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 arena::TypedArena;
  14 use intrinsics::{self, Intrinsic};
  15 use libc;
  16 use llvm;
  17 use llvm::{ValueRef, TypeKind};
  18 use rustc::ty::subst::Substs;
  19 use abi::{Abi, FnType};
  20 use adt;
  21 use base::*;
  22 use build::*;
  23 use callee::{self, Callee};
  24 use cleanup;
  25 use cleanup::CleanupMethods;
  26 use common::*;
  27 use consts;
  28 use datum::*;
  29 use debuginfo::DebugLoc;
  30 use declare;
  31 use expr;
  32 use glue;
  33 use type_of;
  34 use machine;
  35 use type_::Type;
  36 use rustc::ty::{self, Ty};
  37 use Disr;
  38 use rustc::hir;
  39 use syntax::ast;
  40 use syntax::ptr::P;
  41 use syntax::parse::token;
  42
  43 use rustc::session::Session;
  44 use rustc_const_eval::fatal_const_eval_err;
  45 use syntax_pos::{Span, DUMMY_SP};
  46
  47 use std::cmp::Ordering;
  48
  49 fn get_simple_intrinsic(ccx: &CrateContext, name: &str) -> Option<ValueRef> {
  50     let llvm_name = match name {
  51         "sqrtf32" => "llvm.sqrt.f32",
  52         "sqrtf64" => "llvm.sqrt.f64",
  53         "powif32" => "llvm.powi.f32",
  54         "powif64" => "llvm.powi.f64",
  55         "sinf32" => "llvm.sin.f32",
  56         "sinf64" => "llvm.sin.f64",
  57         "cosf32" => "llvm.cos.f32",
  58         "cosf64" => "llvm.cos.f64",
  59         "powf32" => "llvm.pow.f32",
  60         "powf64" => "llvm.pow.f64",
  61         "expf32" => "llvm.exp.f32",
  62         "expf64" => "llvm.exp.f64",
  63         "exp2f32" => "llvm.exp2.f32",
  64         "exp2f64" => "llvm.exp2.f64",
  65         "logf32" => "llvm.log.f32",
  66         "logf64" => "llvm.log.f64",
  67         "log10f32" => "llvm.log10.f32",
  68         "log10f64" => "llvm.log10.f64",
  69         "log2f32" => "llvm.log2.f32",
  70         "log2f64" => "llvm.log2.f64",
  71         "fmaf32" => "llvm.fma.f32",
  72         "fmaf64" => "llvm.fma.f64",
  73         "fabsf32" => "llvm.fabs.f32",
  74         "fabsf64" => "llvm.fabs.f64",
  75         "copysignf32" => "llvm.copysign.f32",
  76         "copysignf64" => "llvm.copysign.f64",
  77         "floorf32" => "llvm.floor.f32",
  78         "floorf64" => "llvm.floor.f64",
  79         "ceilf32" => "llvm.ceil.f32",
  80         "ceilf64" => "llvm.ceil.f64",
  81         "truncf32" => "llvm.trunc.f32",
  82         "truncf64" => "llvm.trunc.f64",
  83         "rintf32" => "llvm.rint.f32",
  84         "rintf64" => "llvm.rint.f64",
  85         "nearbyintf32" => "llvm.nearbyint.f32",
  86         "nearbyintf64" => "llvm.nearbyint.f64",
  87         "roundf32" => "llvm.round.f32",
  88         "roundf64" => "llvm.round.f64",
  89         "assume" => "llvm.assume",
  90         _ => return None
  91     };
  92     Some(ccx.get_intrinsic(&llvm_name))
  93 }
  94
  95 /// Remember to add all intrinsics here, in librustc_typeck/check/mod.rs,
  96 /// and in libcore/intrinsics.rs; if you need access to any llvm intrinsics,
  97 /// add them to librustc_trans/trans/context.rs
  98 pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
  99                                             callee_ty: Ty<'tcx>,
 100                                             fn_ty: &FnType,
 101                                             args: callee::CallArgs<'a, 'tcx>,
 102                                             dest: expr::Dest,
 103                                             call_debug_location: DebugLoc)
 104                                             -> Result<'blk, 'tcx> {
 105     let fcx = bcx.fcx;
 106     let ccx = fcx.ccx;
 107     let tcx = bcx.tcx();
 108
 109     let _icx = push_ctxt("trans_intrinsic_call");
 110
 111     let (def_id, substs, sig) = match callee_ty.sty {
 112         ty::TyFnDef(def_id, substs, fty) => {
 113             let sig = tcx.erase_late_bound_regions(&fty.sig);
 114             (def_id, substs, tcx.normalize_associated_type(&sig))
 115         }
 116         _ => bug!("expected fn item type, found {}", callee_ty)
 117     };
 118     let arg_tys = sig.inputs;
 119     let ret_ty = sig.output;
 120     let name = tcx.item_name(def_id).as_str();
 121
 122     let span = match call_debug_location {
 123         DebugLoc::At(_, span) | DebugLoc::ScopeAt(_, span) => span,
 124         DebugLoc::None => {
 125             span_bug!(fcx.span.unwrap_or(DUMMY_SP),
 126                       "intrinsic `{}` called with missing span", name);
 127         }
 128     };
 129
 130     let cleanup_scope = fcx.push_custom_cleanup_scope();
 131
 132     // For `transmute` we can just trans the input expr directly into dest
 133     if name == "transmute" {
 134         let llret_ty = type_of::type_of(ccx, ret_ty);
 135         match args {
 136             callee::ArgExprs(arg_exprs) => {
 137                 assert_eq!(arg_exprs.len(), 1);
 138
 139                 let (in_type, out_type) = (substs.types[0],
 140                                            substs.types[1]);
 141                 let llintype = type_of::type_of(ccx, in_type);
 142                 let llouttype = type_of::type_of(ccx, out_type);
 143
 144                 let in_type_size = machine::llbitsize_of_real(ccx, llintype);
 145                 let out_type_size = machine::llbitsize_of_real(ccx, llouttype);
 146
 147                 if let ty::TyFnDef(def_id, substs, _) = in_type.sty {
 148                     if out_type_size != 0 {
 149                         // FIXME #19925 Remove this hack after a release cycle.
 150                         let _ = unpack_datum!(bcx, expr::trans(bcx, &arg_exprs[0]));
 151                         let llfn = Callee::def(ccx, def_id, substs).reify(ccx).val;
 152                         let llfnty = val_ty(llfn);
 153                         let llresult = match dest {
 154                             expr::SaveIn(d) => d,
 155                             expr::Ignore => alloc_ty(bcx, out_type, "ret")
 156                         };
 157                         Store(bcx, llfn, PointerCast(bcx, llresult, llfnty.ptr_to()));
 158                         if dest == expr::Ignore {
 159                             bcx = glue::drop_ty(bcx, llresult, out_type,
 160                                                 call_debug_location);
 161                         }
 162                         fcx.scopes.borrow_mut().last_mut().unwrap().drop_non_lifetime_clean();
 163                         fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
 164                         return Result::new(bcx, llresult);
 165                     }
 166                 }
 167
 168                 // This should be caught by the intrinsicck pass
 169                 assert_eq!(in_type_size, out_type_size);
 170
 171                 let nonpointer_nonaggregate = |llkind: TypeKind| -> bool {
 172                     use llvm::TypeKind::*;
 173                     match llkind {
 174                         Half | Float | Double | X86_FP80 | FP128 |
 175                             PPC_FP128 | Integer | Vector | X86_MMX => true,
 176                         _ => false
 177                     }
 178                 };
 179
 180                 // An approximation to which types can be directly cast via
 181                 // LLVM's bitcast.  This doesn't cover pointer -> pointer casts,
 182                 // but does, importantly, cover SIMD types.
 183                 let in_kind = llintype.kind();
 184                 let ret_kind = llret_ty.kind();
 185                 let bitcast_compatible =
 186                     (nonpointer_nonaggregate(in_kind) && nonpointer_nonaggregate(ret_kind)) || {
 187                         in_kind == TypeKind::Pointer && ret_kind == TypeKind::Pointer
 188                     };
 189
 190                 let dest = if bitcast_compatible {
 191                     // if we're here, the type is scalar-like (a primitive, a
 192                     // SIMD type or a pointer), and so can be handled as a
 193                     // by-value ValueRef and can also be directly bitcast to the
 194                     // target type.  Doing this special case makes conversions
 195                     // like `u32x4` -> `u64x2` much nicer for LLVM and so more
 196                     // efficient (these are done efficiently implicitly in C
 197                     // with the `__m128i` type and so this means Rust doesn't
 198                     // lose out there).
 199                     let expr = &arg_exprs[0];
 200                     let datum = unpack_datum!(bcx, expr::trans(bcx, expr));
 201                     let datum = unpack_datum!(bcx, datum.to_rvalue_datum(bcx, "transmute_temp"));
 202                     let val = if datum.kind.is_by_ref() {
 203                         load_ty(bcx, datum.val, datum.ty)
 204                     } else {
 205                         from_immediate(bcx, datum.val)
 206                     };
 207
 208                     let cast_val = BitCast(bcx, val, llret_ty);
 209
 210                     match dest {
 211                         expr::SaveIn(d) => {
 212                             // this often occurs in a sequence like `Store(val,
 213                             // d); val2 = Load(d)`, so disappears easily.
 214                             Store(bcx, cast_val, d);
 215                         }
 216                         expr::Ignore => {}
 217                     }
 218                     dest
 219                 } else {
 220                     // The types are too complicated to do with a by-value
 221                     // bitcast, so pointer cast instead. We need to cast the
 222                     // dest so the types work out.
 223                     let dest = match dest {
 224                         expr::SaveIn(d) => expr::SaveIn(PointerCast(bcx, d, llintype.ptr_to())),
 225                         expr::Ignore => expr::Ignore
 226                     };
 227                     bcx = expr::trans_into(bcx, &arg_exprs[0], dest);
 228                     dest
 229                 };
 230
 231                 fcx.scopes.borrow_mut().last_mut().unwrap().drop_non_lifetime_clean();
 232                 fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
 233
 234                 return match dest {
 235                     expr::SaveIn(d) => Result::new(bcx, d),
 236                     expr::Ignore => Result::new(bcx, C_undef(llret_ty.ptr_to()))
 237                 };
 238
 239             }
 240
 241             _ => {
 242                 bug!("expected expr as argument for transmute");
 243             }
 244         }
 245     }
 246
 247     // For `move_val_init` we can evaluate the destination address
 248     // (the first argument) and then trans the source value (the
 249     // second argument) directly into the resulting destination
 250     // address.
 251     if name == "move_val_init" {
 252         if let callee::ArgExprs(ref exprs) = args {
 253             let (dest_expr, source_expr) = if exprs.len() != 2 {
 254                 bug!("expected two exprs as arguments for `move_val_init` intrinsic");
 255             } else {
 256                 (&exprs[0], &exprs[1])
 257             };
 258
 259             // evaluate destination address
 260             let dest_datum = unpack_datum!(bcx, expr::trans(bcx, dest_expr));
 261             let dest_datum = unpack_datum!(
 262                 bcx, dest_datum.to_rvalue_datum(bcx, "arg"));
 263             let dest_datum = unpack_datum!(
 264                 bcx, dest_datum.to_appropriate_datum(bcx));
 265
 266             // `expr::trans_into(bcx, expr, dest)` is equiv to
 267             //
 268             //    `trans(bcx, expr).store_to_dest(dest)`,
 269             //
 270             // which for `dest == expr::SaveIn(addr)`, is equivalent to:
 271             //
 272             //    `trans(bcx, expr).store_to(bcx, addr)`.
 273             let lldest = expr::Dest::SaveIn(dest_datum.val);
 274             bcx = expr::trans_into(bcx, source_expr, lldest);
 275
 276             let llresult = C_nil(ccx);
 277             fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
 278
 279             return Result::new(bcx, llresult);
 280         } else {
 281             bug!("expected two exprs as arguments for `move_val_init` intrinsic");
 282         }
 283     }
 284
 285     // save the actual AST arguments for later (some places need to do
 286     // const-evaluation on them)
 287     let expr_arguments = match args {
 288         callee::ArgExprs(args) => Some(args),
 289         _ => None,
 290     };
 291
 292     // Push the arguments.
 293     let mut llargs = Vec::new();
 294     bcx = callee::trans_args(bcx,
 295                              Abi::RustIntrinsic,
 296                              fn_ty,
 297                              &mut callee::Intrinsic,
 298                              args,
 299                              &mut llargs,
 300                              cleanup::CustomScope(cleanup_scope));
 301
 302     fcx.scopes.borrow_mut().last_mut().unwrap().drop_non_lifetime_clean();
 303
 304     // These are the only intrinsic functions that diverge.
 305     if name == "abort" {
 306         let llfn = ccx.get_intrinsic(&("llvm.trap"));
 307         Call(bcx, llfn, &[], call_debug_location);
 308         fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
 309         Unreachable(bcx);
 310         return Result::new(bcx, C_undef(Type::nil(ccx).ptr_to()));
 311     } else if &name[..] == "unreachable" {
 312         fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
 313         Unreachable(bcx);
 314         return Result::new(bcx, C_nil(ccx));
 315     }
 316
 317     let llret_ty = type_of::type_of(ccx, ret_ty);
 318
 319     // Get location to store the result. If the user does
 320     // not care about the result, just make a stack slot
 321     let llresult = match dest {
 322         expr::SaveIn(d) => d,
 323         expr::Ignore => {
 324             if !type_is_zero_size(ccx, ret_ty) {
 325                 let llresult = alloc_ty(bcx, ret_ty, "intrinsic_result");
 326                 call_lifetime_start(bcx, llresult);
 327                 llresult
 328             } else {
 329                 C_undef(llret_ty.ptr_to())
 330             }
 331         }
 332     };
 333
 334     let simple = get_simple_intrinsic(ccx, &name);
 335     let llval = match (simple, &name[..]) {
 336         (Some(llfn), _) => {
 337             Call(bcx, llfn, &llargs, call_debug_location)
 338         }
 339         (_, "try") => {
 340             bcx = try_intrinsic(bcx, llargs[0], llargs[1], llargs[2], llresult,
 341                                 call_debug_location);
 342             C_nil(ccx)
 343         }
 344         (_, "breakpoint") => {
 345             let llfn = ccx.get_intrinsic(&("llvm.debugtrap"));
 346             Call(bcx, llfn, &[], call_debug_location)
 347         }
 348         (_, "size_of") => {
 349             let tp_ty = substs.types[0];
 350             let lltp_ty = type_of::type_of(ccx, tp_ty);
 351             C_uint(ccx, machine::llsize_of_alloc(ccx, lltp_ty))
 352         }
 353         (_, "size_of_val") => {
 354             let tp_ty = substs.types[0];
 355             if !type_is_sized(tcx, tp_ty) {
 356                 let (llsize, _) =
 357                     glue::size_and_align_of_dst(&bcx.build(), tp_ty, llargs[1]);
 358                 llsize
 359             } else {
 360                 let lltp_ty = type_of::type_of(ccx, tp_ty);
 361                 C_uint(ccx, machine::llsize_of_alloc(ccx, lltp_ty))
 362             }
 363         }
 364         (_, "min_align_of") => {
 365             let tp_ty = substs.types[0];
 366             C_uint(ccx, type_of::align_of(ccx, tp_ty))
 367         }
 368         (_, "min_align_of_val") => {
 369             let tp_ty = substs.types[0];
 370             if !type_is_sized(tcx, tp_ty) {
 371                 let (_, llalign) =
 372                     glue::size_and_align_of_dst(&bcx.build(), tp_ty, llargs[1]);
 373                 llalign
 374             } else {
 375                 C_uint(ccx, type_of::align_of(ccx, tp_ty))
 376             }
 377         }
 378         (_, "pref_align_of") => {
 379             let tp_ty = substs.types[0];
 380             let lltp_ty = type_of::type_of(ccx, tp_ty);
 381             C_uint(ccx, machine::llalign_of_pref(ccx, lltp_ty))
 382         }
 383         (_, "drop_in_place") => {
 384             let tp_ty = substs.types[0];
 385             let ptr = if type_is_sized(tcx, tp_ty) {
 386                 llargs[0]
 387             } else {
 388                 let scratch = rvalue_scratch_datum(bcx, tp_ty, "tmp");
 389                 Store(bcx, llargs[0], expr::get_dataptr(bcx, scratch.val));
 390                 Store(bcx, llargs[1], expr::get_meta(bcx, scratch.val));
 391                 fcx.schedule_lifetime_end(cleanup::CustomScope(cleanup_scope), scratch.val);
 392                 scratch.val
 393             };
 394             glue::drop_ty(bcx, ptr, tp_ty, call_debug_location);
 395             C_nil(ccx)
 396         }
 397         (_, "type_name") => {
 398             let tp_ty = substs.types[0];
 399             let ty_name = token::intern_and_get_ident(&tp_ty.to_string());
 400             C_str_slice(ccx, ty_name)
 401         }
 402         (_, "type_id") => {
 403             C_u64(ccx, ccx.tcx().type_id_hash(substs.types[0]))
 404         }
 405         (_, "init_dropped") => {
 406             let tp_ty = substs.types[0];
 407             if !type_is_zero_size(ccx, tp_ty) {
 408                 drop_done_fill_mem(bcx, llresult, tp_ty);
 409             }
 410             C_nil(ccx)
 411         }
 412         (_, "init") => {
 413             let tp_ty = substs.types[0];
 414             if !type_is_zero_size(ccx, tp_ty) {
 415                 // Just zero out the stack slot. (See comment on base::memzero for explanation)
 416                 init_zero_mem(bcx, llresult, tp_ty);
 417             }
 418             C_nil(ccx)
 419         }
 420         // Effectively no-ops
 421         (_, "uninit") | (_, "forget") => {
 422             C_nil(ccx)
 423         }
 424         (_, "needs_drop") => {
 425             let tp_ty = substs.types[0];
 426
 427             C_bool(ccx, bcx.fcx.type_needs_drop(tp_ty))
 428         }
 429         (_, "offset") => {
 430             let ptr = llargs[0];
 431             let offset = llargs[1];
 432             InBoundsGEP(bcx, ptr, &[offset])
 433         }
 434         (_, "arith_offset") => {
 435             let ptr = llargs[0];
 436             let offset = llargs[1];
 437             GEP(bcx, ptr, &[offset])
 438         }
 439
 440         (_, "copy_nonoverlapping") => {
 441             copy_intrinsic(bcx,
 442                            false,
 443                            false,
 444                            substs.types[0],
 445                            llargs[1],
 446                            llargs[0],
 447                            llargs[2],
 448                            call_debug_location)
 449         }
 450         (_, "copy") => {
 451             copy_intrinsic(bcx,
 452                            true,
 453                            false,
 454                            substs.types[0],
 455                            llargs[1],
 456                            llargs[0],
 457                            llargs[2],
 458                            call_debug_location)
 459         }
 460         (_, "write_bytes") => {
 461             memset_intrinsic(bcx,
 462                              false,
 463                              substs.types[0],
 464                              llargs[0],
 465                              llargs[1],
 466                              llargs[2],
 467                              call_debug_location)
 468         }
 469
 470         (_, "volatile_copy_nonoverlapping_memory") => {
 471             copy_intrinsic(bcx,
 472                            false,
 473                            true,
 474                            substs.types[0],
 475                            llargs[0],
 476                            llargs[1],
 477                            llargs[2],
 478                            call_debug_location)
 479         }
 480         (_, "volatile_copy_memory") => {
 481             copy_intrinsic(bcx,
 482                            true,
 483                            true,
 484                            substs.types[0],
 485                            llargs[0],
 486                            llargs[1],
 487                            llargs[2],
 488                            call_debug_location)
 489         }
 490         (_, "volatile_set_memory") => {
 491             memset_intrinsic(bcx,
 492                              true,
 493                              substs.types[0],
 494                              llargs[0],
 495                              llargs[1],
 496                              llargs[2],
 497                              call_debug_location)
 498         }
 499         (_, "volatile_load") => {
 500             let tp_ty = substs.types[0];
 501             let mut ptr = llargs[0];
 502             if let Some(ty) = fn_ty.ret.cast {
 503                 ptr = PointerCast(bcx, ptr, ty.ptr_to());
 504             }
 505             let load = VolatileLoad(bcx, ptr);
 506             unsafe {
 507                 llvm::LLVMSetAlignment(load, type_of::align_of(ccx, tp_ty));
 508             }
 509             to_immediate(bcx, load, tp_ty)
 510         },
 511         (_, "volatile_store") => {
 512             let tp_ty = substs.types[0];
 513             if type_is_fat_ptr(bcx.tcx(), tp_ty) {
 514                 VolatileStore(bcx, llargs[1], expr::get_dataptr(bcx, llargs[0]));
 515                 VolatileStore(bcx, llargs[2], expr::get_meta(bcx, llargs[0]));
 516             } else {
 517                 let val = if fn_ty.args[1].is_indirect() {
 518                     Load(bcx, llargs[1])
 519                 } else {
 520                     from_immediate(bcx, llargs[1])
 521                 };
 522                 let ptr = PointerCast(bcx, llargs[0], val_ty(val).ptr_to());
 523                 let store = VolatileStore(bcx, val, ptr);
 524                 unsafe {
 525                     llvm::LLVMSetAlignment(store, type_of::align_of(ccx, tp_ty));
 526                 }
 527             }
 528             C_nil(ccx)
 529         },
 530
 531         (_, "ctlz") | (_, "cttz") | (_, "ctpop") | (_, "bswap") |
 532         (_, "add_with_overflow") | (_, "sub_with_overflow") | (_, "mul_with_overflow") |
 533         (_, "overflowing_add") | (_, "overflowing_sub") | (_, "overflowing_mul") |
 534         (_, "unchecked_div") | (_, "unchecked_rem") => {
 535             let sty = &arg_tys[0].sty;
 536             match int_type_width_signed(sty, ccx) {
 537                 Some((width, signed)) =>
 538                     match &*name {
 539                         "ctlz" => count_zeros_intrinsic(bcx, &format!("llvm.ctlz.i{}", width),
 540                                                         llargs[0], call_debug_location),
 541                         "cttz" => count_zeros_intrinsic(bcx, &format!("llvm.cttz.i{}", width),
 542                                                         llargs[0], call_debug_location),
 543                         "ctpop" => Call(bcx, ccx.get_intrinsic(&format!("llvm.ctpop.i{}", width)),
 544                                         &llargs, call_debug_location),
 545                         "bswap" => {
 546                             if width == 8 {
 547                                 llargs[0] // byte swap a u8/i8 is just a no-op
 548                             } else {
 549                                 Call(bcx, ccx.get_intrinsic(&format!("llvm.bswap.i{}", width)),
 550                                         &llargs, call_debug_location)
 551                             }
 552                         }
 553                         "add_with_overflow" | "sub_with_overflow" | "mul_with_overflow" => {
 554                             let intrinsic = format!("llvm.{}{}.with.overflow.i{}",
 555                                                     if signed { 's' } else { 'u' },
 556                                                     &name[..3], width);
 557                             with_overflow_intrinsic(bcx, &intrinsic, llargs[0], llargs[1], llresult,
 558                                                     call_debug_location)
 559                         },
 560                         "overflowing_add" => Add(bcx, llargs[0], llargs[1], call_debug_location),
 561                         "overflowing_sub" => Sub(bcx, llargs[0], llargs[1], call_debug_location),
 562                         "overflowing_mul" => Mul(bcx, llargs[0], llargs[1], call_debug_location),
 563                         "unchecked_div" =>
 564                             if signed {
 565                                 SDiv(bcx, llargs[0], llargs[1], call_debug_location)
 566                             } else {
 567                                 UDiv(bcx, llargs[0], llargs[1], call_debug_location)
 568                             },
 569                         "unchecked_rem" =>
 570                             if signed {
 571                                 SRem(bcx, llargs[0], llargs[1], call_debug_location)
 572                             } else {
 573                                 URem(bcx, llargs[0], llargs[1], call_debug_location)
 574                             },
 575                         _ => bug!(),
 576                     },
 577                 None => {
 578                     span_invalid_monomorphization_error(
 579                         tcx.sess, span,
 580                         &format!("invalid monomorphization of `{}` intrinsic: \
 581                                   expected basic integer type, found `{}`", name, sty));
 582                         C_nil(ccx)
 583                 }
 584             }
 585
 586         },
 587         (_, "fadd_fast") | (_, "fsub_fast") | (_, "fmul_fast") | (_, "fdiv_fast") |
 588         (_, "frem_fast") => {
 589             let sty = &arg_tys[0].sty;
 590             match float_type_width(sty) {
 591                 Some(_width) =>
 592                     match &*name {
 593                         "fadd_fast" => FAddFast(bcx, llargs[0], llargs[1], call_debug_location),
 594                         "fsub_fast" => FSubFast(bcx, llargs[0], llargs[1], call_debug_location),
 595                         "fmul_fast" => FMulFast(bcx, llargs[0], llargs[1], call_debug_location),
 596                         "fdiv_fast" => FDivFast(bcx, llargs[0], llargs[1], call_debug_location),
 597                         "frem_fast" => FRemFast(bcx, llargs[0], llargs[1], call_debug_location),
 598                         _ => bug!(),
 599                     },
 600                 None => {
 601                     span_invalid_monomorphization_error(
 602                         tcx.sess, span,
 603                         &format!("invalid monomorphization of `{}` intrinsic: \
 604                                   expected basic float type, found `{}`", name, sty));
 605                         C_nil(ccx)
 606                 }
 607             }
 608
 609         },
 610
 611         (_, "discriminant_value") => {
 612             let val_ty = substs.types[0];
 613             match val_ty.sty {
 614                 ty::TyEnum(..) => {
 615                     let repr = adt::represent_type(ccx, val_ty);
 616                     adt::trans_get_discr(bcx, &repr, llargs[0],
 617                                          Some(llret_ty), true)
 618                 }
 619                 _ => C_null(llret_ty)
 620             }
 621         }
 622         (_, name) if name.starts_with("simd_") => {
 623             generic_simd_intrinsic(bcx, name,
 624                                    substs,
 625                                    callee_ty,
 626                                    expr_arguments,
 627                                    &llargs,
 628                                    ret_ty, llret_ty,
 629                                    call_debug_location,
 630                                    span)
 631         }
 632         // This requires that atomic intrinsics follow a specific naming pattern:
 633         // "atomic_<operation>[_<ordering>]", and no ordering means SeqCst
 634         (_, name) if name.starts_with("atomic_") => {
 635             use llvm::AtomicOrdering::*;
 636
 637             let split: Vec<&str> = name.split('_').collect();
 638
 639             let is_cxchg = split[1] == "cxchg" || split[1] == "cxchgweak";
 640             let (order, failorder) = match split.len() {
 641                 2 => (SequentiallyConsistent, SequentiallyConsistent),
 642                 3 => match split[2] {
 643                     "unordered" => (Unordered, Unordered),
 644                     "relaxed" => (Monotonic, Monotonic),
 645                     "acq"     => (Acquire, Acquire),
 646                     "rel"     => (Release, Monotonic),
 647                     "acqrel"  => (AcquireRelease, Acquire),
 648                     "failrelaxed" if is_cxchg =>
 649                         (SequentiallyConsistent, Monotonic),
 650                     "failacq" if is_cxchg =>
 651                         (SequentiallyConsistent, Acquire),
 652                     _ => ccx.sess().fatal("unknown ordering in atomic intrinsic")
 653                 },
 654                 4 => match (split[2], split[3]) {
 655                     ("acq", "failrelaxed") if is_cxchg =>
 656                         (Acquire, Monotonic),
 657                     ("acqrel", "failrelaxed") if is_cxchg =>
 658                         (AcquireRelease, Monotonic),
 659                     _ => ccx.sess().fatal("unknown ordering in atomic intrinsic")
 660                 },
 661                 _ => ccx.sess().fatal("Atomic intrinsic not in correct format"),
 662             };
 663
 664             match split[1] {
 665                 "cxchg" | "cxchgweak" => {
 666                     let sty = &substs.types[0].sty;
 667                     if int_type_width_signed(sty, ccx).is_some() {
 668                         let weak = if split[1] == "cxchgweak" { llvm::True } else { llvm::False };
 669                         let val = AtomicCmpXchg(bcx, llargs[0], llargs[1], llargs[2],
 670                                                 order, failorder, weak);
 671                         let result = ExtractValue(bcx, val, 0);
 672                         let success = ZExt(bcx, ExtractValue(bcx, val, 1), Type::bool(bcx.ccx()));
 673                         Store(bcx, result, StructGEP(bcx, llresult, 0));
 674                         Store(bcx, success, StructGEP(bcx, llresult, 1));
 675                     } else {
 676                         span_invalid_monomorphization_error(
 677                             tcx.sess, span,
 678                             &format!("invalid monomorphization of `{}` intrinsic: \
 679                                       expected basic integer type, found `{}`", name, sty));
 680                     }
 681                     C_nil(ccx)
 682                 }
 683
 684                 "load" => {
 685                     let sty = &substs.types[0].sty;
 686                     if int_type_width_signed(sty, ccx).is_some() {
 687                         AtomicLoad(bcx, llargs[0], order)
 688                     } else {
 689                         span_invalid_monomorphization_error(
 690                             tcx.sess, span,
 691                             &format!("invalid monomorphization of `{}` intrinsic: \
 692                                       expected basic integer type, found `{}`", name, sty));
 693                         C_nil(ccx)
 694                     }
 695                 }
 696
 697                 "store" => {
 698                     let sty = &substs.types[0].sty;
 699                     if int_type_width_signed(sty, ccx).is_some() {
 700                         AtomicStore(bcx, llargs[1], llargs[0], order);
 701                     } else {
 702                         span_invalid_monomorphization_error(
 703                             tcx.sess, span,
 704                             &format!("invalid monomorphization of `{}` intrinsic: \
 705                                       expected basic integer type, found `{}`", name, sty));
 706                     }
 707                     C_nil(ccx)
 708                 }
 709
 710                 "fence" => {
 711                     AtomicFence(bcx, order, llvm::SynchronizationScope::CrossThread);
 712                     C_nil(ccx)
 713                 }
 714
 715                 "singlethreadfence" => {
 716                     AtomicFence(bcx, order, llvm::SynchronizationScope::SingleThread);
 717                     C_nil(ccx)
 718                 }
 719
 720                 // These are all AtomicRMW ops
 721                 op => {
 722                     let atom_op = match op {
 723                         "xchg"  => llvm::AtomicXchg,
 724                         "xadd"  => llvm::AtomicAdd,
 725                         "xsub"  => llvm::AtomicSub,
 726                         "and"   => llvm::AtomicAnd,
 727                         "nand"  => llvm::AtomicNand,
 728                         "or"    => llvm::AtomicOr,
 729                         "xor"   => llvm::AtomicXor,
 730                         "max"   => llvm::AtomicMax,
 731                         "min"   => llvm::AtomicMin,
 732                         "umax"  => llvm::AtomicUMax,
 733                         "umin"  => llvm::AtomicUMin,
 734                         _ => ccx.sess().fatal("unknown atomic operation")
 735                     };
 736
 737                     let sty = &substs.types[0].sty;
 738                     if int_type_width_signed(sty, ccx).is_some() {
 739                         AtomicRMW(bcx, atom_op, llargs[0], llargs[1], order)
 740                     } else {
 741                         span_invalid_monomorphization_error(
 742                             tcx.sess, span,
 743                             &format!("invalid monomorphization of `{}` intrinsic: \
 744                                       expected basic integer type, found `{}`", name, sty));
 745                         C_nil(ccx)
 746                     }
 747                 }
 748             }
 749
 750         }
 751
 752         (_, _) => {
 753             let intr = match Intrinsic::find(&name) {
 754                 Some(intr) => intr,
 755                 None => bug!("unknown intrinsic '{}'", name),
 756             };
 757             fn one<T>(x: Vec<T>) -> T {
 758                 assert_eq!(x.len(), 1);
 759                 x.into_iter().next().unwrap()
 760             }
 761             fn ty_to_type(ccx: &CrateContext, t: &intrinsics::Type,
 762                           any_changes_needed: &mut bool) -> Vec<Type> {
 763                 use intrinsics::Type::*;
 764                 match *t {
 765                     Void => vec![Type::void(ccx)],
 766                     Integer(_signed, width, llvm_width) => {
 767                         *any_changes_needed |= width != llvm_width;
 768                         vec![Type::ix(ccx, llvm_width as u64)]
 769                     }
 770                     Float(x) => {
 771                         match x {
 772                             32 => vec![Type::f32(ccx)],
 773                             64 => vec![Type::f64(ccx)],
 774                             _ => bug!()
 775                         }
 776                     }
 777                     Pointer(ref t, ref llvm_elem, _const) => {
 778                         *any_changes_needed |= llvm_elem.is_some();
 779
 780                         let t = llvm_elem.as_ref().unwrap_or(t);
 781                         let elem = one(ty_to_type(ccx, t,
 782                                                   any_changes_needed));
 783                         vec![elem.ptr_to()]
 784                     }
 785                     Vector(ref t, ref llvm_elem, length) => {
 786                         *any_changes_needed |= llvm_elem.is_some();
 787
 788                         let t = llvm_elem.as_ref().unwrap_or(t);
 789                         let elem = one(ty_to_type(ccx, t,
 790                                                   any_changes_needed));
 791                         vec![Type::vector(&elem,
 792                                           length as u64)]
 793                     }
 794                     Aggregate(false, ref contents) => {
 795                         let elems = contents.iter()
 796                                             .map(|t| one(ty_to_type(ccx, t, any_changes_needed)))
 797                                             .collect::<Vec<_>>();
 798                         vec![Type::struct_(ccx, &elems, false)]
 799                     }
 800                     Aggregate(true, ref contents) => {
 801                         *any_changes_needed = true;
 802                         contents.iter()
 803                                 .flat_map(|t| ty_to_type(ccx, t, any_changes_needed))
 804                                 .collect()
 805                     }
 806                 }
 807             }
 808
 809             // This allows an argument list like `foo, (bar, baz),
 810             // qux` to be converted into `foo, bar, baz, qux`, integer
 811             // arguments to be truncated as needed and pointers to be
 812             // cast.
 813             fn modify_as_needed<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 814                                             t: &intrinsics::Type,
 815                                             arg_type: Ty<'tcx>,
 816                                             llarg: ValueRef)
 817                                             -> Vec<ValueRef>
 818             {
 819                 match *t {
 820                     intrinsics::Type::Aggregate(true, ref contents) => {
 821                         // We found a tuple that needs squishing! So
 822                         // run over the tuple and load each field.
 823                         //
 824                         // This assumes the type is "simple", i.e. no
 825                         // destructors, and the contents are SIMD
 826                         // etc.
 827                         assert!(!bcx.fcx.type_needs_drop(arg_type));
 828
 829                         let repr = adt::represent_type(bcx.ccx(), arg_type);
 830                         let repr_ptr = &repr;
 831                         let arg = adt::MaybeSizedValue::sized(llarg);
 832                         (0..contents.len())
 833                             .map(|i| {
 834                                 Load(bcx, adt::trans_field_ptr(bcx, repr_ptr, arg, Disr(0), i))
 835                             })
 836                             .collect()
 837                     }
 838                     intrinsics::Type::Pointer(_, Some(ref llvm_elem), _) => {
 839                         let llvm_elem = one(ty_to_type(bcx.ccx(), llvm_elem, &mut false));
 840                         vec![PointerCast(bcx, llarg,
 841                                          llvm_elem.ptr_to())]
 842                     }
 843                     intrinsics::Type::Vector(_, Some(ref llvm_elem), length) => {
 844                         let llvm_elem = one(ty_to_type(bcx.ccx(), llvm_elem, &mut false));
 845                         vec![BitCast(bcx, llarg,
 846                                      Type::vector(&llvm_elem, length as u64))]
 847                     }
 848                     intrinsics::Type::Integer(_, width, llvm_width) if width != llvm_width => {
 849                         // the LLVM intrinsic uses a smaller integer
 850                         // size than the C intrinsic's signature, so
 851                         // we have to trim it down here.
 852                         vec![Trunc(bcx, llarg, Type::ix(bcx.ccx(), llvm_width as u64))]
 853                     }
 854                     _ => vec![llarg],
 855                 }
 856             }
 857
 858
 859             let mut any_changes_needed = false;
 860             let inputs = intr.inputs.iter()
 861                                     .flat_map(|t| ty_to_type(ccx, t, &mut any_changes_needed))
 862                                     .collect::<Vec<_>>();
 863
 864             let mut out_changes = false;
 865             let outputs = one(ty_to_type(ccx, &intr.output, &mut out_changes));
 866             // outputting a flattened aggregate is nonsense
 867             assert!(!out_changes);
 868
 869             let llargs = if !any_changes_needed {
 870                 // no aggregates to flatten, so no change needed
 871                 llargs
 872             } else {
 873                 // there are some aggregates that need to be flattened
 874                 // in the LLVM call, so we need to run over the types
 875                 // again to find them and extract the arguments
 876                 intr.inputs.iter()
 877                            .zip(&llargs)
 878                            .zip(&arg_tys)
 879                            .flat_map(|((t, llarg), ty)| modify_as_needed(bcx, t, ty, *llarg))
 880                            .collect()
 881             };
 882             assert_eq!(inputs.len(), llargs.len());
 883
 884             let val = match intr.definition {
 885                 intrinsics::IntrinsicDef::Named(name) => {
 886                     let f = declare::declare_cfn(ccx,
 887                                                  name,
 888                                                  Type::func(&inputs, &outputs));
 889                     Call(bcx, f, &llargs, call_debug_location)
 890                 }
 891             };
 892
 893             match *intr.output {
 894                 intrinsics::Type::Aggregate(flatten, ref elems) => {
 895                     // the output is a tuple so we need to munge it properly
 896                     assert!(!flatten);
 897
 898                     for i in 0..elems.len() {
 899                         let val = ExtractValue(bcx, val, i);
 900                         Store(bcx, val, StructGEP(bcx, llresult, i));
 901                     }
 902                     C_nil(ccx)
 903                 }
 904                 _ => val,
 905             }
 906         }
 907     };
 908
 909     if val_ty(llval) != Type::void(ccx) &&
 910        machine::llsize_of_alloc(ccx, val_ty(llval)) != 0 {
 911         if let Some(ty) = fn_ty.ret.cast {
 912             let ptr = PointerCast(bcx, llresult, ty.ptr_to());
 913             let store = Store(bcx, llval, ptr);
 914             unsafe {
 915                 llvm::LLVMSetAlignment(store, type_of::align_of(ccx, ret_ty));
 916             }
 917         } else {
 918             store_ty(bcx, llval, llresult, ret_ty);
 919         }
 920     }
 921
 922     // If we made a temporary stack slot, let's clean it up
 923     match dest {
 924         expr::Ignore => {
 925             bcx = glue::drop_ty(bcx, llresult, ret_ty, call_debug_location);
 926             call_lifetime_end(bcx, llresult);
 927         }
 928         expr::SaveIn(_) => {}
 929     }
 930
 931     fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
 932
 933     Result::new(bcx, llresult)
 934 }
 935
 936 fn copy_intrinsic<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 937                               allow_overlap: bool,
 938                               volatile: bool,
 939                               tp_ty: Ty<'tcx>,
 940                               dst: ValueRef,
 941                               src: ValueRef,
 942                               count: ValueRef,
 943                               call_debug_location: DebugLoc)
 944                               -> ValueRef {
 945     let ccx = bcx.ccx();
 946     let lltp_ty = type_of::type_of(ccx, tp_ty);
 947     let align = C_i32(ccx, type_of::align_of(ccx, tp_ty) as i32);
 948     let size = machine::llsize_of(ccx, lltp_ty);
 949     let int_size = machine::llbitsize_of_real(ccx, ccx.int_type());
 950
 951     let operation = if allow_overlap {
 952         "memmove"
 953     } else {
 954         "memcpy"
 955     };
 956
 957     let name = format!("llvm.{}.p0i8.p0i8.i{}", operation, int_size);
 958
 959     let dst_ptr = PointerCast(bcx, dst, Type::i8p(ccx));
 960     let src_ptr = PointerCast(bcx, src, Type::i8p(ccx));
 961     let llfn = ccx.get_intrinsic(&name);
 962
 963     Call(bcx,
 964          llfn,
 965          &[dst_ptr,
 966            src_ptr,
 967            Mul(bcx, size, count, DebugLoc::None),
 968            align,
 969            C_bool(ccx, volatile)],
 970          call_debug_location)
 971 }
 972
 973 fn memset_intrinsic<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
 974                                 volatile: bool,
 975                                 tp_ty: Ty<'tcx>,
 976                                 dst: ValueRef,
 977                                 val: ValueRef,
 978                                 count: ValueRef,
 979                                 call_debug_location: DebugLoc)
 980                                 -> ValueRef {
 981     let ccx = bcx.ccx();
 982     let lltp_ty = type_of::type_of(ccx, tp_ty);
 983     let align = C_i32(ccx, type_of::align_of(ccx, tp_ty) as i32);
 984     let size = machine::llsize_of(ccx, lltp_ty);
 985     let int_size = machine::llbitsize_of_real(ccx, ccx.int_type());
 986
 987     let name = format!("llvm.memset.p0i8.i{}", int_size);
 988
 989     let dst_ptr = PointerCast(bcx, dst, Type::i8p(ccx));
 990     let llfn = ccx.get_intrinsic(&name);
 991
 992     Call(bcx,
 993          llfn,
 994          &[dst_ptr,
 995            val,
 996            Mul(bcx, size, count, DebugLoc::None),
 997            align,
 998            C_bool(ccx, volatile)],
 999          call_debug_location)
1000 }
1001
1002 fn count_zeros_intrinsic(bcx: Block,
1003                          name: &str,
1004                          val: ValueRef,
1005                          call_debug_location: DebugLoc)
1006                          -> ValueRef {
1007     let y = C_bool(bcx.ccx(), false);
1008     let llfn = bcx.ccx().get_intrinsic(&name);
1009     Call(bcx, llfn, &[val, y], call_debug_location)
1010 }
1011
1012 fn with_overflow_intrinsic<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1013                                        name: &str,
1014                                        a: ValueRef,
1015                                        b: ValueRef,
1016                                        out: ValueRef,
1017                                        call_debug_location: DebugLoc)
1018                                        -> ValueRef {
1019     let llfn = bcx.ccx().get_intrinsic(&name);
1020
1021     // Convert `i1` to a `bool`, and write it to the out parameter
1022     let val = Call(bcx, llfn, &[a, b], call_debug_location);
1023     let result = ExtractValue(bcx, val, 0);
1024     let overflow = ZExt(bcx, ExtractValue(bcx, val, 1), Type::bool(bcx.ccx()));
1025     Store(bcx, result, StructGEP(bcx, out, 0));
1026     Store(bcx, overflow, StructGEP(bcx, out, 1));
1027
1028     C_nil(bcx.ccx())
1029 }
1030
1031 fn try_intrinsic<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1032                              func: ValueRef,
1033                              data: ValueRef,
1034                              local_ptr: ValueRef,
1035                              dest: ValueRef,
1036                              dloc: DebugLoc) -> Block<'blk, 'tcx> {
1037     if bcx.sess().no_landing_pads() {
1038         Call(bcx, func, &[data], dloc);
1039         Store(bcx, C_null(Type::i8p(bcx.ccx())), dest);
1040         bcx
1041     } else if wants_msvc_seh(bcx.sess()) {
1042         trans_msvc_try(bcx, func, data, local_ptr, dest, dloc)
1043     } else {
1044         trans_gnu_try(bcx, func, data, local_ptr, dest, dloc)
1045     }
1046 }
1047
1048 // MSVC's definition of the `rust_try` function.
1049 //
1050 // This implementation uses the new exception handling instructions in LLVM
1051 // which have support in LLVM for SEH on MSVC targets. Although these
1052 // instructions are meant to work for all targets, as of the time of this
1053 // writing, however, LLVM does not recommend the usage of these new instructions
1054 // as the old ones are still more optimized.
1055 fn trans_msvc_try<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1056                               func: ValueRef,
1057                               data: ValueRef,
1058                               local_ptr: ValueRef,
1059                               dest: ValueRef,
1060                               dloc: DebugLoc) -> Block<'blk, 'tcx> {
1061     let llfn = get_rust_try_fn(bcx.fcx, &mut |bcx| {
1062         let ccx = bcx.ccx();
1063         let dloc = DebugLoc::None;
1064
1065         SetPersonalityFn(bcx, bcx.fcx.eh_personality());
1066
1067         let normal = bcx.fcx.new_temp_block("normal");
1068         let catchswitch = bcx.fcx.new_temp_block("catchswitch");
1069         let catchpad = bcx.fcx.new_temp_block("catchpad");
1070         let caught = bcx.fcx.new_temp_block("caught");
1071
1072         let func = llvm::get_param(bcx.fcx.llfn, 0);
1073         let data = llvm::get_param(bcx.fcx.llfn, 1);
1074         let local_ptr = llvm::get_param(bcx.fcx.llfn, 2);
1075
1076         // We're generating an IR snippet that looks like:
1077         //
1078         //   declare i32 @rust_try(%func, %data, %ptr) {
1079         //      %slot = alloca i64*
1080         //      invoke %func(%data) to label %normal unwind label %catchswitch
1081         //
1082         //   normal:
1083         //      ret i32 0
1084         //
1085         //   catchswitch:
1086         //      %cs = catchswitch within none [%catchpad] unwind to caller
1087         //
1088         //   catchpad:
1089         //      %tok = catchpad within %cs [%type_descriptor, 0, %slot]
1090         //      %ptr[0] = %slot[0]
1091         //      %ptr[1] = %slot[1]
1092         //      catchret from %tok to label %caught
1093         //
1094         //   caught:
1095         //      ret i32 1
1096         //   }
1097         //
1098         // This structure follows the basic usage of throw/try/catch in LLVM.
1099         // For example, compile this C++ snippet to see what LLVM generates:
1100         //
1101         //      #include <stdint.h>
1102         //
1103         //      int bar(void (*foo)(void), uint64_t *ret) {
1104         //          try {
1105         //              foo();
1106         //              return 0;
1107         //          } catch(uint64_t a[2]) {
1108         //              ret[0] = a[0];
1109         //              ret[1] = a[1];
1110         //              return 1;
1111         //          }
1112         //      }
1113         //
1114         // More information can be found in libstd's seh.rs implementation.
1115         let i64p = Type::i64(ccx).ptr_to();
1116         let slot = Alloca(bcx, i64p, "slot");
1117         Invoke(bcx, func, &[data], normal.llbb, catchswitch.llbb, dloc);
1118
1119         Ret(normal, C_i32(ccx, 0), dloc);
1120
1121         let cs = CatchSwitch(catchswitch, None, None, 1);
1122         AddHandler(catchswitch, cs, catchpad.llbb);
1123
1124         let tcx = ccx.tcx();
1125         let tydesc = match tcx.lang_items.msvc_try_filter() {
1126             Some(did) => ::consts::get_static(ccx, did).to_llref(),
1127             None => bug!("msvc_try_filter not defined"),
1128         };
1129         let tok = CatchPad(catchpad, cs, &[tydesc, C_i32(ccx, 0), slot]);
1130         let addr = Load(catchpad, slot);
1131         let arg1 = Load(catchpad, addr);
1132         let val1 = C_i32(ccx, 1);
1133         let arg2 = Load(catchpad, InBoundsGEP(catchpad, addr, &[val1]));
1134         let local_ptr = BitCast(catchpad, local_ptr, i64p);
1135         Store(catchpad, arg1, local_ptr);
1136         Store(catchpad, arg2, InBoundsGEP(catchpad, local_ptr, &[val1]));
1137         CatchRet(catchpad, tok, caught.llbb);
1138
1139         Ret(caught, C_i32(ccx, 1), dloc);
1140     });
1141
1142     // Note that no invoke is used here because by definition this function
1143     // can't panic (that's what it's catching).
1144     let ret = Call(bcx, llfn, &[func, data, local_ptr], dloc);
1145     Store(bcx, ret, dest);
1146     return bcx
1147 }
1148
1149 // Definition of the standard "try" function for Rust using the GNU-like model
1150 // of exceptions (e.g. the normal semantics of LLVM's landingpad and invoke
1151 // instructions).
1152 //
1153 // This translation is a little surprising because we always call a shim
1154 // function instead of inlining the call to `invoke` manually here. This is done
1155 // because in LLVM we're only allowed to have one personality per function
1156 // definition. The call to the `try` intrinsic is being inlined into the
1157 // function calling it, and that function may already have other personality
1158 // functions in play. By calling a shim we're guaranteed that our shim will have
1159 // the right personality function.
1160 fn trans_gnu_try<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1161                              func: ValueRef,
1162                              data: ValueRef,
1163                              local_ptr: ValueRef,
1164                              dest: ValueRef,
1165                              dloc: DebugLoc) -> Block<'blk, 'tcx> {
1166     let llfn = get_rust_try_fn(bcx.fcx, &mut |bcx| {
1167         let ccx = bcx.ccx();
1168         let dloc = DebugLoc::None;
1169
1170         // Translates the shims described above:
1171         //
1172         //   bcx:
1173         //      invoke %func(%args...) normal %normal unwind %catch
1174         //
1175         //   normal:
1176         //      ret 0
1177         //
1178         //   catch:
1179         //      (ptr, _) = landingpad
1180         //      store ptr, %local_ptr
1181         //      ret 1
1182         //
1183         // Note that the `local_ptr` data passed into the `try` intrinsic is
1184         // expected to be `*mut *mut u8` for this to actually work, but that's
1185         // managed by the standard library.
1186
1187         let then = bcx.fcx.new_temp_block("then");
1188         let catch = bcx.fcx.new_temp_block("catch");
1189
1190         let func = llvm::get_param(bcx.fcx.llfn, 0);
1191         let data = llvm::get_param(bcx.fcx.llfn, 1);
1192         let local_ptr = llvm::get_param(bcx.fcx.llfn, 2);
1193         Invoke(bcx, func, &[data], then.llbb, catch.llbb, dloc);
1194         Ret(then, C_i32(ccx, 0), dloc);
1195
1196         // Type indicator for the exception being thrown.
1197         //
1198         // The first value in this tuple is a pointer to the exception object
1199         // being thrown.  The second value is a "selector" indicating which of
1200         // the landing pad clauses the exception's type had been matched to.
1201         // rust_try ignores the selector.
1202         let lpad_ty = Type::struct_(ccx, &[Type::i8p(ccx), Type::i32(ccx)],
1203                                     false);
1204         let vals = LandingPad(catch, lpad_ty, bcx.fcx.eh_personality(), 1);
1205         AddClause(catch, vals, C_null(Type::i8p(ccx)));
1206         let ptr = ExtractValue(catch, vals, 0);
1207         Store(catch, ptr, BitCast(catch, local_ptr, Type::i8p(ccx).ptr_to()));
1208         Ret(catch, C_i32(ccx, 1), dloc);
1209     });
1210
1211     // Note that no invoke is used here because by definition this function
1212     // can't panic (that's what it's catching).
1213     let ret = Call(bcx, llfn, &[func, data, local_ptr], dloc);
1214     Store(bcx, ret, dest);
1215     return bcx;
1216 }
1217
1218 // Helper function to give a Block to a closure to translate a shim function.
1219 // This is currently primarily used for the `try` intrinsic functions above.
1220 fn gen_fn<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1221                     name: &str,
1222                     inputs: Vec<Ty<'tcx>>,
1223                     output: Ty<'tcx>,
1224                     trans: &mut for<'b> FnMut(Block<'b, 'tcx>))
1225                     -> ValueRef {
1226     let ccx = fcx.ccx;
1227     let sig = ty::FnSig {
1228         inputs: inputs,
1229         output: output,
1230         variadic: false,
1231     };
1232     let fn_ty = FnType::new(ccx, Abi::Rust, &sig, &[]);
1233
1234     let rust_fn_ty = ccx.tcx().mk_fn_ptr(ccx.tcx().mk_bare_fn(ty::BareFnTy {
1235         unsafety: hir::Unsafety::Unsafe,
1236         abi: Abi::Rust,
1237         sig: ty::Binder(sig)
1238     }));
1239     let llfn = declare::define_internal_fn(ccx, name, rust_fn_ty);
1240     let (fcx, block_arena);
1241     block_arena = TypedArena::new();
1242     fcx = FunctionContext::new(ccx, llfn, fn_ty, None, &block_arena);
1243     let bcx = fcx.init(true, None);
1244     trans(bcx);
1245     fcx.cleanup();
1246     llfn
1247 }
1248
1249 // Helper function used to get a handle to the `__rust_try` function used to
1250 // catch exceptions.
1251 //
1252 // This function is only generated once and is then cached.
1253 fn get_rust_try_fn<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1254                              trans: &mut for<'b> FnMut(Block<'b, 'tcx>))
1255                              -> ValueRef {
1256     let ccx = fcx.ccx;
1257     if let Some(llfn) = ccx.rust_try_fn().get() {
1258         return llfn;
1259     }
1260
1261     // Define the type up front for the signature of the rust_try function.
1262     let tcx = ccx.tcx();
1263     let i8p = tcx.mk_mut_ptr(tcx.types.i8);
1264     let fn_ty = tcx.mk_fn_ptr(tcx.mk_bare_fn(ty::BareFnTy {
1265         unsafety: hir::Unsafety::Unsafe,
1266         abi: Abi::Rust,
1267         sig: ty::Binder(ty::FnSig {
1268             inputs: vec![i8p],
1269             output: tcx.mk_nil(),
1270             variadic: false,
1271         }),
1272     }));
1273     let output = tcx.types.i32;
1274     let rust_try = gen_fn(fcx, "__rust_try", vec![fn_ty, i8p, i8p], output, trans);
1275     ccx.rust_try_fn().set(Some(rust_try));
1276     return rust_try
1277 }
1278
1279 fn span_invalid_monomorphization_error(a: &Session, b: Span, c: &str) {
1280     span_err!(a, b, E0511, "{}", c);
1281 }
1282
1283 fn generic_simd_intrinsic<'blk, 'tcx, 'a>
1284     (bcx: Block<'blk, 'tcx>,
1285      name: &str,
1286      substs: &'tcx Substs<'tcx>,
1287      callee_ty: Ty<'tcx>,
1288      args: Option<&[P<hir::Expr>]>,
1289      llargs: &[ValueRef],
1290      ret_ty: Ty<'tcx>,
1291      llret_ty: Type,
1292      call_debug_location: DebugLoc,
1293      span: Span) -> ValueRef
1294 {
1295     // macros for error handling:
1296     macro_rules! emit_error {
1297         ($msg: tt) => {
1298             emit_error!($msg, )
1299         };
1300         ($msg: tt, $($fmt: tt)*) => {
1301             span_invalid_monomorphization_error(
1302                 bcx.sess(), span,
1303                 &format!(concat!("invalid monomorphization of `{}` intrinsic: ",
1304                                  $msg),
1305                          name, $($fmt)*));
1306         }
1307     }
1308     macro_rules! require {
1309         ($cond: expr, $($fmt: tt)*) => {
1310             if !$cond {
1311                 emit_error!($($fmt)*);
1312                 return C_nil(bcx.ccx())
1313             }
1314         }
1315     }
1316     macro_rules! require_simd {
1317         ($ty: expr, $position: expr) => {
1318             require!($ty.is_simd(), "expected SIMD {} type, found non-SIMD `{}`", $position, $ty)
1319         }
1320     }
1321
1322
1323
1324     let tcx = bcx.tcx();
1325     let sig = tcx.erase_late_bound_regions(callee_ty.fn_sig());
1326     let sig = tcx.normalize_associated_type(&sig);
1327     let arg_tys = sig.inputs;
1328
1329     // every intrinsic takes a SIMD vector as its first argument
1330     require_simd!(arg_tys[0], "input");
1331     let in_ty = arg_tys[0];
1332     let in_elem = arg_tys[0].simd_type(tcx);
1333     let in_len = arg_tys[0].simd_size(tcx);
1334
1335     let comparison = match name {
1336         "simd_eq" => Some(hir::BiEq),
1337         "simd_ne" => Some(hir::BiNe),
1338         "simd_lt" => Some(hir::BiLt),
1339         "simd_le" => Some(hir::BiLe),
1340         "simd_gt" => Some(hir::BiGt),
1341         "simd_ge" => Some(hir::BiGe),
1342         _ => None
1343     };
1344
1345     if let Some(cmp_op) = comparison {
1346         require_simd!(ret_ty, "return");
1347
1348         let out_len = ret_ty.simd_size(tcx);
1349         require!(in_len == out_len,
1350                  "expected return type with length {} (same as input type `{}`), \
1351                   found `{}` with length {}",
1352                  in_len, in_ty,
1353                  ret_ty, out_len);
1354         require!(llret_ty.element_type().kind() == llvm::Integer,
1355                  "expected return type with integer elements, found `{}` with non-integer `{}`",
1356                  ret_ty,
1357                  ret_ty.simd_type(tcx));
1358
1359         return compare_simd_types(bcx,
1360                                   llargs[0],
1361                                   llargs[1],
1362                                   in_elem,
1363                                   llret_ty,
1364                                   cmp_op,
1365                                   call_debug_location)
1366     }
1367
1368     if name.starts_with("simd_shuffle") {
1369         let n: usize = match name["simd_shuffle".len()..].parse() {
1370             Ok(n) => n,
1371             Err(_) => span_bug!(span,
1372                                 "bad `simd_shuffle` instruction only caught in trans?")
1373         };
1374
1375         require_simd!(ret_ty, "return");
1376
1377         let out_len = ret_ty.simd_size(tcx);
1378         require!(out_len == n,
1379                  "expected return type of length {}, found `{}` with length {}",
1380                  n, ret_ty, out_len);
1381         require!(in_elem == ret_ty.simd_type(tcx),
1382                  "expected return element type `{}` (element of input `{}`), \
1383                   found `{}` with element type `{}`",
1384                  in_elem, in_ty,
1385                  ret_ty, ret_ty.simd_type(tcx));
1386
1387         let total_len = in_len as u64 * 2;
1388
1389         let vector = match args {
1390             Some(args) => {
1391                 match consts::const_expr(bcx.ccx(), &args[2], substs, None,
1392                                          // this should probably help simd error reporting
1393                                          consts::TrueConst::Yes) {
1394                     Ok((vector, _)) => vector,
1395                     Err(err) => {
1396                         fatal_const_eval_err(bcx.tcx(), err.as_inner(), span,
1397                                              "shuffle indices");
1398                     }
1399                 }
1400             }
1401             None => llargs[2]
1402         };
1403
1404         let indices: Option<Vec<_>> = (0..n)
1405             .map(|i| {
1406                 let arg_idx = i;
1407                 let val = const_get_elt(vector, &[i as libc::c_uint]);
1408                 match const_to_opt_uint(val) {
1409                     None => {
1410                         emit_error!("shuffle index #{} is not a constant", arg_idx);
1411                         None
1412                     }
1413                     Some(idx) if idx >= total_len => {
1414                         emit_error!("shuffle index #{} is out of bounds (limit {})",
1415                                     arg_idx, total_len);
1416                         None
1417                     }
1418                     Some(idx) => Some(C_i32(bcx.ccx(), idx as i32)),
1419                 }
1420             })
1421             .collect();
1422         let indices = match indices {
1423             Some(i) => i,
1424             None => return C_null(llret_ty)
1425         };
1426
1427         return ShuffleVector(bcx, llargs[0], llargs[1], C_vector(&indices))
1428     }
1429
1430     if name == "simd_insert" {
1431         require!(in_elem == arg_tys[2],
1432                  "expected inserted type `{}` (element of input `{}`), found `{}`",
1433                  in_elem, in_ty, arg_tys[2]);
1434         return InsertElement(bcx, llargs[0], llargs[2], llargs[1])
1435     }
1436     if name == "simd_extract" {
1437         require!(ret_ty == in_elem,
1438                  "expected return type `{}` (element of input `{}`), found `{}`",
1439                  in_elem, in_ty, ret_ty);
1440         return ExtractElement(bcx, llargs[0], llargs[1])
1441     }
1442
1443     if name == "simd_cast" {
1444         require_simd!(ret_ty, "return");
1445         let out_len = ret_ty.simd_size(tcx);
1446         require!(in_len == out_len,
1447                  "expected return type with length {} (same as input type `{}`), \
1448                   found `{}` with length {}",
1449                  in_len, in_ty,
1450                  ret_ty, out_len);
1451         // casting cares about nominal type, not just structural type
1452         let out_elem = ret_ty.simd_type(tcx);
1453
1454         if in_elem == out_elem { return llargs[0]; }
1455
1456         enum Style { Float, Int(/* is signed? */ bool), Unsupported }
1457
1458         let (in_style, in_width) = match in_elem.sty {
1459             // vectors of pointer-sized integers should've been
1460             // disallowed before here, so this unwrap is safe.
1461             ty::TyInt(i) => (Style::Int(true), i.bit_width().unwrap()),
1462             ty::TyUint(u) => (Style::Int(false), u.bit_width().unwrap()),
1463             ty::TyFloat(f) => (Style::Float, f.bit_width()),
1464             _ => (Style::Unsupported, 0)
1465         };
1466         let (out_style, out_width) = match out_elem.sty {
1467             ty::TyInt(i) => (Style::Int(true), i.bit_width().unwrap()),
1468             ty::TyUint(u) => (Style::Int(false), u.bit_width().unwrap()),
1469             ty::TyFloat(f) => (Style::Float, f.bit_width()),
1470             _ => (Style::Unsupported, 0)
1471         };
1472
1473         match (in_style, out_style) {
1474             (Style::Int(in_is_signed), Style::Int(_)) => {
1475                 return match in_width.cmp(&out_width) {
1476                     Ordering::Greater => Trunc(bcx, llargs[0], llret_ty),
1477                     Ordering::Equal => llargs[0],
1478                     Ordering::Less => if in_is_signed {
1479                         SExt(bcx, llargs[0], llret_ty)
1480                     } else {
1481                         ZExt(bcx, llargs[0], llret_ty)
1482                     }
1483                 }
1484             }
1485             (Style::Int(in_is_signed), Style::Float) => {
1486                 return if in_is_signed {
1487                     SIToFP(bcx, llargs[0], llret_ty)
1488                 } else {
1489                     UIToFP(bcx, llargs[0], llret_ty)
1490                 }
1491             }
1492             (Style::Float, Style::Int(out_is_signed)) => {
1493                 return if out_is_signed {
1494                     FPToSI(bcx, llargs[0], llret_ty)
1495                 } else {
1496                     FPToUI(bcx, llargs[0], llret_ty)
1497                 }
1498             }
1499             (Style::Float, Style::Float) => {
1500                 return match in_width.cmp(&out_width) {
1501                     Ordering::Greater => FPTrunc(bcx, llargs[0], llret_ty),
1502                     Ordering::Equal => llargs[0],
1503                     Ordering::Less => FPExt(bcx, llargs[0], llret_ty)
1504                 }
1505             }
1506             _ => {/* Unsupported. Fallthrough. */}
1507         }
1508         require!(false,
1509                  "unsupported cast from `{}` with element `{}` to `{}` with element `{}`",
1510                  in_ty, in_elem,
1511                  ret_ty, out_elem);
1512     }
1513     macro_rules! arith {
1514         ($($name: ident: $($($p: ident),* => $call: expr),*;)*) => {
1515             $(
1516                 if name == stringify!($name) {
1517                     match in_elem.sty {
1518                         $(
1519                             $(ty::$p(_))|* => {
1520                                 return $call(bcx, llargs[0], llargs[1], call_debug_location)
1521                             }
1522                             )*
1523                         _ => {},
1524                     }
1525                     require!(false,
1526                              "unsupported operation on `{}` with element `{}`",
1527                              in_ty,
1528                              in_elem)
1529                 })*
1530         }
1531     }
1532     arith! {
1533         simd_add: TyUint, TyInt => Add, TyFloat => FAdd;
1534         simd_sub: TyUint, TyInt => Sub, TyFloat => FSub;
1535         simd_mul: TyUint, TyInt => Mul, TyFloat => FMul;
1536         simd_div: TyFloat => FDiv;
1537         simd_shl: TyUint, TyInt => Shl;
1538         simd_shr: TyUint => LShr, TyInt => AShr;
1539         simd_and: TyUint, TyInt => And;
1540         simd_or: TyUint, TyInt => Or;
1541         simd_xor: TyUint, TyInt => Xor;
1542     }
1543     span_bug!(span, "unknown SIMD intrinsic");
1544 }
1545
1546 // Returns the width of an int TypeVariant, and if it's signed or not
1547 // Returns None if the type is not an integer
1548 fn int_type_width_signed<'tcx>(sty: &ty::TypeVariants<'tcx>, ccx: &CrateContext)
1549         -> Option<(u64, bool)> {
1550     use rustc::ty::{TyInt, TyUint};
1551     match *sty {
1552         TyInt(t) => Some((match t {
1553             ast::IntTy::Is => {
1554                 match &ccx.tcx().sess.target.target.target_pointer_width[..] {
1555                     "16" => 16,
1556                     "32" => 32,
1557                     "64" => 64,
1558                     tws => bug!("Unsupported target word size for isize: {}", tws),
1559                 }
1560             },
1561             ast::IntTy::I8 => 8,
1562             ast::IntTy::I16 => 16,
1563             ast::IntTy::I32 => 32,
1564             ast::IntTy::I64 => 64,
1565         }, true)),
1566         TyUint(t) => Some((match t {
1567             ast::UintTy::Us => {
1568                 match &ccx.tcx().sess.target.target.target_pointer_width[..] {
1569                     "16" => 16,
1570                     "32" => 32,
1571                     "64" => 64,
1572                     tws => bug!("Unsupported target word size for usize: {}", tws),
1573                 }
1574             },
1575             ast::UintTy::U8 => 8,
1576             ast::UintTy::U16 => 16,
1577             ast::UintTy::U32 => 32,
1578             ast::UintTy::U64 => 64,
1579         }, false)),
1580         _ => None,
1581     }
1582 }
1583
1584 // Returns the width of a float TypeVariant
1585 // Returns None if the type is not a float
1586 fn float_type_width<'tcx>(sty: &ty::TypeVariants<'tcx>)
1587         -> Option<u64> {
1588     use rustc::ty::TyFloat;
1589     match *sty {
1590         TyFloat(t) => Some(match t {
1591             ast::FloatTy::F32 => 32,
1592             ast::FloatTy::F64 => 64,
1593         }),
1594         _ => None,
1595     }
1596 }