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, Alignment};
  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 fn get_simple_intrinsic(ccx: &CrateContext, name: &str) -> Option<ValueRef> {
  40     let llvm_name = match name {
  41         "sqrtf32" => "llvm.sqrt.f32",
  42         "sqrtf64" => "llvm.sqrt.f64",
  43         "powif32" => "llvm.powi.f32",
  44         "powif64" => "llvm.powi.f64",
  45         "sinf32" => "llvm.sin.f32",
  46         "sinf64" => "llvm.sin.f64",
  47         "cosf32" => "llvm.cos.f32",
  48         "cosf64" => "llvm.cos.f64",
  49         "powf32" => "llvm.pow.f32",
  50         "powf64" => "llvm.pow.f64",
  51         "expf32" => "llvm.exp.f32",
  52         "expf64" => "llvm.exp.f64",
  53         "exp2f32" => "llvm.exp2.f32",
  54         "exp2f64" => "llvm.exp2.f64",
  55         "logf32" => "llvm.log.f32",
  56         "logf64" => "llvm.log.f64",
  57         "log10f32" => "llvm.log10.f32",
  58         "log10f64" => "llvm.log10.f64",
  59         "log2f32" => "llvm.log2.f32",
  60         "log2f64" => "llvm.log2.f64",
  61         "fmaf32" => "llvm.fma.f32",
  62         "fmaf64" => "llvm.fma.f64",
  63         "fabsf32" => "llvm.fabs.f32",
  64         "fabsf64" => "llvm.fabs.f64",
  65         "copysignf32" => "llvm.copysign.f32",
  66         "copysignf64" => "llvm.copysign.f64",
  67         "floorf32" => "llvm.floor.f32",
  68         "floorf64" => "llvm.floor.f64",
  69         "ceilf32" => "llvm.ceil.f32",
  70         "ceilf64" => "llvm.ceil.f64",
  71         "truncf32" => "llvm.trunc.f32",
  72         "truncf64" => "llvm.trunc.f64",
  73         "rintf32" => "llvm.rint.f32",
  74         "rintf64" => "llvm.rint.f64",
  75         "nearbyintf32" => "llvm.nearbyint.f32",
  76         "nearbyintf64" => "llvm.nearbyint.f64",
  77         "roundf32" => "llvm.round.f32",
  78         "roundf64" => "llvm.round.f64",
  79         "assume" => "llvm.assume",
  80         "abort" => "llvm.trap",
  81         _ => return None
  82     };
  83     Some(ccx.get_intrinsic(&llvm_name))
  84 }
  85
  86 /// Remember to add all intrinsics here, in librustc_typeck/check/mod.rs,
  87 /// and in libcore/intrinsics.rs; if you need access to any llvm intrinsics,
  88 /// add them to librustc_trans/trans/context.rs
  89 pub fn trans_intrinsic_call<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
  90                                       callee_ty: Ty<'tcx>,
  91                                       fn_ty: &FnType,
  92                                       llargs: &[ValueRef],
  93                                       llresult: ValueRef,
  94                                       span: Span) {
  95     let ccx = bcx.ccx;
  96     let tcx = ccx.tcx();
  97
  98     let (def_id, substs, sig) = match callee_ty.sty {
  99         ty::TyFnDef(def_id, substs, sig) => (def_id, substs, sig),
 100         _ => bug!("expected fn item type, found {}", callee_ty)
 101     };
 102
 103     let sig = tcx.erase_late_bound_regions_and_normalize(&sig);
 104     let arg_tys = sig.inputs();
 105     let ret_ty = sig.output();
 106     let name = &*tcx.item_name(def_id).as_str();
 107
 108     let llret_ty = type_of::type_of(ccx, ret_ty);
 109
 110     let simple = get_simple_intrinsic(ccx, name);
 111     let llval = match name {
 112         _ if simple.is_some() => {
 113             bcx.call(simple.unwrap(), &llargs, None)
 114         }
 115         "unreachable" => {
 116             return;
 117         },
 118         "likely" => {
 119             let expect = ccx.get_intrinsic(&("llvm.expect.i1"));
 120             bcx.call(expect, &[llargs[0], C_bool(ccx, true)], None)
 121         }
 122         "unlikely" => {
 123             let expect = ccx.get_intrinsic(&("llvm.expect.i1"));
 124             bcx.call(expect, &[llargs[0], C_bool(ccx, false)], None)
 125         }
 126         "try" => {
 127             try_intrinsic(bcx, ccx, llargs[0], llargs[1], llargs[2], llresult);
 128             C_nil(ccx)
 129         }
 130         "breakpoint" => {
 131             let llfn = ccx.get_intrinsic(&("llvm.debugtrap"));
 132             bcx.call(llfn, &[], None)
 133         }
 134         "size_of" => {
 135             let tp_ty = substs.type_at(0);
 136             let lltp_ty = type_of::type_of(ccx, tp_ty);
 137             C_uint(ccx, machine::llsize_of_alloc(ccx, lltp_ty))
 138         }
 139         "size_of_val" => {
 140             let tp_ty = substs.type_at(0);
 141             if !bcx.ccx.shared().type_is_sized(tp_ty) {
 142                 let (llsize, _) =
 143                     glue::size_and_align_of_dst(bcx, tp_ty, llargs[1]);
 144                 llsize
 145             } else {
 146                 let lltp_ty = type_of::type_of(ccx, tp_ty);
 147                 C_uint(ccx, machine::llsize_of_alloc(ccx, lltp_ty))
 148             }
 149         }
 150         "min_align_of" => {
 151             let tp_ty = substs.type_at(0);
 152             C_uint(ccx, ccx.align_of(tp_ty))
 153         }
 154         "min_align_of_val" => {
 155             let tp_ty = substs.type_at(0);
 156             if !bcx.ccx.shared().type_is_sized(tp_ty) {
 157                 let (_, llalign) =
 158                     glue::size_and_align_of_dst(bcx, tp_ty, llargs[1]);
 159                 llalign
 160             } else {
 161                 C_uint(ccx, ccx.align_of(tp_ty))
 162             }
 163         }
 164         "pref_align_of" => {
 165             let tp_ty = substs.type_at(0);
 166             let lltp_ty = type_of::type_of(ccx, tp_ty);
 167             C_uint(ccx, machine::llalign_of_pref(ccx, lltp_ty))
 168         }
 169         "type_name" => {
 170             let tp_ty = substs.type_at(0);
 171             let ty_name = Symbol::intern(&tp_ty.to_string()).as_str();
 172             C_str_slice(ccx, ty_name)
 173         }
 174         "type_id" => {
 175             C_u64(ccx, ccx.tcx().type_id_hash(substs.type_at(0)))
 176         }
 177         "init" => {
 178             let ty = substs.type_at(0);
 179             if !type_is_zero_size(ccx, ty) {
 180                 // Just zero out the stack slot.
 181                 // If we store a zero constant, LLVM will drown in vreg allocation for large data
 182                 // structures, and the generated code will be awful. (A telltale sign of this is
 183                 // large quantities of `mov [byte ptr foo],0` in the generated code.)
 184                 memset_intrinsic(bcx, false, ty, llresult, C_u8(ccx, 0), C_uint(ccx, 1usize));
 185             }
 186             C_nil(ccx)
 187         }
 188         // Effectively no-ops
 189         "uninit" => {
 190             C_nil(ccx)
 191         }
 192         "needs_drop" => {
 193             let tp_ty = substs.type_at(0);
 194
 195             C_bool(ccx, bcx.ccx.shared().type_needs_drop(tp_ty))
 196         }
 197         "offset" => {
 198             let ptr = llargs[0];
 199             let offset = llargs[1];
 200             bcx.inbounds_gep(ptr, &[offset])
 201         }
 202         "arith_offset" => {
 203             let ptr = llargs[0];
 204             let offset = llargs[1];
 205             bcx.gep(ptr, &[offset])
 206         }
 207
 208         "copy_nonoverlapping" => {
 209             copy_intrinsic(bcx, false, false, substs.type_at(0), llargs[1], llargs[0], llargs[2])
 210         }
 211         "copy" => {
 212             copy_intrinsic(bcx, true, false, substs.type_at(0), llargs[1], llargs[0], llargs[2])
 213         }
 214         "write_bytes" => {
 215             memset_intrinsic(bcx, false, substs.type_at(0), llargs[0], llargs[1], llargs[2])
 216         }
 217
 218         "volatile_copy_nonoverlapping_memory" => {
 219             copy_intrinsic(bcx, false, true, substs.type_at(0), llargs[0], llargs[1], llargs[2])
 220         }
 221         "volatile_copy_memory" => {
 222             copy_intrinsic(bcx, true, true, substs.type_at(0), llargs[0], llargs[1], llargs[2])
 223         }
 224         "volatile_set_memory" => {
 225             memset_intrinsic(bcx, true, substs.type_at(0), llargs[0], llargs[1], llargs[2])
 226         }
 227         "volatile_load" => {
 228             let tp_ty = substs.type_at(0);
 229             let mut ptr = llargs[0];
 230             if let Some(ty) = fn_ty.ret.cast {
 231                 ptr = bcx.pointercast(ptr, ty.ptr_to());
 232             }
 233             let load = bcx.volatile_load(ptr);
 234             unsafe {
 235                 llvm::LLVMSetAlignment(load, ccx.align_of(tp_ty));
 236             }
 237             to_immediate(bcx, load, tp_ty)
 238         },
 239         "volatile_store" => {
 240             let tp_ty = substs.type_at(0);
 241             if type_is_fat_ptr(bcx.ccx, tp_ty) {
 242                 bcx.volatile_store(llargs[1], get_dataptr(bcx, llargs[0]));
 243                 bcx.volatile_store(llargs[2], get_meta(bcx, llargs[0]));
 244             } else {
 245                 let val = if fn_ty.args[1].is_indirect() {
 246                     bcx.load(llargs[1], None)
 247                 } else {
 248                     from_immediate(bcx, llargs[1])
 249                 };
 250                 let ptr = bcx.pointercast(llargs[0], val_ty(val).ptr_to());
 251                 let store = bcx.volatile_store(val, ptr);
 252                 unsafe {
 253                     llvm::LLVMSetAlignment(store, ccx.align_of(tp_ty));
 254                 }
 255             }
 256             C_nil(ccx)
 257         },
 258
 259         "ctlz" | "cttz" | "ctpop" | "bswap" |
 260         "add_with_overflow" | "sub_with_overflow" | "mul_with_overflow" |
 261         "overflowing_add" | "overflowing_sub" | "overflowing_mul" |
 262         "unchecked_div" | "unchecked_rem" | "unchecked_shl" | "unchecked_shr" => {
 263             let sty = &arg_tys[0].sty;
 264             match int_type_width_signed(sty, ccx) {
 265                 Some((width, signed)) =>
 266                     match name {
 267                         "ctlz" | "cttz" => {
 268                             let y = C_bool(bcx.ccx, false);
 269                             let llfn = ccx.get_intrinsic(&format!("llvm.{}.i{}", name, width));
 270                             bcx.call(llfn, &[llargs[0], y], None)
 271                         }
 272                         "ctpop" => bcx.call(ccx.get_intrinsic(&format!("llvm.ctpop.i{}", width)),
 273                                         &llargs, None),
 274                         "bswap" => {
 275                             if width == 8 {
 276                                 llargs[0] // byte swap a u8/i8 is just a no-op
 277                             } else {
 278                                 bcx.call(ccx.get_intrinsic(&format!("llvm.bswap.i{}", width)),
 279                                         &llargs, None)
 280                             }
 281                         }
 282                         "add_with_overflow" | "sub_with_overflow" | "mul_with_overflow" => {
 283                             let intrinsic = format!("llvm.{}{}.with.overflow.i{}",
 284                                                     if signed { 's' } else { 'u' },
 285                                                     &name[..3], width);
 286                             let llfn = bcx.ccx.get_intrinsic(&intrinsic);
 287
 288                             // Convert `i1` to a `bool`, and write it to the out parameter
 289                             let val = bcx.call(llfn, &[llargs[0], llargs[1]], None);
 290                             let result = bcx.extract_value(val, 0);
 291                             let overflow = bcx.zext(bcx.extract_value(val, 1), Type::bool(ccx));
 292                             bcx.store(result, bcx.struct_gep(llresult, 0), None);
 293                             bcx.store(overflow, bcx.struct_gep(llresult, 1), None);
 294
 295                             C_nil(bcx.ccx)
 296                         },
 297                         "overflowing_add" => bcx.add(llargs[0], llargs[1]),
 298                         "overflowing_sub" => bcx.sub(llargs[0], llargs[1]),
 299                         "overflowing_mul" => bcx.mul(llargs[0], llargs[1]),
 300                         "unchecked_div" =>
 301                             if signed {
 302                                 bcx.sdiv(llargs[0], llargs[1])
 303                             } else {
 304                                 bcx.udiv(llargs[0], llargs[1])
 305                             },
 306                         "unchecked_rem" =>
 307                             if signed {
 308                                 bcx.srem(llargs[0], llargs[1])
 309                             } else {
 310                                 bcx.urem(llargs[0], llargs[1])
 311                             },
 312                         "unchecked_shl" => bcx.shl(llargs[0], llargs[1]),
 313                         "unchecked_shr" =>
 314                             if signed {
 315                                 bcx.ashr(llargs[0], llargs[1])
 316                             } else {
 317                                 bcx.lshr(llargs[0], llargs[1])
 318                             },
 319                         _ => bug!(),
 320                     },
 321                 None => {
 322                     span_invalid_monomorphization_error(
 323                         tcx.sess, span,
 324                         &format!("invalid monomorphization of `{}` intrinsic: \
 325                                   expected basic integer type, found `{}`", name, sty));
 326                         C_nil(ccx)
 327                 }
 328             }
 329
 330         },
 331         "fadd_fast" | "fsub_fast" | "fmul_fast" | "fdiv_fast" | "frem_fast" => {
 332             let sty = &arg_tys[0].sty;
 333             match float_type_width(sty) {
 334                 Some(_width) =>
 335                     match name {
 336                         "fadd_fast" => bcx.fadd_fast(llargs[0], llargs[1]),
 337                         "fsub_fast" => bcx.fsub_fast(llargs[0], llargs[1]),
 338                         "fmul_fast" => bcx.fmul_fast(llargs[0], llargs[1]),
 339                         "fdiv_fast" => bcx.fdiv_fast(llargs[0], llargs[1]),
 340                         "frem_fast" => bcx.frem_fast(llargs[0], llargs[1]),
 341                         _ => bug!(),
 342                     },
 343                 None => {
 344                     span_invalid_monomorphization_error(
 345                         tcx.sess, span,
 346                         &format!("invalid monomorphization of `{}` intrinsic: \
 347                                   expected basic float type, found `{}`", name, sty));
 348                         C_nil(ccx)
 349                 }
 350             }
 351
 352         },
 353
 354         "discriminant_value" => {
 355             let val_ty = substs.type_at(0);
 356             match val_ty.sty {
 357                 ty::TyAdt(adt, ..) if adt.is_enum() => {
 358                     adt::trans_get_discr(bcx, val_ty, llargs[0], Alignment::AbiAligned,
 359                                          Some(llret_ty), true)
 360                 }
 361                 _ => C_null(llret_ty)
 362             }
 363         }
 364         name if name.starts_with("simd_") => {
 365             generic_simd_intrinsic(bcx, name,
 366                                    callee_ty,
 367                                    &llargs,
 368                                    ret_ty, llret_ty,
 369                                    span)
 370         }
 371         // This requires that atomic intrinsics follow a specific naming pattern:
 372         // "atomic_<operation>[_<ordering>]", and no ordering means SeqCst
 373         name if name.starts_with("atomic_") => {
 374             use llvm::AtomicOrdering::*;
 375
 376             let split: Vec<&str> = name.split('_').collect();
 377
 378             let is_cxchg = split[1] == "cxchg" || split[1] == "cxchgweak";
 379             let (order, failorder) = match split.len() {
 380                 2 => (SequentiallyConsistent, SequentiallyConsistent),
 381                 3 => match split[2] {
 382                     "unordered" => (Unordered, Unordered),
 383                     "relaxed" => (Monotonic, Monotonic),
 384                     "acq"     => (Acquire, Acquire),
 385                     "rel"     => (Release, Monotonic),
 386                     "acqrel"  => (AcquireRelease, Acquire),
 387                     "failrelaxed" if is_cxchg =>
 388                         (SequentiallyConsistent, Monotonic),
 389                     "failacq" if is_cxchg =>
 390                         (SequentiallyConsistent, Acquire),
 391                     _ => ccx.sess().fatal("unknown ordering in atomic intrinsic")
 392                 },
 393                 4 => match (split[2], split[3]) {
 394                     ("acq", "failrelaxed") if is_cxchg =>
 395                         (Acquire, Monotonic),
 396                     ("acqrel", "failrelaxed") if is_cxchg =>
 397                         (AcquireRelease, Monotonic),
 398                     _ => ccx.sess().fatal("unknown ordering in atomic intrinsic")
 399                 },
 400                 _ => ccx.sess().fatal("Atomic intrinsic not in correct format"),
 401             };
 402
 403             let invalid_monomorphization = |sty| {
 404                 span_invalid_monomorphization_error(tcx.sess, span,
 405                     &format!("invalid monomorphization of `{}` intrinsic: \
 406                               expected basic integer type, found `{}`", name, sty));
 407             };
 408
 409             match split[1] {
 410                 "cxchg" | "cxchgweak" => {
 411                     let sty = &substs.type_at(0).sty;
 412                     if int_type_width_signed(sty, ccx).is_some() {
 413                         let weak = if split[1] == "cxchgweak" { llvm::True } else { llvm::False };
 414                         let val = bcx.atomic_cmpxchg(llargs[0], llargs[1], llargs[2], order,
 415                             failorder, weak);
 416                         let result = bcx.extract_value(val, 0);
 417                         let success = bcx.zext(bcx.extract_value(val, 1), Type::bool(bcx.ccx));
 418                         bcx.store(result, bcx.struct_gep(llresult, 0), None);
 419                         bcx.store(success, bcx.struct_gep(llresult, 1), None);
 420                     } else {
 421                         invalid_monomorphization(sty);
 422                     }
 423                     C_nil(ccx)
 424                 }
 425
 426                 "load" => {
 427                     let sty = &substs.type_at(0).sty;
 428                     if int_type_width_signed(sty, ccx).is_some() {
 429                         bcx.atomic_load(llargs[0], order)
 430                     } else {
 431                         invalid_monomorphization(sty);
 432                         C_nil(ccx)
 433                     }
 434                 }
 435
 436                 "store" => {
 437                     let sty = &substs.type_at(0).sty;
 438                     if int_type_width_signed(sty, ccx).is_some() {
 439                         bcx.atomic_store(llargs[1], llargs[0], order);
 440                     } else {
 441                         invalid_monomorphization(sty);
 442                     }
 443                     C_nil(ccx)
 444                 }
 445
 446                 "fence" => {
 447                     bcx.atomic_fence(order, llvm::SynchronizationScope::CrossThread);
 448                     C_nil(ccx)
 449                 }
 450
 451                 "singlethreadfence" => {
 452                     bcx.atomic_fence(order, llvm::SynchronizationScope::SingleThread);
 453                     C_nil(ccx)
 454                 }
 455
 456                 // These are all AtomicRMW ops
 457                 op => {
 458                     let atom_op = match op {
 459                         "xchg"  => llvm::AtomicXchg,
 460                         "xadd"  => llvm::AtomicAdd,
 461                         "xsub"  => llvm::AtomicSub,
 462                         "and"   => llvm::AtomicAnd,
 463                         "nand"  => llvm::AtomicNand,
 464                         "or"    => llvm::AtomicOr,
 465                         "xor"   => llvm::AtomicXor,
 466                         "max"   => llvm::AtomicMax,
 467                         "min"   => llvm::AtomicMin,
 468                         "umax"  => llvm::AtomicUMax,
 469                         "umin"  => llvm::AtomicUMin,
 470                         _ => ccx.sess().fatal("unknown atomic operation")
 471                     };
 472
 473                     let sty = &substs.type_at(0).sty;
 474                     if int_type_width_signed(sty, ccx).is_some() {
 475                         bcx.atomic_rmw(atom_op, llargs[0], llargs[1], order)
 476                     } else {
 477                         invalid_monomorphization(sty);
 478                         C_nil(ccx)
 479                     }
 480                 }
 481             }
 482         }
 483
 484         _ => {
 485             let intr = match Intrinsic::find(&name) {
 486                 Some(intr) => intr,
 487                 None => bug!("unknown intrinsic '{}'", name),
 488             };
 489             fn one<T>(x: Vec<T>) -> T {
 490                 assert_eq!(x.len(), 1);
 491                 x.into_iter().next().unwrap()
 492             }
 493             fn ty_to_type(ccx: &CrateContext, t: &intrinsics::Type,
 494                           any_changes_needed: &mut bool) -> Vec<Type> {
 495                 use intrinsics::Type::*;
 496                 match *t {
 497                     Void => vec![Type::void(ccx)],
 498                     Integer(_signed, width, llvm_width) => {
 499                         *any_changes_needed |= width != llvm_width;
 500                         vec![Type::ix(ccx, llvm_width as u64)]
 501                     }
 502                     Float(x) => {
 503                         match x {
 504                             32 => vec![Type::f32(ccx)],
 505                             64 => vec![Type::f64(ccx)],
 506                             _ => bug!()
 507                         }
 508                     }
 509                     Pointer(ref t, ref llvm_elem, _const) => {
 510                         *any_changes_needed |= llvm_elem.is_some();
 511
 512                         let t = llvm_elem.as_ref().unwrap_or(t);
 513                         let elem = one(ty_to_type(ccx, t, any_changes_needed));
 514                         vec![elem.ptr_to()]
 515                     }
 516                     Vector(ref t, ref llvm_elem, length) => {
 517                         *any_changes_needed |= llvm_elem.is_some();
 518
 519                         let t = llvm_elem.as_ref().unwrap_or(t);
 520                         let elem = one(ty_to_type(ccx, t, any_changes_needed));
 521                         vec![Type::vector(&elem, length as u64)]
 522                     }
 523                     Aggregate(false, ref contents) => {
 524                         let elems = contents.iter()
 525                                             .map(|t| one(ty_to_type(ccx, t, any_changes_needed)))
 526                                             .collect::<Vec<_>>();
 527                         vec![Type::struct_(ccx, &elems, false)]
 528                     }
 529                     Aggregate(true, ref contents) => {
 530                         *any_changes_needed = true;
 531                         contents.iter()
 532                                 .flat_map(|t| ty_to_type(ccx, t, any_changes_needed))
 533                                 .collect()
 534                     }
 535                 }
 536             }
 537
 538             // This allows an argument list like `foo, (bar, baz),
 539             // qux` to be converted into `foo, bar, baz, qux`, integer
 540             // arguments to be truncated as needed and pointers to be
 541             // cast.
 542             fn modify_as_needed<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
 543                                           t: &intrinsics::Type,
 544                                           arg_type: Ty<'tcx>,
 545                                           llarg: ValueRef)
 546                                           -> Vec<ValueRef>
 547             {
 548                 match *t {
 549                     intrinsics::Type::Aggregate(true, ref contents) => {
 550                         // We found a tuple that needs squishing! So
 551                         // run over the tuple and load each field.
 552                         //
 553                         // This assumes the type is "simple", i.e. no
 554                         // destructors, and the contents are SIMD
 555                         // etc.
 556                         assert!(!bcx.ccx.shared().type_needs_drop(arg_type));
 557                         let arg = LvalueRef::new_sized_ty(llarg, arg_type, Alignment::AbiAligned);
 558                         (0..contents.len()).map(|i| {
 559                             let (ptr, align) = arg.trans_field_ptr(bcx, i);
 560                             bcx.load(ptr, align.to_align())
 561                         }).collect()
 562                     }
 563                     intrinsics::Type::Pointer(_, Some(ref llvm_elem), _) => {
 564                         let llvm_elem = one(ty_to_type(bcx.ccx, llvm_elem, &mut false));
 565                         vec![bcx.pointercast(llarg, llvm_elem.ptr_to())]
 566                     }
 567                     intrinsics::Type::Vector(_, Some(ref llvm_elem), length) => {
 568                         let llvm_elem = one(ty_to_type(bcx.ccx, llvm_elem, &mut false));
 569                         vec![bcx.bitcast(llarg, Type::vector(&llvm_elem, length as u64))]
 570                     }
 571                     intrinsics::Type::Integer(_, width, llvm_width) if width != llvm_width => {
 572                         // the LLVM intrinsic uses a smaller integer
 573                         // size than the C intrinsic's signature, so
 574                         // we have to trim it down here.
 575                         vec![bcx.trunc(llarg, Type::ix(bcx.ccx, llvm_width as u64))]
 576                     }
 577                     _ => vec![llarg],
 578                 }
 579             }
 580
 581
 582             let mut any_changes_needed = false;
 583             let inputs = intr.inputs.iter()
 584                                     .flat_map(|t| ty_to_type(ccx, t, &mut any_changes_needed))
 585                                     .collect::<Vec<_>>();
 586
 587             let mut out_changes = false;
 588             let outputs = one(ty_to_type(ccx, &intr.output, &mut out_changes));
 589             // outputting a flattened aggregate is nonsense
 590             assert!(!out_changes);
 591
 592             let llargs = if !any_changes_needed {
 593                 // no aggregates to flatten, so no change needed
 594                 llargs.to_vec()
 595             } else {
 596                 // there are some aggregates that need to be flattened
 597                 // in the LLVM call, so we need to run over the types
 598                 // again to find them and extract the arguments
 599                 intr.inputs.iter()
 600                            .zip(llargs)
 601                            .zip(arg_tys)
 602                            .flat_map(|((t, llarg), ty)| modify_as_needed(bcx, t, ty, *llarg))
 603                            .collect()
 604             };
 605             assert_eq!(inputs.len(), llargs.len());
 606
 607             let val = match intr.definition {
 608                 intrinsics::IntrinsicDef::Named(name) => {
 609                     let f = declare::declare_cfn(ccx,
 610                                                  name,
 611                                                  Type::func(&inputs, &outputs));
 612                     bcx.call(f, &llargs, None)
 613                 }
 614             };
 615
 616             match *intr.output {
 617                 intrinsics::Type::Aggregate(flatten, ref elems) => {
 618                     // the output is a tuple so we need to munge it properly
 619                     assert!(!flatten);
 620
 621                     for i in 0..elems.len() {
 622                         let val = bcx.extract_value(val, i);
 623                         let lval = LvalueRef::new_sized_ty(llresult, ret_ty,
 624                                                            Alignment::AbiAligned);
 625                         let (dest, align) = lval.trans_field_ptr(bcx, i);
 626                         bcx.store(val, dest, align.to_align());
 627                     }
 628                     C_nil(ccx)
 629                 }
 630                 _ => val,
 631             }
 632         }
 633     };
 634
 635     if val_ty(llval) != Type::void(ccx) && machine::llsize_of_alloc(ccx, val_ty(llval)) != 0 {
 636         if let Some(ty) = fn_ty.ret.cast {
 637             let ptr = bcx.pointercast(llresult, ty.ptr_to());
 638             bcx.store(llval, ptr, Some(ccx.align_of(ret_ty)));
 639         } else {
 640             store_ty(bcx, llval, llresult, Alignment::AbiAligned, ret_ty);
 641         }
 642     }
 643 }
 644
 645 fn copy_intrinsic<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
 646                             allow_overlap: bool,
 647                             volatile: bool,
 648                             tp_ty: Ty<'tcx>,
 649                             dst: ValueRef,
 650                             src: ValueRef,
 651                             count: ValueRef)
 652                             -> ValueRef {
 653     let ccx = bcx.ccx;
 654     let lltp_ty = type_of::type_of(ccx, tp_ty);
 655     let align = C_i32(ccx, ccx.align_of(tp_ty) as i32);
 656     let size = machine::llsize_of(ccx, lltp_ty);
 657     let int_size = machine::llbitsize_of_real(ccx, ccx.int_type());
 658
 659     let operation = if allow_overlap {
 660         "memmove"
 661     } else {
 662         "memcpy"
 663     };
 664
 665     let name = format!("llvm.{}.p0i8.p0i8.i{}", operation, int_size);
 666
 667     let dst_ptr = bcx.pointercast(dst, Type::i8p(ccx));
 668     let src_ptr = bcx.pointercast(src, Type::i8p(ccx));
 669     let llfn = ccx.get_intrinsic(&name);
 670
 671     bcx.call(llfn,
 672         &[dst_ptr,
 673         src_ptr,
 674         bcx.mul(size, count),
 675         align,
 676         C_bool(ccx, volatile)],
 677         None)
 678 }
 679
 680 fn memset_intrinsic<'a, 'tcx>(
 681     bcx: &Builder<'a, 'tcx>,
 682     volatile: bool,
 683     ty: Ty<'tcx>,
 684     dst: ValueRef,
 685     val: ValueRef,
 686     count: ValueRef
 687 ) -> ValueRef {
 688     let ccx = bcx.ccx;
 689     let align = C_i32(ccx, ccx.align_of(ty) as i32);
 690     let lltp_ty = type_of::type_of(ccx, ty);
 691     let size = machine::llsize_of(ccx, lltp_ty);
 692     let dst = bcx.pointercast(dst, Type::i8p(ccx));
 693     call_memset(bcx, dst, val, bcx.mul(size, count), align, volatile)
 694 }
 695
 696 fn try_intrinsic<'a, 'tcx>(
 697     bcx: &Builder<'a, 'tcx>,
 698     ccx: &CrateContext,
 699     func: ValueRef,
 700     data: ValueRef,
 701     local_ptr: ValueRef,
 702     dest: ValueRef,
 703 ) {
 704     if bcx.sess().no_landing_pads() {
 705         bcx.call(func, &[data], None);
 706         bcx.store(C_null(Type::i8p(&bcx.ccx)), dest, None);
 707     } else if wants_msvc_seh(bcx.sess()) {
 708         trans_msvc_try(bcx, ccx, func, data, local_ptr, dest);
 709     } else {
 710         trans_gnu_try(bcx, ccx, func, data, local_ptr, dest);
 711     }
 712 }
 713
 714 // MSVC's definition of the `rust_try` function.
 715 //
 716 // This implementation uses the new exception handling instructions in LLVM
 717 // which have support in LLVM for SEH on MSVC targets. Although these
 718 // instructions are meant to work for all targets, as of the time of this
 719 // writing, however, LLVM does not recommend the usage of these new instructions
 720 // as the old ones are still more optimized.
 721 fn trans_msvc_try<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
 722                             ccx: &CrateContext,
 723                             func: ValueRef,
 724                             data: ValueRef,
 725                             local_ptr: ValueRef,
 726                             dest: ValueRef) {
 727     let llfn = get_rust_try_fn(ccx, &mut |bcx| {
 728         let ccx = bcx.ccx;
 729
 730         bcx.set_personality_fn(bcx.ccx.eh_personality());
 731
 732         let normal = bcx.build_sibling_block("normal");
 733         let catchswitch = bcx.build_sibling_block("catchswitch");
 734         let catchpad = bcx.build_sibling_block("catchpad");
 735         let caught = bcx.build_sibling_block("caught");
 736
 737         let func = llvm::get_param(bcx.llfn(), 0);
 738         let data = llvm::get_param(bcx.llfn(), 1);
 739         let local_ptr = llvm::get_param(bcx.llfn(), 2);
 740
 741         // We're generating an IR snippet that looks like:
 742         //
 743         //   declare i32 @rust_try(%func, %data, %ptr) {
 744         //      %slot = alloca i64*
 745         //      invoke %func(%data) to label %normal unwind label %catchswitch
 746         //
 747         //   normal:
 748         //      ret i32 0
 749         //
 750         //   catchswitch:
 751         //      %cs = catchswitch within none [%catchpad] unwind to caller
 752         //
 753         //   catchpad:
 754         //      %tok = catchpad within %cs [%type_descriptor, 0, %slot]
 755         //      %ptr[0] = %slot[0]
 756         //      %ptr[1] = %slot[1]
 757         //      catchret from %tok to label %caught
 758         //
 759         //   caught:
 760         //      ret i32 1
 761         //   }
 762         //
 763         // This structure follows the basic usage of throw/try/catch in LLVM.
 764         // For example, compile this C++ snippet to see what LLVM generates:
 765         //
 766         //      #include <stdint.h>
 767         //
 768         //      int bar(void (*foo)(void), uint64_t *ret) {
 769         //          try {
 770         //              foo();
 771         //              return 0;
 772         //          } catch(uint64_t a[2]) {
 773         //              ret[0] = a[0];
 774         //              ret[1] = a[1];
 775         //              return 1;
 776         //          }
 777         //      }
 778         //
 779         // More information can be found in libstd's seh.rs implementation.
 780         let i64p = Type::i64(ccx).ptr_to();
 781         let slot = bcx.alloca(i64p, "slot", None);
 782         bcx.invoke(func, &[data], normal.llbb(), catchswitch.llbb(),
 783             None);
 784
 785         normal.ret(C_i32(ccx, 0));
 786
 787         let cs = catchswitch.catch_switch(None, None, 1);
 788         catchswitch.add_handler(cs, catchpad.llbb());
 789
 790         let tcx = ccx.tcx();
 791         let tydesc = match tcx.lang_items.msvc_try_filter() {
 792             Some(did) => ::consts::get_static(ccx, did),
 793             None => bug!("msvc_try_filter not defined"),
 794         };
 795         let tok = catchpad.catch_pad(cs, &[tydesc, C_i32(ccx, 0), slot]);
 796         let addr = catchpad.load(slot, None);
 797         let arg1 = catchpad.load(addr, None);
 798         let val1 = C_i32(ccx, 1);
 799         let arg2 = catchpad.load(catchpad.inbounds_gep(addr, &[val1]), None);
 800         let local_ptr = catchpad.bitcast(local_ptr, i64p);
 801         catchpad.store(arg1, local_ptr, None);
 802         catchpad.store(arg2, catchpad.inbounds_gep(local_ptr, &[val1]), None);
 803         catchpad.catch_ret(tok, caught.llbb());
 804
 805         caught.ret(C_i32(ccx, 1));
 806     });
 807
 808     // Note that no invoke is used here because by definition this function
 809     // can't panic (that's what it's catching).
 810     let ret = bcx.call(llfn, &[func, data, local_ptr], None);
 811     bcx.store(ret, dest, None);
 812 }
 813
 814 // Definition of the standard "try" function for Rust using the GNU-like model
 815 // of exceptions (e.g. the normal semantics of LLVM's landingpad and invoke
 816 // instructions).
 817 //
 818 // This translation is a little surprising because we always call a shim
 819 // function instead of inlining the call to `invoke` manually here. This is done
 820 // because in LLVM we're only allowed to have one personality per function
 821 // definition. The call to the `try` intrinsic is being inlined into the
 822 // function calling it, and that function may already have other personality
 823 // functions in play. By calling a shim we're guaranteed that our shim will have
 824 // the right personality function.
 825 fn trans_gnu_try<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
 826                            ccx: &CrateContext,
 827                            func: ValueRef,
 828                            data: ValueRef,
 829                            local_ptr: ValueRef,
 830                            dest: ValueRef) {
 831     let llfn = get_rust_try_fn(ccx, &mut |bcx| {
 832         let ccx = bcx.ccx;
 833
 834         // Translates the shims described above:
 835         //
 836         //   bcx:
 837         //      invoke %func(%args...) normal %normal unwind %catch
 838         //
 839         //   normal:
 840         //      ret 0
 841         //
 842         //   catch:
 843         //      (ptr, _) = landingpad
 844         //      store ptr, %local_ptr
 845         //      ret 1
 846         //
 847         // Note that the `local_ptr` data passed into the `try` intrinsic is
 848         // expected to be `*mut *mut u8` for this to actually work, but that's
 849         // managed by the standard library.
 850
 851         let then = bcx.build_sibling_block("then");
 852         let catch = bcx.build_sibling_block("catch");
 853
 854         let func = llvm::get_param(bcx.llfn(), 0);
 855         let data = llvm::get_param(bcx.llfn(), 1);
 856         let local_ptr = llvm::get_param(bcx.llfn(), 2);
 857         bcx.invoke(func, &[data], then.llbb(), catch.llbb(), None);
 858         then.ret(C_i32(ccx, 0));
 859
 860         // Type indicator for the exception being thrown.
 861         //
 862         // The first value in this tuple is a pointer to the exception object
 863         // being thrown.  The second value is a "selector" indicating which of
 864         // the landing pad clauses the exception's type had been matched to.
 865         // rust_try ignores the selector.
 866         let lpad_ty = Type::struct_(ccx, &[Type::i8p(ccx), Type::i32(ccx)],
 867                                     false);
 868         let vals = catch.landing_pad(lpad_ty, bcx.ccx.eh_personality(), 1, catch.llfn());
 869         catch.add_clause(vals, C_null(Type::i8p(ccx)));
 870         let ptr = catch.extract_value(vals, 0);
 871         catch.store(ptr, catch.bitcast(local_ptr, Type::i8p(ccx).ptr_to()), None);
 872         catch.ret(C_i32(ccx, 1));
 873     });
 874
 875     // Note that no invoke is used here because by definition this function
 876     // can't panic (that's what it's catching).
 877     let ret = bcx.call(llfn, &[func, data, local_ptr], None);
 878     bcx.store(ret, dest, None);
 879 }
 880
 881 // Helper function to give a Block to a closure to translate a shim function.
 882 // This is currently primarily used for the `try` intrinsic functions above.
 883 fn gen_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
 884                     name: &str,
 885                     inputs: Vec<Ty<'tcx>>,
 886                     output: Ty<'tcx>,
 887                     trans: &mut for<'b> FnMut(Builder<'b, 'tcx>))
 888                     -> ValueRef {
 889     let rust_fn_ty = ccx.tcx().mk_fn_ptr(ty::Binder(ccx.tcx().mk_fn_sig(
 890         inputs.into_iter(),
 891         output,
 892         false,
 893         hir::Unsafety::Unsafe,
 894         Abi::Rust
 895     )));
 896     let llfn = declare::define_internal_fn(ccx, name, rust_fn_ty);
 897     let bcx = Builder::new_block(ccx, llfn, "entry-block");
 898     trans(bcx);
 899     llfn
 900 }
 901
 902 // Helper function used to get a handle to the `__rust_try` function used to
 903 // catch exceptions.
 904 //
 905 // This function is only generated once and is then cached.
 906 fn get_rust_try_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
 907                              trans: &mut for<'b> FnMut(Builder<'b, 'tcx>))
 908                              -> ValueRef {
 909     if let Some(llfn) = ccx.rust_try_fn().get() {
 910         return llfn;
 911     }
 912
 913     // Define the type up front for the signature of the rust_try function.
 914     let tcx = ccx.tcx();
 915     let i8p = tcx.mk_mut_ptr(tcx.types.i8);
 916     let fn_ty = tcx.mk_fn_ptr(ty::Binder(tcx.mk_fn_sig(
 917         iter::once(i8p),
 918         tcx.mk_nil(),
 919         false,
 920         hir::Unsafety::Unsafe,
 921         Abi::Rust
 922     )));
 923     let output = tcx.types.i32;
 924     let rust_try = gen_fn(ccx, "__rust_try", vec![fn_ty, i8p, i8p], output, trans);
 925     ccx.rust_try_fn().set(Some(rust_try));
 926     return rust_try
 927 }
 928
 929 fn span_invalid_monomorphization_error(a: &Session, b: Span, c: &str) {
 930     span_err!(a, b, E0511, "{}", c);
 931 }
 932
 933 fn generic_simd_intrinsic<'a, 'tcx>(
 934     bcx: &Builder<'a, 'tcx>,
 935     name: &str,
 936     callee_ty: Ty<'tcx>,
 937     llargs: &[ValueRef],
 938     ret_ty: Ty<'tcx>,
 939     llret_ty: Type,
 940     span: Span
 941 ) -> ValueRef {
 942     // macros for error handling:
 943     macro_rules! emit_error {
 944         ($msg: tt) => {
 945             emit_error!($msg, )
 946         };
 947         ($msg: tt, $($fmt: tt)*) => {
 948             span_invalid_monomorphization_error(
 949                 bcx.sess(), span,
 950                 &format!(concat!("invalid monomorphization of `{}` intrinsic: ",
 951                                  $msg),
 952                          name, $($fmt)*));
 953         }
 954     }
 955     macro_rules! require {
 956         ($cond: expr, $($fmt: tt)*) => {
 957             if !$cond {
 958                 emit_error!($($fmt)*);
 959                 return C_nil(bcx.ccx)
 960             }
 961         }
 962     }
 963     macro_rules! require_simd {
 964         ($ty: expr, $position: expr) => {
 965             require!($ty.is_simd(), "expected SIMD {} type, found non-SIMD `{}`", $position, $ty)
 966         }
 967     }
 968
 969
 970
 971     let tcx = bcx.tcx();
 972     let sig = tcx.erase_late_bound_regions_and_normalize(&callee_ty.fn_sig());
 973     let arg_tys = sig.inputs();
 974
 975     // every intrinsic takes a SIMD vector as its first argument
 976     require_simd!(arg_tys[0], "input");
 977     let in_ty = arg_tys[0];
 978     let in_elem = arg_tys[0].simd_type(tcx);
 979     let in_len = arg_tys[0].simd_size(tcx);
 980
 981     let comparison = match name {
 982         "simd_eq" => Some(hir::BiEq),
 983         "simd_ne" => Some(hir::BiNe),
 984         "simd_lt" => Some(hir::BiLt),
 985         "simd_le" => Some(hir::BiLe),
 986         "simd_gt" => Some(hir::BiGt),
 987         "simd_ge" => Some(hir::BiGe),
 988         _ => None
 989     };
 990
 991     if let Some(cmp_op) = comparison {
 992         require_simd!(ret_ty, "return");
 993
 994         let out_len = ret_ty.simd_size(tcx);
 995         require!(in_len == out_len,
 996                  "expected return type with length {} (same as input type `{}`), \
 997                   found `{}` with length {}",
 998                  in_len, in_ty,
 999                  ret_ty, out_len);
1000         require!(llret_ty.element_type().kind() == llvm::Integer,
1001                  "expected return type with integer elements, found `{}` with non-integer `{}`",
1002                  ret_ty,
1003                  ret_ty.simd_type(tcx));
1004
1005         return compare_simd_types(bcx,
1006                                   llargs[0],
1007                                   llargs[1],
1008                                   in_elem,
1009                                   llret_ty,
1010                                   cmp_op)
1011     }
1012
1013     if name.starts_with("simd_shuffle") {
1014         let n: usize = match name["simd_shuffle".len()..].parse() {
1015             Ok(n) => n,
1016             Err(_) => span_bug!(span,
1017                                 "bad `simd_shuffle` instruction only caught in trans?")
1018         };
1019
1020         require_simd!(ret_ty, "return");
1021
1022         let out_len = ret_ty.simd_size(tcx);
1023         require!(out_len == n,
1024                  "expected return type of length {}, found `{}` with length {}",
1025                  n, ret_ty, out_len);
1026         require!(in_elem == ret_ty.simd_type(tcx),
1027                  "expected return element type `{}` (element of input `{}`), \
1028                   found `{}` with element type `{}`",
1029                  in_elem, in_ty,
1030                  ret_ty, ret_ty.simd_type(tcx));
1031
1032         let total_len = in_len as u128 * 2;
1033
1034         let vector = llargs[2];
1035
1036         let indices: Option<Vec<_>> = (0..n)
1037             .map(|i| {
1038                 let arg_idx = i;
1039                 let val = const_get_elt(vector, &[i as libc::c_uint]);
1040                 match const_to_opt_u128(val, true) {
1041                     None => {
1042                         emit_error!("shuffle index #{} is not a constant", arg_idx);
1043                         None
1044                     }
1045                     Some(idx) if idx >= total_len => {
1046                         emit_error!("shuffle index #{} is out of bounds (limit {})",
1047                                     arg_idx, total_len);
1048                         None
1049                     }
1050                     Some(idx) => Some(C_i32(bcx.ccx, idx as i32)),
1051                 }
1052             })
1053             .collect();
1054         let indices = match indices {
1055             Some(i) => i,
1056             None => return C_null(llret_ty)
1057         };
1058
1059         return bcx.shuffle_vector(llargs[0], llargs[1], C_vector(&indices))
1060     }
1061
1062     if name == "simd_insert" {
1063         require!(in_elem == arg_tys[2],
1064                  "expected inserted type `{}` (element of input `{}`), found `{}`",
1065                  in_elem, in_ty, arg_tys[2]);
1066         return bcx.insert_element(llargs[0], llargs[2], llargs[1])
1067     }
1068     if name == "simd_extract" {
1069         require!(ret_ty == in_elem,
1070                  "expected return type `{}` (element of input `{}`), found `{}`",
1071                  in_elem, in_ty, ret_ty);
1072         return bcx.extract_element(llargs[0], llargs[1])
1073     }
1074
1075     if name == "simd_cast" {
1076         require_simd!(ret_ty, "return");
1077         let out_len = ret_ty.simd_size(tcx);
1078         require!(in_len == out_len,
1079                  "expected return type with length {} (same as input type `{}`), \
1080                   found `{}` with length {}",
1081                  in_len, in_ty,
1082                  ret_ty, out_len);
1083         // casting cares about nominal type, not just structural type
1084         let out_elem = ret_ty.simd_type(tcx);
1085
1086         if in_elem == out_elem { return llargs[0]; }
1087
1088         enum Style { Float, Int(/* is signed? */ bool), Unsupported }
1089
1090         let (in_style, in_width) = match in_elem.sty {
1091             // vectors of pointer-sized integers should've been
1092             // disallowed before here, so this unwrap is safe.
1093             ty::TyInt(i) => (Style::Int(true), i.bit_width().unwrap()),
1094             ty::TyUint(u) => (Style::Int(false), u.bit_width().unwrap()),
1095             ty::TyFloat(f) => (Style::Float, f.bit_width()),
1096             _ => (Style::Unsupported, 0)
1097         };
1098         let (out_style, out_width) = match out_elem.sty {
1099             ty::TyInt(i) => (Style::Int(true), i.bit_width().unwrap()),
1100             ty::TyUint(u) => (Style::Int(false), u.bit_width().unwrap()),
1101             ty::TyFloat(f) => (Style::Float, f.bit_width()),
1102             _ => (Style::Unsupported, 0)
1103         };
1104
1105         match (in_style, out_style) {
1106             (Style::Int(in_is_signed), Style::Int(_)) => {
1107                 return match in_width.cmp(&out_width) {
1108                     Ordering::Greater => bcx.trunc(llargs[0], llret_ty),
1109                     Ordering::Equal => llargs[0],
1110                     Ordering::Less => if in_is_signed {
1111                         bcx.sext(llargs[0], llret_ty)
1112                     } else {
1113                         bcx.zext(llargs[0], llret_ty)
1114                     }
1115                 }
1116             }
1117             (Style::Int(in_is_signed), Style::Float) => {
1118                 return if in_is_signed {
1119                     bcx.sitofp(llargs[0], llret_ty)
1120                 } else {
1121                     bcx.uitofp(llargs[0], llret_ty)
1122                 }
1123             }
1124             (Style::Float, Style::Int(out_is_signed)) => {
1125                 return if out_is_signed {
1126                     bcx.fptosi(llargs[0], llret_ty)
1127                 } else {
1128                     bcx.fptoui(llargs[0], llret_ty)
1129                 }
1130             }
1131             (Style::Float, Style::Float) => {
1132                 return match in_width.cmp(&out_width) {
1133                     Ordering::Greater => bcx.fptrunc(llargs[0], llret_ty),
1134                     Ordering::Equal => llargs[0],
1135                     Ordering::Less => bcx.fpext(llargs[0], llret_ty)
1136                 }
1137             }
1138             _ => {/* Unsupported. Fallthrough. */}
1139         }
1140         require!(false,
1141                  "unsupported cast from `{}` with element `{}` to `{}` with element `{}`",
1142                  in_ty, in_elem,
1143                  ret_ty, out_elem);
1144     }
1145     macro_rules! arith {
1146         ($($name: ident: $($($p: ident),* => $call: ident),*;)*) => {
1147             $(
1148                 if name == stringify!($name) {
1149                     match in_elem.sty {
1150                         $(
1151                             $(ty::$p(_))|* => {
1152                                 return bcx.$call(llargs[0], llargs[1])
1153                             }
1154                             )*
1155                         _ => {},
1156                     }
1157                     require!(false,
1158                              "unsupported operation on `{}` with element `{}`",
1159                              in_ty,
1160                              in_elem)
1161                 })*
1162         }
1163     }
1164     arith! {
1165         simd_add: TyUint, TyInt => add, TyFloat => fadd;
1166         simd_sub: TyUint, TyInt => sub, TyFloat => fsub;
1167         simd_mul: TyUint, TyInt => mul, TyFloat => fmul;
1168         simd_div: TyFloat => fdiv;
1169         simd_shl: TyUint, TyInt => shl;
1170         simd_shr: TyUint => lshr, TyInt => ashr;
1171         simd_and: TyUint, TyInt => and;
1172         simd_or: TyUint, TyInt => or;
1173         simd_xor: TyUint, TyInt => xor;
1174     }
1175     span_bug!(span, "unknown SIMD intrinsic");
1176 }
1177
1178 // Returns the width of an int TypeVariant, and if it's signed or not
1179 // Returns None if the type is not an integer
1180 // FIXME: there’s multiple of this functions, investigate using some of the already existing
1181 // stuffs.
1182 fn int_type_width_signed<'tcx>(sty: &ty::TypeVariants<'tcx>, ccx: &CrateContext)
1183         -> Option<(u64, bool)> {
1184     use rustc::ty::{TyInt, TyUint};
1185     match *sty {
1186         TyInt(t) => Some((match t {
1187             ast::IntTy::Is => {
1188                 match &ccx.tcx().sess.target.target.target_pointer_width[..] {
1189                     "16" => 16,
1190                     "32" => 32,
1191                     "64" => 64,
1192                     tws => bug!("Unsupported target word size for isize: {}", tws),
1193                 }
1194             },
1195             ast::IntTy::I8 => 8,
1196             ast::IntTy::I16 => 16,
1197             ast::IntTy::I32 => 32,
1198             ast::IntTy::I64 => 64,
1199             ast::IntTy::I128 => 128,
1200         }, true)),
1201         TyUint(t) => Some((match t {
1202             ast::UintTy::Us => {
1203                 match &ccx.tcx().sess.target.target.target_pointer_width[..] {
1204                     "16" => 16,
1205                     "32" => 32,
1206                     "64" => 64,
1207                     tws => bug!("Unsupported target word size for usize: {}", tws),
1208                 }
1209             },
1210             ast::UintTy::U8 => 8,
1211             ast::UintTy::U16 => 16,
1212             ast::UintTy::U32 => 32,
1213             ast::UintTy::U64 => 64,
1214             ast::UintTy::U128 => 128,
1215         }, false)),
1216         _ => None,
1217     }
1218 }
1219
1220 // Returns the width of a float TypeVariant
1221 // Returns None if the type is not a float
1222 fn float_type_width<'tcx>(sty: &ty::TypeVariants<'tcx>)
1223         -> Option<u64> {
1224     use rustc::ty::TyFloat;
1225     match *sty {
1226         TyFloat(t) => Some(match t {
1227             ast::FloatTy::F32 => 32,
1228             ast::FloatTy::F64 => 64,
1229         }),
1230         _ => None,
1231     }
1232 }