src/intrinsics/mod.rs

   1 //! Codegen of intrinsics. This includes `extern "rust-intrinsic"`, `extern "platform-intrinsic"`
   2 //! and LLVM intrinsics that have symbol names starting with `llvm.`.
   3
   4 mod cpuid;
   5 mod llvm;
   6 mod simd;
   7
   8 pub(crate) use cpuid::codegen_cpuid_call;
   9 pub(crate) use llvm::codegen_llvm_intrinsic_call;
  10
  11 use crate::prelude::*;
  12 use cranelift_codegen::ir::AtomicRmwOp;
  13 use rustc_middle::ty::print::with_no_trimmed_paths;
  14
  15 macro intrinsic_pat {
  16     (_) => {
  17         _
  18     },
  19     ($name:ident) => {
  20         stringify!($name)
  21     },
  22     ($name:literal) => {
  23         stringify!($name)
  24     },
  25     ($x:ident . $($xs:tt).*) => {
  26         concat!(stringify!($x), ".", intrinsic_pat!($($xs).*))
  27     }
  28 }
  29
  30 macro intrinsic_arg {
  31     (o $fx:expr, $arg:ident) => {
  32         $arg
  33     },
  34     (c $fx:expr, $arg:ident) => {
  35         codegen_operand($fx, $arg)
  36     },
  37     (v $fx:expr, $arg:ident) => {
  38         codegen_operand($fx, $arg).load_scalar($fx)
  39     }
  40 }
  41
  42 macro intrinsic_substs {
  43     ($substs:expr, $index:expr,) => {},
  44     ($substs:expr, $index:expr, $first:ident $(,$rest:ident)*) => {
  45         let $first = $substs.type_at($index);
  46         intrinsic_substs!($substs, $index+1, $($rest),*);
  47     }
  48 }
  49
  50 macro intrinsic_match {
  51     ($fx:expr, $intrinsic:expr, $substs:expr, $args:expr,
  52     _ => $unknown:block;
  53     $(
  54         $($($name:tt).*)|+ $(if $cond:expr)?, $(<$($subst:ident),*>)? ($($a:ident $arg:ident),*) $content:block;
  55     )*) => {
  56         let _ = $substs; // Silence warning when substs is unused.
  57         match $intrinsic {
  58             $(
  59                 $(intrinsic_pat!($($name).*))|* $(if $cond)? => {
  60                     #[allow(unused_parens, non_snake_case)]
  61                     {
  62                         $(
  63                             intrinsic_substs!($substs, 0, $($subst),*);
  64                         )?
  65                         if let [$($arg),*] = $args {
  66                             let ($($arg,)*) = (
  67                                 $(intrinsic_arg!($a $fx, $arg),)*
  68                             );
  69                             #[warn(unused_parens, non_snake_case)]
  70                             {
  71                                 $content
  72                             }
  73                         } else {
  74                             bug!("wrong number of args for intrinsic {:?}", $intrinsic);
  75                         }
  76                     }
  77                 }
  78             )*
  79             _ => $unknown,
  80         }
  81     }
  82 }
  83
  84 macro call_intrinsic_match {
  85     ($fx:expr, $intrinsic:expr, $substs:expr, $ret:expr, $destination:expr, $args:expr, $(
  86         $name:ident($($arg:ident),*) -> $ty:ident => $func:ident,
  87     )*) => {
  88         match $intrinsic {
  89             $(
  90                 stringify!($name) => {
  91                     assert!($substs.is_noop());
  92                     if let [$(ref $arg),*] = *$args {
  93                         let ($($arg,)*) = (
  94                             $(codegen_operand($fx, $arg),)*
  95                         );
  96                         let res = $fx.easy_call(stringify!($func), &[$($arg),*], $fx.tcx.types.$ty);
  97                         $ret.write_cvalue($fx, res);
  98
  99                         if let Some((_, dest)) = $destination {
 100                             let ret_block = $fx.get_block(dest);
 101                             $fx.bcx.ins().jump(ret_block, &[]);
 102                             return;
 103                         } else {
 104                             unreachable!();
 105                         }
 106                     } else {
 107                         bug!("wrong number of args for intrinsic {:?}", $intrinsic);
 108                     }
 109                 }
 110             )*
 111             _ => {}
 112         }
 113     }
 114 }
 115
 116 macro validate_atomic_type($fx:ident, $intrinsic:ident, $span:ident, $ty:expr) {
 117     match $ty.kind() {
 118         ty::Uint(_) | ty::Int(_) | ty::RawPtr(..) => {}
 119         _ => {
 120             $fx.tcx.sess.span_err(
 121                 $span,
 122                 &format!(
 123                     "`{}` intrinsic: expected basic integer or raw pointer type, found `{:?}`",
 124                     $intrinsic, $ty
 125                 ),
 126             );
 127             // Prevent verifier error
 128             crate::trap::trap_unreachable($fx, "compilation should not have succeeded");
 129             return;
 130         }
 131     }
 132 }
 133
 134 macro validate_simd_type($fx:ident, $intrinsic:ident, $span:ident, $ty:expr) {
 135     if !$ty.is_simd() {
 136         $fx.tcx.sess.span_err($span, &format!("invalid monomorphization of `{}` intrinsic: expected SIMD input type, found non-SIMD `{}`", $intrinsic, $ty));
 137         // Prevent verifier error
 138         crate::trap::trap_unreachable($fx, "compilation should not have succeeded");
 139         return;
 140     }
 141 }
 142
 143 pub(crate) fn clif_vector_type<'tcx>(tcx: TyCtxt<'tcx>, layout: TyAndLayout<'tcx>) -> Option<Type> {
 144     let (element, count) = match &layout.abi {
 145         Abi::Vector { element, count } => (element.clone(), *count),
 146         _ => unreachable!(),
 147     };
 148
 149     match scalar_to_clif_type(tcx, element).by(u16::try_from(count).unwrap()) {
 150         // Cranelift currently only implements icmp for 128bit vectors.
 151         Some(vector_ty) if vector_ty.bits() == 128 => Some(vector_ty),
 152         _ => None,
 153     }
 154 }
 155
 156 fn simd_for_each_lane<'tcx>(
 157     fx: &mut FunctionCx<'_, '_, 'tcx>,
 158     val: CValue<'tcx>,
 159     ret: CPlace<'tcx>,
 160     f: impl Fn(
 161         &mut FunctionCx<'_, '_, 'tcx>,
 162         TyAndLayout<'tcx>,
 163         TyAndLayout<'tcx>,
 164         Value,
 165     ) -> CValue<'tcx>,
 166 ) {
 167     let layout = val.layout();
 168
 169     let (lane_count, lane_ty) = layout.ty.simd_size_and_type(fx.tcx);
 170     let lane_layout = fx.layout_of(lane_ty);
 171     let (ret_lane_count, ret_lane_ty) = ret.layout().ty.simd_size_and_type(fx.tcx);
 172     let ret_lane_layout = fx.layout_of(ret_lane_ty);
 173     assert_eq!(lane_count, ret_lane_count);
 174
 175     for lane_idx in 0..lane_count {
 176         let lane_idx = mir::Field::new(lane_idx.try_into().unwrap());
 177         let lane = val.value_field(fx, lane_idx).load_scalar(fx);
 178
 179         let res_lane = f(fx, lane_layout, ret_lane_layout, lane);
 180
 181         ret.place_field(fx, lane_idx).write_cvalue(fx, res_lane);
 182     }
 183 }
 184
 185 fn simd_pair_for_each_lane<'tcx>(
 186     fx: &mut FunctionCx<'_, '_, 'tcx>,
 187     x: CValue<'tcx>,
 188     y: CValue<'tcx>,
 189     ret: CPlace<'tcx>,
 190     f: impl Fn(
 191         &mut FunctionCx<'_, '_, 'tcx>,
 192         TyAndLayout<'tcx>,
 193         TyAndLayout<'tcx>,
 194         Value,
 195         Value,
 196     ) -> CValue<'tcx>,
 197 ) {
 198     assert_eq!(x.layout(), y.layout());
 199     let layout = x.layout();
 200
 201     let (lane_count, lane_ty) = layout.ty.simd_size_and_type(fx.tcx);
 202     let lane_layout = fx.layout_of(lane_ty);
 203     let (ret_lane_count, ret_lane_ty) = ret.layout().ty.simd_size_and_type(fx.tcx);
 204     let ret_lane_layout = fx.layout_of(ret_lane_ty);
 205     assert_eq!(lane_count, ret_lane_count);
 206
 207     for lane in 0..lane_count {
 208         let lane = mir::Field::new(lane.try_into().unwrap());
 209         let x_lane = x.value_field(fx, lane).load_scalar(fx);
 210         let y_lane = y.value_field(fx, lane).load_scalar(fx);
 211
 212         let res_lane = f(fx, lane_layout, ret_lane_layout, x_lane, y_lane);
 213
 214         ret.place_field(fx, lane).write_cvalue(fx, res_lane);
 215     }
 216 }
 217
 218 fn simd_reduce<'tcx>(
 219     fx: &mut FunctionCx<'_, '_, 'tcx>,
 220     val: CValue<'tcx>,
 221     ret: CPlace<'tcx>,
 222     f: impl Fn(&mut FunctionCx<'_, '_, 'tcx>, TyAndLayout<'tcx>, Value, Value) -> Value,
 223 ) {
 224     let (lane_count, lane_ty) = val.layout().ty.simd_size_and_type(fx.tcx);
 225     let lane_layout = fx.layout_of(lane_ty);
 226     assert_eq!(lane_layout, ret.layout());
 227
 228     let mut res_val = val.value_field(fx, mir::Field::new(0)).load_scalar(fx);
 229     for lane_idx in 1..lane_count {
 230         let lane =
 231             val.value_field(fx, mir::Field::new(lane_idx.try_into().unwrap())).load_scalar(fx);
 232         res_val = f(fx, lane_layout, res_val, lane);
 233     }
 234     let res = CValue::by_val(res_val, lane_layout);
 235     ret.write_cvalue(fx, res);
 236 }
 237
 238 fn simd_reduce_bool<'tcx>(
 239     fx: &mut FunctionCx<'_, '_, 'tcx>,
 240     val: CValue<'tcx>,
 241     ret: CPlace<'tcx>,
 242     f: impl Fn(&mut FunctionCx<'_, '_, 'tcx>, Value, Value) -> Value,
 243 ) {
 244     let (lane_count, _lane_ty) = val.layout().ty.simd_size_and_type(fx.tcx);
 245     assert!(ret.layout().ty.is_bool());
 246
 247     let res_val = val.value_field(fx, mir::Field::new(0)).load_scalar(fx);
 248     let mut res_val = fx.bcx.ins().band_imm(res_val, 1); // mask to boolean
 249     for lane_idx in 1..lane_count {
 250         let lane =
 251             val.value_field(fx, mir::Field::new(lane_idx.try_into().unwrap())).load_scalar(fx);
 252         let lane = fx.bcx.ins().band_imm(lane, 1); // mask to boolean
 253         res_val = f(fx, res_val, lane);
 254     }
 255     let res = CValue::by_val(res_val, ret.layout());
 256     ret.write_cvalue(fx, res);
 257 }
 258
 259 fn bool_to_zero_or_max_uint<'tcx>(
 260     fx: &mut FunctionCx<'_, '_, 'tcx>,
 261     layout: TyAndLayout<'tcx>,
 262     val: Value,
 263 ) -> CValue<'tcx> {
 264     let ty = fx.clif_type(layout.ty).unwrap();
 265
 266     let int_ty = match ty {
 267         types::F32 => types::I32,
 268         types::F64 => types::I64,
 269         ty => ty,
 270     };
 271
 272     let val = fx.bcx.ins().bint(int_ty, val);
 273     let mut res = fx.bcx.ins().ineg(val);
 274
 275     if ty.is_float() {
 276         res = fx.bcx.ins().bitcast(ty, res);
 277     }
 278
 279     CValue::by_val(res, layout)
 280 }
 281
 282 macro simd_cmp {
 283     ($fx:expr, $cc:ident|$cc_f:ident($x:ident, $y:ident) -> $ret:ident) => {
 284         let vector_ty = clif_vector_type($fx.tcx, $x.layout());
 285
 286         if let Some(vector_ty) = vector_ty {
 287             let x = $x.load_scalar($fx);
 288             let y = $y.load_scalar($fx);
 289             let val = $fx.bcx.ins().icmp(IntCC::$cc, x, y);
 290
 291             // HACK This depends on the fact that icmp for vectors represents bools as 0 and !0, not 0 and 1.
 292             let val = $fx.bcx.ins().raw_bitcast(vector_ty, val);
 293
 294             $ret.write_cvalue($fx, CValue::by_val(val, $ret.layout()));
 295         } else {
 296             simd_pair_for_each_lane(
 297                 $fx,
 298                 $x,
 299                 $y,
 300                 $ret,
 301                 |fx, lane_layout, res_lane_layout, x_lane, y_lane| {
 302                     let res_lane = match lane_layout.ty.kind() {
 303                         ty::Uint(_) | ty::Int(_) => fx.bcx.ins().icmp(IntCC::$cc, x_lane, y_lane),
 304                         ty::Float(_) => fx.bcx.ins().fcmp(FloatCC::$cc_f, x_lane, y_lane),
 305                         _ => unreachable!("{:?}", lane_layout.ty),
 306                     };
 307                     bool_to_zero_or_max_uint(fx, res_lane_layout, res_lane)
 308                 },
 309             );
 310         }
 311     },
 312     ($fx:expr, $cc_u:ident|$cc_s:ident|$cc_f:ident($x:ident, $y:ident) -> $ret:ident) => {
 313         // FIXME use vector icmp when possible
 314         simd_pair_for_each_lane(
 315             $fx,
 316             $x,
 317             $y,
 318             $ret,
 319             |fx, lane_layout, res_lane_layout, x_lane, y_lane| {
 320                 let res_lane = match lane_layout.ty.kind() {
 321                     ty::Uint(_) => fx.bcx.ins().icmp(IntCC::$cc_u, x_lane, y_lane),
 322                     ty::Int(_) => fx.bcx.ins().icmp(IntCC::$cc_s, x_lane, y_lane),
 323                     ty::Float(_) => fx.bcx.ins().fcmp(FloatCC::$cc_f, x_lane, y_lane),
 324                     _ => unreachable!("{:?}", lane_layout.ty),
 325                 };
 326                 bool_to_zero_or_max_uint(fx, res_lane_layout, res_lane)
 327             },
 328         );
 329     },
 330 }
 331
 332 macro simd_int_binop {
 333     ($fx:expr, $op:ident($x:ident, $y:ident) -> $ret:ident) => {
 334         simd_int_binop!($fx, $op|$op($x, $y) -> $ret);
 335     },
 336     ($fx:expr, $op_u:ident|$op_s:ident($x:ident, $y:ident) -> $ret:ident) => {
 337         simd_pair_for_each_lane(
 338             $fx,
 339             $x,
 340             $y,
 341             $ret,
 342             |fx, lane_layout, ret_lane_layout, x_lane, y_lane| {
 343                 let res_lane = match lane_layout.ty.kind() {
 344                     ty::Uint(_) => fx.bcx.ins().$op_u(x_lane, y_lane),
 345                     ty::Int(_) => fx.bcx.ins().$op_s(x_lane, y_lane),
 346                     _ => unreachable!("{:?}", lane_layout.ty),
 347                 };
 348                 CValue::by_val(res_lane, ret_lane_layout)
 349             },
 350         );
 351     },
 352 }
 353
 354 macro simd_int_flt_binop {
 355     ($fx:expr, $op:ident|$op_f:ident($x:ident, $y:ident) -> $ret:ident) => {
 356         simd_int_flt_binop!($fx, $op|$op|$op_f($x, $y) -> $ret);
 357     },
 358     ($fx:expr, $op_u:ident|$op_s:ident|$op_f:ident($x:ident, $y:ident) -> $ret:ident) => {
 359         simd_pair_for_each_lane(
 360             $fx,
 361             $x,
 362             $y,
 363             $ret,
 364             |fx, lane_layout, ret_lane_layout, x_lane, y_lane| {
 365                 let res_lane = match lane_layout.ty.kind() {
 366                     ty::Uint(_) => fx.bcx.ins().$op_u(x_lane, y_lane),
 367                     ty::Int(_) => fx.bcx.ins().$op_s(x_lane, y_lane),
 368                     ty::Float(_) => fx.bcx.ins().$op_f(x_lane, y_lane),
 369                     _ => unreachable!("{:?}", lane_layout.ty),
 370                 };
 371                 CValue::by_val(res_lane, ret_lane_layout)
 372             },
 373         );
 374     },
 375 }
 376
 377 macro simd_flt_binop($fx:expr, $op:ident($x:ident, $y:ident) -> $ret:ident) {
 378     simd_pair_for_each_lane(
 379         $fx,
 380         $x,
 381         $y,
 382         $ret,
 383         |fx, lane_layout, ret_lane_layout, x_lane, y_lane| {
 384             let res_lane = match lane_layout.ty.kind() {
 385                 ty::Float(_) => fx.bcx.ins().$op(x_lane, y_lane),
 386                 _ => unreachable!("{:?}", lane_layout.ty),
 387             };
 388             CValue::by_val(res_lane, ret_lane_layout)
 389         },
 390     );
 391 }
 392
 393 pub(crate) fn codegen_intrinsic_call<'tcx>(
 394     fx: &mut FunctionCx<'_, '_, 'tcx>,
 395     instance: Instance<'tcx>,
 396     args: &[mir::Operand<'tcx>],
 397     destination: Option<(CPlace<'tcx>, BasicBlock)>,
 398     span: Span,
 399 ) {
 400     let def_id = instance.def_id();
 401     let substs = instance.substs;
 402
 403     let intrinsic = fx.tcx.item_name(def_id).as_str();
 404     let intrinsic = &intrinsic[..];
 405
 406     let ret = match destination {
 407         Some((place, _)) => place,
 408         None => {
 409             // Insert non returning intrinsics here
 410             match intrinsic {
 411                 "abort" => {
 412                     trap_abort(fx, "Called intrinsic::abort.");
 413                 }
 414                 "transmute" => {
 415                     crate::base::codegen_panic(fx, "Transmuting to uninhabited type.", span);
 416                 }
 417                 _ => unimplemented!("unsupported instrinsic {}", intrinsic),
 418             }
 419             return;
 420         }
 421     };
 422
 423     if intrinsic.starts_with("simd_") {
 424         self::simd::codegen_simd_intrinsic_call(fx, instance, args, ret, span);
 425         let ret_block = fx.get_block(destination.expect("SIMD intrinsics don't diverge").1);
 426         fx.bcx.ins().jump(ret_block, &[]);
 427         return;
 428     }
 429
 430     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 431
 432     call_intrinsic_match! {
 433         fx, intrinsic, substs, ret, destination, args,
 434         expf32(flt) -> f32 => expf,
 435         expf64(flt) -> f64 => exp,
 436         exp2f32(flt) -> f32 => exp2f,
 437         exp2f64(flt) -> f64 => exp2,
 438         sqrtf32(flt) -> f32 => sqrtf,
 439         sqrtf64(flt) -> f64 => sqrt,
 440         powif32(a, x) -> f32 => __powisf2, // compiler-builtins
 441         powif64(a, x) -> f64 => __powidf2, // compiler-builtins
 442         powf32(a, x) -> f32 => powf,
 443         powf64(a, x) -> f64 => pow,
 444         logf32(flt) -> f32 => logf,
 445         logf64(flt) -> f64 => log,
 446         log2f32(flt) -> f32 => log2f,
 447         log2f64(flt) -> f64 => log2,
 448         log10f32(flt) -> f32 => log10f,
 449         log10f64(flt) -> f64 => log10,
 450         fabsf32(flt) -> f32 => fabsf,
 451         fabsf64(flt) -> f64 => fabs,
 452         fmaf32(x, y, z) -> f32 => fmaf,
 453         fmaf64(x, y, z) -> f64 => fma,
 454         copysignf32(x, y) -> f32 => copysignf,
 455         copysignf64(x, y) -> f64 => copysign,
 456
 457         // rounding variants
 458         // FIXME use clif insts
 459         floorf32(flt) -> f32 => floorf,
 460         floorf64(flt) -> f64 => floor,
 461         ceilf32(flt) -> f32 => ceilf,
 462         ceilf64(flt) -> f64 => ceil,
 463         truncf32(flt) -> f32 => truncf,
 464         truncf64(flt) -> f64 => trunc,
 465         roundf32(flt) -> f32 => roundf,
 466         roundf64(flt) -> f64 => round,
 467
 468         // trigonometry
 469         sinf32(flt) -> f32 => sinf,
 470         sinf64(flt) -> f64 => sin,
 471         cosf32(flt) -> f32 => cosf,
 472         cosf64(flt) -> f64 => cos,
 473         tanf32(flt) -> f32 => tanf,
 474         tanf64(flt) -> f64 => tan,
 475     }
 476
 477     intrinsic_match! {
 478         fx, intrinsic, substs, args,
 479         _ => {
 480             fx.tcx.sess.span_fatal(span, &format!("unsupported intrinsic {}", intrinsic));
 481         };
 482
 483         assume, (c _a) {};
 484         likely | unlikely, (c a) {
 485             ret.write_cvalue(fx, a);
 486         };
 487         breakpoint, () {
 488             fx.bcx.ins().debugtrap();
 489         };
 490         copy | copy_nonoverlapping, <elem_ty> (v src, v dst, v count) {
 491             let elem_size: u64 = fx.layout_of(elem_ty).size.bytes();
 492             assert_eq!(args.len(), 3);
 493             let byte_amount = if elem_size != 1 {
 494                 fx.bcx.ins().imul_imm(count, elem_size as i64)
 495             } else {
 496                 count
 497             };
 498
 499             if intrinsic.contains("nonoverlapping") {
 500                 // FIXME emit_small_memcpy
 501                 fx.bcx.call_memcpy(fx.module.target_config(), dst, src, byte_amount);
 502             } else {
 503                 // FIXME emit_small_memmove
 504                 fx.bcx.call_memmove(fx.module.target_config(), dst, src, byte_amount);
 505             }
 506         };
 507         // NOTE: the volatile variants have src and dst swapped
 508         volatile_copy_memory | volatile_copy_nonoverlapping_memory, <elem_ty> (v dst, v src, v count) {
 509             let elem_size: u64 = fx.layout_of(elem_ty).size.bytes();
 510             assert_eq!(args.len(), 3);
 511             let byte_amount = if elem_size != 1 {
 512                 fx.bcx.ins().imul_imm(count, elem_size as i64)
 513             } else {
 514                 count
 515             };
 516
 517             // FIXME make the copy actually volatile when using emit_small_mem{cpy,move}
 518             if intrinsic.contains("nonoverlapping") {
 519                 // FIXME emit_small_memcpy
 520                 fx.bcx.call_memcpy(fx.module.target_config(), dst, src, byte_amount);
 521             } else {
 522                 // FIXME emit_small_memmove
 523                 fx.bcx.call_memmove(fx.module.target_config(), dst, src, byte_amount);
 524             }
 525         };
 526         size_of_val, <T> (c ptr) {
 527             let layout = fx.layout_of(T);
 528             let size = if layout.is_unsized() {
 529                 let (_ptr, info) = ptr.load_scalar_pair(fx);
 530                 let (size, _align) = crate::unsize::size_and_align_of_dst(fx, layout, info);
 531                 size
 532             } else {
 533                 fx
 534                     .bcx
 535                     .ins()
 536                     .iconst(fx.pointer_type, layout.size.bytes() as i64)
 537             };
 538             ret.write_cvalue(fx, CValue::by_val(size, usize_layout));
 539         };
 540         min_align_of_val, <T> (c ptr) {
 541             let layout = fx.layout_of(T);
 542             let align = if layout.is_unsized() {
 543                 let (_ptr, info) = ptr.load_scalar_pair(fx);
 544                 let (_size, align) = crate::unsize::size_and_align_of_dst(fx, layout, info);
 545                 align
 546             } else {
 547                 fx
 548                     .bcx
 549                     .ins()
 550                     .iconst(fx.pointer_type, layout.align.abi.bytes() as i64)
 551             };
 552             ret.write_cvalue(fx, CValue::by_val(align, usize_layout));
 553         };
 554
 555         _ if intrinsic.starts_with("unchecked_") || intrinsic == "exact_div", (c x, c y) {
 556             // FIXME trap on overflow
 557             let bin_op = match intrinsic {
 558                 "unchecked_add" => BinOp::Add,
 559                 "unchecked_sub" => BinOp::Sub,
 560                 "unchecked_div" | "exact_div" => BinOp::Div,
 561                 "unchecked_rem" => BinOp::Rem,
 562                 "unchecked_shl" => BinOp::Shl,
 563                 "unchecked_shr" => BinOp::Shr,
 564                 _ => unreachable!("intrinsic {}", intrinsic),
 565             };
 566             let res = crate::num::codegen_int_binop(fx, bin_op, x, y);
 567             ret.write_cvalue(fx, res);
 568         };
 569         _ if intrinsic.ends_with("_with_overflow"), (c x, c y) {
 570             assert_eq!(x.layout().ty, y.layout().ty);
 571             let bin_op = match intrinsic {
 572                 "add_with_overflow" => BinOp::Add,
 573                 "sub_with_overflow" => BinOp::Sub,
 574                 "mul_with_overflow" => BinOp::Mul,
 575                 _ => unreachable!("intrinsic {}", intrinsic),
 576             };
 577
 578             let res = crate::num::codegen_checked_int_binop(
 579                 fx,
 580                 bin_op,
 581                 x,
 582                 y,
 583             );
 584             ret.write_cvalue(fx, res);
 585         };
 586         _ if intrinsic.starts_with("saturating_"), <T> (c lhs, c rhs) {
 587             assert_eq!(lhs.layout().ty, rhs.layout().ty);
 588             let bin_op = match intrinsic {
 589                 "saturating_add" => BinOp::Add,
 590                 "saturating_sub" => BinOp::Sub,
 591                 _ => unreachable!("intrinsic {}", intrinsic),
 592             };
 593
 594             let signed = type_sign(T);
 595
 596             let checked_res = crate::num::codegen_checked_int_binop(
 597                 fx,
 598                 bin_op,
 599                 lhs,
 600                 rhs,
 601             );
 602
 603             let (val, has_overflow) = checked_res.load_scalar_pair(fx);
 604             let clif_ty = fx.clif_type(T).unwrap();
 605
 606             // `select.i8` is not implemented by Cranelift.
 607             let has_overflow = fx.bcx.ins().uextend(types::I32, has_overflow);
 608
 609             let (min, max) = type_min_max_value(&mut fx.bcx, clif_ty, signed);
 610
 611             let val = match (intrinsic, signed) {
 612                 ("saturating_add", false) => fx.bcx.ins().select(has_overflow, max, val),
 613                 ("saturating_sub", false) => fx.bcx.ins().select(has_overflow, min, val),
 614                 ("saturating_add", true) => {
 615                     let rhs = rhs.load_scalar(fx);
 616                     let rhs_ge_zero = fx.bcx.ins().icmp_imm(IntCC::SignedGreaterThanOrEqual, rhs, 0);
 617                     let sat_val = fx.bcx.ins().select(rhs_ge_zero, max, min);
 618                     fx.bcx.ins().select(has_overflow, sat_val, val)
 619                 }
 620                 ("saturating_sub", true) => {
 621                     let rhs = rhs.load_scalar(fx);
 622                     let rhs_ge_zero = fx.bcx.ins().icmp_imm(IntCC::SignedGreaterThanOrEqual, rhs, 0);
 623                     let sat_val = fx.bcx.ins().select(rhs_ge_zero, min, max);
 624                     fx.bcx.ins().select(has_overflow, sat_val, val)
 625                 }
 626                 _ => unreachable!(),
 627             };
 628
 629             let res = CValue::by_val(val, fx.layout_of(T));
 630
 631             ret.write_cvalue(fx, res);
 632         };
 633         rotate_left, <T>(v x, v y) {
 634             let layout = fx.layout_of(T);
 635             let res = fx.bcx.ins().rotl(x, y);
 636             ret.write_cvalue(fx, CValue::by_val(res, layout));
 637         };
 638         rotate_right, <T>(v x, v y) {
 639             let layout = fx.layout_of(T);
 640             let res = fx.bcx.ins().rotr(x, y);
 641             ret.write_cvalue(fx, CValue::by_val(res, layout));
 642         };
 643
 644         // The only difference between offset and arith_offset is regarding UB. Because Cranelift
 645         // doesn't have UB both are codegen'ed the same way
 646         offset | arith_offset, (c base, v offset) {
 647             let pointee_ty = base.layout().ty.builtin_deref(true).unwrap().ty;
 648             let pointee_size = fx.layout_of(pointee_ty).size.bytes();
 649             let ptr_diff = if pointee_size != 1 {
 650                 fx.bcx.ins().imul_imm(offset, pointee_size as i64)
 651             } else {
 652                 offset
 653             };
 654             let base_val = base.load_scalar(fx);
 655             let res = fx.bcx.ins().iadd(base_val, ptr_diff);
 656             ret.write_cvalue(fx, CValue::by_val(res, base.layout()));
 657         };
 658
 659         transmute, (c from) {
 660             ret.write_cvalue_transmute(fx, from);
 661         };
 662         write_bytes | volatile_set_memory, (c dst, v val, v count) {
 663             let pointee_ty = dst.layout().ty.builtin_deref(true).unwrap().ty;
 664             let pointee_size = fx.layout_of(pointee_ty).size.bytes();
 665             let count = if pointee_size != 1 {
 666                 fx.bcx.ins().imul_imm(count, pointee_size as i64)
 667             } else {
 668                 count
 669             };
 670             let dst_ptr = dst.load_scalar(fx);
 671             // FIXME make the memset actually volatile when switching to emit_small_memset
 672             // FIXME use emit_small_memset
 673             fx.bcx.call_memset(fx.module.target_config(), dst_ptr, val, count);
 674         };
 675         ctlz | ctlz_nonzero, <T> (v arg) {
 676             // FIXME trap on `ctlz_nonzero` with zero arg.
 677             let res = if T == fx.tcx.types.u128 || T == fx.tcx.types.i128 {
 678                 // FIXME verify this algorithm is correct
 679                 let (lsb, msb) = fx.bcx.ins().isplit(arg);
 680                 let lsb_lz = fx.bcx.ins().clz(lsb);
 681                 let msb_lz = fx.bcx.ins().clz(msb);
 682                 let msb_is_zero = fx.bcx.ins().icmp_imm(IntCC::Equal, msb, 0);
 683                 let lsb_lz_plus_64 = fx.bcx.ins().iadd_imm(lsb_lz, 64);
 684                 let res = fx.bcx.ins().select(msb_is_zero, lsb_lz_plus_64, msb_lz);
 685                 fx.bcx.ins().uextend(types::I128, res)
 686             } else {
 687                 fx.bcx.ins().clz(arg)
 688             };
 689             let res = CValue::by_val(res, fx.layout_of(T));
 690             ret.write_cvalue(fx, res);
 691         };
 692         cttz | cttz_nonzero, <T> (v arg) {
 693             // FIXME trap on `cttz_nonzero` with zero arg.
 694             let res = if T == fx.tcx.types.u128 || T == fx.tcx.types.i128 {
 695                 // FIXME verify this algorithm is correct
 696                 let (lsb, msb) = fx.bcx.ins().isplit(arg);
 697                 let lsb_tz = fx.bcx.ins().ctz(lsb);
 698                 let msb_tz = fx.bcx.ins().ctz(msb);
 699                 let lsb_is_zero = fx.bcx.ins().icmp_imm(IntCC::Equal, lsb, 0);
 700                 let msb_tz_plus_64 = fx.bcx.ins().iadd_imm(msb_tz, 64);
 701                 let res = fx.bcx.ins().select(lsb_is_zero, msb_tz_plus_64, lsb_tz);
 702                 fx.bcx.ins().uextend(types::I128, res)
 703             } else {
 704                 fx.bcx.ins().ctz(arg)
 705             };
 706             let res = CValue::by_val(res, fx.layout_of(T));
 707             ret.write_cvalue(fx, res);
 708         };
 709         ctpop, <T> (v arg) {
 710             let res = fx.bcx.ins().popcnt(arg);
 711             let res = CValue::by_val(res, fx.layout_of(T));
 712             ret.write_cvalue(fx, res);
 713         };
 714         bitreverse, <T> (v arg) {
 715             let res = fx.bcx.ins().bitrev(arg);
 716             let res = CValue::by_val(res, fx.layout_of(T));
 717             ret.write_cvalue(fx, res);
 718         };
 719         bswap, <T> (v arg) {
 720             // FIXME(CraneStation/cranelift#794) add bswap instruction to cranelift
 721             fn swap(bcx: &mut FunctionBuilder<'_>, v: Value) -> Value {
 722                 match bcx.func.dfg.value_type(v) {
 723                     types::I8 => v,
 724
 725                     // https://code.woboq.org/gcc/include/bits/byteswap.h.html
 726                     types::I16 => {
 727                         let tmp1 = bcx.ins().ishl_imm(v, 8);
 728                         let n1 = bcx.ins().band_imm(tmp1, 0xFF00);
 729
 730                         let tmp2 = bcx.ins().ushr_imm(v, 8);
 731                         let n2 = bcx.ins().band_imm(tmp2, 0x00FF);
 732
 733                         bcx.ins().bor(n1, n2)
 734                     }
 735                     types::I32 => {
 736                         let tmp1 = bcx.ins().ishl_imm(v, 24);
 737                         let n1 = bcx.ins().band_imm(tmp1, 0xFF00_0000);
 738
 739                         let tmp2 = bcx.ins().ishl_imm(v, 8);
 740                         let n2 = bcx.ins().band_imm(tmp2, 0x00FF_0000);
 741
 742                         let tmp3 = bcx.ins().ushr_imm(v, 8);
 743                         let n3 = bcx.ins().band_imm(tmp3, 0x0000_FF00);
 744
 745                         let tmp4 = bcx.ins().ushr_imm(v, 24);
 746                         let n4 = bcx.ins().band_imm(tmp4, 0x0000_00FF);
 747
 748                         let or_tmp1 = bcx.ins().bor(n1, n2);
 749                         let or_tmp2 = bcx.ins().bor(n3, n4);
 750                         bcx.ins().bor(or_tmp1, or_tmp2)
 751                     }
 752                     types::I64 => {
 753                         let tmp1 = bcx.ins().ishl_imm(v, 56);
 754                         let n1 = bcx.ins().band_imm(tmp1, 0xFF00_0000_0000_0000u64 as i64);
 755
 756                         let tmp2 = bcx.ins().ishl_imm(v, 40);
 757                         let n2 = bcx.ins().band_imm(tmp2, 0x00FF_0000_0000_0000u64 as i64);
 758
 759                         let tmp3 = bcx.ins().ishl_imm(v, 24);
 760                         let n3 = bcx.ins().band_imm(tmp3, 0x0000_FF00_0000_0000u64 as i64);
 761
 762                         let tmp4 = bcx.ins().ishl_imm(v, 8);
 763                         let n4 = bcx.ins().band_imm(tmp4, 0x0000_00FF_0000_0000u64 as i64);
 764
 765                         let tmp5 = bcx.ins().ushr_imm(v, 8);
 766                         let n5 = bcx.ins().band_imm(tmp5, 0x0000_0000_FF00_0000u64 as i64);
 767
 768                         let tmp6 = bcx.ins().ushr_imm(v, 24);
 769                         let n6 = bcx.ins().band_imm(tmp6, 0x0000_0000_00FF_0000u64 as i64);
 770
 771                         let tmp7 = bcx.ins().ushr_imm(v, 40);
 772                         let n7 = bcx.ins().band_imm(tmp7, 0x0000_0000_0000_FF00u64 as i64);
 773
 774                         let tmp8 = bcx.ins().ushr_imm(v, 56);
 775                         let n8 = bcx.ins().band_imm(tmp8, 0x0000_0000_0000_00FFu64 as i64);
 776
 777                         let or_tmp1 = bcx.ins().bor(n1, n2);
 778                         let or_tmp2 = bcx.ins().bor(n3, n4);
 779                         let or_tmp3 = bcx.ins().bor(n5, n6);
 780                         let or_tmp4 = bcx.ins().bor(n7, n8);
 781
 782                         let or_tmp5 = bcx.ins().bor(or_tmp1, or_tmp2);
 783                         let or_tmp6 = bcx.ins().bor(or_tmp3, or_tmp4);
 784                         bcx.ins().bor(or_tmp5, or_tmp6)
 785                     }
 786                     types::I128 => {
 787                         let (lo, hi) = bcx.ins().isplit(v);
 788                         let lo = swap(bcx, lo);
 789                         let hi = swap(bcx, hi);
 790                         bcx.ins().iconcat(hi, lo)
 791                     }
 792                     ty => unreachable!("bswap {}", ty),
 793                 }
 794             }
 795             let res = CValue::by_val(swap(&mut fx.bcx, arg), fx.layout_of(T));
 796             ret.write_cvalue(fx, res);
 797         };
 798         assert_inhabited | assert_zero_valid | assert_uninit_valid, <T> () {
 799             let layout = fx.layout_of(T);
 800             if layout.abi.is_uninhabited() {
 801                 with_no_trimmed_paths(|| crate::base::codegen_panic(
 802                     fx,
 803                     &format!("attempted to instantiate uninhabited type `{}`", T),
 804                     span,
 805                 ));
 806                 return;
 807             }
 808
 809             if intrinsic == "assert_zero_valid" && !layout.might_permit_raw_init(fx, /*zero:*/ true).unwrap() {
 810                 with_no_trimmed_paths(|| crate::base::codegen_panic(
 811                     fx,
 812                     &format!("attempted to zero-initialize type `{}`, which is invalid", T),
 813                     span,
 814                 ));
 815                 return;
 816             }
 817
 818             if intrinsic == "assert_uninit_valid" && !layout.might_permit_raw_init(fx, /*zero:*/ false).unwrap() {
 819                 with_no_trimmed_paths(|| crate::base::codegen_panic(
 820                     fx,
 821                     &format!("attempted to leave type `{}` uninitialized, which is invalid", T),
 822                     span,
 823                 ));
 824                 return;
 825             }
 826         };
 827
 828         volatile_load | unaligned_volatile_load, (c ptr) {
 829             // Cranelift treats loads as volatile by default
 830             // FIXME correctly handle unaligned_volatile_load
 831             let inner_layout =
 832                 fx.layout_of(ptr.layout().ty.builtin_deref(true).unwrap().ty);
 833             let val = CValue::by_ref(Pointer::new(ptr.load_scalar(fx)), inner_layout);
 834             ret.write_cvalue(fx, val);
 835         };
 836         volatile_store | unaligned_volatile_store, (v ptr, c val) {
 837             // Cranelift treats stores as volatile by default
 838             // FIXME correctly handle unaligned_volatile_store
 839             let dest = CPlace::for_ptr(Pointer::new(ptr), val.layout());
 840             dest.write_cvalue(fx, val);
 841         };
 842
 843         pref_align_of | min_align_of | needs_drop | type_id | type_name | variant_count, () {
 844             let const_val =
 845                 fx.tcx.const_eval_instance(ParamEnv::reveal_all(), instance, None).unwrap();
 846             let val = crate::constant::codegen_const_value(
 847                 fx,
 848                 const_val,
 849                 ret.layout().ty,
 850             );
 851             ret.write_cvalue(fx, val);
 852         };
 853
 854         ptr_offset_from, <T> (v ptr, v base) {
 855             let isize_layout = fx.layout_of(fx.tcx.types.isize);
 856
 857             let pointee_size: u64 = fx.layout_of(T).size.bytes();
 858             let diff = fx.bcx.ins().isub(ptr, base);
 859             // FIXME this can be an exact division.
 860             let val = CValue::by_val(fx.bcx.ins().sdiv_imm(diff, pointee_size as i64), isize_layout);
 861             ret.write_cvalue(fx, val);
 862         };
 863
 864         ptr_guaranteed_eq, (c a, c b) {
 865             let val = crate::num::codegen_ptr_binop(fx, BinOp::Eq, a, b);
 866             ret.write_cvalue(fx, val);
 867         };
 868
 869         ptr_guaranteed_ne, (c a, c b) {
 870             let val = crate::num::codegen_ptr_binop(fx, BinOp::Ne, a, b);
 871             ret.write_cvalue(fx, val);
 872         };
 873
 874         caller_location, () {
 875             let caller_location = fx.get_caller_location(span);
 876             ret.write_cvalue(fx, caller_location);
 877         };
 878
 879         _ if intrinsic.starts_with("atomic_fence"), () {
 880             fx.bcx.ins().fence();
 881         };
 882         _ if intrinsic.starts_with("atomic_singlethreadfence"), () {
 883             // FIXME use a compiler fence once Cranelift supports it
 884             fx.bcx.ins().fence();
 885         };
 886         _ if intrinsic.starts_with("atomic_load"), <T> (v ptr) {
 887             validate_atomic_type!(fx, intrinsic, span, T);
 888             let ty = fx.clif_type(T).unwrap();
 889
 890             let val = fx.bcx.ins().atomic_load(ty, MemFlags::trusted(), ptr);
 891
 892             let val = CValue::by_val(val, fx.layout_of(T));
 893             ret.write_cvalue(fx, val);
 894         };
 895         _ if intrinsic.starts_with("atomic_store"), (v ptr, c val) {
 896             validate_atomic_type!(fx, intrinsic, span, val.layout().ty);
 897
 898             let val = val.load_scalar(fx);
 899
 900             fx.bcx.ins().atomic_store(MemFlags::trusted(), val, ptr);
 901         };
 902         _ if intrinsic.starts_with("atomic_xchg"), (v ptr, c new) {
 903             let layout = new.layout();
 904             validate_atomic_type!(fx, intrinsic, span, layout.ty);
 905             let ty = fx.clif_type(layout.ty).unwrap();
 906
 907             let new = new.load_scalar(fx);
 908
 909             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Xchg, ptr, new);
 910
 911             let old = CValue::by_val(old, layout);
 912             ret.write_cvalue(fx, old);
 913         };
 914         _ if intrinsic.starts_with("atomic_cxchg"), (v ptr, c test_old, c new) { // both atomic_cxchg_* and atomic_cxchgweak_*
 915             let layout = new.layout();
 916             validate_atomic_type!(fx, intrinsic, span, layout.ty);
 917
 918             let test_old = test_old.load_scalar(fx);
 919             let new = new.load_scalar(fx);
 920
 921             let old = fx.bcx.ins().atomic_cas(MemFlags::trusted(), ptr, test_old, new);
 922             let is_eq = fx.bcx.ins().icmp(IntCC::Equal, old, test_old);
 923
 924             let ret_val = CValue::by_val_pair(old, fx.bcx.ins().bint(types::I8, is_eq), ret.layout());
 925             ret.write_cvalue(fx, ret_val)
 926         };
 927
 928         _ if intrinsic.starts_with("atomic_xadd"), (v ptr, c amount) {
 929             let layout = amount.layout();
 930             validate_atomic_type!(fx, intrinsic, span, layout.ty);
 931             let ty = fx.clif_type(layout.ty).unwrap();
 932
 933             let amount = amount.load_scalar(fx);
 934
 935             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Add, ptr, amount);
 936
 937             let old = CValue::by_val(old, layout);
 938             ret.write_cvalue(fx, old);
 939         };
 940         _ if intrinsic.starts_with("atomic_xsub"), (v ptr, c amount) {
 941             let layout = amount.layout();
 942             validate_atomic_type!(fx, intrinsic, span, layout.ty);
 943             let ty = fx.clif_type(layout.ty).unwrap();
 944
 945             let amount = amount.load_scalar(fx);
 946
 947             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Sub, ptr, amount);
 948
 949             let old = CValue::by_val(old, layout);
 950             ret.write_cvalue(fx, old);
 951         };
 952         _ if intrinsic.starts_with("atomic_and"), (v ptr, c src) {
 953             let layout = src.layout();
 954             validate_atomic_type!(fx, intrinsic, span, layout.ty);
 955             let ty = fx.clif_type(layout.ty).unwrap();
 956
 957             let src = src.load_scalar(fx);
 958
 959             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::And, ptr, src);
 960
 961             let old = CValue::by_val(old, layout);
 962             ret.write_cvalue(fx, old);
 963         };
 964         _ if intrinsic.starts_with("atomic_or"), (v ptr, c src) {
 965             let layout = src.layout();
 966             validate_atomic_type!(fx, intrinsic, span, layout.ty);
 967             let ty = fx.clif_type(layout.ty).unwrap();
 968
 969             let src = src.load_scalar(fx);
 970
 971             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Or, ptr, src);
 972
 973             let old = CValue::by_val(old, layout);
 974             ret.write_cvalue(fx, old);
 975         };
 976         _ if intrinsic.starts_with("atomic_xor"), (v ptr, c src) {
 977             let layout = src.layout();
 978             validate_atomic_type!(fx, intrinsic, span, layout.ty);
 979             let ty = fx.clif_type(layout.ty).unwrap();
 980
 981             let src = src.load_scalar(fx);
 982
 983             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Xor, ptr, src);
 984
 985             let old = CValue::by_val(old, layout);
 986             ret.write_cvalue(fx, old);
 987         };
 988
 989         // FIXME https://github.com/bytecodealliance/wasmtime/issues/2647
 990         _ if intrinsic.starts_with("atomic_nand"), (v ptr, c src) {
 991             let layout = src.layout();
 992             validate_atomic_type!(fx, intrinsic, span, layout.ty);
 993             let ty = fx.clif_type(layout.ty).unwrap();
 994
 995             let src = src.load_scalar(fx);
 996
 997             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Nand, ptr, src);
 998
 999             let old = CValue::by_val(old, layout);
1000             ret.write_cvalue(fx, old);
1001         };
1002         _ if intrinsic.starts_with("atomic_max"), (v ptr, c src) {
1003             let layout = src.layout();
1004             validate_atomic_type!(fx, intrinsic, span, layout.ty);
1005             let ty = fx.clif_type(layout.ty).unwrap();
1006
1007             let src = src.load_scalar(fx);
1008
1009             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Smax, ptr, src);
1010
1011             let old = CValue::by_val(old, layout);
1012             ret.write_cvalue(fx, old);
1013         };
1014         _ if intrinsic.starts_with("atomic_umax"), (v ptr, c src) {
1015             let layout = src.layout();
1016             validate_atomic_type!(fx, intrinsic, span, layout.ty);
1017             let ty = fx.clif_type(layout.ty).unwrap();
1018
1019             let src = src.load_scalar(fx);
1020
1021             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Umax, ptr, src);
1022
1023             let old = CValue::by_val(old, layout);
1024             ret.write_cvalue(fx, old);
1025         };
1026         _ if intrinsic.starts_with("atomic_min"), (v ptr, c src) {
1027             let layout = src.layout();
1028             validate_atomic_type!(fx, intrinsic, span, layout.ty);
1029             let ty = fx.clif_type(layout.ty).unwrap();
1030
1031             let src = src.load_scalar(fx);
1032
1033             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Smin, ptr, src);
1034
1035             let old = CValue::by_val(old, layout);
1036             ret.write_cvalue(fx, old);
1037         };
1038         _ if intrinsic.starts_with("atomic_umin"), (v ptr, c src) {
1039             let layout = src.layout();
1040             validate_atomic_type!(fx, intrinsic, span, layout.ty);
1041             let ty = fx.clif_type(layout.ty).unwrap();
1042
1043             let src = src.load_scalar(fx);
1044
1045             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Umin, ptr, src);
1046
1047             let old = CValue::by_val(old, layout);
1048             ret.write_cvalue(fx, old);
1049         };
1050
1051         minnumf32, (v a, v b) {
1052             let val = fx.bcx.ins().fmin(a, b);
1053             let val = CValue::by_val(val, fx.layout_of(fx.tcx.types.f32));
1054             ret.write_cvalue(fx, val);
1055         };
1056         minnumf64, (v a, v b) {
1057             let val = fx.bcx.ins().fmin(a, b);
1058             let val = CValue::by_val(val, fx.layout_of(fx.tcx.types.f64));
1059             ret.write_cvalue(fx, val);
1060         };
1061         maxnumf32, (v a, v b) {
1062             let val = fx.bcx.ins().fmax(a, b);
1063             let val = CValue::by_val(val, fx.layout_of(fx.tcx.types.f32));
1064             ret.write_cvalue(fx, val);
1065         };
1066         maxnumf64, (v a, v b) {
1067             let val = fx.bcx.ins().fmax(a, b);
1068             let val = CValue::by_val(val, fx.layout_of(fx.tcx.types.f64));
1069             ret.write_cvalue(fx, val);
1070         };
1071
1072         try, (v f, v data, v _catch_fn) {
1073             // FIXME once unwinding is supported, change this to actually catch panics
1074             let f_sig = fx.bcx.func.import_signature(Signature {
1075                 call_conv: CallConv::triple_default(fx.triple()),
1076                 params: vec![AbiParam::new(fx.bcx.func.dfg.value_type(data))],
1077                 returns: vec![],
1078             });
1079
1080             fx.bcx.ins().call_indirect(f_sig, f, &[data]);
1081
1082             let layout = ret.layout();
1083             let ret_val = CValue::const_val(fx, layout, ty::ScalarInt::null(layout.size));
1084             ret.write_cvalue(fx, ret_val);
1085         };
1086
1087         fadd_fast | fsub_fast | fmul_fast | fdiv_fast | frem_fast, (c x, c y) {
1088             let res = crate::num::codegen_float_binop(fx, match intrinsic {
1089                 "fadd_fast" => BinOp::Add,
1090                 "fsub_fast" => BinOp::Sub,
1091                 "fmul_fast" => BinOp::Mul,
1092                 "fdiv_fast" => BinOp::Div,
1093                 "frem_fast" => BinOp::Rem,
1094                 _ => unreachable!(),
1095             }, x, y);
1096             ret.write_cvalue(fx, res);
1097         };
1098         float_to_int_unchecked, (v f) {
1099             let res = crate::cast::clif_int_or_float_cast(
1100                 fx,
1101                 f,
1102                 false,
1103                 fx.clif_type(ret.layout().ty).unwrap(),
1104                 type_sign(ret.layout().ty),
1105             );
1106             ret.write_cvalue(fx, CValue::by_val(res, ret.layout()));
1107         };
1108     }
1109
1110     if let Some((_, dest)) = destination {
1111         let ret_block = fx.get_block(dest);
1112         fx.bcx.ins().jump(ret_block, &[]);
1113     } else {
1114         trap_unreachable(fx, "[corruption] Diverging intrinsic returned.");
1115     }
1116 }