likely" => {
 126             let expect = cx.get_intrinsic(&("llvm.expect.i1"));
 127             bx.call(expect, &[args[0].immediate(), C_bool(cx, true)], None)
 128         }
 129         "unlikely" => {
 130             let expect = cx.get_intrinsic(&("llvm.expect.i1"));
 131             bx.call(expect, &[args[0].immediate(), C_bool(cx, false)], None)
 132         }
 133         "try" => {
 134             try_intrinsic(bx, cx,
 135                           args[0].immediate(),
 136                           args[1].immediate(),
 137                           args[2].immediate(),
 138                           llresult);
 139             return;
 140         }
 141         "breakpoint" => {
 142             let llfn = cx.get_intrinsic(&("llvm.debugtrap"));
 143             bx.call(llfn, &[], None)
 144         }
 145         "size_of" => {
 146             let tp_ty = substs.type_at(0);
 147             C_usize(cx, cx.size_of(tp_ty).bytes())
 148         }
 149         "size_of_val" => {
 150             let tp_ty = substs.type_at(0);
 151             if let OperandValue::Pair(_, meta) = args[0].val {
 152                 let (llsize, _) =
 153                     glue::size_and_align_of_dst(bx, tp_ty, Some(meta));
 154                 llsize
 155             } else {
 156                 C_usize(cx, cx.size_of(tp_ty).bytes())
 157             }
 158         }
 159         "min_align_of" => {
 160             let tp_ty = substs.type_at(0);
 161             C_usize(cx, cx.align_of(tp_ty).abi())
 162         }
 163         "min_align_of_val" => {
 164             let tp_ty = substs.type_at(0);
 165             if let OperandValue::Pair(_, meta) = args[0].val {
 166                 let (_, llalign) =
 167                     glue::size_and_align_of_dst(bx, tp_ty, Some(meta));
 168                 llalign
 169             } else {
 170                 C_usize(cx, cx.align_of(tp_ty).abi())
 171             }
 172         }
 173         "pref_align_of" => {
 174             let tp_ty = substs.type_at(0);
 175             C_usize(cx, cx.align_of(tp_ty).pref())
 176         }
 177         "type_name" => {
 178             let tp_ty = substs.type_at(0);
 179             let ty_name = Symbol::intern(&tp_ty.to_string()).as_str();
 180             C_str_slice(cx, ty_name)
 181         }
 182         "type_id" => {
 183             C_u64(cx, cx.tcx.type_id_hash(substs.type_at(0)))
 184         }
 185         "init" => {
 186             let ty = substs.type_at(0);
 187             if !cx.layout_of(ty).is_zst() {
 188                 // Just zero out the stack slot.
 189                 // If we store a zero constant, LLVM will drown in vreg allocation for large data
 190                 // structures, and the generated code will be awful. (A telltale sign of this is
 191                 // large quantities of `mov [byte ptr foo],0` in the generated code.)
 192                 memset_intrinsic(bx, false, ty, llresult, C_u8(cx, 0), C_usize(cx, 1));
 193             }
 194             return;
 195         }
 196         // Effectively no-ops
 197         "uninit" => {
 198             return;
 199         }
 200         "needs_drop" => {
 201             let tp_ty = substs.type_at(0);
 202
 203             C_bool(cx, bx.cx.type_needs_drop(tp_ty))
 204         }
 205         "offset" => {
 206             let ptr = args[0].immediate();
 207             let offset = args[1].immediate();
 208             bx.inbounds_gep(ptr, &[offset])
 209         }
 210         "arith_offset" => {
 211             let ptr = args[0].immediate();
 212             let offset = args[1].immediate();
 213             bx.gep(ptr, &[offset])
 214         }
 215
 216         "copy_nonoverlapping" => {
 217             copy_intrinsic(bx, false, false, substs.type_at(0),
 218                            args[1].immediate(), args[0].immediate(), args[2].immediate())
 219         }
 220         "copy" => {
 221             copy_intrinsic(bx, true, false, substs.type_at(0),
 222                            args[1].immediate(), args[0].immediate(), args[2].immediate())
 223         }
 224         "write_bytes" => {
 225             memset_intrinsic(bx, false, substs.type_at(0),
 226                              args[0].immediate(), args[1].immediate(), args[2].immediate())
 227         }
 228
 229         "volatile_copy_nonoverlapping_memory" => {
 230             copy_intrinsic(bx, false, true, substs.type_at(0),
 231                            args[0].immediate(), args[1].immediate(), args[2].immediate())
 232         }
 233         "volatile_copy_memory" => {
 234             copy_intrinsic(bx, true, true, substs.type_at(0),
 235                            args[0].immediate(), args[1].immediate(), args[2].immediate())
 236         }
 237         "volatile_set_memory" => {
 238             memset_intrinsic(bx, true, substs.type_at(0),
 239                              args[0].immediate(), args[1].immediate(), args[2].immediate())
 240         }
 241         "volatile_load" | "unaligned_volatile_load" => {
 242             let tp_ty = substs.type_at(0);
 243             let mut ptr = args[0].immediate();
 244             if let PassMode::Cast(ty) = fn_ty.ret.mode {
 245                 ptr = bx.pointercast(ptr, ty.llvm_type(cx).ptr_to());
 246             }
 247             let load = bx.volatile_load(ptr);
 248             let align = if name == "unaligned_volatile_load" {
 249                 1
 250             } else {
 251                 cx.align_of(tp_ty).abi() as u32
 252             };
 253             unsafe {
 254                 llvm::LLVMSetAlignment(load, align);
 255             }
 256             to_immediate(bx, load, cx.layout_of(tp_ty))
 257         },
 258         "volatile_store" => {
 259             let dst = args[0].deref(bx.cx);
 260             args[1].val.volatile_store(bx, dst);
 261             return;
 262         },
 263         "unaligned_volatile_store" => {
 264             let dst = args[0].deref(bx.cx);
 265             args[1].val.unaligned_volatile_store(bx, dst);
 266             return;
 267         },
 268         "prefetch_read_data" | "prefetch_write_data" |
 269         "prefetch_read_instruction" | "prefetch_write_instruction" => {
 270             let expect = cx.get_intrinsic(&("llvm.prefetch"));
 271             let (rw, cache_type) = match name {
 272                 "prefetch_read_data" => (0, 1),
 273                 "prefetch_write_data" => (1, 1),
 274                 "prefetch_read_instruction" => (0, 0),
 275                 "prefetch_write_instruction" => (1, 0),
 276                 _ => bug!()
 277             };
 278             bx.call(expect, &[
 279                 args[0].immediate(),
 280                 C_i32(cx, rw),
 281                 args[1].immediate(),
 282                 C_i32(cx, cache_type)
 283             ], None)
 284         },
 285         "ctlz" | "ctlz_nonzero" | "cttz" | "cttz_nonzero" | "ctpop" | "bswap" |
 286         "bitreverse" | "add_with_overflow" | "sub_with_overflow" |
 287         "mul_with_overflow" | "overflowing_add" | "overflowing_sub" | "overflowing_mul" |
 288         "unchecked_div" | "unchecked_rem" | "unchecked_shl" | "unchecked_shr" | "exact_div" |
 289         "rotate_left" | "rotate_right" => {
 290             let ty = arg_tys[0];
 291             match int_type_width_signed(ty, cx) {
 292                 Some((width, signed)) =>
 293                     match name {
 294                         "ctlz" | "cttz" => {
 295                             let y = C_bool(bx.cx, false);
 296                             let llfn = cx.get_intrinsic(&format!("llvm.{}.i{}", name, width));
 297                             bx.call(llfn, &[args[0].immediate(), y], None)
 298                         }
 299                         "ctlz_nonzero" | "cttz_nonzero" => {
 300                             let y = C_bool(bx.cx, true);
 301                             let llvm_name = &format!("llvm.{}.i{}", &name[..4], width);
 302                             let llfn = cx.get_intrinsic(llvm_name);
 303                             bx.call(llfn, &[args[0].immediate(), y], None)
 304                         }
 305                         "ctpop" => bx.call(cx.get_intrinsic(&format!("llvm.ctpop.i{}", width)),
 306                                         &[args[0].immediate()], None),
 307                         "bswap" => {
 308                             if width == 8 {
 309                                 args[0].immediate() // byte swap a u8/i8 is just a no-op
 310                             } else {
 311                                 bx.call(cx.get_intrinsic(&format!("llvm.bswap.i{}", width)),
 312                                         &[args[0].immediate()], None)
 313                             }
 314                         }
 315                         "bitreverse" => {
 316                             bx.call(cx.get_intrinsic(&format!("llvm.bitreverse.i{}", width)),
 317                                 &[args[0].immediate()], None)
 318                         }
 319                         "add_with_overflow" | "sub_with_overflow" | "mul_with_overflow" => {
 320                             let intrinsic = format!("llvm.{}{}.with.overflow.i{}",
 321                                                     if signed { 's' } else { 'u' },
 322                                                     &name[..3], width);
 323                             let llfn = bx.cx.get_intrinsic(&intrinsic);
 324
 325                             // Convert `i1` to a `bool`, and write it to the out parameter
 326                             let pair = bx.call(llfn, &[
 327                                 args[0].immediate(),
 328                                 args[1].immediate()
 329                             ], None);
 330                             let val = bx.extract_value(pair, 0);
 331                             let overflow = bx.zext(bx.extract_value(pair, 1), Type::bool(cx));
 332
 333                             let dest = result.project_field(bx, 0);
 334                             bx.store(val, dest.llval, dest.align);
 335                             let dest = result.project_field(bx, 1);
 336                             bx.store(overflow, dest.llval, dest.align);
 337
 338                             return;
 339                         },
 340                         "overflowing_add" => bx.add(args[0].immediate(), args[1].immediate()),
 341                         "overflowing_sub" => bx.sub(args[0].immediate(), args[1].immediate()),
 342                         "overflowing_mul" => bx.mul(args[0].immediate(), args[1].immediate()),
 343                         "exact_div" =>
 344                             if signed {
 345                                 bx.exactsdiv(args[0].immediate(), args[1].immediate())
 346                             } else {
 347                                 bx.exactudiv(args[0].immediate(), args[1].immediate())
 348                             },
 349                         "unchecked_div" =>
 350                             if signed {
 351                                 bx.sdiv(args[0].immediate(), args[1].immediate())
 352                             } else {
 353                                 bx.udiv(args[0].immediate(), args[1].immediate())
 354                             },
 355                         "unchecked_rem" =>
 356                             if signed {
 357                                 bx.srem(args[0].immediate(), args[1].immediate())
 358                             } else {
 359                                 bx.urem(args[0].immediate(), args[1].immediate())
 360                             },
 361                         "unchecked_shl" => bx.shl(args[0].immediate(), args[1].immediate()),
 362                         "unchecked_shr" =>
 363                             if signed {
 364                                 bx.ashr(args[0].immediate(), args[1].immediate())
 365                             } else {
 366                                 bx.lshr(args[0].immediate(), args[1].immediate())
 367                             },
 368                         "rotate_left" | "rotate_right" => {
 369                             let is_left = name == "rotate_left";
 370                             let val = args[0].immediate();
 371                             let raw_shift = args[1].immediate();
 372                             if llvm_util::get_major_version() >= 7 {
 373                                 // rotate = funnel shift with first two args the same
 374                                 let llvm_name = &format!("llvm.fsh{}.i{}",
 375                                                          if is_left { 'l' } else { 'r' }, width);
 376                                 let llfn = cx.get_intrinsic(llvm_name);
 377                                 bx.call(llfn, &[val, val, raw_shift], None)
 378                             } else {
 379                                 // rotate_left: (X << (S % BW)) | (X >> ((BW - S) % BW))
 380                                 // rotate_right: (X << ((BW - S) % BW)) | (X >> (S % BW))
 381                                 let width = C_uint(Type::ix(cx, width), width);
 382                                 let shift = bx.urem(raw_shift, width);
 383                                 let inv_shift = bx.urem(bx.sub(width, raw_shift), width);
 384                                 let shift1 = bx.shl(val, if is_left { shift } else { inv_shift });
 385                                 let shift2 = bx.lshr(val, if !is_left { shift } else { inv_shift });
 386                                 bx.or(shift1, shift2)
 387                             }
 388                         },
 389                         _ => bug!(),
 390                     },
 391                 None => {
 392                     span_invalid_monomorphization_error(
 393                         tcx.sess, span,
 394                         &format!("invalid monomorphization of `{}` intrinsic: \
 395                                   expected basic integer type, found `{}`", name, ty));
 396                     return;
 397                 }
 398             }
 399         },
 400         "fadd_fast" | "fsub_fast" | "fmul_fast" | "fdiv_fast" | "frem_fast" => {
 401             let sty = &arg_tys[0].sty;
 402             match float_type_width(sty) {
 403                 Some(_width) =>
 404                     match name {
 405                         "fadd_fast" => bx.fadd_fast(args[0].immediate(), args[1].immediate()),
 406                         "fsub_fast" => bx.fsub_fast(args[0].immediate(), args[1].immediate()),
 407                         "fmul_fast" => bx.fmul_fast(args[0].immediate(), args[1].immediate()),
 408                         "fdiv_fast" => bx.fdiv_fast(args[0].immediate(), args[1].immediate()),
 409                         "frem_fast" => bx.frem_fast(args[0].immediate(), args[1].immediate()),
 410                         _ => bug!(),
 411                     },
 412                 None => {
 413                     span_invalid_monomorphization_error(
 414                         tcx.sess, span,
 415                         &format!("invalid monomorphization of `{}` intrinsic: \
 416                                   expected basic float type, found `{}`", name, sty));
 417                     return;
 418                 }
 419             }
 420
 421         },
 422
 423         "discriminant_value" => {
 424             args[0].deref(bx.cx).codegen_get_discr(bx, ret_ty)
 425         }
 426
 427         name if name.starts_with("simd_") => {
 428             match generic_simd_intrinsic(bx, name,
 429                                          callee_ty,
 430                                          args,
 431                                          ret_ty, llret_ty,
 432                                          span) {
 433                 Ok(llval) => llval,
 434                 Err(()) => return
 435             }
 436         }
 437         // This requires that atomic intrinsics follow a specific naming pattern:
 438         // "atomic_<operation>[_<ordering>]", and no ordering means SeqCst
 439         name if name.starts_with("atomic_") => {
 440             use llvm::AtomicOrdering::*;
 441
 442             let split: Vec<&str> = name.split('_').collect();
 443
 444             let is_cxchg = split[1] == "cxchg" || split[1] == "cxchgweak";
 445             let (order, failorder) = match split.len() {
 446                 2 => (SequentiallyConsistent, SequentiallyConsistent),
 447                 3 => match split[2] {
 448                     "unordered" => (Unordered, Unordered),
 449                     "relaxed" => (Monotonic, Monotonic),
 450                     "acq"     => (Acquire, Acquire),
 451                     "rel"     => (Release, Monotonic),
 452                     "acqrel"  => (AcquireRelease, Acquire),
 453                     "failrelaxed" if is_cxchg =>
 454                         (SequentiallyConsistent, Monotonic),
 455                     "failacq" if is_cxchg =>
 456                         (SequentiallyConsistent, Acquire),
 457                     _ => cx.sess().fatal("unknown ordering in atomic intrinsic")
 458                 },
 459                 4 => match (split[2], split[3]) {
 460                     ("acq", "failrelaxed") if is_cxchg =>
 461                         (Acquire, Monotonic),
 462                     ("acqrel", "failrelaxed") if is_cxchg =>
 463                         (AcquireRelease, Monotonic),
 464                     _ => cx.sess().fatal("unknown ordering in atomic intrinsic")
 465                 },
 466                 _ => cx.sess().fatal("Atomic intrinsic not in correct format"),
 467             };
 468
 469             let invalid_monomorphization = |ty| {
 470                 span_invalid_monomorphization_error(tcx.sess, span,
 471                     &format!("invalid monomorphization of `{}` intrinsic: \
 472                               expected basic integer type, found `{}`", name, ty));
 473             };
 474
 475             match split[1] {
 476                 "cxchg" | "cxchgweak" => {
 477                     let ty = substs.type_at(0);
 478                     if int_type_width_signed(ty, cx).is_some() {
 479                         let weak = if split[1] == "cxchgweak" { llvm::True } else { llvm::False };
 480                         let pair = bx.atomic_cmpxchg(
 481                             args[0].immediate(),
 482                             args[1].immediate(),
 483                             args[2].immediate(),
 484                             order,
 485                             failorder,
 486                             weak);
 487                         let val = bx.extract_value(pair, 0);
 488                         let success = bx.zext(bx.extract_value(pair, 1), Type::bool(bx.cx));
 489
 490                         let dest = result.project_field(bx, 0);
 491                         bx.store(val, dest.llval, dest.align);
 492                         let dest = result.project_field(bx, 1);
 493                         bx.store(success, dest.llval, dest.align);
 494                         return;
 495                     } else {
 496                         return invalid_monomorphization(ty);
 497                     }
 498                 }
 499
 500                 "load" => {
 501                     let ty = substs.type_at(0);
 502                     if int_type_width_signed(ty, cx).is_some() {
 503                         let size = cx.size_of(ty);
 504                         bx.atomic_load(args[0].immediate(), order, size)
 505                     } else {
 506                         return invalid_monomorphization(ty);
 507                     }
 508                 }
 509
 510                 "store" => {
 511                     let ty = substs.type_at(0);
 512                     if int_type_width_signed(ty, cx).is_some() {
 513                         let size = cx.size_of(ty);
 514                         bx.atomic_store(args[1].immediate(), args[0].immediate(), order, size);
 515                         return;
 516                     } else {
 517                         return invalid_monomorphization(ty);
 518                     }
 519                 }
 520
 521                 "fence" => {
 522                     bx.atomic_fence(order, llvm::SynchronizationScope::CrossThread);
 523                     return;
 524                 }
 525
 526                 "singlethreadfence" => {
 527                     bx.atomic_fence(order, llvm::SynchronizationScope::SingleThread);
 528                     return;
 529                 }
 530
 531                 // These are all AtomicRMW ops
 532                 op => {
 533                     let atom_op = match op {
 534                         "xchg"  => llvm::AtomicXchg,
 535                         "xadd"  => llvm::AtomicAdd,
 536                         "xsub"  => llvm::AtomicSub,
 537                         "and"   => llvm::AtomicAnd,
 538                         "nand"  => llvm::AtomicNand,
 539                         "or"    => llvm::AtomicOr,
 540                         "xor"   => llvm::AtomicXor,
 541                         "max"   => llvm::AtomicMax,
 542                         "min"   => llvm::AtomicMin,
 543                         "umax"  => llvm::AtomicUMax,
 544                         "umin"  => llvm::AtomicUMin,
 545                         _ => cx.sess().fatal("unknown atomic operation")
 546                     };
 547
 548                     let ty = substs.type_at(0);
 549                     if int_type_width_signed(ty, cx).is_some() {
 550                         bx.atomic_rmw(atom_op, args[0].immediate(), args[1].immediate(), order)
 551                     } else {
 552                         return invalid_monomorphization(ty);
 553                     }
 554                 }
 555             }
 556         }
 557
 558         "nontemporal_store" => {
 559             let dst = args[0].deref(bx.cx);
 560             args[1].val.nontemporal_store(bx, dst);
 561             return;
 562         }
 563
 564         _ => {
 565             let intr = Intrinsic::find(&name).unwrap_or_else(||
 566                 bug!("unknown intrinsic '{}'", name));
 567
 568             fn one<T>(x: Vec<T>) -> T {
 569                 assert_eq!(x.len(), 1);
 570                 x.into_iter().next().unwrap()
 571             }
 572             fn ty_to_type(cx: &CodegenCx<'ll, '_>, t: &intrinsics::Type) -> Vec<&'ll Type> {
 573                 use intrinsics::Type::*;
 574                 match *t {
 575                     Void => vec![Type::void(cx)],
 576                     Integer(_signed, _width, llvm_width) => {
 577                         vec![Type::ix(cx, llvm_width as u64)]
 578                     }
 579                     Float(x) => {
 580                         match x {
 581                             32 => vec![Type::f32(cx)],
 582                             64 => vec![Type::f64(cx)],
 583                             _ => bug!()
 584                         }
 585                     }
 586                     Pointer(ref t, ref llvm_elem, _const) => {
 587                         let t = llvm_elem.as_ref().unwrap_or(t);
 588                         let elem = one(ty_to_type(cx, t));
 589                         vec![elem.ptr_to()]
 590                     }
 591                     Vector(ref t, ref llvm_elem, length) => {
 592                         let t = llvm_elem.as_ref().unwrap_or(t);
 593                         let elem = one(ty_to_type(cx, t));
 594                         vec![Type::vector(elem, length as u64)]
 595                     }
 596                     Aggregate(false, ref contents) => {
 597                         let elems = contents.iter()
 598                                             .map(|t| one(ty_to_type(cx, t)))
 599                                             .collect::<Vec<_>>();
 600                         vec![Type::struct_(cx, &elems, false)]
 601                     }
 602                     Aggregate(true, ref contents) => {
 603                         contents.iter()
 604                                 .flat_map(|t| ty_to_type(cx, t))
 605                                 .collect()
 606                     }
 607                 }
 608             }
 609
 610             // This allows an argument list like `foo, (bar, baz),
 611             // qux` to be converted into `foo, bar, baz, qux`, integer
 612             // arguments to be truncated as needed and pointers to be
 613             // cast.
 614             fn modify_as_needed(
 615                 bx: &Builder<'a, 'll, 'tcx>,
 616                 t: &intrinsics::Type,
 617                 arg: &OperandRef<'ll, 'tcx>,
 618             ) -> Vec<&'ll Value> {
 619                 match *t {
 620                     intrinsics::Type::Aggregate(true, ref contents) => {
 621                         // We found a tuple that needs squishing! So
 622                         // run over the tuple and load each field.
 623                         //
 624                         // This assumes the type is "simple", i.e. no
 625                         // destructors, and the contents are SIMD
 626                         // etc.
 627                         assert!(!bx.cx.type_needs_drop(arg.layout.ty));
 628                         let (ptr, align) = match arg.val {
 629                             OperandValue::Ref(ptr, None, align) => (ptr, align),
 630                             _ => bug!()
 631                         };
 632                         let arg = PlaceRef::new_sized(ptr, arg.layout, align);
 633                         (0..contents.len()).map(|i| {
 634                             arg.project_field(bx, i).load(bx).immediate()
 635                         }).collect()
 636                     }
 637                     intrinsics::Type::Pointer(_, Some(ref llvm_elem), _) => {
 638                         let llvm_elem = one(ty_to_type(bx.cx, llvm_elem));
 639                         vec![bx.pointercast(arg.immediate(), llvm_elem.ptr_to())]
 640                     }
 641                     intrinsics::Type::Vector(_, Some(ref llvm_elem), length) => {
 642                         let llvm_elem = one(ty_to_type(bx.cx, llvm_elem));
 643                         vec![bx.bitcast(arg.immediate(), Type::vector(llvm_elem, length as u64))]
 644                     }
 645                     intrinsics::Type::Integer(_, width, llvm_width) if width != llvm_width => {
 646                         // the LLVM intrinsic uses a smaller integer
 647                         // size than the C intrinsic's signature, so
 648                         // we have to trim it down here.
 649                         vec![bx.trunc(arg.immediate(), Type::ix(bx.cx, llvm_width as u64))]
 650                     }
 651                     _ => vec![arg.immediate()],
 652                 }
 653             }
 654
 655
 656             let inputs = intr.inputs.iter()
 657                                     .flat_map(|t| ty_to_type(cx, t))
 658                                     .collect::<Vec<_>>();
 659
 660             let outputs = one(ty_to_type(cx, &intr.output));
 661
 662             let llargs: Vec<_> = intr.inputs.iter().zip(args).flat_map(|(t, arg)| {
 663                 modify_as_needed(bx, t, arg)
 664             }).collect();
 665             assert_eq!(inputs.len(), llargs.len());
 666
 667             let val = match intr.definition {
 668                 intrinsics::IntrinsicDef::Named(name) => {
 669                     let f = declare::declare_cfn(cx,
 670                                                  name,
 671                                                  Type::func(&inputs, outputs));
 672                     bx.call(f, &llargs, None)
 673                 }
 674             };
 675
 676             match *intr.output {
 677                 intrinsics::Type::Aggregate(flatten, ref elems) => {
 678                     // the output is a tuple so we need to munge it properly
 679                     assert!(!flatten);
 680
 681                     for i in 0..elems.len() {
 682                         let dest = result.project_field(bx, i);
 683                         let val = bx.extract_value(val, i as u64);
 684                         bx.store(val, dest.llval, dest.align);
 685                     }
 686                     return;
 687                 }
 688                 _ => val,
 689             }
 690         }
 691     };
 692
 693     if !fn_ty.ret.is_ignore() {
 694         if let PassMode::Cast(ty) = fn_ty.ret.mode {
 695             let ptr = bx.pointercast(result.llval, ty.llvm_type(cx).ptr_to());
 696             bx.store(llval, ptr, result.align);
 697         } else {
 698             OperandRef::from_immediate_or_packed_pair(bx, llval, result.layout)
 699                 .val.store(bx, result);
 700         }
 701     }
 702 }
 703
 704 fn copy_intrinsic(
 705     bx: &Builder<'a, 'll, 'tcx>,
 706     allow_overlap: bool,
 707     volatile: bool,
 708     ty: Ty<'tcx>,
 709     dst: &'ll Value,
 710     src: &'ll Value,
 711     count: &'ll Value,
 712 ) -> &'ll Value {
 713     let cx = bx.cx;
 714     let (size, align) = cx.size_and_align_of(ty);
 715     let size = C_usize(cx, size.bytes());
 716     let align = align.abi();
 717     let dst_ptr = bx.pointercast(dst, Type::i8p(cx));
 718     let src_ptr = bx.pointercast(src, Type::i8p(cx));
 719     if allow_overlap {
 720         bx.memmove(dst_ptr, align, src_ptr, align, bx.mul(size, count), volatile)
 721     } else {
 722         bx.memcpy(dst_ptr, align, src_ptr, align, bx.mul(size, count), volatile)
 723     }
 724 }
 725
 726 fn memset_intrinsic(
 727     bx: &Builder<'a, 'll, 'tcx>,
 728     volatile: bool,
 729     ty: Ty<'tcx>,
 730     dst: &'ll Value,
 731     val: &'ll Value,
 732     count: &'ll Value
 733 ) -> &'ll Value {
 734     let cx = bx.cx;
 735     let (size, align) = cx.size_and_align_of(ty);
 736     let size = C_usize(cx, size.bytes());
 737     let align = C_i32(cx, align.abi() as i32);
 738     let dst = bx.pointercast(dst, Type::i8p(cx));
 739     call_memset(bx, dst, val, bx.mul(size, count), align, volatile)
 740 }
 741
 742 fn try_intrinsic(
 743     bx: &Builder<'a, 'll, 'tcx>,
 744     cx: &CodegenCx<'ll, 'tcx>,
 745     func: &'ll Value,
 746     data: &'ll Value,
 747     local_ptr: &'ll Value,
 748     dest: &'ll Value,
 749 ) {
 750     if bx.sess().no_landing_pads() {
 751         bx.call(func, &[data], None);
 752         let ptr_align = bx.tcx().data_layout.pointer_align;
 753         bx.store(C_null(Type::i8p(&bx.cx)), dest, ptr_align);
 754     } else if wants_msvc_seh(bx.sess()) {
 755         codegen_msvc_try(bx, cx, func, data, local_ptr, dest);
 756     } else {
 757         codegen_gnu_try(bx, cx, func, data, local_ptr, dest);
 758     }
 759 }
 760
 761 // MSVC's definition of the `rust_try` function.
 762 //
 763 // This implementation uses the new exception handling instructions in LLVM
 764 // which have support in LLVM for SEH on MSVC targets. Although these
 765 // instructions are meant to work for all targets, as of the time of this
 766 // writing, however, LLVM does not recommend the usage of these new instructions
 767 // as the old ones are still more optimized.
 768 fn codegen_msvc_try(
 769     bx: &Builder<'a, 'll, 'tcx>,
 770     cx: &CodegenCx<'ll, 'tcx>,
 771     func: &'ll Value,
 772     data: &'ll Value,
 773     local_ptr: &'ll Value,
 774     dest: &'ll Value,
 775 ) {
 776     let llfn = get_rust_try_fn(cx, &mut |bx| {
 777         let cx = bx.cx;
 778
 779         bx.set_personality_fn(bx.cx.eh_personality());
 780
 781         let normal = bx.build_sibling_block("normal");
 782         let catchswitch = bx.build_sibling_block("catchswitch");
 783         let catchpad = bx.build_sibling_block("catchpad");
 784         let caught = bx.build_sibling_block("caught");
 785
 786         let func = llvm::get_param(bx.llfn(), 0);
 787         let data = llvm::get_param(bx.llfn(), 1);
 788         let local_ptr = llvm::get_param(bx.llfn(), 2);
 789
 790         // We're generating an IR snippet that looks like:
 791         //
 792         //   declare i32 @rust_try(%func, %data, %ptr) {
 793         //      %slot = alloca i64*
 794         //      invoke %func(%data) to label %normal unwind label %catchswitch
 795         //
 796         //   normal:
 797         //      ret i32 0
 798         //
 799         //   catchswitch:
 800         //      %cs = catchswitch within none [%catchpad] unwind to caller
 801         //
 802         //   catchpad:
 803         //      %tok = catchpad within %cs [%type_descriptor, 0, %slot]
 804         //      %ptr[0] = %slot[0]
 805         //      %ptr[1] = %slot[1]
 806         //      catchret from %tok to label %caught
 807         //
 808         //   caught:
 809         //      ret i32 1
 810         //   }
 811         //
 812         // This structure follows the basic usage of throw/try/catch in LLVM.
 813         // For example, compile this C++ snippet to see what LLVM generates:
 814         //
 815         //      #include <stdint.h>
 816         //
 817         //      int bar(void (*foo)(void), uint64_t *ret) {
 818         //          try {
 819         //              foo();
 820         //              return 0;
 821         //          } catch(uint64_t a[2]) {
 822         //              ret[0] = a[0];
 823         //              ret[1] = a[1];
 824         //              return 1;
 825         //          }
 826         //      }
 827         //
 828         // More information can be found in libstd's seh.rs implementation.
 829         let i64p = Type::i64(cx).ptr_to();
 830         let ptr_align = bx.tcx().data_layout.pointer_align;
 831         let slot = bx.alloca(i64p, "slot", ptr_align);
 832         bx.invoke(func, &[data], normal.llbb(), catchswitch.llbb(), None);
 833
 834         normal.ret(C_i32(cx, 0));
 835
 836         let cs = catchswitch.catch_switch(None, None, 1);
 837         catchswitch.add_handler(cs, catchpad.llbb());
 838
 839         let tcx = cx.tcx;
 840         let tydesc = match tcx.lang_items().msvc_try_filter() {
 841             Some(did) => ::consts::get_static(cx, did),
 842             None => bug!("msvc_try_filter not defined"),
 843         };
 844         let tok = catchpad.catch_pad(cs, &[tydesc, C_i32(cx, 0), slot]);
 845         let addr = catchpad.load(slot, ptr_align);
 846
 847         let i64_align = bx.tcx().data_layout.i64_align;
 848         let arg1 = catchpad.load(addr, i64_align);
 849         let val1 = C_i32(cx, 1);
 850         let arg2 = catchpad.load(catchpad.inbounds_gep(addr, &[val1]), i64_align);
 851         let local_ptr = catchpad.bitcast(local_ptr, i64p);
 852         catchpad.store(arg1, local_ptr, i64_align);
 853         catchpad.store(arg2, catchpad.inbounds_gep(local_ptr, &[val1]), i64_align);
 854         catchpad.catch_ret(tok, caught.llbb());
 855
 856         caught.ret(C_i32(cx, 1));
 857     });
 858
 859     // Note that no invoke is used here because by definition this function
 860     // can't panic (that's what it's catching).
 861     let ret = bx.call(llfn, &[func, data, local_ptr], None);
 862     let i32_align = bx.tcx().data_layout.i32_align;
 863     bx.store(ret, dest, i32_align);
 864 }
 865
 866 // Definition of the standard "try" function for Rust using the GNU-like model
 867 // of exceptions (e.g. the normal semantics of LLVM's landingpad and invoke
 868 // instructions).
 869 //
 870 // This codegen is a little surprising because we always call a shim
 871 // function instead of inlining the call to `invoke` manually here. This is done
 872 // because in LLVM we're only allowed to have one personality per function
 873 // definition. The call to the `try` intrinsic is being inlined into the
 874 // function calling it, and that function may already have other personality
 875 // functions in play. By calling a shim we're guaranteed that our shim will have
 876 // the right personality function.
 877 fn codegen_gnu_try(
 878     bx: &Builder<'a, 'll, 'tcx>,
 879     cx: &CodegenCx<'ll, 'tcx>,
 880     func: &'ll Value,
 881     data: &'ll Value,
 882     local_ptr: &'ll Value,
 883     dest: &'ll Value,
 884 ) {
 885     let llfn = get_rust_try_fn(cx, &mut |bx| {
 886         let cx = bx.cx;
 887
 888         // Codegens the shims described above:
 889         //
 890         //   bx:
 891         //      invoke %func(%args...) normal %normal unwind %catch
 892         //
 893         //   normal:
 894         //      ret 0
 895         //
 896         //   catch:
 897         //      (ptr, _) = landingpad
 898         //      store ptr, %local_ptr
 899         //      ret 1
 900         //
 901         // Note that the `local_ptr` data passed into the `try` intrinsic is
 902         // expected to be `*mut *mut u8` for this to actually work, but that's
 903         // managed by the standard library.
 904
 905         let then = bx.build_sibling_block("then");
 906         let catch = bx.build_sibling_block("catch");
 907
 908         let func = llvm::get_param(bx.llfn(), 0);
 909         let data = llvm::get_param(bx.llfn(), 1);
 910         let local_ptr = llvm::get_param(bx.llfn(), 2);
 911         bx.invoke(func, &[data], then.llbb(), catch.llbb(), None);
 912         then.ret(C_i32(cx, 0));
 913
 914         // Type indicator for the exception being thrown.
 915         //
 916         // The first value in this tuple is a pointer to the exception object
 917         // being thrown.  The second value is a "selector" indicating which of
 918         // the landing pad clauses the exception's type had been matched to.
 919         // rust_try ignores the selector.
 920         let lpad_ty = Type::struct_(cx, &[Type::i8p(cx), Type::i32(cx)], false);
 921         let vals = catch.landing_pad(lpad_ty, bx.cx.eh_personality(), 1);
 922         catch.add_clause(vals, C_null(Type::i8p(cx)));
 923         let ptr = catch.extract_value(vals, 0);
 924         let ptr_align = bx.tcx().data_layout.pointer_align;
 925         catch.store(ptr, catch.bitcast(local_ptr, Type::i8p(cx).ptr_to()), ptr_align);
 926         catch.ret(C_i32(cx, 1));
 927     });
 928
 929     // Note that no invoke is used here because by definition this function
 930     // can't panic (that's what it's catching).
 931     let ret = bx.call(llfn, &[func, data, local_ptr], None);
 932     let i32_align = bx.tcx().data_layout.i32_align;
 933     bx.store(ret, dest, i32_align);
 934 }
 935
 936 // Helper function to give a Block to a closure to codegen a shim function.
 937 // This is currently primarily used for the `try` intrinsic functions above.
 938 fn gen_fn<'ll, 'tcx>(
 939     cx: &CodegenCx<'ll, 'tcx>,
 940     name: &str,
 941     inputs: Vec<Ty<'tcx>>,
 942     output: Ty<'tcx>,
 943     codegen: &mut dyn FnMut(Builder<'_, 'll, 'tcx>),
 944 ) -> &'ll Value {
 945     let rust_fn_sig = ty::Binder::bind(cx.tcx.mk_fn_sig(
 946         inputs.into_iter(),
 947         output,
 948         false,
 949         hir::Unsafety::Unsafe,
 950         Abi::Rust
 951     ));
 952     let llfn = declare::define_internal_fn(cx, name, rust_fn_sig);
 953     attributes::from_fn_attrs(cx, llfn, None);
 954     let bx = Builder::new_block(cx, llfn, "entry-block");
 955     codegen(bx);
 956     llfn
 957 }
 958
 959 // Helper function used to get a handle to the `__rust_try` function used to
 960 // catch exceptions.
 961 //
 962 // This function is only generated once and is then cached.
 963 fn get_rust_try_fn<'ll, 'tcx>(
 964     cx: &CodegenCx<'ll, 'tcx>,
 965     codegen: &mut dyn FnMut(Builder<'_, 'll, 'tcx>),
 966 ) -> &'ll Value {
 967     if let Some(llfn) = cx.rust_try_fn.get() {
 968         return llfn;
 969     }
 970
 971     // Define the type up front for the signature of the rust_try function.
 972     let tcx = cx.tcx;
 973     let i8p = tcx.mk_mut_ptr(tcx.types.i8);
 974     let fn_ty = tcx.mk_fn_ptr(ty::Binder::bind(tcx.mk_fn_sig(
 975         iter::once(i8p),
 976         tcx.mk_unit(),
 977         false,
 978         hir::Unsafety::Unsafe,
 979         Abi::Rust
 980     )));
 981     let output = tcx.types.i32;
 982     let rust_try = gen_fn(cx, "__rust_try", vec![fn_ty, i8p, i8p], output, codegen);
 983     cx.rust_try_fn.set(Some(rust_try));
 984     rust_try
 985 }
 986
 987 fn span_invalid_monomorphization_error(a: &Session, b: Span, c: &str) {
 988     span_err!(a, b, E0511, "{}", c);
 989 }
 990
 991 fn generic_simd_intrinsic(
 992     bx: &Builder<'a, 'll, 'tcx>,
 993     name: &str,
 994     callee_ty: Ty<'tcx>,
 995     args: &[OperandRef<'ll, 'tcx>],
 996     ret_ty: Ty<'tcx>,
 997     llret_ty: &'ll Type,
 998     span: Span
 999 ) -> Result<&'ll Value, ()> {
1000     // macros for error handling:
1001     macro_rules! emit_error {
1002         ($msg: tt) => {
1003             emit_error!($msg, )
1004         };
1005         ($msg: tt, $($fmt: tt)*) => {
1006             span_invalid_monomorphization_error(
1007                 bx.sess(), span,
1008                 &format!(concat!("invalid monomorphization of `{}` intrinsic: ", $msg),
1009                          name, $($fmt)*));
1010         }
1011     }
1012
1013     macro_rules! return_error {
1014         ($($fmt: tt)*) => {
1015             {
1016                 emit_error!($($fmt)*);
1017                 return Err(());
1018             }
1019         }
1020     }
1021
1022     macro_rules! require {
1023         ($cond: expr, $($fmt: tt)*) => {
1024             if !$cond {
1025                 return_error!($($fmt)*);
1026             }
1027         };
1028     }
1029
1030     macro_rules! require_simd {
1031         ($ty: expr, $position: expr) => {
1032             require!($ty.is_simd(), "expected SIMD {} type, found non-SIMD `{}`", $position, $ty)
1033         }
1034     }
1035
1036     let tcx = bx.tcx();
1037     let sig = tcx.normalize_erasing_late_bound_regions(
1038         ty::ParamEnv::reveal_all(),
1039         &callee_ty.fn_sig(tcx),
1040     );
1041     let arg_tys = sig.inputs();
1042
1043     // every intrinsic takes a SIMD vector as its first argument
1044     require_simd!(arg_tys[0], "input");
1045     let in_ty = arg_tys[0];
1046     let in_elem = arg_tys[0].simd_type(tcx);
1047     let in_len = arg_tys[0].simd_size(tcx);
1048
1049     let comparison = match name {
1050         "simd_eq" => Some(hir::BinOpKind::Eq),
1051         "simd_ne" => Some(hir::BinOpKind::Ne),
1052         "simd_lt" => Some(hir::BinOpKind::Lt),
1053         "simd_le" => Some(hir::BinOpKind::Le),
1054         "simd_gt" => Some(hir::BinOpKind::Gt),
1055         "simd_ge" => Some(hir::BinOpKind::Ge),
1056         _ => None
1057     };
1058
1059     if let Some(cmp_op) = comparison {
1060         require_simd!(ret_ty, "return");
1061
1062         let out_len = ret_ty.simd_size(tcx);
1063         require!(in_len == out_len,
1064                  "expected return type with length {} (same as input type `{}`), \
1065                   found `{}` with length {}",
1066                  in_len, in_ty,
1067                  ret_ty, out_len);
1068         require!(llret_ty.element_type().kind() == TypeKind::Integer,
1069                  "expected return type with integer elements, found `{}` with non-integer `{}`",
1070                  ret_ty,
1071                  ret_ty.simd_type(tcx));
1072
1073         return Ok(compare_simd_types(bx,
1074                                      args[0].immediate(),
1075                                      args[1].immediate(),
1076                                      in_elem,
1077                                      llret_ty,
1078                                      cmp_op))
1079     }
1080
1081     if name.starts_with("simd_shuffle") {
1082         let n: usize = name["simd_shuffle".len()..].parse().unwrap_or_else(|_|
1083             span_bug!(span, "bad `simd_shuffle` instruction only caught in codegen?"));
1084
1085         require_simd!(ret_ty, "return");
1086
1087         let out_len = ret_ty.simd_size(tcx);
1088         require!(out_len == n,
1089                  "expected return type of length {}, found `{}` with length {}",
1090                  n, ret_ty, out_len);
1091         require!(in_elem == ret_ty.simd_type(tcx),
1092                  "expected return element type `{}` (element of input `{}`), \
1093                   found `{}` with element type `{}`",
1094                  in_elem, in_ty,
1095                  ret_ty, ret_ty.simd_type(tcx));
1096
1097         let total_len = in_len as u128 * 2;
1098
1099         let vector = args[2].immediate();
1100
1101         let indices: Option<Vec<_>> = (0..n)
1102             .map(|i| {
1103                 let arg_idx = i;
1104                 let val = const_get_elt(vector, i as u64);
1105                 match const_to_opt_u128(val, true) {
1106                     None => {
1107                         emit_error!("shuffle index #{} is not a constant", arg_idx);
1108                         None
1109                     }
1110                     Some(idx) if idx >= total_len => {
1111                         emit_error!("shuffle index #{} is out of bounds (limit {})",
1112                                     arg_idx, total_len);
1113                         None
1114                     }
1115                     Some(idx) => Some(C_i32(bx.cx, idx as i32)),
1116                 }
1117             })
1118             .collect();
1119         let indices = match indices {
1120             Some(i) => i,
1121             None => return Ok(C_null(llret_ty))
1122         };
1123
1124         return Ok(bx.shuffle_vector(args[0].immediate(),
1125                                     args[1].immediate(),
1126                                     C_vector(&indices)))
1127     }
1128
1129     if name == "simd_insert" {
1130         require!(in_elem == arg_tys[2],
1131                  "expected inserted type `{}` (element of input `{}`), found `{}`",
1132                  in_elem, in_ty, arg_tys[2]);
1133         return Ok(bx.insert_element(args[0].immediate(),
1134                                     args[2].immediate(),
1135                                     args[1].immediate()))
1136     }
1137     if name == "simd_extract" {
1138         require!(ret_ty == in_elem,
1139                  "expected return type `{}` (element of input `{}`), found `{}`",
1140                  in_elem, in_ty, ret_ty);
1141         return Ok(bx.extract_element(args[0].immediate(), args[1].immediate()))
1142     }
1143
1144     if name == "simd_select" {
1145         let m_elem_ty = in_elem;
1146         let m_len = in_len;
1147         let v_len = arg_tys[1].simd_size(tcx);
1148         require!(m_len == v_len,
1149                  "mismatched lengths: mask length `{}` != other vector length `{}`",
1150                  m_len, v_len
1151         );
1152         match m_elem_ty.sty {
1153             ty::Int(_) => {},
1154             _ => return_error!("mask element type is `{}`, expected `i_`", m_elem_ty)
1155         }
1156         // truncate the mask to a vector of i1s
1157         let i1 = Type::i1(bx.cx);
1158         let i1xn = Type::vector(i1, m_len as u64);
1159         let m_i1s = bx.trunc(args[0].immediate(), i1xn);
1160         return Ok(bx.select(m_i1s, args[1].immediate(), args[2].immediate()));
1161     }
1162
1163     fn simd_simple_float_intrinsic(
1164         name: &str,
1165         in_elem: &::rustc::ty::TyS,
1166         in_ty: &::rustc::ty::TyS,
1167         in_len: usize,
1168         bx: &Builder<'a, 'll, 'tcx>,
1169         span: Span,
1170         args: &[OperandRef<'ll, 'tcx>],
1171     ) -> Result<&'ll Value, ()> {
1172         macro_rules! emit_error {
1173             ($msg: tt) => {
1174                 emit_error!($msg, )
1175             };
1176             ($msg: tt, $($fmt: tt)*) => {
1177                 span_invalid_monomorphization_error(
1178                     bx.sess(), span,
1179                     &format!(concat!("invalid monomorphization of `{}` intrinsic: ", $msg),
1180                              name, $($fmt)*));
1181             }
1182         }
1183         macro_rules! return_error {
1184             ($($fmt: tt)*) => {
1185                 {
1186                     emit_error!($($fmt)*);
1187                     return Err(());
1188                 }
1189             }
1190         }
1191         let ety = match in_elem.sty {
1192             ty::Float(f) if f.bit_width() == 32 => {
1193                 if in_len < 2 || in_len > 16 {
1194                     return_error!(
1195                         "unsupported floating-point vector `{}` with length `{}` \
1196                          out-of-range [2, 16]",
1197                         in_ty, in_len);
1198                 }
1199                 "f32"
1200             },
1201             ty::Float(f) if f.bit_width() == 64 => {
1202                 if in_len < 2 || in_len > 8 {
1203                     return_error!("unsupported floating-point vector `{}` with length `{}` \
1204                                    out-of-range [2, 8]",
1205                                   in_ty, in_len);
1206                 }
1207                 "f64"
1208             },
1209             ty::Float(f) => {
1210                 return_error!("unsupported element type `{}` of floating-point vector `{}`",
1211                               f, in_ty);
1212             },
1213             _ => {
1214                 return_error!("`{}` is not a floating-point type", in_ty);
1215             }
1216         };
1217
1218         let llvm_name = &format!("llvm.{0}.v{1}{2}", name, in_len, ety);
1219         let intrinsic = bx.cx.get_intrinsic(&llvm_name);
1220         let c = bx.call(intrinsic,
1221                         &args.iter().map(|arg| arg.immediate()).collect::<Vec<_>>(),
1222                         None);
1223         unsafe { llvm::LLVMRustSetHasUnsafeAlgebra(c) };
1224         Ok(c)
1225     }
1226
1227     match name {
1228         "simd_fsqrt" => {
1229             return simd_simple_float_intrinsic("sqrt", in_elem, in_ty, in_len, bx, span, args);
1230         }
1231         "simd_fsin" => {
1232             return simd_simple_float_intrinsic("sin", in_elem, in_ty, in_len, bx, span, args);
1233         }
1234         "simd_fcos" => {
1235             return simd_simple_float_intrinsic("cos", in_elem, in_ty, in_len, bx, span, args);
1236         }
1237         "simd_fabs" => {
1238             return simd_simple_float_intrinsic("fabs", in_elem, in_ty, in_len, bx, span, args);
1239         }
1240         "simd_floor" => {
1241             return simd_simple_float_intrinsic("floor", in_elem, in_ty, in_len, bx, span, args);
1242         }
1243         "simd_ceil" => {
1244             return simd_simple_float_intrinsic("ceil", in_elem, in_ty, in_len, bx, span, args);
1245         }
1246         "simd_fexp" => {
1247             return simd_simple_float_intrinsic("exp", in_elem, in_ty, in_len, bx, span, args);
1248         }
1249         "simd_fexp2" => {
1250             return simd_simple_float_intrinsic("exp2", in_elem, in_ty, in_len, bx, span, args);
1251         }
1252         "simd_flog10" => {
1253             return simd_simple_float_intrinsic("log10", in_elem, in_ty, in_len, bx, span, args);
1254         }
1255         "simd_flog2" => {
1256             return simd_simple_float_intrinsic("log2", in_elem, in_ty, in_len, bx, span, args);
1257         }
1258         "simd_flog" => {
1259             return simd_simple_float_intrinsic("log", in_elem, in_ty, in_len, bx, span, args);
1260         }
1261         "simd_fpowi" => {
1262             return simd_simple_float_intrinsic("powi", in_elem, in_ty, in_len, bx, span, args);
1263         }
1264         "simd_fpow" => {
1265             return simd_simple_float_intrinsic("pow", in_elem, in_ty, in_len, bx, span, args);
1266         }
1267         "simd_fma" => {
1268             return simd_simple_float_intrinsic("fma", in_elem, in_ty, in_len, bx, span, args);
1269         }
1270         _ => { /* fallthrough */ }
1271     }
1272
1273     // FIXME: use:
1274     //  https://github.com/llvm-mirror/llvm/blob/master/include/llvm/IR/Function.h#L182
1275     //  https://github.com/llvm-mirror/llvm/blob/master/include/llvm/IR/Intrinsics.h#L81
1276     fn llvm_vector_str(elem_ty: ty::Ty, vec_len: usize, no_pointers: usize) -> String {
1277         let p0s: String = "p0".repeat(no_pointers);
1278         match elem_ty.sty {
1279             ty::Int(v) => format!("v{}{}i{}", vec_len, p0s, v.bit_width().unwrap()),
1280             ty::Uint(v) => format!("v{}{}i{}", vec_len, p0s, v.bit_width().unwrap()),
1281             ty::Float(v) => format!("v{}{}f{}", vec_len, p0s, v.bit_width()),
1282             _ => unreachable!(),
1283         }
1284     }
1285
1286     fn llvm_vector_ty(cx: &CodegenCx<'ll, '_>, elem_ty: ty::Ty, vec_len: usize,
1287                       mut no_pointers: usize) -> &'ll Type {
1288         // FIXME: use cx.layout_of(ty).llvm_type() ?
1289         let mut elem_ty = match elem_ty.sty {
1290             ty::Int(v) => Type::int_from_ty(cx, v),
1291             ty::Uint(v) => Type::uint_from_ty(cx, v),
1292             ty::Float(v) => Type::float_from_ty(cx, v),
1293             _ => unreachable!(),
1294         };
1295         while no_pointers > 0 {
1296             elem_ty = elem_ty.ptr_to();
1297             no_pointers -= 1;
1298         }
1299         Type::vector(elem_ty, vec_len as u64)
1300     }
1301
1302
1303     if name == "simd_gather" {
1304         // simd_gather(values: <N x T>, pointers: <N x *_ T>,
1305         //             mask: <N x i{M}>) -> <N x T>
1306         // * N: number of elements in the input vectors
1307         // * T: type of the element to load
1308         // * M: any integer width is supported, will be truncated to i1
1309
1310         // All types must be simd vector types
1311         require_simd!(in_ty, "first");
1312         require_simd!(arg_tys[1], "second");
1313         require_simd!(arg_tys[2], "third");
1314         require_simd!(ret_ty, "return");
1315
1316         // Of the same length:
1317         require!(in_len == arg_tys[1].simd_size(tcx),
1318                  "expected {} argument with length {} (same as input type `{}`), \
1319                   found `{}` with length {}", "second", in_len, in_ty, arg_tys[1],
1320                  arg_tys[1].simd_size(tcx));
1321         require!(in_len == arg_tys[2].simd_size(tcx),
1322                  "expected {} argument with length {} (same as input type `{}`), \
1323                   found `{}` with length {}", "third", in_len, in_ty, arg_tys[2],
1324                  arg_tys[2].simd_size(tcx));
1325
1326         // The return type must match the first argument type
1327         require!(ret_ty == in_ty,
1328                  "expected return type `{}`, found `{}`",
1329                  in_ty, ret_ty);
1330
1331         // This counts how many pointers
1332         fn ptr_count(t: ty::Ty) -> usize {
1333             match t.sty {
1334                 ty::RawPtr(p) => 1 + ptr_count(p.ty),
1335                 _ => 0,
1336             }
1337         }
1338
1339         // Non-ptr type
1340         fn non_ptr(t: ty::Ty) -> ty::Ty {
1341             match t.sty {
1342                 ty::RawPtr(p) => non_ptr(p.ty),
1343                 _ => t,
1344             }
1345         }
1346
1347         // The second argument must be a simd vector with an element type that's a pointer
1348         // to the element type of the first argument
1349         let (pointer_count, underlying_ty) = match arg_tys[1].simd_type(tcx).sty {
1350             ty::RawPtr(p) if p.ty == in_elem => (ptr_count(arg_tys[1].simd_type(tcx)),
1351                                                  non_ptr(arg_tys[1].simd_type(tcx))),
1352             _ => {
1353                 require!(false, "expected element type `{}` of second argument `{}` \
1354                                  to be a pointer to the element type `{}` of the first \
1355                                  argument `{}`, found `{}` != `*_ {}`",
1356                          arg_tys[1].simd_type(tcx).sty, arg_tys[1], in_elem, in_ty,
1357                          arg_tys[1].simd_type(tcx).sty, in_elem);
1358                 unreachable!();
1359             }
1360         };
1361         assert!(pointer_count > 0);
1362         assert_eq!(pointer_count - 1, ptr_count(arg_tys[0].simd_type(tcx)));
1363         assert_eq!(underlying_ty, non_ptr(arg_tys[0].simd_type(tcx)));
1364
1365         // The element type of the third argument must be a signed integer type of any width:
1366         match arg_tys[2].simd_type(tcx).sty {
1367             ty::Int(_) => (),
1368             _ => {
1369                 require!(false, "expected element type `{}` of third argument `{}` \
1370                                  to be a signed integer type",
1371                          arg_tys[2].simd_type(tcx).sty, arg_tys[2]);
1372             }
1373         }
1374
1375         // Alignment of T, must be a constant integer value:
1376         let alignment_ty = Type::i32(bx.cx);
1377         let alignment = C_i32(bx.cx, bx.cx.align_of(in_elem).abi() as i32);
1378
1379         // Truncate the mask vector to a vector of i1s:
1380         let (mask, mask_ty) = {
1381             let i1 = Type::i1(bx.cx);
1382             let i1xn = Type::vector(i1, in_len as u64);
1383             (bx.trunc(args[2].immediate(), i1xn), i1xn)
1384         };
1385
1386         // Type of the vector of pointers:
1387         let llvm_pointer_vec_ty = llvm_vector_ty(bx.cx, underlying_ty, in_len, pointer_count);
1388         let llvm_pointer_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count);
1389
1390         // Type of the vector of elements:
1391         let llvm_elem_vec_ty = llvm_vector_ty(bx.cx, underlying_ty, in_len, pointer_count - 1);
1392         let llvm_elem_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count - 1);
1393
1394         let llvm_intrinsic = format!("llvm.masked.gather.{}.{}",
1395                                      llvm_elem_vec_str, llvm_pointer_vec_str);
1396         let f = declare::declare_cfn(bx.cx, &llvm_intrinsic,
1397                                      Type::func(&[llvm_pointer_vec_ty, alignment_ty, mask_ty,
1398                                                   llvm_elem_vec_ty], llvm_elem_vec_ty));
1399         llvm::SetUnnamedAddr(f, false);
1400         let v = bx.call(f, &[args[1].immediate(), alignment, mask, args[0].immediate()],
1401                         None);
1402         return Ok(v);
1403     }
1404
1405     if name == "simd_scatter" {
1406         // simd_scatter(values: <N x T>, pointers: <N x *mut T>,
1407         //             mask: <N x i{M}>) -> ()
1408         // * N: number of elements in the input vectors
1409         // * T: type of the element to load
1410         // * M: any integer width is supported, will be truncated to i1
1411
1412         // All types must be simd vector types
1413         require_simd!(in_ty, "first");
1414         require_simd!(arg_tys[1], "second");
1415         require_simd!(arg_tys[2], "third");
1416
1417         // Of the same length:
1418         require!(in_len == arg_tys[1].simd_size(tcx),
1419                  "expected {} argument with length {} (same as input type `{}`), \
1420                   found `{}` with length {}", "second", in_len, in_ty, arg_tys[1],
1421                  arg_tys[1].simd_size(tcx));
1422         require!(in_len == arg_tys[2].simd_size(tcx),
1423                  "expected {} argument with length {} (same as input type `{}`), \
1424                   found `{}` with length {}", "third", in_len, in_ty, arg_tys[2],
1425                  arg_tys[2].simd_size(tcx));
1426
1427         // This counts how many pointers
1428         fn ptr_count(t: ty::Ty) -> usize {
1429             match t.sty {
1430                 ty::RawPtr(p) => 1 + ptr_count(p.ty),
1431                 _ => 0,
1432             }
1433         }
1434
1435         // Non-ptr type
1436         fn non_ptr(t: ty::Ty) -> ty::Ty {
1437             match t.sty {
1438                 ty::RawPtr(p) => non_ptr(p.ty),
1439                 _ => t,
1440             }
1441         }
1442
1443         // The second argument must be a simd vector with an element type that's a pointer
1444         // to the element type of the first argument
1445         let (pointer_count, underlying_ty) = match arg_tys[1].simd_type(tcx).sty {
1446             ty::RawPtr(p) if p.ty == in_elem && p.mutbl == hir::MutMutable
1447                 => (ptr_count(arg_tys[1].simd_type(tcx)),
1448                     non_ptr(arg_tys[1].simd_type(tcx))),
1449             _ => {
1450                 require!(false, "expected element type `{}` of second argument `{}` \
1451                                  to be a pointer to the element type `{}` of the first \
1452                                  argument `{}`, found `{}` != `*mut {}`",
1453                          arg_tys[1].simd_type(tcx).sty, arg_tys[1], in_elem, in_ty,
1454                          arg_tys[1].simd_type(tcx).sty, in_elem);
1455                 unreachable!();
1456             }
1457         };
1458         assert!(pointer_count > 0);
1459         assert_eq!(pointer_count - 1, ptr_count(arg_tys[0].simd_type(tcx)));
1460         assert_eq!(underlying_ty, non_ptr(arg_tys[0].simd_type(tcx)));
1461
1462         // The element type of the third argument must be a signed integer type of any width:
1463         match arg_tys[2].simd_type(tcx).sty {
1464             ty::Int(_) => (),
1465             _ => {
1466                 require!(false, "expected element type `{}` of third argument `{}` \
1467                                  to be a signed integer type",
1468                          arg_tys[2].simd_type(tcx).sty, arg_tys[2]);
1469             }
1470         }
1471
1472         // Alignment of T, must be a constant integer value:
1473         let alignment_ty = Type::i32(bx.cx);
1474         let alignment = C_i32(bx.cx, bx.cx.align_of(in_elem).abi() as i32);
1475
1476         // Truncate the mask vector to a vector of i1s:
1477         let (mask, mask_ty) = {
1478             let i1 = Type::i1(bx.cx);
1479             let i1xn = Type::vector(i1, in_len as u64);
1480             (bx.trunc(args[2].immediate(), i1xn), i1xn)
1481         };
1482
1483         let ret_t = Type::void(bx.cx);
1484
1485         // Type of the vector of pointers:
1486         let llvm_pointer_vec_ty = llvm_vector_ty(bx.cx, underlying_ty, in_len, pointer_count);
1487         let llvm_pointer_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count);
1488
1489         // Type of the vector of elements:
1490         let llvm_elem_vec_ty = llvm_vector_ty(bx.cx, underlying_ty, in_len, pointer_count - 1);
1491         let llvm_elem_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count - 1);
1492
1493         let llvm_intrinsic = format!("llvm.masked.scatter.{}.{}",
1494                                      llvm_elem_vec_str, llvm_pointer_vec_str);
1495         let f = declare::declare_cfn(bx.cx, &llvm_intrinsic,
1496                                      Type::func(&[llvm_elem_vec_ty,
1497                                                   llvm_pointer_vec_ty,
1498                                                   alignment_ty,
1499                                                   mask_ty], ret_t));
1500         llvm::SetUnnamedAddr(f, false);
1501         let v = bx.call(f, &[args[0].immediate(), args[1].immediate(), alignment, mask],
1502                         None);
1503         return Ok(v);
1504     }
1505
1506     macro_rules! arith_red {
1507         ($name:tt : $integer_reduce:ident, $float_reduce:ident, $ordered:expr) => {
1508             if name == $name {
1509                 require!(ret_ty == in_elem,
1510                          "expected return type `{}` (element of input `{}`), found `{}`",
1511                          in_elem, in_ty, ret_ty);
1512                 return match in_elem.sty {
1513                     ty::Int(_) | ty::Uint(_) => {
1514                         let r = bx.$integer_reduce(args[0].immediate());
1515                         if $ordered {
1516                             // if overflow occurs, the result is the
1517                             // mathematical result modulo 2^n:
1518                             if name.contains("mul") {
1519                                 Ok(bx.mul(args[1].immediate(), r))
1520                             } else {
1521                                 Ok(bx.add(args[1].immediate(), r))
1522                             }
1523                         } else {
1524                             Ok(bx.$integer_reduce(args[0].immediate()))
1525                         }
1526                     },
1527                     ty::Float(f) => {
1528                         // ordered arithmetic reductions take an accumulator
1529                         let acc = if $ordered {
1530                             let acc = args[1].immediate();
1531                             // FIXME: https://bugs.llvm.org/show_bug.cgi?id=36734
1532                             // * if the accumulator of the fadd isn't 0, incorrect
1533                             //   code is generated
1534                             // * if the accumulator of the fmul isn't 1, incorrect
1535                             //   code is generated
1536                             match const_get_real(acc) {
1537                                 None => return_error!("accumulator of {} is not a constant", $name),
1538                                 Some((v, loses_info)) => {
1539                                     if $name.contains("mul") && v != 1.0_f64 {
1540                                         return_error!("accumulator of {} is not 1.0", $name);
1541                                     } else if $name.contains("add") && v != 0.0_f64 {
1542                                         return_error!("accumulator of {} is not 0.0", $name);
1543                                     } else if loses_info {
1544                                         return_error!("accumulator of {} loses information", $name);
1545                                     }
1546                                 }
1547                             }
1548                             acc
1549                         } else {
1550                             // unordered arithmetic reductions do not:
1551                             match f.bit_width() {
1552                                 32 => C_undef(Type::f32(bx.cx)),
1553                                 64 => C_undef(Type::f64(bx.cx)),
1554                                 v => {
1555                                     return_error!(r#"
1556 unsupported {} from `{}` with element `{}` of size `{}` to `{}`"#,
1557                                         $name, in_ty, in_elem, v, ret_ty
1558                                     )
1559                                 }
1560                             }
1561                         };
1562                         Ok(bx.$float_reduce(acc, args[0].immediate()))
1563                     }
1564                     _ => {
1565                         return_error!(
1566                             "unsupported {} from `{}` with element `{}` to `{}`",
1567                             $name, in_ty, in_elem, ret_ty
1568                         )
1569                     },
1570                 }
1571             }
1572         }
1573     }
1574
1575     arith_red!("simd_reduce_add_ordered": vector_reduce_add, vector_reduce_fadd_fast, true);
1576     arith_red!("simd_reduce_mul_ordered": vector_reduce_mul, vector_reduce_fmul_fast, true);
1577     arith_red!("simd_reduce_add_unordered": vector_reduce_add, vector_reduce_fadd_fast, false);
1578     arith_red!("simd_reduce_mul_unordered": vector_reduce_mul, vector_reduce_fmul_fast, false);
1579
1580     macro_rules! minmax_red {
1581         ($name:tt: $int_red:ident, $float_red:ident) => {
1582             if name == $name {
1583                 require!(ret_ty == in_elem,
1584                          "expected return type `{}` (element of input `{}`), found `{}`",
1585                          in_elem, in_ty, ret_ty);
1586                 return match in_elem.sty {
1587                     ty::Int(_i) => {
1588                         Ok(bx.$int_red(args[0].immediate(), true))
1589                     },
1590                     ty::Uint(_u) => {
1591                         Ok(bx.$int_red(args[0].immediate(), false))
1592                     },
1593                     ty::Float(_f) => {
1594                         Ok(bx.$float_red(args[0].immediate()))
1595                     }
1596                     _ => {
1597                         return_error!("unsupported {} from `{}` with element `{}` to `{}`",
1598                                       $name, in_ty, in_elem, ret_ty)
1599                     },
1600                 }
1601             }
1602
1603         }
1604     }
1605
1606     minmax_red!("simd_reduce_min": vector_reduce_min, vector_reduce_fmin);
1607     minmax_red!("simd_reduce_max": vector_reduce_max, vector_reduce_fmax);
1608
1609     minmax_red!("simd_reduce_min_nanless": vector_reduce_min, vector_reduce_fmin_fast);
1610     minmax_red!("simd_reduce_max_nanless": vector_reduce_max, vector_reduce_fmax_fast);
1611
1612     macro_rules! bitwise_red {
1613         ($name:tt : $red:ident, $boolean:expr) => {
1614             if name == $name {
1615                 let input = if !$boolean {
1616                     require!(ret_ty == in_elem,
1617                              "expected return type `{}` (element of input `{}`), found `{}`",
1618                              in_elem, in_ty, ret_ty);
1619                     args[0].immediate()
1620                 } else {
1621                     match in_elem.sty {
1622                         ty::Int(_) | ty::Uint(_) => {},
1623                         _ => {
1624                             return_error!("unsupported {} from `{}` with element `{}` to `{}`",
1625                                           $name, in_ty, in_elem, ret_ty)
1626                         }
1627                     }
1628
1629                     // boolean reductions operate on vectors of i1s:
1630                     let i1 = Type::i1(bx.cx);
1631                     let i1xn = Type::vector(i1, in_len as u64);
1632                     bx.trunc(args[0].immediate(), i1xn)
1633                 };
1634                 return match in_elem.sty {
1635                     ty::Int(_) | ty::Uint(_) => {
1636                         let r = bx.$red(input);
1637                         Ok(
1638                             if !$boolean {
1639                                 r
1640                             } else {
1641                                 bx.zext(r, Type::bool(bx.cx))
1642                             }
1643                         )
1644                     },
1645                     _ => {
1646                         return_error!("unsupported {} from `{}` with element `{}` to `{}`",
1647                                       $name, in_ty, in_elem, ret_ty)
1648                     },
1649                 }
1650             }
1651         }
1652     }
1653
1654     bitwise_red!("simd_reduce_and": vector_reduce_and, false);
1655     bitwise_red!("simd_reduce_or": vector_reduce_or, false);
1656     bitwise_red!("simd_reduce_xor": vector_reduce_xor, false);
1657     bitwise_red!("simd_reduce_all": vector_reduce_and, true);
1658     bitwise_red!("simd_reduce_any": vector_reduce_or, true);
1659
1660     if name == "simd_cast" {
1661         require_simd!(ret_ty, "return");
1662         let out_len = ret_ty.simd_size(tcx);
1663         require!(in_len == out_len,
1664                  "expected return type with length {} (same as input type `{}`), \
1665                   found `{}` with length {}",
1666                  in_len, in_ty,
1667                  ret_ty, out_len);
1668         // casting cares about nominal type, not just structural type
1669         let out_elem = ret_ty.simd_type(tcx);
1670
1671         if in_elem == out_elem { return Ok(args[0].immediate()); }
1672
1673         enum Style { Float, Int(/* is signed? */ bool), Unsupported }
1674
1675         let (in_style, in_width) = match in_elem.sty {
1676             // vectors of pointer-sized integers should've been
1677             // disallowed before here, so this unwrap is safe.
1678             ty::Int(i) => (Style::Int(true), i.bit_width().unwrap()),
1679             ty::Uint(u) => (Style::Int(false), u.bit_width().unwrap()),
1680             ty::Float(f) => (Style::Float, f.bit_width()),
1681             _ => (Style::Unsupported, 0)
1682         };
1683         let (out_style, out_width) = match out_elem.sty {
1684             ty::Int(i) => (Style::Int(true), i.bit_width().unwrap()),
1685             ty::Uint(u) => (Style::Int(false), u.bit_width().unwrap()),
1686             ty::Float(f) => (Style::Float, f.bit_width()),
1687             _ => (Style::Unsupported, 0)
1688         };
1689
1690         match (in_style, out_style) {
1691             (Style::Int(in_is_signed), Style::Int(_)) => {
1692                 return Ok(match in_width.cmp(&out_width) {
1693                     Ordering::Greater => bx.trunc(args[0].immediate(), llret_ty),
1694                     Ordering::Equal => args[0].immediate(),
1695                     Ordering::Less => if in_is_signed {
1696                         bx.sext(args[0].immediate(), llret_ty)
1697                     } else {
1698                         bx.zext(args[0].immediate(), llret_ty)
1699                     }
1700                 })
1701             }
1702             (Style::Int(in_is_signed), Style::Float) => {
1703                 return Ok(if in_is_signed {
1704                     bx.sitofp(args[0].immediate(), llret_ty)
1705                 } else {
1706                     bx.uitofp(args[0].immediate(), llret_ty)
1707                 })
1708             }
1709             (Style::Float, Style::Int(out_is_signed)) => {
1710                 return Ok(if out_is_signed {
1711                     bx.fptosi(args[0].immediate(), llret_ty)
1712                 } else {
1713                     bx.fptoui(args[0].immediate(), llret_ty)
1714                 })
1715             }
1716             (Style::Float, Style::Float) => {
1717                 return Ok(match in_width.cmp(&out_width) {
1718                     Ordering::Greater => bx.fptrunc(args[0].immediate(), llret_ty),
1719                     Ordering::Equal => args[0].immediate(),
1720                     Ordering::Less => bx.fpext(args[0].immediate(), llret_ty)
1721                 })
1722             }
1723             _ => {/* Unsupported. Fallthrough. */}
1724         }
1725         require!(false,
1726                  "unsupported cast from `{}` with element `{}` to `{}` with element `{}`",
1727                  in_ty, in_elem,
1728                  ret_ty, out_elem);
1729     }
1730     macro_rules! arith {
1731         ($($name: ident: $($($p: ident),* => $call: ident),*;)*) => {
1732             $(if name == stringify!($name) {
1733                 match in_elem.sty {
1734                     $($(ty::$p(_))|* => {
1735                         return Ok(bx.$call(args[0].immediate(), args[1].immediate()))
1736                     })*
1737                     _ => {},
1738                 }
1739                 require!(false,
1740                          "unsupported operation on `{}` with element `{}`",
1741                          in_ty,
1742                          in_elem)
1743             })*
1744         }
1745     }
1746     arith! {
1747         simd_add: Uint, Int => add, Float => fadd;
1748         simd_sub: Uint, Int => sub, Float => fsub;
1749         simd_mul: Uint, Int => mul, Float => fmul;
1750         simd_div: Uint => udiv, Int => sdiv, Float => fdiv;
1751         simd_rem: Uint => urem, Int => srem, Float => frem;
1752         simd_shl: Uint, Int => shl;
1753         simd_shr: Uint => lshr, Int => ashr;
1754         simd_and: Uint, Int => and;
1755         simd_or: Uint, Int => or;
1756         simd_xor: Uint, Int => xor;
1757         simd_fmax: Float => maxnum;
1758         simd_fmin: Float => minnum;
1759     }
1760     span_bug!(span, "unknown SIMD intrinsic");
1761 }
1762
1763 // Returns the width of an int Ty, and if it's signed or not
1764 // Returns None if the type is not an integer
1765 // FIXME: there’s multiple of this functions, investigate using some of the already existing
1766 // stuffs.
1767 fn int_type_width_signed(ty: Ty, cx: &CodegenCx) -> Option<(u64, bool)> {
1768     match ty.sty {
1769         ty::Int(t) => Some((match t {
1770             ast::IntTy::Isize => cx.tcx.sess.target.isize_ty.bit_width().unwrap() as u64,
1771             ast::IntTy::I8 => 8,
1772             ast::IntTy::I16 => 16,
1773             ast::IntTy::I32 => 32,
1774             ast::IntTy::I64 => 64,
1775             ast::IntTy::I128 => 128,
1776         }, true)),
1777         ty::Uint(t) => Some((match t {
1778             ast::UintTy::Usize => cx.tcx.sess.target.usize_ty.bit_width().unwrap() as u64,
1779             ast::UintTy::U8 => 8,
1780             ast::UintTy::U16 => 16,
1781             ast::UintTy::U32 => 32,
1782             ast::UintTy::U64 => 64,
1783             ast::UintTy::U128 => 128,
1784         }, false)),
1785         _ => None,
1786     }
1787 }
1788
1789 // Returns the width of a float TypeVariant
1790 // Returns None if the type is not a float
1791 fn float_type_width<'tcx>(sty: &ty::TyKind<'tcx>) -> Option<u64> {
1792     match *sty {
1793         ty::Float(t) => Some(t.bit_width() as u64),
1794         _ => None,
1795     }
1796 }