src/shims/intrinsics.rs

   1 use std::iter;
   2
   3 use log::trace;
   4
   5 use rustc_apfloat::{Float, Round};
   6 use rustc_middle::ty::layout::{IntegerExt, LayoutOf};
   7 use rustc_middle::{mir, mir::BinOp, ty, ty::FloatTy};
   8 use rustc_target::abi::{Align, Integer};
   9
  10 use crate::*;
  11 use helpers::{bool_to_simd_element, check_arg_count, simd_element_to_bool};
  12
  13 pub enum AtomicOp {
  14     MirOp(mir::BinOp, bool),
  15     Max,
  16     Min,
  17 }
  18
  19 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
  20 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
  21     fn call_intrinsic(
  22         &mut self,
  23         instance: ty::Instance<'tcx>,
  24         args: &[OpTy<'tcx, Tag>],
  25         ret: Option<(&PlaceTy<'tcx, Tag>, mir::BasicBlock)>,
  26         _unwind: StackPopUnwind,
  27     ) -> InterpResult<'tcx> {
  28         let this = self.eval_context_mut();
  29
  30         if this.emulate_intrinsic(instance, args, ret)? {
  31             return Ok(());
  32         }
  33
  34         // All supported intrinsics have a return place.
  35         let intrinsic_name = this.tcx.item_name(instance.def_id());
  36         let intrinsic_name = intrinsic_name.as_str();
  37         let (dest, ret) = match ret {
  38             None => throw_unsup_format!("unimplemented (diverging) intrinsic: {}", intrinsic_name),
  39             Some(p) => p,
  40         };
  41
  42         // Then handle terminating intrinsics.
  43         match intrinsic_name {
  44             // Miri overwriting CTFE intrinsics.
  45             "ptr_guaranteed_eq" => {
  46                 let &[ref left, ref right] = check_arg_count(args)?;
  47                 let left = this.read_immediate(left)?;
  48                 let right = this.read_immediate(right)?;
  49                 this.binop_ignore_overflow(mir::BinOp::Eq, &left, &right, dest)?;
  50             }
  51             "ptr_guaranteed_ne" => {
  52                 let &[ref left, ref right] = check_arg_count(args)?;
  53                 let left = this.read_immediate(left)?;
  54                 let right = this.read_immediate(right)?;
  55                 this.binop_ignore_overflow(mir::BinOp::Ne, &left, &right, dest)?;
  56             }
  57             "const_allocate" => {
  58                 // For now, for compatibility with the run-time implementation of this, we just return null.
  59                 // See <https://github.com/rust-lang/rust/issues/93935>.
  60                 this.write_null(dest)?;
  61             }
  62             "const_deallocate" => {
  63                 // complete NOP
  64             }
  65
  66             // Raw memory accesses
  67             "volatile_load" => {
  68                 let &[ref place] = check_arg_count(args)?;
  69                 let place = this.deref_operand(place)?;
  70                 this.copy_op(&place.into(), dest)?;
  71             }
  72             "volatile_store" => {
  73                 let &[ref place, ref dest] = check_arg_count(args)?;
  74                 let place = this.deref_operand(place)?;
  75                 this.copy_op(dest, &place.into())?;
  76             }
  77
  78             "write_bytes" | "volatile_set_memory" => {
  79                 let &[ref ptr, ref val_byte, ref count] = check_arg_count(args)?;
  80                 let ty = instance.substs.type_at(0);
  81                 let ty_layout = this.layout_of(ty)?;
  82                 let val_byte = this.read_scalar(val_byte)?.to_u8()?;
  83                 let ptr = this.read_pointer(ptr)?;
  84                 let count = this.read_scalar(count)?.to_machine_usize(this)?;
  85                 let byte_count = ty_layout.size.checked_mul(count, this).ok_or_else(|| {
  86                     err_ub_format!("overflow computing total size of `{}`", intrinsic_name)
  87                 })?;
  88                 this.memory
  89                     .write_bytes(ptr, iter::repeat(val_byte).take(byte_count.bytes() as usize))?;
  90             }
  91
  92             // Floating-point operations
  93             #[rustfmt::skip]
  94             | "sinf32"
  95             | "fabsf32"
  96             | "cosf32"
  97             | "sqrtf32"
  98             | "expf32"
  99             | "exp2f32"
 100             | "logf32"
 101             | "log10f32"
 102             | "log2f32"
 103             | "floorf32"
 104             | "ceilf32"
 105             | "truncf32"
 106             | "roundf32"
 107             => {
 108                 let &[ref f] = check_arg_count(args)?;
 109                 // FIXME: Using host floats.
 110                 let f = f32::from_bits(this.read_scalar(f)?.to_u32()?);
 111                 let f = match intrinsic_name {
 112                     "sinf32" => f.sin(),
 113                     "fabsf32" => f.abs(),
 114                     "cosf32" => f.cos(),
 115                     "sqrtf32" => f.sqrt(),
 116                     "expf32" => f.exp(),
 117                     "exp2f32" => f.exp2(),
 118                     "logf32" => f.ln(),
 119                     "log10f32" => f.log10(),
 120                     "log2f32" => f.log2(),
 121                     "floorf32" => f.floor(),
 122                     "ceilf32" => f.ceil(),
 123                     "truncf32" => f.trunc(),
 124                     "roundf32" => f.round(),
 125                     _ => bug!(),
 126                 };
 127                 this.write_scalar(Scalar::from_u32(f.to_bits()), dest)?;
 128             }
 129
 130             #[rustfmt::skip]
 131             | "sinf64"
 132             | "fabsf64"
 133             | "cosf64"
 134             | "sqrtf64"
 135             | "expf64"
 136             | "exp2f64"
 137             | "logf64"
 138             | "log10f64"
 139             | "log2f64"
 140             | "floorf64"
 141             | "ceilf64"
 142             | "truncf64"
 143             | "roundf64"
 144             => {
 145                 let &[ref f] = check_arg_count(args)?;
 146                 // FIXME: Using host floats.
 147                 let f = f64::from_bits(this.read_scalar(f)?.to_u64()?);
 148                 let f = match intrinsic_name {
 149                     "sinf64" => f.sin(),
 150                     "fabsf64" => f.abs(),
 151                     "cosf64" => f.cos(),
 152                     "sqrtf64" => f.sqrt(),
 153                     "expf64" => f.exp(),
 154                     "exp2f64" => f.exp2(),
 155                     "logf64" => f.ln(),
 156                     "log10f64" => f.log10(),
 157                     "log2f64" => f.log2(),
 158                     "floorf64" => f.floor(),
 159                     "ceilf64" => f.ceil(),
 160                     "truncf64" => f.trunc(),
 161                     "roundf64" => f.round(),
 162                     _ => bug!(),
 163                 };
 164                 this.write_scalar(Scalar::from_u64(f.to_bits()), dest)?;
 165             }
 166
 167             #[rustfmt::skip]
 168             | "fadd_fast"
 169             | "fsub_fast"
 170             | "fmul_fast"
 171             | "fdiv_fast"
 172             | "frem_fast"
 173             => {
 174                 let &[ref a, ref b] = check_arg_count(args)?;
 175                 let a = this.read_immediate(a)?;
 176                 let b = this.read_immediate(b)?;
 177                 let op = match intrinsic_name {
 178                     "fadd_fast" => mir::BinOp::Add,
 179                     "fsub_fast" => mir::BinOp::Sub,
 180                     "fmul_fast" => mir::BinOp::Mul,
 181                     "fdiv_fast" => mir::BinOp::Div,
 182                     "frem_fast" => mir::BinOp::Rem,
 183                     _ => bug!(),
 184                 };
 185                 let float_finite = |x: ImmTy<'tcx, _>| -> InterpResult<'tcx, bool> {
 186                     Ok(match x.layout.ty.kind() {
 187                         ty::Float(FloatTy::F32) => x.to_scalar()?.to_f32()?.is_finite(),
 188                         ty::Float(FloatTy::F64) => x.to_scalar()?.to_f64()?.is_finite(),
 189                         _ => bug!(
 190                             "`{}` called with non-float input type {:?}",
 191                             intrinsic_name,
 192                             x.layout.ty
 193                         ),
 194                     })
 195                 };
 196                 match (float_finite(a)?, float_finite(b)?) {
 197                     (false, false) => throw_ub_format!(
 198                         "`{}` intrinsic called with non-finite value as both parameters",
 199                         intrinsic_name,
 200                     ),
 201                     (false, _) => throw_ub_format!(
 202                         "`{}` intrinsic called with non-finite value as first parameter",
 203                         intrinsic_name,
 204                     ),
 205                     (_, false) => throw_ub_format!(
 206                         "`{}` intrinsic called with non-finite value as second parameter",
 207                         intrinsic_name,
 208                     ),
 209                     _ => {}
 210                 }
 211                 this.binop_ignore_overflow(op, &a, &b, dest)?;
 212             }
 213
 214             #[rustfmt::skip]
 215             | "minnumf32"
 216             | "maxnumf32"
 217             | "copysignf32"
 218             => {
 219                 let &[ref a, ref b] = check_arg_count(args)?;
 220                 let a = this.read_scalar(a)?.to_f32()?;
 221                 let b = this.read_scalar(b)?.to_f32()?;
 222                 let res = match intrinsic_name {
 223                     "minnumf32" => a.min(b),
 224                     "maxnumf32" => a.max(b),
 225                     "copysignf32" => a.copy_sign(b),
 226                     _ => bug!(),
 227                 };
 228                 this.write_scalar(Scalar::from_f32(res), dest)?;
 229             }
 230
 231             #[rustfmt::skip]
 232             | "minnumf64"
 233             | "maxnumf64"
 234             | "copysignf64"
 235             => {
 236                 let &[ref a, ref b] = check_arg_count(args)?;
 237                 let a = this.read_scalar(a)?.to_f64()?;
 238                 let b = this.read_scalar(b)?.to_f64()?;
 239                 let res = match intrinsic_name {
 240                     "minnumf64" => a.min(b),
 241                     "maxnumf64" => a.max(b),
 242                     "copysignf64" => a.copy_sign(b),
 243                     _ => bug!(),
 244                 };
 245                 this.write_scalar(Scalar::from_f64(res), dest)?;
 246             }
 247
 248             "powf32" => {
 249                 let &[ref f, ref f2] = check_arg_count(args)?;
 250                 // FIXME: Using host floats.
 251                 let f = f32::from_bits(this.read_scalar(f)?.to_u32()?);
 252                 let f2 = f32::from_bits(this.read_scalar(f2)?.to_u32()?);
 253                 this.write_scalar(Scalar::from_u32(f.powf(f2).to_bits()), dest)?;
 254             }
 255
 256             "powf64" => {
 257                 let &[ref f, ref f2] = check_arg_count(args)?;
 258                 // FIXME: Using host floats.
 259                 let f = f64::from_bits(this.read_scalar(f)?.to_u64()?);
 260                 let f2 = f64::from_bits(this.read_scalar(f2)?.to_u64()?);
 261                 this.write_scalar(Scalar::from_u64(f.powf(f2).to_bits()), dest)?;
 262             }
 263
 264             "fmaf32" => {
 265                 let &[ref a, ref b, ref c] = check_arg_count(args)?;
 266                 let a = this.read_scalar(a)?.to_f32()?;
 267                 let b = this.read_scalar(b)?.to_f32()?;
 268                 let c = this.read_scalar(c)?.to_f32()?;
 269                 let res = a.mul_add(b, c).value;
 270                 this.write_scalar(Scalar::from_f32(res), dest)?;
 271             }
 272
 273             "fmaf64" => {
 274                 let &[ref a, ref b, ref c] = check_arg_count(args)?;
 275                 let a = this.read_scalar(a)?.to_f64()?;
 276                 let b = this.read_scalar(b)?.to_f64()?;
 277                 let c = this.read_scalar(c)?.to_f64()?;
 278                 let res = a.mul_add(b, c).value;
 279                 this.write_scalar(Scalar::from_f64(res), dest)?;
 280             }
 281
 282             "powif32" => {
 283                 let &[ref f, ref i] = check_arg_count(args)?;
 284                 // FIXME: Using host floats.
 285                 let f = f32::from_bits(this.read_scalar(f)?.to_u32()?);
 286                 let i = this.read_scalar(i)?.to_i32()?;
 287                 this.write_scalar(Scalar::from_u32(f.powi(i).to_bits()), dest)?;
 288             }
 289
 290             "powif64" => {
 291                 let &[ref f, ref i] = check_arg_count(args)?;
 292                 // FIXME: Using host floats.
 293                 let f = f64::from_bits(this.read_scalar(f)?.to_u64()?);
 294                 let i = this.read_scalar(i)?.to_i32()?;
 295                 this.write_scalar(Scalar::from_u64(f.powi(i).to_bits()), dest)?;
 296             }
 297
 298             "float_to_int_unchecked" => {
 299                 let &[ref val] = check_arg_count(args)?;
 300                 let val = this.read_immediate(val)?;
 301
 302                 let res = match val.layout.ty.kind() {
 303                     ty::Float(FloatTy::F32) =>
 304                         this.float_to_int_unchecked(val.to_scalar()?.to_f32()?, dest.layout.ty)?,
 305                     ty::Float(FloatTy::F64) =>
 306                         this.float_to_int_unchecked(val.to_scalar()?.to_f64()?, dest.layout.ty)?,
 307                     _ =>
 308                         bug!(
 309                             "`float_to_int_unchecked` called with non-float input type {:?}",
 310                             val.layout.ty
 311                         ),
 312                 };
 313
 314                 this.write_scalar(res, dest)?;
 315             }
 316
 317             // SIMD operations
 318             #[rustfmt::skip]
 319             | "simd_neg"
 320             | "simd_fabs" => {
 321                 let &[ref op] = check_arg_count(args)?;
 322                 let (op, op_len) = this.operand_to_simd(op)?;
 323                 let (dest, dest_len) = this.place_to_simd(dest)?;
 324
 325                 assert_eq!(dest_len, op_len);
 326
 327                 for i in 0..dest_len {
 328                     let op = this.read_immediate(&this.mplace_index(&op, i)?.into())?;
 329                     let dest = this.mplace_index(&dest, i)?;
 330                     let val = match intrinsic_name {
 331                         "simd_neg" => this.unary_op(mir::UnOp::Neg, &op)?.to_scalar()?,
 332                         "simd_fabs" => {
 333                             // Works for f32 and f64.
 334                             let ty::Float(float_ty) = op.layout.ty.kind() else {
 335                                 bug!("simd_fabs operand is not a float")
 336                             };
 337                             let op = op.to_scalar()?;
 338                             // FIXME: Using host floats.
 339                             match float_ty {
 340                                 FloatTy::F32 => Scalar::from_f32(op.to_f32()?.abs()),
 341                                 FloatTy::F64 => Scalar::from_f64(op.to_f64()?.abs()),
 342                             }
 343                         }
 344                         _ => bug!(),
 345                     };
 346                     this.write_scalar(val, &dest.into())?;
 347                 }
 348             }
 349             #[rustfmt::skip]
 350             | "simd_add"
 351             | "simd_sub"
 352             | "simd_mul"
 353             | "simd_div"
 354             | "simd_rem"
 355             | "simd_shl"
 356             | "simd_shr"
 357             | "simd_and"
 358             | "simd_or"
 359             | "simd_eq" => {
 360                 let &[ref left, ref right] = check_arg_count(args)?;
 361                 let (left, left_len) = this.operand_to_simd(left)?;
 362                 let (right, right_len) = this.operand_to_simd(right)?;
 363                 let (dest, dest_len) = this.place_to_simd(dest)?;
 364
 365                 assert_eq!(dest_len, left_len);
 366                 assert_eq!(dest_len, right_len);
 367
 368                 let op = match intrinsic_name {
 369                     "simd_add" => mir::BinOp::Add,
 370                     "simd_sub" => mir::BinOp::Sub,
 371                     "simd_mul" => mir::BinOp::Mul,
 372                     "simd_div" => mir::BinOp::Div,
 373                     "simd_rem" => mir::BinOp::Rem,
 374                     "simd_shl" => mir::BinOp::Shl,
 375                     "simd_shr" => mir::BinOp::Shr,
 376                     "simd_and" => mir::BinOp::BitAnd,
 377                     "simd_or" => mir::BinOp::BitOr,
 378                     "simd_eq" => mir::BinOp::Eq,
 379                     _ => unreachable!(),
 380                 };
 381
 382                 for i in 0..dest_len {
 383                     let left = this.read_immediate(&this.mplace_index(&left, i)?.into())?;
 384                     let right = this.read_immediate(&this.mplace_index(&right, i)?.into())?;
 385                     let dest = this.mplace_index(&dest, i)?;
 386                     let (val, overflowed, ty) = this.overflowing_binary_op(op, &left, &right)?;
 387                     if matches!(op, mir::BinOp::Shl | mir::BinOp::Shr) {
 388                         // Shifts have extra UB as SIMD operations that the MIR binop does not have.
 389                         // See <https://github.com/rust-lang/rust/issues/91237>.
 390                         if overflowed {
 391                             let r_val = right.to_scalar()?.to_bits(right.layout.size)?;
 392                             throw_ub_format!("overflowing shift by {} in `{}` in SIMD lane {}", r_val, intrinsic_name, i);
 393                         }
 394                     }
 395                     if matches!(op, mir::BinOp::Eq) {
 396                         // Special handling for boolean-returning operations
 397                         assert_eq!(ty, this.tcx.types.bool);
 398                         let val = val.to_bool().unwrap();
 399                         let val = bool_to_simd_element(val, dest.layout.size);
 400                         this.write_scalar(val, &dest.into())?;
 401                     } else {
 402                         assert_eq!(ty, dest.layout.ty);
 403                         this.write_scalar(val, &dest.into())?;
 404                     }
 405                 }
 406             }
 407             "simd_reduce_any" => {
 408                 let &[ref op] = check_arg_count(args)?;
 409                 let (op, op_len) = this.operand_to_simd(op)?;
 410
 411                 let mut res = false; // the neutral element
 412                 for i in 0..op_len {
 413                     let op = this.read_immediate(&this.mplace_index(&op, i)?.into())?;
 414                     let val = simd_element_to_bool(op)?;
 415                     res = res | val;
 416                 }
 417
 418                 this.write_scalar(Scalar::from_bool(res), dest)?;
 419             }
 420             "simd_select" => {
 421                 let &[ref mask, ref yes, ref no] = check_arg_count(args)?;
 422                 let (mask, mask_len) = this.operand_to_simd(mask)?;
 423                 let (yes, yes_len) = this.operand_to_simd(yes)?;
 424                 let (no, no_len) = this.operand_to_simd(no)?;
 425                 let (dest, dest_len) = this.place_to_simd(dest)?;
 426
 427                 assert_eq!(dest_len, mask_len);
 428                 assert_eq!(dest_len, yes_len);
 429                 assert_eq!(dest_len, no_len);
 430
 431                 for i in 0..dest_len {
 432                     let mask = this.read_immediate(&this.mplace_index(&mask, i)?.into())?;
 433                     let yes = this.read_immediate(&this.mplace_index(&yes, i)?.into())?;
 434                     let no = this.read_immediate(&this.mplace_index(&no, i)?.into())?;
 435                     let dest = this.mplace_index(&dest, i)?;
 436
 437                     let mask = simd_element_to_bool(mask)?;
 438                     let val = if mask { yes } else { no };
 439                     this.write_immediate(*val, &dest.into())?;
 440                 }
 441             }
 442
 443             // Atomic operations
 444             "atomic_load" => this.atomic_load(args, dest, AtomicReadOp::SeqCst)?,
 445             "atomic_load_relaxed" => this.atomic_load(args, dest, AtomicReadOp::Relaxed)?,
 446             "atomic_load_acq" => this.atomic_load(args, dest, AtomicReadOp::Acquire)?,
 447
 448             "atomic_store" => this.atomic_store(args, AtomicWriteOp::SeqCst)?,
 449             "atomic_store_relaxed" => this.atomic_store(args, AtomicWriteOp::Relaxed)?,
 450             "atomic_store_rel" => this.atomic_store(args, AtomicWriteOp::Release)?,
 451
 452             "atomic_fence_acq" => this.atomic_fence(args, AtomicFenceOp::Acquire)?,
 453             "atomic_fence_rel" => this.atomic_fence(args, AtomicFenceOp::Release)?,
 454             "atomic_fence_acqrel" => this.atomic_fence(args, AtomicFenceOp::AcqRel)?,
 455             "atomic_fence" => this.atomic_fence(args, AtomicFenceOp::SeqCst)?,
 456
 457             "atomic_singlethreadfence_acq" => this.compiler_fence(args, AtomicFenceOp::Acquire)?,
 458             "atomic_singlethreadfence_rel" => this.compiler_fence(args, AtomicFenceOp::Release)?,
 459             "atomic_singlethreadfence_acqrel" =>
 460                 this.compiler_fence(args, AtomicFenceOp::AcqRel)?,
 461             "atomic_singlethreadfence" => this.compiler_fence(args, AtomicFenceOp::SeqCst)?,
 462
 463             "atomic_xchg" => this.atomic_exchange(args, dest, AtomicRwOp::SeqCst)?,
 464             "atomic_xchg_acq" => this.atomic_exchange(args, dest, AtomicRwOp::Acquire)?,
 465             "atomic_xchg_rel" => this.atomic_exchange(args, dest, AtomicRwOp::Release)?,
 466             "atomic_xchg_acqrel" => this.atomic_exchange(args, dest, AtomicRwOp::AcqRel)?,
 467             "atomic_xchg_relaxed" => this.atomic_exchange(args, dest, AtomicRwOp::Relaxed)?,
 468
 469             #[rustfmt::skip]
 470             "atomic_cxchg" =>
 471                 this.atomic_compare_exchange(args, dest, AtomicRwOp::SeqCst, AtomicReadOp::SeqCst)?,
 472             #[rustfmt::skip]
 473             "atomic_cxchg_acq" =>
 474                 this.atomic_compare_exchange(args, dest, AtomicRwOp::Acquire, AtomicReadOp::Acquire)?,
 475             #[rustfmt::skip]
 476             "atomic_cxchg_rel" =>
 477                 this.atomic_compare_exchange(args, dest, AtomicRwOp::Release, AtomicReadOp::Relaxed)?,
 478             #[rustfmt::skip]
 479             "atomic_cxchg_acqrel" =>
 480                 this.atomic_compare_exchange(args, dest, AtomicRwOp::AcqRel, AtomicReadOp::Acquire)?,
 481             #[rustfmt::skip]
 482             "atomic_cxchg_relaxed" =>
 483                 this.atomic_compare_exchange(args, dest, AtomicRwOp::Relaxed, AtomicReadOp::Relaxed)?,
 484             #[rustfmt::skip]
 485             "atomic_cxchg_acq_failrelaxed" =>
 486                 this.atomic_compare_exchange(args, dest, AtomicRwOp::Acquire, AtomicReadOp::Relaxed)?,
 487             #[rustfmt::skip]
 488             "atomic_cxchg_acqrel_failrelaxed" =>
 489                 this.atomic_compare_exchange(args, dest, AtomicRwOp::AcqRel, AtomicReadOp::Relaxed)?,
 490             #[rustfmt::skip]
 491             "atomic_cxchg_failrelaxed" =>
 492                 this.atomic_compare_exchange(args, dest, AtomicRwOp::SeqCst, AtomicReadOp::Relaxed)?,
 493             #[rustfmt::skip]
 494             "atomic_cxchg_failacq" =>
 495                 this.atomic_compare_exchange(args, dest, AtomicRwOp::SeqCst, AtomicReadOp::Acquire)?,
 496
 497             #[rustfmt::skip]
 498             "atomic_cxchgweak" =>
 499                 this.atomic_compare_exchange_weak(args, dest, AtomicRwOp::SeqCst, AtomicReadOp::SeqCst)?,
 500             #[rustfmt::skip]
 501             "atomic_cxchgweak_acq" =>
 502                 this.atomic_compare_exchange_weak(args, dest, AtomicRwOp::Acquire, AtomicReadOp::Acquire)?,
 503             #[rustfmt::skip]
 504             "atomic_cxchgweak_rel" =>
 505                 this.atomic_compare_exchange_weak(args, dest, AtomicRwOp::Release, AtomicReadOp::Relaxed)?,
 506             #[rustfmt::skip]
 507             "atomic_cxchgweak_acqrel" =>
 508                 this.atomic_compare_exchange_weak(args, dest, AtomicRwOp::AcqRel, AtomicReadOp::Acquire)?,
 509             #[rustfmt::skip]
 510             "atomic_cxchgweak_relaxed" =>
 511                 this.atomic_compare_exchange_weak(args, dest, AtomicRwOp::Relaxed, AtomicReadOp::Relaxed)?,
 512             #[rustfmt::skip]
 513             "atomic_cxchgweak_acq_failrelaxed" =>
 514                 this.atomic_compare_exchange_weak(args, dest, AtomicRwOp::Acquire, AtomicReadOp::Relaxed)?,
 515             #[rustfmt::skip]
 516             "atomic_cxchgweak_acqrel_failrelaxed" =>
 517                 this.atomic_compare_exchange_weak(args, dest, AtomicRwOp::AcqRel, AtomicReadOp::Relaxed)?,
 518             #[rustfmt::skip]
 519             "atomic_cxchgweak_failrelaxed" =>
 520                 this.atomic_compare_exchange_weak(args, dest, AtomicRwOp::SeqCst, AtomicReadOp::Relaxed)?,
 521             #[rustfmt::skip]
 522             "atomic_cxchgweak_failacq" =>
 523                 this.atomic_compare_exchange_weak(args, dest, AtomicRwOp::SeqCst, AtomicReadOp::Acquire)?,
 524
 525             #[rustfmt::skip]
 526             "atomic_or" =>
 527                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitOr, false), AtomicRwOp::SeqCst)?,
 528             #[rustfmt::skip]
 529             "atomic_or_acq" =>
 530                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitOr, false), AtomicRwOp::Acquire)?,
 531             #[rustfmt::skip]
 532             "atomic_or_rel" =>
 533                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitOr, false), AtomicRwOp::Release)?,
 534             #[rustfmt::skip]
 535             "atomic_or_acqrel" =>
 536                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitOr, false), AtomicRwOp::AcqRel)?,
 537             #[rustfmt::skip]
 538             "atomic_or_relaxed" =>
 539                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitOr, false), AtomicRwOp::Relaxed)?,
 540             #[rustfmt::skip]
 541             "atomic_xor" =>
 542                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitXor, false), AtomicRwOp::SeqCst)?,
 543             #[rustfmt::skip]
 544             "atomic_xor_acq" =>
 545                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitXor, false), AtomicRwOp::Acquire)?,
 546             #[rustfmt::skip]
 547             "atomic_xor_rel" =>
 548                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitXor, false), AtomicRwOp::Release)?,
 549             #[rustfmt::skip]
 550             "atomic_xor_acqrel" =>
 551                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitXor, false), AtomicRwOp::AcqRel)?,
 552             #[rustfmt::skip]
 553             "atomic_xor_relaxed" =>
 554                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitXor, false), AtomicRwOp::Relaxed)?,
 555             #[rustfmt::skip]
 556             "atomic_and" =>
 557                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitAnd, false), AtomicRwOp::SeqCst)?,
 558             #[rustfmt::skip]
 559             "atomic_and_acq" =>
 560                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitAnd, false), AtomicRwOp::Acquire)?,
 561             #[rustfmt::skip]
 562             "atomic_and_rel" =>
 563                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitAnd, false), AtomicRwOp::Release)?,
 564             #[rustfmt::skip]
 565             "atomic_and_acqrel" =>
 566                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitAnd, false), AtomicRwOp::AcqRel)?,
 567             #[rustfmt::skip]
 568             "atomic_and_relaxed" =>
 569                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitAnd, false), AtomicRwOp::Relaxed)?,
 570             #[rustfmt::skip]
 571             "atomic_nand" =>
 572                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitAnd, true), AtomicRwOp::SeqCst)?,
 573             #[rustfmt::skip]
 574             "atomic_nand_acq" =>
 575                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitAnd, true), AtomicRwOp::Acquire)?,
 576             #[rustfmt::skip]
 577             "atomic_nand_rel" =>
 578                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitAnd, true), AtomicRwOp::Release)?,
 579             #[rustfmt::skip]
 580             "atomic_nand_acqrel" =>
 581                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitAnd, true), AtomicRwOp::AcqRel)?,
 582             #[rustfmt::skip]
 583             "atomic_nand_relaxed" =>
 584                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::BitAnd, true), AtomicRwOp::Relaxed)?,
 585             #[rustfmt::skip]
 586             "atomic_xadd" =>
 587                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::Add, false), AtomicRwOp::SeqCst)?,
 588             #[rustfmt::skip]
 589             "atomic_xadd_acq" =>
 590                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::Add, false), AtomicRwOp::Acquire)?,
 591             #[rustfmt::skip]
 592             "atomic_xadd_rel" =>
 593                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::Add, false), AtomicRwOp::Release)?,
 594             #[rustfmt::skip]
 595             "atomic_xadd_acqrel" =>
 596                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::Add, false), AtomicRwOp::AcqRel)?,
 597             #[rustfmt::skip]
 598             "atomic_xadd_relaxed" =>
 599                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::Add, false), AtomicRwOp::Relaxed)?,
 600             #[rustfmt::skip]
 601             "atomic_xsub" =>
 602                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::Sub, false), AtomicRwOp::SeqCst)?,
 603             #[rustfmt::skip]
 604             "atomic_xsub_acq" =>
 605                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::Sub, false), AtomicRwOp::Acquire)?,
 606             #[rustfmt::skip]
 607             "atomic_xsub_rel" =>
 608                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::Sub, false), AtomicRwOp::Release)?,
 609             #[rustfmt::skip]
 610             "atomic_xsub_acqrel" =>
 611                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::Sub, false), AtomicRwOp::AcqRel)?,
 612             #[rustfmt::skip]
 613             "atomic_xsub_relaxed" =>
 614                 this.atomic_op(args, dest, AtomicOp::MirOp(BinOp::Sub, false), AtomicRwOp::Relaxed)?,
 615             "atomic_min" => this.atomic_op(args, dest, AtomicOp::Min, AtomicRwOp::SeqCst)?,
 616             "atomic_min_acq" => this.atomic_op(args, dest, AtomicOp::Min, AtomicRwOp::Acquire)?,
 617             "atomic_min_rel" => this.atomic_op(args, dest, AtomicOp::Min, AtomicRwOp::Release)?,
 618             "atomic_min_acqrel" => this.atomic_op(args, dest, AtomicOp::Min, AtomicRwOp::AcqRel)?,
 619             "atomic_min_relaxed" =>
 620                 this.atomic_op(args, dest, AtomicOp::Min, AtomicRwOp::Relaxed)?,
 621             "atomic_max" => this.atomic_op(args, dest, AtomicOp::Max, AtomicRwOp::SeqCst)?,
 622             "atomic_max_acq" => this.atomic_op(args, dest, AtomicOp::Max, AtomicRwOp::Acquire)?,
 623             "atomic_max_rel" => this.atomic_op(args, dest, AtomicOp::Max, AtomicRwOp::Release)?,
 624             "atomic_max_acqrel" => this.atomic_op(args, dest, AtomicOp::Max, AtomicRwOp::AcqRel)?,
 625             "atomic_max_relaxed" =>
 626                 this.atomic_op(args, dest, AtomicOp::Max, AtomicRwOp::Relaxed)?,
 627             "atomic_umin" => this.atomic_op(args, dest, AtomicOp::Min, AtomicRwOp::SeqCst)?,
 628             "atomic_umin_acq" => this.atomic_op(args, dest, AtomicOp::Min, AtomicRwOp::Acquire)?,
 629             "atomic_umin_rel" => this.atomic_op(args, dest, AtomicOp::Min, AtomicRwOp::Release)?,
 630             "atomic_umin_acqrel" =>
 631                 this.atomic_op(args, dest, AtomicOp::Min, AtomicRwOp::AcqRel)?,
 632             "atomic_umin_relaxed" =>
 633                 this.atomic_op(args, dest, AtomicOp::Min, AtomicRwOp::Relaxed)?,
 634             "atomic_umax" => this.atomic_op(args, dest, AtomicOp::Max, AtomicRwOp::SeqCst)?,
 635             "atomic_umax_acq" => this.atomic_op(args, dest, AtomicOp::Max, AtomicRwOp::Acquire)?,
 636             "atomic_umax_rel" => this.atomic_op(args, dest, AtomicOp::Max, AtomicRwOp::Release)?,
 637             "atomic_umax_acqrel" =>
 638                 this.atomic_op(args, dest, AtomicOp::Max, AtomicRwOp::AcqRel)?,
 639             "atomic_umax_relaxed" =>
 640                 this.atomic_op(args, dest, AtomicOp::Max, AtomicRwOp::Relaxed)?,
 641
 642             // Other
 643             "exact_div" => {
 644                 let &[ref num, ref denom] = check_arg_count(args)?;
 645                 this.exact_div(&this.read_immediate(num)?, &this.read_immediate(denom)?, dest)?;
 646             }
 647
 648             "try" => return this.handle_try(args, dest, ret),
 649
 650             "breakpoint" => {
 651                 let &[] = check_arg_count(args)?;
 652                 // normally this would raise a SIGTRAP, which aborts if no debugger is connected
 653                 throw_machine_stop!(TerminationInfo::Abort("Trace/breakpoint trap".to_string()))
 654             }
 655
 656             name => throw_unsup_format!("unimplemented intrinsic: {}", name),
 657         }
 658
 659         trace!("{:?}", this.dump_place(**dest));
 660         this.go_to_block(ret);
 661         Ok(())
 662     }
 663
 664     fn atomic_load(
 665         &mut self,
 666         args: &[OpTy<'tcx, Tag>],
 667         dest: &PlaceTy<'tcx, Tag>,
 668         atomic: AtomicReadOp,
 669     ) -> InterpResult<'tcx> {
 670         let this = self.eval_context_mut();
 671
 672         let &[ref place] = check_arg_count(args)?;
 673         let place = this.deref_operand(place)?;
 674
 675         // make sure it fits into a scalar; otherwise it cannot be atomic
 676         let val = this.read_scalar_atomic(&place, atomic)?;
 677
 678         // Check alignment requirements. Atomics must always be aligned to their size,
 679         // even if the type they wrap would be less aligned (e.g. AtomicU64 on 32bit must
 680         // be 8-aligned).
 681         let align = Align::from_bytes(place.layout.size.bytes()).unwrap();
 682         this.memory.check_ptr_access_align(
 683             place.ptr,
 684             place.layout.size,
 685             align,
 686             CheckInAllocMsg::MemoryAccessTest,
 687         )?;
 688         // Perform regular access.
 689         this.write_scalar(val, dest)?;
 690         Ok(())
 691     }
 692
 693     fn atomic_store(
 694         &mut self,
 695         args: &[OpTy<'tcx, Tag>],
 696         atomic: AtomicWriteOp,
 697     ) -> InterpResult<'tcx> {
 698         let this = self.eval_context_mut();
 699
 700         let &[ref place, ref val] = check_arg_count(args)?;
 701         let place = this.deref_operand(place)?;
 702         let val = this.read_scalar(val)?; // make sure it fits into a scalar; otherwise it cannot be atomic
 703
 704         // Check alignment requirements. Atomics must always be aligned to their size,
 705         // even if the type they wrap would be less aligned (e.g. AtomicU64 on 32bit must
 706         // be 8-aligned).
 707         let align = Align::from_bytes(place.layout.size.bytes()).unwrap();
 708         this.memory.check_ptr_access_align(
 709             place.ptr,
 710             place.layout.size,
 711             align,
 712             CheckInAllocMsg::MemoryAccessTest,
 713         )?;
 714
 715         // Perform atomic store
 716         this.write_scalar_atomic(val, &place, atomic)?;
 717         Ok(())
 718     }
 719
 720     fn compiler_fence(
 721         &mut self,
 722         args: &[OpTy<'tcx, Tag>],
 723         atomic: AtomicFenceOp,
 724     ) -> InterpResult<'tcx> {
 725         let &[] = check_arg_count(args)?;
 726         let _ = atomic;
 727         //FIXME: compiler fences are currently ignored
 728         Ok(())
 729     }
 730
 731     fn atomic_fence(
 732         &mut self,
 733         args: &[OpTy<'tcx, Tag>],
 734         atomic: AtomicFenceOp,
 735     ) -> InterpResult<'tcx> {
 736         let this = self.eval_context_mut();
 737         let &[] = check_arg_count(args)?;
 738         this.validate_atomic_fence(atomic)?;
 739         Ok(())
 740     }
 741
 742     fn atomic_op(
 743         &mut self,
 744         args: &[OpTy<'tcx, Tag>],
 745         dest: &PlaceTy<'tcx, Tag>,
 746         atomic_op: AtomicOp,
 747         atomic: AtomicRwOp,
 748     ) -> InterpResult<'tcx> {
 749         let this = self.eval_context_mut();
 750
 751         let &[ref place, ref rhs] = check_arg_count(args)?;
 752         let place = this.deref_operand(place)?;
 753
 754         if !place.layout.ty.is_integral() {
 755             bug!("Atomic arithmetic operations only work on integer types");
 756         }
 757         let rhs = this.read_immediate(rhs)?;
 758
 759         // Check alignment requirements. Atomics must always be aligned to their size,
 760         // even if the type they wrap would be less aligned (e.g. AtomicU64 on 32bit must
 761         // be 8-aligned).
 762         let align = Align::from_bytes(place.layout.size.bytes()).unwrap();
 763         this.memory.check_ptr_access_align(
 764             place.ptr,
 765             place.layout.size,
 766             align,
 767             CheckInAllocMsg::MemoryAccessTest,
 768         )?;
 769
 770         match atomic_op {
 771             AtomicOp::Min => {
 772                 let old = this.atomic_min_max_scalar(&place, rhs, true, atomic)?;
 773                 this.write_immediate(*old, &dest)?; // old value is returned
 774                 Ok(())
 775             }
 776             AtomicOp::Max => {
 777                 let old = this.atomic_min_max_scalar(&place, rhs, false, atomic)?;
 778                 this.write_immediate(*old, &dest)?; // old value is returned
 779                 Ok(())
 780             }
 781             AtomicOp::MirOp(op, neg) => {
 782                 let old = this.atomic_op_immediate(&place, &rhs, op, neg, atomic)?;
 783                 this.write_immediate(*old, dest)?; // old value is returned
 784                 Ok(())
 785             }
 786         }
 787     }
 788
 789     fn atomic_exchange(
 790         &mut self,
 791         args: &[OpTy<'tcx, Tag>],
 792         dest: &PlaceTy<'tcx, Tag>,
 793         atomic: AtomicRwOp,
 794     ) -> InterpResult<'tcx> {
 795         let this = self.eval_context_mut();
 796
 797         let &[ref place, ref new] = check_arg_count(args)?;
 798         let place = this.deref_operand(place)?;
 799         let new = this.read_scalar(new)?;
 800
 801         // Check alignment requirements. Atomics must always be aligned to their size,
 802         // even if the type they wrap would be less aligned (e.g. AtomicU64 on 32bit must
 803         // be 8-aligned).
 804         let align = Align::from_bytes(place.layout.size.bytes()).unwrap();
 805         this.memory.check_ptr_access_align(
 806             place.ptr,
 807             place.layout.size,
 808             align,
 809             CheckInAllocMsg::MemoryAccessTest,
 810         )?;
 811
 812         let old = this.atomic_exchange_scalar(&place, new, atomic)?;
 813         this.write_scalar(old, dest)?; // old value is returned
 814         Ok(())
 815     }
 816
 817     fn atomic_compare_exchange_impl(
 818         &mut self,
 819         args: &[OpTy<'tcx, Tag>],
 820         dest: &PlaceTy<'tcx, Tag>,
 821         success: AtomicRwOp,
 822         fail: AtomicReadOp,
 823         can_fail_spuriously: bool,
 824     ) -> InterpResult<'tcx> {
 825         let this = self.eval_context_mut();
 826
 827         let &[ref place, ref expect_old, ref new] = check_arg_count(args)?;
 828         let place = this.deref_operand(place)?;
 829         let expect_old = this.read_immediate(expect_old)?; // read as immediate for the sake of `binary_op()`
 830         let new = this.read_scalar(new)?;
 831
 832         // Check alignment requirements. Atomics must always be aligned to their size,
 833         // even if the type they wrap would be less aligned (e.g. AtomicU64 on 32bit must
 834         // be 8-aligned).
 835         let align = Align::from_bytes(place.layout.size.bytes()).unwrap();
 836         this.memory.check_ptr_access_align(
 837             place.ptr,
 838             place.layout.size,
 839             align,
 840             CheckInAllocMsg::MemoryAccessTest,
 841         )?;
 842
 843         let old = this.atomic_compare_exchange_scalar(
 844             &place,
 845             &expect_old,
 846             new,
 847             success,
 848             fail,
 849             can_fail_spuriously,
 850         )?;
 851
 852         // Return old value.
 853         this.write_immediate(old, dest)?;
 854         Ok(())
 855     }
 856
 857     fn atomic_compare_exchange(
 858         &mut self,
 859         args: &[OpTy<'tcx, Tag>],
 860         dest: &PlaceTy<'tcx, Tag>,
 861         success: AtomicRwOp,
 862         fail: AtomicReadOp,
 863     ) -> InterpResult<'tcx> {
 864         self.atomic_compare_exchange_impl(args, dest, success, fail, false)
 865     }
 866
 867     fn atomic_compare_exchange_weak(
 868         &mut self,
 869         args: &[OpTy<'tcx, Tag>],
 870         dest: &PlaceTy<'tcx, Tag>,
 871         success: AtomicRwOp,
 872         fail: AtomicReadOp,
 873     ) -> InterpResult<'tcx> {
 874         self.atomic_compare_exchange_impl(args, dest, success, fail, true)
 875     }
 876
 877     fn float_to_int_unchecked<F>(
 878         &self,
 879         f: F,
 880         dest_ty: ty::Ty<'tcx>,
 881     ) -> InterpResult<'tcx, Scalar<Tag>>
 882     where
 883         F: Float + Into<Scalar<Tag>>,
 884     {
 885         let this = self.eval_context_ref();
 886
 887         // Step 1: cut off the fractional part of `f`. The result of this is
 888         // guaranteed to be precisely representable in IEEE floats.
 889         let f = f.round_to_integral(Round::TowardZero).value;
 890
 891         // Step 2: Cast the truncated float to the target integer type and see if we lose any information in this step.
 892         Ok(match dest_ty.kind() {
 893             // Unsigned
 894             ty::Uint(t) => {
 895                 let size = Integer::from_uint_ty(this, *t).size();
 896                 let res = f.to_u128(size.bits_usize());
 897                 if res.status.is_empty() {
 898                     // No status flags means there was no further rounding or other loss of precision.
 899                     Scalar::from_uint(res.value, size)
 900                 } else {
 901                     // `f` was not representable in this integer type.
 902                     throw_ub_format!(
 903                         "`float_to_int_unchecked` intrinsic called on {} which cannot be represented in target type `{:?}`",
 904                         f,
 905                         dest_ty,
 906                     );
 907                 }
 908             }
 909             // Signed
 910             ty::Int(t) => {
 911                 let size = Integer::from_int_ty(this, *t).size();
 912                 let res = f.to_i128(size.bits_usize());
 913                 if res.status.is_empty() {
 914                     // No status flags means there was no further rounding or other loss of precision.
 915                     Scalar::from_int(res.value, size)
 916                 } else {
 917                     // `f` was not representable in this integer type.
 918                     throw_ub_format!(
 919                         "`float_to_int_unchecked` intrinsic called on {} which cannot be represented in target type `{:?}`",
 920                         f,
 921                         dest_ty,
 922                     );
 923                 }
 924             }
 925             // Nothing else
 926             _ => bug!("`float_to_int_unchecked` called with non-int output type {:?}", dest_ty),
 927         })
 928     }
 929 }