src/librustc_trans/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 intrinsics::{self, Intrinsic};
  14 use libc;
  15 use llvm;
  16 use llvm::{ValueRef};
  17 use abi::{Abi, FnType};
  18 use adt;
  19 use mir::lvalue::LvalueRef;
  20 use base::*;
  21 use common::*;
  22 use declare;
  23 use glue;
  24 use type_of;
  25 use machine;
  26 use type_::Type;
  27 use rustc::ty::{self, Ty};
  28 use rustc::hir;
  29 use syntax::ast;
  30 use syntax::symbol::Symbol;
  31 use builder::Builder;
  32
  33 use rustc::session::Session;
  34 use syntax_pos::Span;
  35
  36 use std::cmp::Ordering;
  37 use std::iter;
  38
  39 use mir::lvalue::Alignment;
  40
  41 fn get_simple_intrinsic(ccx: &CrateContext, name: &str) -> Option<ValueRef> {
  42     let llvm_name = match name {
  43         "sqrtf32" => "llvm.sqrt.f32",
  44         "sqrtf64" => "llvm.sqrt.f64",
  45         "powif32" => "llvm.powi.f32",
  46         "powif64" => "llvm.powi.f64",
  47         "sinf32" => "llvm.sin.f32",
  48         "sinf64" => "llvm.sin.f64",
  49         "cosf32" => "llvm.cos.f32",
  50         "cosf64" => "llvm.cos.f64",
  51         "powf32" => "llvm.pow.f32",
  52         "powf64" => "llvm.pow.f64",
  53         "expf32" => "llvm.exp.f32",
  54         "expf64" => "llvm.exp.f64",
  55         "exp2f32" => "llvm.exp2.f32",
  56         "exp2f64" => "llvm.exp2.f64",
  57         "logf32" => "llvm.log.f32",
  58         "logf64" => "llvm.log.f64",
  59         "log10f32" => "llvm.log10.f32",
  60         "log10f64" => "llvm.log10.f64",
  61         "log2f32" => "llvm.log2.f32",
  62         "log2f64" => "llvm.log2.f64",
  63         "fmaf32" => "llvm.fma.f32",
  64         "fmaf64" => "llvm.fma.f64",
  65         "fabsf32" => "llvm.fabs.f32",
  66         "fabsf64" => "llvm.fabs.f64",
  67         "copysignf32" => "llvm.copysign.f32",
  68         "copysignf64" => "llvm.copysign.f64",
  69         "floorf32" => "llvm.floor.f32",
  70         "floorf64" => "llvm.floor.f64",
  71         "ceilf32" => "llvm.ceil.f32",
  72         "ceilf64" => "llvm.ceil.f64",
  73         "truncf32" => "llvm.trunc.f32",
  74         "truncf64" => "llvm.trunc.f64",
  75         "rintf32" => "llvm.rint.f32",
  76         "rintf64" => "llvm.rint.f64",
  77         "nearbyintf32" => "llvm.nearbyint.f32",
  78         "nearbyintf64" => "llvm.nearbyint.f64",
  79         "roundf32" => "llvm.round.f32",
  80         "roundf64" => "llvm.round.f64",
  81         "assume" => "llvm.assume",
  82         "abort" => "llvm.trap",
  83         _ => return None
  84     };
  85     Some(ccx.get_intrinsic(&llvm_name))
  86 }
  87
  88 /// Remember to add all intrinsics here, in librustc_typeck/check/mod.rs,
  89 /// and in libcore/intrinsics.rs; if you need access to any llvm intrinsics,
  90 /// add them to librustc_trans/trans/context.rs
  91 pub fn trans_intrinsic_call<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
  92                                       callee_ty: Ty<'tcx>,
  93                                       fn_ty: &FnType,
  94                                       llargs: &[ValueRef],
  95                                       llresult: ValueRef,
  96                                       span: Span) {
  97     let ccx = bcx.ccx;
  98     let tcx = ccx.tcx();
  99
 100     let (def_id, substs, sig) = match callee_ty.sty {
 101         ty::TyFnDef(def_id, substs, sig) => (def_id, substs, sig),
 102         _ => bug!("expected fn item type, found {}", callee_ty)
 103     };
 104
 105     let sig = tcx.erase_late_bound_regions_and_normalize(&sig);
 106     let arg_tys = sig.inputs();
 107     let ret_ty = sig.output();
 108     let name = &*tcx.item_name(def_id).as_str();
 109
 110     let llret_ty = type_of::type_of(ccx, ret_ty);
 111
 112     let simple = get_simple_intrinsic(ccx, name);
 113     let llval = match name {
 114         _ if simple.is_some() => {
 115             bcx.call(simple.unwrap(), &llargs, None)
 116         }
 117         "unreachable" => {
 118             return;
 119         },
 120         "likely" => {
 121             let expect = ccx.get_intrinsic(&("llvm.expect.i1"));
 122             bcx.call(expect, &[llargs[0], C_bool(ccx, true)], None)
 123         }
 124         "unlikely" => {
 125             let expect = ccx.get_intrinsic(&("llvm.expect.i1"));
 126             bcx.call(expect, &[llargs[0], C_bool(ccx, false)], None)
 127         }
 128         "try" => {
 129             try_intrinsic(bcx, ccx, llargs[0], llargs[1], llargs[2], llresult);
 130             C_nil(ccx)
 131         }
 132         "breakpoint" => {
 133             let llfn = ccx.get_intrinsic(&("llvm.debugtrap"));
 134             bcx.call(llfn, &[], None)
 135         }
 136         "size_of" => {
 137             let tp_ty = substs.type_at(0);
 138             let lltp_ty = type_of::type_of(ccx, tp_ty);
 139             C_uint(ccx, machine::llsize_of_alloc(ccx, lltp_ty))
 140         }
 141         "size_of_val" => {
 142             let tp_ty = substs.type_at(0);
 143             if !bcx.ccx.shared().type_is_sized(tp_ty) {
 144                 let (llsize, _) =
 145                     glue::size_and_align_of_dst(bcx, tp_ty, llargs[1]);
 146                 llsize
 147             } else {
 148                 let lltp_ty = type_of::type_of(ccx, tp_ty);
 149                 C_uint(ccx, machine::llsize_of_alloc(ccx, lltp_ty))
 150             }
 151         }
 152         "min_align_of" => {
 153             let tp_ty = substs.type_at(0);
 154             C_uint(ccx, ccx.align_of(tp_ty))
 155         }
 156         "min_align_of_val" => {
 157             let tp_ty = substs.type_at(0);
 158             if !bcx.ccx.shared().type_is_sized(tp_ty) {
 159                 let (_, llalign) =
 160                     glue::size_and_align_of_dst(bcx, tp_ty, llargs[1]);
 161                 llalign
 162             } else {
 163                 C_uint(ccx, ccx.align_of(tp_ty))
 164             }
 165         }
 166         "pref_align_of" => {
 167             let tp_ty = substs.type_at(0);
 168             let lltp_ty = type_of::type_of(ccx, tp_ty);
 169             C_uint(ccx, machine::llalign_of_pref(ccx, lltp_ty))
 170         }
 171         "type_name" => {
 172             let tp_ty = substs.type_at(0);
 173             let ty_name = Symbol::intern(&tp_ty.to_string()).as_str();
 174             C_str_slice(ccx, ty_name)
 175         }
 176         "type_id" => {
 177             C_u64(ccx, ccx.tcx().type_id_hash(substs.type_at(0)))
 178         }
 179         "init" => {
 180             let ty = substs.type_at(0);
 181             if !type_is_zero_size(ccx, ty) {
 182                 // Just zero out the stack slot.
 183                 // If we store a zero constant, LLVM will drown in vreg allocation for large data
 184                 // structures, and the generated code will be awful. (A telltale sign of this is
 185                 // large quantities of `mov [byte ptr foo],0` in the generated code.)
 186                 memset_intrinsic(bcx, false, ty, llresult, C_u8(ccx, 0), C_uint(ccx, 1usize));
 187             }
 188             C_nil(ccx)
 189         }
 190         // Effectively no-ops
 191         "uninit" | "forget" => {
 192             C_nil(ccx)
 193         }
 194         "needs_drop" => {
 195             let tp_ty = substs.type_at(0);
 196
 197             C_bool(ccx, bcx.ccx.shared().type_needs_drop(tp_ty))
 198         }
 199         "offset" => {
 200             let ptr = llargs[0];
 201             let offset = llargs[1];
 202             bcx.inbounds_gep(ptr, &[offset])
 203         }
 204         "arith_offset" => {
 205             let ptr = llargs[0];
 206             let offset = llargs[1];
 207             bcx.gep(ptr, &[offset])
 208         }
 209
 210         "copy_nonoverlapping" => {
 211             copy_intrinsic(bcx, false, false, substs.type_at(0), llargs[1], llargs[0], llargs[2])
 212         }
 213         "copy" => {
 214             copy_intrinsic(bcx, true, false, substs.type_at(0), llargs[1], llargs[0], llargs[2])
 215         }
 216         "write_bytes" => {
 217             memset_intrinsic(bcx, false, substs.type_at(0), llargs[0], llargs[1], llargs[2])
 218         }
 219
 220         "volatile_copy_nonoverlapping_memory" => {
 221             copy_intrinsic(bcx, false, true, substs.type_at(0), llargs[0], llargs[1], llargs[2])
 222         }
 223         "volatile_copy_memory" => {
 224             copy_intrinsic(bcx, true, true, substs.type_at(0), llargs[0], llargs[1], llargs[2])
 225         }
 226         "volatile_set_memory" => {
 227             memset_intrinsic(bcx, true, substs.type_at(0), llargs[0], llargs[1], llargs[2])
 228         }
 229         "volatile_load" => {
 230             let tp_ty = substs.type_at(0);
 231             let mut ptr = llargs[0];
 232             if let Some(ty) = fn_ty.ret.cast {
 233                 ptr = bcx.pointercast(ptr, ty.ptr_to());
 234             }
 235             let load = bcx.volatile_load(ptr);
 236             unsafe {
 237                 llvm::LLVMSetAlignment(load, ccx.align_of(tp_ty));
 238             }
 239             to_immediate(bcx, load, tp_ty)
 240         },
 241         "volatile_store" => {
 242             let tp_ty = substs.type_at(0);
 243             if type_is_fat_ptr(bcx.ccx, tp_ty) {
 244                 bcx.volatile_store(llargs[1], get_dataptr(bcx, llargs[0]));
 245                 bcx.volatile_store(llargs[2], get_meta(bcx, llargs[0]));
 246             } else {
 247                 let val = if fn_ty.args[1].is_indirect() {
 248                     bcx.load(llargs[1], None)
 249                 } else {
 250                     from_immediate(bcx, llargs[1])
 251                 };
 252                 let ptr = bcx.pointercast(llargs[0], val_ty(val).ptr_to());
 253                 let store = bcx.volatile_store(val, ptr);
 254                 unsafe {
 255                     llvm::LLVMSetAlignment(store, ccx.align_of(tp_ty));
 256                 }
 257             }
 258             C_nil(ccx)
 259         },
 260
 261         "ctlz" | "cttz" | "ctpop" | "bswap" |
 262         "add_with_overflow" | "sub_with_overflow" | "mul_with_overflow" |
 263         "overflowing_add" | "overflowing_sub" | "overflowing_mul" |
 264         "unchecked_div" | "unchecked_rem" | "unchecked_shl" | "unchecked_shr" => {
 265             let sty = &arg_tys[0].sty;
 266             match int_type_width_signed(sty, ccx) {
 267                 Some((width, signed)) =>
 268                     match name {
 269                         "ctlz" | "cttz" => {
 270                             let y = C_bool(bcx.ccx, false);
 271                             let llfn = ccx.get_intrinsic(&format!("llvm.{}.i{}", name, width));
 272                             bcx.call(llfn, &[llargs[0], y], None)
 273                         }
 274                         "ctpop" => bcx.call(ccx.get_intrinsic(&format!("llvm.ctpop.i{}", width)),
 275                                         &llargs, None),
 276                         "bswap" => {
 277                             if width == 8 {
 278                                 llargs[0] // byte swap a u8/i8 is just a no-op
 279                             } else {
 280                                 bcx.call(ccx.get_intrinsic(&format!("llvm.bswap.i{}", width)),
 281                                         &llargs, None)
 282                             }
 283                         }
 284                         "add_with_overflow" | "sub_with_overflow" | "mul_with_overflow" => {
 285                             let intrinsic = format!("llvm.{}{}.with.overflow.i{}",
 286                                                     if signed { 's' } else { 'u' },
 287                                                     &name[..3], width);
 288                             let llfn = bcx.ccx.get_intrinsic(&intrinsic);
 289
 290                             // Convert `i1` to a `bool`, and write it to the out parameter
 291                             let val = bcx.call(llfn, &[llargs[0], llargs[1]], None);
 292                             let result = bcx.extract_value(val, 0);
 293                             let overflow = bcx.zext(bcx.extract_value(val, 1), Type::bool(ccx));
 294                             bcx.store(result, bcx.struct_gep(llresult, 0), None);
 295                             bcx.store(overflow, bcx.struct_gep(llresult, 1), None);
 296
 297                             C_nil(bcx.ccx)
 298                         },
 299                         "overflowing_add" => bcx.add(llargs[0], llargs[1]),
 300                         "overflowing_sub" => bcx.sub(llargs[0], llargs[1]),
 301                         "overflowing_mul" => bcx.mul(llargs[0], llargs[1]),
 302                         "unchecked_div" =>
 303                             if signed {
 304                                 bcx.sdiv(llargs[0], llargs[1])
 305                             } else {
 306                                 bcx.udiv(llargs[0], llargs[1])
 307                             },
 308                         "unchecked_rem" =>
 309                             if signed {
 310                                 bcx.srem(llargs[0], llargs[1])
 311                             } else {
 312                                 bcx.urem(llargs[0], llargs[1])
 313                             },
 314                         "unchecked_shl" => bcx.shl(llargs[0], llargs[1]),
 315                         "unchecked_shr" =>
 316                             if signed {
 317                                 bcx.ashr(llargs[0], llargs[1])
 318                             } else {
 319                                 bcx.lshr(llargs[0], llargs[1])
 320                             },
 321                         _ => bug!(),
 322                     },
 323                 None => {
 324                     span_invalid_monomorphization_error(
 325                         tcx.sess, span,
 326                         &format!("invalid monomorphization of `{}` intrinsic: \
 327                                   expected basic integer type, found `{}`", name, sty));
 328                         C_nil(ccx)
 329                 }
 330             }
 331
 332         },
 333         "fadd_fast" | "fsub_fast" | "fmul_fast" | "fdiv_fast" | "frem_fast" => {
 334             let sty = &arg_tys[0].sty;
 335             match float_type_width(sty) {
 336                 Some(_width) =>
 337                     match name {
 338                         "fadd_fast" => bcx.fadd_fast(llargs[0], llargs[1]),
 339                         "fsub_fast" => bcx.fsub_fast(llargs[0], llargs[1]),
 340                         "fmul_fast" => bcx.fmul_fast(llargs[0], llargs[1]),
 341                         "fdiv_fast" => bcx.fdiv_fast(llargs[0], llargs[1]),
 342                         "frem_fast" => bcx.frem_fast(llargs[0], llargs[1]),
 343                         _ => bug!(),
 344                     },
 345                 None => {
 346                     span_invalid_monomorphization_error(
 347                         tcx.sess, span,
 348                         &format!("invalid monomorphization of `{}` intrinsic: \
 349                                   expected basic float type, found `{}`", name, sty));
 350                         C_nil(ccx)
 351                 }
 352             }
 353
 354         },
 355
 356         "discriminant_value" => {
 357             let val_ty = substs.type_at(0);
 358             match val_ty.sty {
 359                 ty::TyAdt(adt, ..) if adt.is_enum() => {
 360                     adt::trans_get_discr(bcx, val_ty, llargs[0], Alignment::AbiAligned,
 361                                          Some(llret_ty), true)
 362                 }
 363                 _ => C_null(llret_ty)
 364             }
 365         }
 366         name if name.starts_with("simd_") => {
 367             generic_simd_intrinsic(bcx, name,
 368                                    callee_ty,
 369                                    &llargs,
 370                                    ret_ty, llret_ty,
 371                                    span)
 372         }
 373         // This requires that atomic intrinsics follow a specific naming pattern:
 374         // "atomic_<operation>[_<ordering>]", and no ordering means SeqCst
 375         name if name.starts_with("atomic_") => {
 376             use llvm::AtomicOrdering::*;
 377
 378             let split: Vec<&str> = name.split('_').collect();
 379
 380             let is_cxchg = split[1] == "cxchg" || split[1] == "cxchgweak";
 381             let (order, failorder) = match split.len() {
 382                 2 => (SequentiallyConsistent, SequentiallyConsistent),
 383                 3 => match split[2] {
 384                     "unordered" => (Unordered, Unordered),
 385                     "relaxed" => (Monotonic, Monotonic),
 386                     "acq"     => (Acquire, Acquire),
 387                     "rel"     => (Release, Monotonic),
 388                     "acqrel"  => (AcquireRelease, Acquire),
 389                     "failrelaxed" if is_cxchg =>
 390                         (SequentiallyConsistent, Monotonic),
 391                     "failacq" if is_cxchg =>
 392                         (SequentiallyConsistent, Acquire),
 393                     _ => ccx.sess().fatal("unknown ordering in atomic intrinsic")
 394                 },
 395                 4 => match (split[2], split[3]) {
 396                     ("acq", "failrelaxed") if is_cxchg =>
 397                         (Acquire, Monotonic),
 398                     ("acqrel", "failrelaxed") if is_cxchg =>
 399                         (AcquireRelease, Monotonic),
 400                     _ => ccx.sess().fatal("unknown ordering in atomic intrinsic")
 401                 },
 402                 _ => ccx.sess().fatal("Atomic intrinsic not in correct format"),
 403             };
 404
 405             let invalid_monomorphization = |sty| {
 406                 span_invalid_monomorphization_error(tcx.sess, span,
 407                     &format!("invalid monomorphization of `{}` intrinsic: \
 408                               expected basic integer type, found `{}`", name, sty));
 409             };
 410
 411             match split[1] {
 412                 "cxchg" | "cxchgweak" => {
 413                     let sty = &substs.type_at(0).sty;
 414                     if int_type_width_signed(sty, ccx).is_some() {
 415                         let weak = if split[1] == "cxchgweak" { llvm::True } else { llvm::False };
 416                         let val = bcx.atomic_cmpxchg(llargs[0], llargs[1], llargs[2], order,
 417                             failorder, weak);
 418                         let result = bcx.extract_value(val, 0);
 419                         let success = bcx.zext(bcx.extract_value(val, 1), Type::bool(bcx.ccx));
 420                         bcx.store(result, bcx.struct_gep(llresult, 0), None);
 421                         bcx.store(success, bcx.struct_gep(llresult, 1), None);
 422                     } else {
 423                         invalid_monomorphization(sty);
 424                     }
 425                     C_nil(ccx)
 426                 }
 427
 428                 "load" => {
 429                     let sty = &substs.type_at(0).sty;
 430                     if int_type_width_signed(sty, ccx).is_some() {
 431                         bcx.atomic_load(llargs[0], order)
 432                     } else {
 433                         invalid_monomorphization(sty);
 434                         C_nil(ccx)
 435                     }
 436                 }
 437
 438                 "store" => {
 439                     let sty = &substs.type_at(0).sty;
 440                     if int_type_width_signed(sty, ccx).is_some() {
 441                         bcx.atomic_store(llargs[1], llargs[0], order);
 442                     } else {
 443                         invalid_monomorphization(sty);
 444                     }
 445                     C_nil(ccx)
 446                 }
 447
 448                 "fence" => {
 449                     bcx.atomic_fence(order, llvm::SynchronizationScope::CrossThread);
 450                     C_nil(ccx)
 451                 }
 452
 453                 "singlethreadfence" => {
 454                     bcx.atomic_fence(order, llvm::SynchronizationScope::SingleThread);
 455                     C_nil(ccx)
 456                 }
 457
 458                 // These are all AtomicRMW ops
 459                 op => {
 460                     let atom_op = match op {
 461                         "xchg"  => llvm::AtomicXchg,
 462                         "xadd"  => llvm::AtomicAdd,
 463                         "xsub"  => llvm::AtomicSub,
 464                         "and"   => llvm::AtomicAnd,
 465                         "nand"  => llvm::AtomicNand,
 466                         "or"    => llvm::AtomicOr,
 467                         "xor"   => llvm::AtomicXor,
 468                         "max"   => llvm::AtomicMax,
 469                         "min"   => llvm::AtomicMin,
 470                         "umax"  => llvm::AtomicUMax,
 471                         "umin"  => llvm::AtomicUMin,
 472                         _ => ccx.sess().fatal("unknown atomic operation")
 473                     };
 474
 475                     let sty = &substs.type_at(0).sty;
 476                     if int_type_width_signed(sty, ccx).is_some() {
 477                         bcx.atomic_rmw(atom_op, llargs[0], llargs[1], order)
 478                     } else {
 479                         invalid_monomorphization(sty);
 480                         C_nil(ccx)
 481                     }
 482                 }
 483             }
 484         }
 485
 486         _ => {
 487             let intr = match Intrinsic::find(&name) {
 488                 Some(intr) => intr,
 489                 None => bug!("unknown intrinsic '{}'", name),
 490             };
 491             fn one<T>(x: Vec<T>) -> T {
 492                 assert_eq!(x.len(), 1);
 493                 x.into_iter().next().unwrap()
 494             }
 495             fn ty_to_type(ccx: &CrateContext, t: &intrinsics::Type,
 496                           any_changes_needed: &mut bool) -> Vec<Type> {
 497                 use intrinsics::Type::*;
 498                 match *t {
 499                     Void => vec![Type::void(ccx)],
 500                     Integer(_signed, width, llvm_width) => {
 501                         *any_changes_needed |= width != llvm_width;
 502                         vec![Type::ix(ccx, llvm_width as u64)]
 503                     }
 504                     Float(x) => {
 505                         match x {
 506                             32 => vec![Type::f32(ccx)],
 507                             64 => vec![Type::f64(ccx)],
 508                             _ => bug!()
 509                         }
 510                     }
 511                     Pointer(ref t, ref llvm_elem, _const) => {
 512                         *any_changes_needed |= llvm_elem.is_some();
 513
 514                         let t = llvm_elem.as_ref().unwrap_or(t);
 515                         let elem = one(ty_to_type(ccx, t, any_changes_needed));
 516                         vec![elem.ptr_to()]
 517                     }
 518                     Vector(ref t, ref llvm_elem, length) => {
 519                         *any_changes_needed |= llvm_elem.is_some();
 520
 521                         let t = llvm_elem.as_ref().unwrap_or(t);
 522                         let elem = one(ty_to_type(ccx, t, any_changes_needed));
 523                         vec![Type::vector(&elem, length as u64)]
 524                     }
 525                     Aggregate(false, ref contents) => {
 526                         let elems = contents.iter()
 527                                             .map(|t| one(ty_to_type(ccx, t, any_changes_needed)))
 528                                             .collect::<Vec<_>>();
 529                         vec![Type::struct_(ccx, &elems, false)]
 530                     }
 531                     Aggregate(true, ref contents) => {
 532                         *any_changes_needed = true;
 533                         contents.iter()
 534                                 .flat_map(|t| ty_to_type(ccx, t, any_changes_needed))
 535                                 .collect()
 536                     }
 537                 }
 538             }
 539
 540             // This allows an argument list like `foo, (bar, baz),
 541             // qux` to be converted into `foo, bar, baz, qux`, integer
 542             // arguments to be truncated as needed and pointers to be
 543             // cast.
 544             fn modify_as_needed<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
 545                                           t: &intrinsics::Type,
 546                                           arg_type: Ty<'tcx>,
 547                                           llarg: ValueRef)
 548                                           -> Vec<ValueRef>
 549             {
 550                 match *t {
 551                     intrinsics::Type::Aggregate(true, ref contents) => {
 552                         // We found a tuple that needs squishing! So
 553                         // run over the tuple and load each field.
 554                         //
 555                         // This assumes the type is "simple", i.e. no
 556                         // destructors, and the contents are SIMD
 557                         // etc.
 558                         assert!(!bcx.ccx.shared().type_needs_drop(arg_type));
 559                         let arg = LvalueRef::new_sized_ty(llarg, arg_type, Alignment::AbiAligned);
 560                         (0..contents.len()).map(|i| {
 561                             let (ptr, align) = arg.trans_field_ptr(bcx, i);
 562                             bcx.load(ptr, align.to_align())
 563                         }).collect()
 564                     }
 565                     intrinsics::Type::Pointer(_, Some(ref llvm_elem), _) => {
 566                         let llvm_elem = one(ty_to_type(bcx.ccx, llvm_elem, &mut false));
 567                         vec![bcx.pointercast(llarg, llvm_elem.ptr_to())]
 568                     }
 569                     intrinsics::Type::Vector(_, Some(ref llvm_elem), length) => {
 570                         let llvm_elem = one(ty_to_type(bcx.ccx, llvm_elem, &mut false));
 571                         vec![bcx.bitcast(llarg, Type::vector(&llvm_elem, length as u64))]
 572                     }
 573                     intrinsics::Type::Integer(_, width, llvm_width) if width != llvm_width => {
 574                         // the LLVM intrinsic uses a smaller integer
 575                         // size than the C intrinsic's signature, so
 576                         // we have to trim it down here.
 577                         vec![bcx.trunc(llarg, Type::ix(bcx.ccx, llvm_width as u64))]
 578                     }
 579                     _ => vec![llarg],
 580                 }
 581             }
 582
 583
 584             let mut any_changes_needed = false;
 585             let inputs = intr.inputs.iter()
 586                                     .flat_map(|t| ty_to_type(ccx, t, &mut any_changes_needed))
 587                                     .collect::<Vec<_>>();
 588
 589             let mut out_changes = false;
 590             let outputs = one(ty_to_type(ccx, &intr.output, &mut out_changes));
 591             // outputting a flattened aggregate is nonsense
 592             assert!(!out_changes);
 593
 594             let llargs = if !any_changes_needed {
 595                 // no aggregates to flatten, so no change needed
 596                 llargs.to_vec()
 597             } else {
 598                 // there are some aggregates that need to be flattened
 599                 // in the LLVM call, so we need to run over the types
 600                 // again to find them and extract the arguments
 601                 intr.inputs.iter()
 602                            .zip(llargs)
 603                            .zip(arg_tys)
 604                            .flat_map(|((t, llarg), ty)| modify_as_needed(bcx, t, ty, *llarg))
 605                            .collect()
 606             };
 607             assert_eq!(inputs.len(), llargs.len());
 608
 609             let val = match intr.definition {
 610                 intrinsics::IntrinsicDef::Named(name) => {
 611                     let f = declare::declare_cfn(ccx,
 612                                                  name,
 613                                                  Type::func(&inputs, &outputs));
 614                     bcx.call(f, &llargs, None)
 615                 }
 616             };
 617
 618             match *intr.output {
 619                 intrinsics::Type::Aggregate(flatten, ref elems) => {
 620                     // the output is a tuple so we need to munge it properly
 621                     assert!(!flatten);
 622
 623                     for i in 0..elems.len() {
 624                         let val = bcx.extract_value(val, i);
 625                         bcx.store(val, bcx.struct_gep(llresult, i), None);
 626                     }
 627                     C_nil(ccx)
 628                 }
 629                 _ => val,
 630             }
 631         }
 632     };
 633
 634     if val_ty(llval) != Type::void(ccx) && machine::llsize_of_alloc(ccx, val_ty(llval)) != 0 {
 635         if let Some(ty) = fn_ty.ret.cast {
 636             let ptr = bcx.pointercast(llresult, ty.ptr_to());
 637             bcx.store(llval, ptr, Some(ccx.align_of(ret_ty)));
 638         } else {
 639             store_ty(bcx, llval, llresult, Alignment::AbiAligned, ret_ty);
 640         }
 641     }
 642 }
 643
 644 fn copy_intrinsic<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
 645                             allow_overlap: bool,
 646                             volatile: bool,
 647                             tp_ty: Ty<'tcx>,
 648                             dst: ValueRef,
 649                             src: ValueRef,
 650                             count: ValueRef)
 651                             -> ValueRef {
 652     let ccx = bcx.ccx;
 653     let lltp_ty = type_of::type_of(ccx, tp_ty);
 654     let align = C_i32(ccx, ccx.align_of(tp_ty) as i32);
 655     let size = machine::llsize_of(ccx, lltp_ty);
 656     let int_size = machine::llbitsize_of_real(ccx, ccx.int_type());
 657
 658     let operation = if allow_overlap {
 659         "memmove"
 660     } else {
 661         "memcpy"
 662     };
 663
 664     let name = format!("llvm.{}.p0i8.p0i8.i{}", operation, int_size);
 665
 666     let dst_ptr = bcx.pointercast(dst, Type::i8p(ccx));
 667     let src_ptr = bcx.pointercast(src, Type::i8p(ccx));
 668     let llfn = ccx.get_intrinsic(&name);
 669
 670     bcx.call(llfn,
 671         &[dst_ptr,
 672         src_ptr,
 673         bcx.mul(size, count),
 674         align,
 675         C_bool(ccx, volatile)],
 676         None)
 677 }
 678
 679 fn memset_intrinsic<'a, 'tcx>(
 680     bcx: &Builder<'a, 'tcx>,
 681     volatile: bool,
 682     ty: Ty<'tcx>,
 683     dst: ValueRef,
 684     val: ValueRef,
 685     count: ValueRef
 686 ) -> ValueRef {
 687     let ccx = bcx.ccx;
 688     let align = C_i32(ccx, ccx.align_of(ty) as i32);
 689     let lltp_ty = type_of::type_of(ccx, ty);
 690     let size = machine::llsize_of(ccx, lltp_ty);
 691     let dst = bcx.pointercast(dst, Type::i8p(ccx));
 692     call_memset(bcx, dst, val, bcx.mul(size, count), align, volatile)
 693 }
 694
 695 fn try_intrinsic<'a, 'tcx>(
 696     bcx: &Builder<'a, 'tcx>,
 697     ccx: &CrateContext,
 698     func: ValueRef,
 699     data: ValueRef,
 700     local_ptr: ValueRef,
 701     dest: ValueRef,
 702 ) {
 703     if bcx.sess().no_landing_pads() {
 704         bcx.call(func, &[data], None);
 705         bcx.store(C_null(Type::i8p(&bcx.ccx)), dest, None);
 706     } else if wants_msvc_seh(bcx.sess()) {
 707         trans_msvc_try(bcx, ccx, func, data, local_ptr, dest);
 708     } else {
 709         trans_gnu_try(bcx, ccx, func, data, local_ptr, dest);
 710     }
 711 }
 712
 713 // MSVC's definition of the `rust_try` function.
 714 //
 715 // This implementation uses the new exception handling instructions in LLVM
 716 // which have support in LLVM for SEH on MSVC targets. Although these
 717 // instructions are meant to work for all targets, as of the time of this
 718 // writing, however, LLVM does not recommend the usage of these new instructions
 719 // as the old ones are still more optimized.
 720 fn trans_msvc_try<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
 721                             ccx: &CrateContext,
 722                             func: ValueRef,
 723                             data: ValueRef,
 724                             local_ptr: ValueRef,
 725                             dest: ValueRef) {
 726     let llfn = get_rust_try_fn(ccx, &mut |bcx| {
 727         let ccx = bcx.ccx;
 728
 729         bcx.set_personality_fn(bcx.ccx.eh_personality());
 730
 731         let normal = bcx.build_sibling_block("normal");
 732         let catchswitch = bcx.build_sibling_block("catchswitch");
 733         let catchpad = bcx.build_sibling_block("catchpad");
 734         let caught = bcx.build_sibling_block("caught");
 735
 736         let func = llvm::get_param(bcx.llfn(), 0);
 737         let data = llvm::get_param(bcx.llfn(), 1);
 738         let local_ptr = llvm::get_param(bcx.llfn(), 2);
 739
 740         // We're generating an IR snippet that looks like:
 741         //
 742         //   declare i32 @rust_try(%func, %data, %ptr) {
 743         //      %slot = alloca i64*
 744         //      invoke %func(%data) to label %normal unwind label %catchswitch
 745         //
 746         //   normal:
 747         //      ret i32 0
 748         //
 749         //   catchswitch:
 750         //      %cs = catchswitch within none [%catchpad] unwind to caller
 751         //
 752         //   catchpad:
 753         //      %tok = catchpad within %cs [%type_descriptor, 0, %slot]
 754         //      %ptr[0] = %slot[0]
 755         //      %ptr[1] = %slot[1]
 756         //      catchret from %tok to label %caught
 757         //
 758         //   caught:
 759         //      ret i32 1
 760         //   }
 761         //
 762         // This structure follows the basic usage of throw/try/catch in LLVM.
 763         // For example, compile this C++ snippet to see what LLVM generates:
 764         //
 765         //      #include <stdint.h>
 766         //
 767         //      int bar(void (*foo)(void), uint64_t *ret) {
 768         //          try {
 769         //              foo();
 770         //              return 0;
 771         //          } catch(uint64_t a[2]) {
 772         //              ret[0] = a[0];
 773         //              ret[1] = a[1];
 774         //              return 1;
 775         //          }
 776         //      }
 777         //
 778         // More information can be found in libstd's seh.rs implementation.
 779         let i64p = Type::i64(ccx).ptr_to();
 780         let slot = bcx.alloca(i64p, "slot");
 781         bcx.invoke(func, &[data], normal.llbb(), catchswitch.llbb(),
 782             None);
 783
 784         normal.ret(C_i32(ccx, 0));
 785
 786         let cs = catchswitch.catch_switch(None, None, 1);
 787         catchswitch.add_handler(cs, catchpad.llbb());
 788
 789         let tcx = ccx.tcx();
 790         let tydesc = match tcx.lang_items.msvc_try_filter() {
 791             Some(did) => ::consts::get_static(ccx, did),
 792             None => bug!("msvc_try_filter not defined"),
 793         };
 794         let tok = catchpad.catch_pad(cs, &[tydesc, C_i32(ccx, 0), slot]);
 795         let addr = catchpad.load(slot, None);
 796         let arg1 = catchpad.load(addr, None);
 797         let val1 = C_i32(ccx, 1);
 798         let arg2 = catchpad.load(catchpad.inbounds_gep(addr, &[val1]), None);
 799         let local_ptr = catchpad.bitcast(local_ptr, i64p);
 800         catchpad.store(arg1, local_ptr, None);
 801         catchpad.store(arg2, catchpad.inbounds_gep(local_ptr, &[val1]), None);
 802         catchpad.catch_ret(tok, caught.llbb());
 803
 804         caught.ret(C_i32(ccx, 1));
 805     });
 806
 807     // Note that no invoke is used here because by definition this function
 808     // can't panic (that's what it's catching).
 809     let ret = bcx.call(llfn, &[func, data, local_ptr], None);
 810     bcx.store(ret, dest, None);
 811 }
 812
 813 // Definition of the standard "try" function for Rust using the GNU-like model
 814 // of exceptions (e.g. the normal semantics of LLVM's landingpad and invoke
 815 // instructions).
 816 //
 817 // This translation is a little surprising because we always call a shim
 818 // function instead of inlining the call to `invoke` manually here. This is done
 819 // because in LLVM we're only allowed to have one personality per function
 820 // definition. The call to the `try` intrinsic is being inlined into the
 821 // function calling it, and that function may already have other personality
 822 // functions in play. By calling a shim we're guaranteed that our shim will have
 823 // the right personality function.
 824 fn trans_gnu_try<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
 825                            ccx: &CrateContext,
 826                            func: ValueRef,
 827                            data: ValueRef,
 828                            local_ptr: ValueRef,
 829                            dest: ValueRef) {
 830     let llfn = get_rust_try_fn(ccx, &mut |bcx| {
 831         let ccx = bcx.ccx;
 832
 833         // Translates the shims described above:
 834         //
 835         //   bcx:
 836         //      invoke %func(%args...) normal %normal unwind %catch
 837         //
 838         //   normal:
 839         //      ret 0
 840         //
 841         //   catch:
 842         //      (ptr, _) = landingpad
 843         //      store ptr, %local_ptr
 844         //      ret 1
 845         //
 846         // Note that the `local_ptr` data passed into the `try` intrinsic is
 847         // expected to be `*mut *mut u8` for this to actually work, but that's
 848         // managed by the standard library.
 849
 850         let then = bcx.build_sibling_block("then");
 851         let catch = bcx.build_sibling_block("catch");
 852
 853         let func = llvm::get_param(bcx.llfn(), 0);
 854         let data = llvm::get_param(bcx.llfn(), 1);
 855         let local_ptr = llvm::get_param(bcx.llfn(), 2);
 856         bcx.invoke(func, &[data], then.llbb(), catch.llbb(), None);
 857         then.ret(C_i32(ccx, 0));
 858
 859         // Type indicator for the exception being thrown.
 860         //
 861         // The first value in this tuple is a pointer to the exception object
 862         // being thrown.  The second value is a "selector" indicating which of
 863         // the landing pad clauses the exception's type had been matched to.
 864         // rust_try ignores the selector.
 865         let lpad_ty = Type::struct_(ccx, &[Type::i8p(ccx), Type::i32(ccx)],
 866                                     false);
 867         let vals = catch.landing_pad(lpad_ty, bcx.ccx.eh_personality(), 1, catch.llfn());
 868         catch.add_clause(vals, C_null(Type::i8p(ccx)));
 869         let ptr = catch.extract_value(vals, 0);
 870         catch.store(ptr, catch.bitcast(local_ptr, Type::i8p(ccx).ptr_to()), None);
 871         catch.ret(C_i32(ccx, 1));
 872     });
 873
 874     // Note that no invoke is used here because by definition this function
 875     // can't panic (that's what it's catching).
 876     let ret = bcx.call(llfn, &[func, data, local_ptr], None);
 877     bcx.store(ret, dest, None);
 878 }
 879
 880 // Helper function to give a Block to a closure to translate a shim function.
 881 // This is currently primarily used for the `try` intrinsic functions above.
 882 fn gen_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
 883                     name: &str,
 884                     inputs: Vec<Ty<'tcx>>,
 885                     output: Ty<'tcx>,
 886                     trans: &mut for<'b> FnMut(Builder<'b, 'tcx>))
 887                     -> ValueRef {
 888     let rust_fn_ty = ccx.tcx().mk_fn_ptr(ty::Binder(ccx.tcx().mk_fn_sig(
 889         inputs.into_iter(),
 890         output,
 891         false,
 892         hir::Unsafety::Unsafe,
 893         Abi::Rust
 894     )));
 895     let llfn = declare::define_internal_fn(ccx, name, rust_fn_ty);
 896     let bcx = Builder::new_block(ccx, llfn, "entry-block");
 897     trans(bcx);
 898     llfn
 899 }
 900
 901 // Helper function used to get a handle to the `__rust_try` function used to
 902 // catch exceptions.
 903 //
 904 // This function is only generated once and is then cached.
 905 fn get_rust_try_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
 906                              trans: &mut for<'b> FnMut(Builder<'b, 'tcx>))
 907                              -> ValueRef {
 908     if let Some(llfn) = ccx.rust_try_fn().get() {
 909         return llfn;
 910     }
 911
 912     // Define the type up front for the signature of the rust_try function.
 913     let tcx = ccx.tcx();
 914     let i8p = tcx.mk_mut_ptr(tcx.types.i8);
 915     let fn_ty = tcx.mk_fn_ptr(ty::Binder(tcx.mk_fn_sig(
 916         iter::once(i8p),
 917         tcx.mk_nil(),
 918         false,
 919         hir::Unsafety::Unsafe,
 920         Abi::Rust
 921     )));
 922     let output = tcx.types.i32;
 923     let rust_try = gen_fn(ccx, "__rust_try", vec![fn_ty, i8p, i8p], output, trans);
 924     ccx.rust_try_fn().set(Some(rust_try));
 925     return rust_try
 926 }
 927
 928 fn span_invalid_monomorphization_error(a: &Session, b: Span, c: &str) {
 929     span_err!(a, b, E0511, "{}", c);
 930 }
 931
 932 fn generic_simd_intrinsic<'a, 'tcx>(
 933     bcx: &Builder<'a, 'tcx>,
 934     name: &str,
 935     callee_ty: Ty<'tcx>,
 936     llargs: &[ValueRef],
 937     ret_ty: Ty<'tcx>,
 938     llret_ty: Type,
 939     span: Span
 940 ) -> ValueRef {
 941     // macros for error handling:
 942     macro_rules! emit_error {
 943         ($msg: tt) => {
 944             emit_error!($msg, )
 945         };
 946         ($msg: tt, $($fmt: tt)*) => {
 947             span_invalid_monomorphization_error(
 948                 bcx.sess(), span,
 949                 &format!(concat!("invalid monomorphization of `{}` intrinsic: ",
 950                                  $msg),
 951                          name, $($fmt)*));
 952         }
 953     }
 954     macro_rules! require {
 955         ($cond: expr, $($fmt: tt)*) => {
 956             if !$cond {
 957                 emit_error!($($fmt)*);
 958                 return C_nil(bcx.ccx)
 959             }
 960         }
 961     }
 962     macro_rules! require_simd {
 963         ($ty: expr, $position: expr) => {
 964             require!($ty.is_simd(), "expected SIMD {} type, found non-SIMD `{}`", $position, $ty)
 965         }
 966     }
 967
 968
 969
 970     let tcx = bcx.tcx();
 971     let sig = tcx.erase_late_bound_regions_and_normalize(&callee_ty.fn_sig());
 972     let arg_tys = sig.inputs();
 973
 974     // every intrinsic takes a SIMD vector as its first argument
 975     require_simd!(arg_tys[0], "input");
 976     let in_ty = arg_tys[0];
 977     let in_elem = arg_tys[0].simd_type(tcx);
 978     let in_len = arg_tys[0].simd_size(tcx);
 979
 980     let comparison = match name {
 981         "simd_eq" => Some(hir::BiEq),
 982         "simd_ne" => Some(hir::BiNe),
 983         "simd_lt" => Some(hir::BiLt),
 984         "simd_le" => Some(hir::BiLe),
 985         "simd_gt" => Some(hir::BiGt),
 986         "simd_ge" => Some(hir::BiGe),
 987         _ => None
 988     };
 989
 990     if let Some(cmp_op) = comparison {
 991         require_simd!(ret_ty, "return");
 992
 993         let out_len = ret_ty.simd_size(tcx);
 994         require!(in_len == out_len,
 995                  "expected return type with length {} (same as input type `{}`), \
 996                   found `{}` with length {}",
 997                  in_len, in_ty,
 998                  ret_ty, out_len);
 999         require!(llret_ty.element_type().kind() == llvm::Integer,
1000                  "expected return type with integer elements, found `{}` with non-integer `{}`",
1001                  ret_ty,
1002                  ret_ty.simd_type(tcx));
1003
1004         return compare_simd_types(bcx,
1005                                   llargs[0],
1006                                   llargs[1],
1007                                   in_elem,
1008                                   llret_ty,
1009                                   cmp_op)
1010     }
1011
1012     if name.starts_with("simd_shuffle") {
1013         let n: usize = match name["simd_shuffle".len()..].parse() {
1014             Ok(n) => n,
1015             Err(_) => span_bug!(span,
1016                                 "bad `simd_shuffle` instruction only caught in trans?")
1017         };
1018
1019         require_simd!(ret_ty, "return");
1020
1021         let out_len = ret_ty.simd_size(tcx);
1022         require!(out_len == n,
1023                  "expected return type of length {}, found `{}` with length {}",
1024                  n, ret_ty, out_len);
1025         require!(in_elem == ret_ty.simd_type(tcx),
1026                  "expected return element type `{}` (element of input `{}`), \
1027                   found `{}` with element type `{}`",
1028                  in_elem, in_ty,
1029                  ret_ty, ret_ty.simd_type(tcx));
1030
1031         let total_len = in_len as u128 * 2;
1032
1033         let vector = llargs[2];
1034
1035         let indices: Option<Vec<_>> = (0..n)
1036             .map(|i| {
1037                 let arg_idx = i;
1038                 let val = const_get_elt(vector, &[i as libc::c_uint]);
1039                 match const_to_opt_u128(val, true) {
1040                     None => {
1041                         emit_error!("shuffle index #{} is not a constant", arg_idx);
1042                         None
1043                     }
1044                     Some(idx) if idx >= total_len => {
1045                         emit_error!("shuffle index #{} is out of bounds (limit {})",
1046                                     arg_idx, total_len);
1047                         None
1048                     }
1049                     Some(idx) => Some(C_i32(bcx.ccx, idx as i32)),
1050                 }
1051             })
1052             .collect();
1053         let indices = match indices {
1054             Some(i) => i,
1055             None => return C_null(llret_ty)
1056         };
1057
1058         return bcx.shuffle_vector(llargs[0], llargs[1], C_vector(&indices))
1059     }
1060
1061     if name == "simd_insert" {
1062         require!(in_elem == arg_tys[2],
1063                  "expected inserted type `{}` (element of input `{}`), found `{}`",
1064                  in_elem, in_ty, arg_tys[2]);
1065         return bcx.insert_element(llargs[0], llargs[2], llargs[1])
1066     }
1067     if name == "simd_extract" {
1068         require!(ret_ty == in_elem,
1069                  "expected return type `{}` (element of input `{}`), found `{}`",
1070                  in_elem, in_ty, ret_ty);
1071         return bcx.extract_element(llargs[0], llargs[1])
1072     }
1073
1074     if name == "simd_cast" {
1075         require_simd!(ret_ty, "return");
1076         let out_len = ret_ty.simd_size(tcx);
1077         require!(in_len == out_len,
1078                  "expected return type with length {} (same as input type `{}`), \
1079                   found `{}` with length {}",
1080                  in_len, in_ty,
1081                  ret_ty, out_len);
1082         // casting cares about nominal type, not just structural type
1083         let out_elem = ret_ty.simd_type(tcx);
1084
1085         if in_elem == out_elem { return llargs[0]; }
1086
1087         enum Style { Float, Int(/* is signed? */ bool), Unsupported }
1088
1089         let (in_style, in_width) = match in_elem.sty {
1090             // vectors of pointer-sized integers should've been
1091             // disallowed before here, so this unwrap is safe.
1092             ty::TyInt(i) => (Style::Int(true), i.bit_width().unwrap()),
1093             ty::TyUint(u) => (Style::Int(false), u.bit_width().unwrap()),
1094             ty::TyFloat(f) => (Style::Float, f.bit_width()),
1095             _ => (Style::Unsupported, 0)
1096         };
1097         let (out_style, out_width) = match out_elem.sty {
1098             ty::TyInt(i) => (Style::Int(true), i.bit_width().unwrap()),
1099             ty::TyUint(u) => (Style::Int(false), u.bit_width().unwrap()),
1100             ty::TyFloat(f) => (Style::Float, f.bit_width()),
1101             _ => (Style::Unsupported, 0)
1102         };
1103
1104         match (in_style, out_style) {
1105             (Style::Int(in_is_signed), Style::Int(_)) => {
1106                 return match in_width.cmp(&out_width) {
1107                     Ordering::Greater => bcx.trunc(llargs[0], llret_ty),
1108                     Ordering::Equal => llargs[0],
1109                     Ordering::Less => if in_is_signed {
1110                         bcx.sext(llargs[0], llret_ty)
1111                     } else {
1112                         bcx.zext(llargs[0], llret_ty)
1113                     }
1114                 }
1115             }
1116             (Style::Int(in_is_signed), Style::Float) => {
1117                 return if in_is_signed {
1118                     bcx.sitofp(llargs[0], llret_ty)
1119                 } else {
1120                     bcx.uitofp(llargs[0], llret_ty)
1121                 }
1122             }
1123             (Style::Float, Style::Int(out_is_signed)) => {
1124                 return if out_is_signed {
1125                     bcx.fptosi(llargs[0], llret_ty)
1126                 } else {
1127                     bcx.fptoui(llargs[0], llret_ty)
1128                 }
1129             }
1130             (Style::Float, Style::Float) => {
1131                 return match in_width.cmp(&out_width) {
1132                     Ordering::Greater => bcx.fptrunc(llargs[0], llret_ty),
1133                     Ordering::Equal => llargs[0],
1134                     Ordering::Less => bcx.fpext(llargs[0], llret_ty)
1135                 }
1136             }
1137             _ => {/* Unsupported. Fallthrough. */}
1138         }
1139         require!(false,
1140                  "unsupported cast from `{}` with element `{}` to `{}` with element `{}`",
1141                  in_ty, in_elem,
1142                  ret_ty, out_elem);
1143     }
1144     macro_rules! arith {
1145         ($($name: ident: $($($p: ident),* => $call: ident),*;)*) => {
1146             $(
1147                 if name == stringify!($name) {
1148                     match in_elem.sty {
1149                         $(
1150                             $(ty::$p(_))|* => {
1151                                 return bcx.$call(llargs[0], llargs[1])
1152                             }
1153                             )*
1154                         _ => {},
1155                     }
1156                     require!(false,
1157                              "unsupported operation on `{}` with element `{}`",
1158                              in_ty,
1159                              in_elem)
1160                 })*
1161         }
1162     }
1163     arith! {
1164         simd_add: TyUint, TyInt => add, TyFloat => fadd;
1165         simd_sub: TyUint, TyInt => sub, TyFloat => fsub;
1166         simd_mul: TyUint, TyInt => mul, TyFloat => fmul;
1167         simd_div: TyFloat => fdiv;
1168         simd_shl: TyUint, TyInt => shl;
1169         simd_shr: TyUint => lshr, TyInt => ashr;
1170         simd_and: TyUint, TyInt => and;
1171         simd_or: TyUint, TyInt => or;
1172         simd_xor: TyUint, TyInt => xor;
1173     }
1174     span_bug!(span, "unknown SIMD intrinsic");
1175 }
1176
1177 // Returns the width of an int TypeVariant, and if it's signed or not
1178 // Returns None if the type is not an integer
1179 // FIXME: there’s multiple of this functions, investigate using some of the already existing
1180 // stuffs.
1181 fn int_type_width_signed<'tcx>(sty: &ty::TypeVariants<'tcx>, ccx: &CrateContext)
1182         -> Option<(u64, bool)> {
1183     use rustc::ty::{TyInt, TyUint};
1184     match *sty {
1185         TyInt(t) => Some((match t {
1186             ast::IntTy::Is => {
1187                 match &ccx.tcx().sess.target.target.target_pointer_width[..] {
1188                     "16" => 16,
1189                     "32" => 32,
1190                     "64" => 64,
1191                     tws => bug!("Unsupported target word size for isize: {}", tws),
1192                 }
1193             },
1194             ast::IntTy::I8 => 8,
1195             ast::IntTy::I16 => 16,
1196             ast::IntTy::I32 => 32,
1197             ast::IntTy::I64 => 64,
1198             ast::IntTy::I128 => 128,
1199         }, true)),
1200         TyUint(t) => Some((match t {
1201             ast::UintTy::Us => {
1202                 match &ccx.tcx().sess.target.target.target_pointer_width[..] {
1203                     "16" => 16,
1204                     "32" => 32,
1205                     "64" => 64,
1206                     tws => bug!("Unsupported target word size for usize: {}", tws),
1207                 }
1208             },
1209             ast::UintTy::U8 => 8,
1210             ast::UintTy::U16 => 16,
1211             ast::UintTy::U32 => 32,
1212             ast::UintTy::U64 => 64,
1213             ast::UintTy::U128 => 128,
1214         }, false)),
1215         _ => None,
1216     }
1217 }
1218
1219 // Returns the width of a float TypeVariant
1220 // Returns None if the type is not a float
1221 fn float_type_width<'tcx>(sty: &ty::TypeVariants<'tcx>)
1222         -> Option<u64> {
1223     use rustc::ty::TyFloat;
1224     match *sty {
1225         TyFloat(t) => Some(match t {
1226             ast::FloatTy::F32 => 32,
1227             ast::FloatTy::F64 => 64,
1228         }),
1229         _ => None,
1230     }
1231 }