src/intrinsics.rs

   1
   2 use crate::prelude::*;
   3
   4 macro_rules! intrinsic_pat {
   5     (_) => {
   6         _
   7     };
   8     ($name:ident) => {
   9         stringify!($name)
  10     }
  11 }
  12
  13 macro_rules! intrinsic_arg {
  14     (c $fx:expr, $arg:ident) => {
  15         $arg
  16     };
  17     (v $fx:expr, $arg:ident) => {
  18         $arg.load_value($fx)
  19     };
  20 }
  21
  22 macro_rules! intrinsic_substs {
  23     ($substs:expr, $index:expr,) => {};
  24     ($substs:expr, $index:expr, $first:ident $(,$rest:ident)*) => {
  25         let $first = $substs.type_at($index);
  26         intrinsic_substs!($substs, $index+1, $($rest),*);
  27     };
  28 }
  29
  30 macro_rules! intrinsic_match {
  31     ($fx:expr, $intrinsic:expr, $substs:expr, $args:expr, $(
  32         $($name:tt)|+ $(if $cond:expr)?, $(<$($subst:ident),*>)? ($($a:ident $arg:ident),*) $content:block;
  33     )*) => {
  34         match $intrinsic {
  35             $(
  36                 $(intrinsic_pat!($name))|* $(if $cond)? => {
  37                     #[allow(unused_parens, non_snake_case)]
  38                     {
  39                         $(
  40                             intrinsic_substs!($substs, 0, $($subst),*);
  41                         )?
  42                         if let [$($arg),*] = *$args {
  43                             let ($($arg),*) = (
  44                                 $(intrinsic_arg!($a $fx, $arg)),*
  45                             );
  46                             #[warn(unused_parens, non_snake_case)]
  47                             {
  48                                 $content
  49                             }
  50                         } else {
  51                             bug!("wrong number of args for intrinsic {:?}", $intrinsic);
  52                         }
  53                     }
  54                 }
  55             )*
  56             _ => unimpl!("unsupported intrinsic {}", $intrinsic),
  57         }
  58     };
  59 }
  60
  61 macro_rules! atomic_binop_return_old {
  62     ($fx:expr, $op:ident<$T:ident>($ptr:ident, $src:ident) -> $ret:ident) => {
  63         let clif_ty = $fx.cton_type($T).unwrap();
  64         let old = $fx.bcx.ins().load(clif_ty, MemFlags::new(), $ptr, 0);
  65         let new = $fx.bcx.ins().band(old, $src);
  66         $fx.bcx.ins().store(MemFlags::new(), new, $ptr, 0);
  67         $ret.write_cvalue($fx, CValue::ByVal(old, $fx.layout_of($T)));
  68     };
  69 }
  70
  71 macro_rules! atomic_minmax {
  72     ($fx:expr, $cc:expr, <$T:ident> ($ptr:ident, $src:ident) -> $ret:ident) => {
  73         // Read old
  74         let clif_ty = $fx.cton_type($T).unwrap();
  75         let old = $fx.bcx.ins().load(clif_ty, MemFlags::new(), $ptr, 0);
  76
  77         // Compare
  78         let is_eq = $fx.bcx.ins().icmp(IntCC::SignedGreaterThan, old, $src);
  79         let new = crate::common::codegen_select(&mut $fx.bcx, is_eq, old, $src);
  80
  81         // Write new
  82         $fx.bcx.ins().store(MemFlags::new(), new, $ptr, 0);
  83
  84         let ret_val = CValue::ByVal(old, $ret.layout());
  85         $ret.write_cvalue($fx, ret_val);
  86     };
  87 }
  88
  89 pub fn codegen_intrinsic_call<'a, 'tcx: 'a>(
  90     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
  91     def_id: DefId,
  92     substs: &'tcx Substs,
  93     args: Vec<CValue<'tcx>>,
  94     destination: Option<(CPlace<'tcx>, BasicBlock)>,
  95 ) {
  96     let intrinsic = fx.tcx.item_name(def_id).as_str();
  97     let intrinsic = &intrinsic[..];
  98
  99     let ret = match destination {
 100         Some((place, _)) => place,
 101         None => {
 102             // Insert non returning intrinsics here
 103             match intrinsic {
 104                 "abort" => {
 105                     fx.bcx.ins().trap(TrapCode::User(!0 - 1));
 106                 }
 107                 "unreachable" => {
 108                     fx.bcx.ins().trap(TrapCode::User(!0 - 1));
 109                 }
 110                 _ => unimplemented!("unsupported instrinsic {}", intrinsic),
 111             }
 112             return;
 113         }
 114     };
 115
 116     let u64_layout = fx.layout_of(fx.tcx.types.u64);
 117     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 118
 119     intrinsic_match! {
 120         fx, intrinsic, substs, args,
 121
 122         assume, (c _a) {};
 123         arith_offset, (v base, v offset) {
 124             let res = fx.bcx.ins().iadd(base, offset);
 125             let res = CValue::ByVal(res, ret.layout());
 126             ret.write_cvalue(fx, res);
 127         };
 128         likely | unlikely, (c a) {
 129             ret.write_cvalue(fx, a);
 130         };
 131         copy | copy_nonoverlapping, <elem_ty> (v src, v dst, v count) {
 132             let elem_size: u64 = fx.layout_of(elem_ty).size.bytes();
 133             let elem_size = fx
 134                 .bcx
 135                 .ins()
 136                 .iconst(fx.module.pointer_type(), elem_size as i64);
 137             assert_eq!(args.len(), 3);
 138             let byte_amount = fx.bcx.ins().imul(count, elem_size);
 139
 140             if intrinsic.ends_with("_nonoverlapping") {
 141                 fx.bcx.call_memcpy(fx.isa, dst, src, byte_amount);
 142             } else {
 143                 fx.bcx.call_memmove(fx.isa, dst, src, byte_amount);
 144             }
 145         };
 146         discriminant_value, (c val) {
 147             let discr = crate::base::trans_get_discriminant(fx, val, ret.layout());
 148             ret.write_cvalue(fx, discr);
 149         };
 150         size_of, <T> () {
 151             let size_of = fx.layout_of(T).size.bytes();
 152             let size_of = CValue::const_val(fx, usize_layout.ty, size_of as i64);
 153             ret.write_cvalue(fx, size_of);
 154         };
 155         size_of_val, <T> (c ptr) {
 156             let layout = fx.layout_of(T);
 157             let size = match &layout.ty.sty {
 158                 _ if !layout.is_unsized() => fx
 159                     .bcx
 160                     .ins()
 161                     .iconst(fx.module.pointer_type(), layout.size.bytes() as i64),
 162                 ty::Slice(elem) => {
 163                     let len = ptr.load_value_pair(fx).1;
 164                     let elem_size = fx.layout_of(elem).size.bytes();
 165                     fx.bcx.ins().imul_imm(len, elem_size as i64)
 166                 }
 167                 ty::Dynamic(..) => crate::vtable::size_of_obj(fx, ptr),
 168                 ty => bug!("size_of_val for unknown unsized type {:?}", ty),
 169             };
 170             ret.write_cvalue(fx, CValue::ByVal(size, usize_layout));
 171         };
 172         min_align_of, <T> () {
 173             let min_align = fx.layout_of(T).align.abi();
 174             let min_align = CValue::const_val(fx, usize_layout.ty, min_align as i64);
 175             ret.write_cvalue(fx, min_align);
 176         };
 177         min_align_of_val, <T> (c ptr) {
 178             let layout = fx.layout_of(T);
 179             let align = match &layout.ty.sty {
 180                 _ if !layout.is_unsized() => fx
 181                     .bcx
 182                     .ins()
 183                     .iconst(fx.module.pointer_type(), layout.align.abi() as i64),
 184                 ty::Slice(elem) => {
 185                     let align = fx.layout_of(elem).align.abi() as i64;
 186                     fx.bcx.ins().iconst(fx.module.pointer_type(), align)
 187                 }
 188                 ty::Dynamic(..) => crate::vtable::min_align_of_obj(fx, ptr),
 189                 ty => unimplemented!("min_align_of_val for {:?}", ty),
 190             };
 191             ret.write_cvalue(fx, CValue::ByVal(align, usize_layout));
 192         };
 193         type_id, <T> () {
 194             let type_id = fx.tcx.type_id_hash(T);
 195             let type_id = CValue::const_val(fx, u64_layout.ty, type_id as i64);
 196             ret.write_cvalue(fx, type_id);
 197         };
 198         _ if intrinsic.starts_with("unchecked_"), (c x, c y) {
 199             let bin_op = match intrinsic {
 200                 "unchecked_div" => BinOp::Div,
 201                 "unchecked_rem" => BinOp::Rem,
 202                 "unchecked_shl" => BinOp::Shl,
 203                 "unchecked_shr" => BinOp::Shr,
 204                 _ => unimplemented!("intrinsic {}", intrinsic),
 205             };
 206             let res = match ret.layout().ty.sty {
 207                 ty::Uint(_) => crate::base::trans_int_binop(
 208                     fx,
 209                     bin_op,
 210                     x,
 211                     y,
 212                     ret.layout().ty,
 213                     false,
 214                 ),
 215                 ty::Int(_) => crate::base::trans_int_binop(
 216                     fx,
 217                     bin_op,
 218                     x,
 219                     y,
 220                     ret.layout().ty,
 221                     true,
 222                 ),
 223                 _ => panic!(),
 224             };
 225             ret.write_cvalue(fx, res);
 226         };
 227         _ if intrinsic.ends_with("_with_overflow"), <T> (c x, c y) {
 228             assert_eq!(x.layout().ty, y.layout().ty);
 229             let bin_op = match intrinsic {
 230                 "add_with_overflow" => BinOp::Add,
 231                 "sub_with_overflow" => BinOp::Sub,
 232                 "mul_with_overflow" => BinOp::Mul,
 233                 _ => unimplemented!("intrinsic {}", intrinsic),
 234             };
 235             let res = match T.sty {
 236                 ty::Uint(_) => crate::base::trans_checked_int_binop(
 237                     fx,
 238                     bin_op,
 239                     x,
 240                     y,
 241                     ret.layout().ty,
 242                     false,
 243                 ),
 244                 ty::Int(_) => crate::base::trans_checked_int_binop(
 245                     fx,
 246                     bin_op,
 247                     x,
 248                     y,
 249                     ret.layout().ty,
 250                     true,
 251                 ),
 252                 _ => panic!(),
 253             };
 254             ret.write_cvalue(fx, res);
 255         };
 256         _ if intrinsic.starts_with("overflowing_"), <T> (c x, c y) {
 257             assert_eq!(x.layout().ty, y.layout().ty);
 258             let bin_op = match intrinsic {
 259                 "overflowing_add" => BinOp::Add,
 260                 "overflowing_sub" => BinOp::Sub,
 261                 "overflowing_mul" => BinOp::Mul,
 262                 _ => unimplemented!("intrinsic {}", intrinsic),
 263             };
 264             let res = match T.sty {
 265                 ty::Uint(_) => crate::base::trans_int_binop(
 266                     fx,
 267                     bin_op,
 268                     x,
 269                     y,
 270                     ret.layout().ty,
 271                     false,
 272                 ),
 273                 ty::Int(_) => crate::base::trans_int_binop(
 274                     fx,
 275                     bin_op,
 276                     x,
 277                     y,
 278                     ret.layout().ty,
 279                     true,
 280                 ),
 281                 _ => panic!(),
 282             };
 283             ret.write_cvalue(fx, res);
 284         };
 285         offset, (v base, v offset) {
 286             let res = fx.bcx.ins().iadd(base, offset);
 287             ret.write_cvalue(fx, CValue::ByVal(res, args[0].layout()));
 288         };
 289         transmute, <src_ty, dst_ty> (c from) {
 290             assert_eq!(from.layout().ty, src_ty);
 291             let addr = from.force_stack(fx);
 292             let dst_layout = fx.layout_of(dst_ty);
 293             ret.write_cvalue(fx, CValue::ByRef(addr, dst_layout))
 294         };
 295         init, <T> () {
 296             let layout = fx.layout_of(T);
 297             let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 298                 kind: StackSlotKind::ExplicitSlot,
 299                 size: layout.size.bytes() as u32,
 300                 offset: None,
 301             });
 302             let addr = fx.bcx.ins().stack_addr(pointer_ty(fx.tcx), stack_slot, 0);
 303             let zero_val = fx.bcx.ins().iconst(types::I8, 0);
 304             let len_val = fx.bcx.ins().iconst(pointer_ty(fx.tcx), layout.size.bytes() as i64);
 305             fx.bcx.call_memset(fx.isa, addr, zero_val, len_val);
 306
 307             let uninit_place = CPlace::from_stack_slot(fx, stack_slot, T);
 308             let uninit_val = uninit_place.to_cvalue(fx);
 309             ret.write_cvalue(fx, uninit_val);
 310         };
 311         write_bytes, <T> (v dst, v val, v count) {
 312             fx.bcx.call_memset(fx.isa, dst, val, count);
 313         };
 314         uninit, <T> () {
 315             let layout = fx.layout_of(T);
 316             let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 317                 kind: StackSlotKind::ExplicitSlot,
 318                 size: layout.size.bytes() as u32,
 319                 offset: None,
 320             });
 321
 322             let uninit_place = CPlace::from_stack_slot(fx, stack_slot, T);
 323             let uninit_val = uninit_place.to_cvalue(fx);
 324             ret.write_cvalue(fx, uninit_val);
 325         };
 326         ctlz | ctlz_nonzero, <T> (v arg) {
 327             let res = CValue::ByVal(fx.bcx.ins().clz(arg), fx.layout_of(T));
 328             ret.write_cvalue(fx, res);
 329         };
 330         cttz | cttz_nonzero, <T> (v arg) {
 331             let res = CValue::ByVal(fx.bcx.ins().clz(arg), fx.layout_of(T));
 332             ret.write_cvalue(fx, res);
 333         };
 334         ctpop, <T> (v arg) {
 335             let res = CValue::ByVal(fx.bcx.ins().popcnt(arg), fx.layout_of(T));
 336             ret.write_cvalue(fx, res);
 337         };
 338         bitreverse, <T> (v arg) {
 339             let res = CValue::ByVal(fx.bcx.ins().bitrev(arg), fx.layout_of(T));
 340             ret.write_cvalue(fx, res);
 341         };
 342         needs_drop, <T> () {
 343             let needs_drop = if T.needs_drop(fx.tcx, ParamEnv::reveal_all()) {
 344                 1
 345             } else {
 346                 0
 347             };
 348             let needs_drop = CValue::const_val(fx, fx.tcx.types.bool, needs_drop);
 349             ret.write_cvalue(fx, needs_drop);
 350         };
 351
 352         _ if intrinsic.starts_with("atomic_fence"), () {};
 353         _ if intrinsic.starts_with("atomic_singlethreadfence"), () {};
 354         _ if intrinsic.starts_with("atomic_load"), (c ptr) {
 355             let inner_layout =
 356                 fx.layout_of(ptr.layout().ty.builtin_deref(true).unwrap().ty);
 357             let val = CValue::ByRef(ptr.load_value(fx), inner_layout);
 358             ret.write_cvalue(fx, val);
 359         };
 360         _ if intrinsic.starts_with("atomic_store"), (v ptr, c val) {
 361             let dest = CPlace::Addr(ptr, None, val.layout());
 362             dest.write_cvalue(fx, val);
 363         };
 364         _ if intrinsic.starts_with("atomic_xchg"), <T> (v ptr, c src) {
 365             // Read old
 366             let clif_ty = fx.cton_type(T).unwrap();
 367             let old = fx.bcx.ins().load(clif_ty, MemFlags::new(), ptr, 0);
 368             ret.write_cvalue(fx, CValue::ByVal(old, fx.layout_of(T)));
 369
 370             // Write new
 371             let dest = CPlace::Addr(ptr, None, src.layout());
 372             dest.write_cvalue(fx, src);
 373         };
 374         _ if intrinsic.starts_with("atomic_cxchg"), <T> (v ptr, v test_old, v new) { // both atomic_cxchg_* and atomic_cxchgweak_*
 375             // Read old
 376             let clif_ty = fx.cton_type(T).unwrap();
 377             let old = fx.bcx.ins().load(clif_ty, MemFlags::new(), ptr, 0);
 378
 379             // Compare
 380             let is_eq = fx.bcx.ins().icmp(IntCC::Equal, old, test_old);
 381             let new = crate::common::codegen_select(&mut fx.bcx, is_eq, old, new); // Keep old if not equal to test_old
 382
 383             // Write new
 384             fx.bcx.ins().store(MemFlags::new(), new, ptr, 0);
 385
 386             let ret_val = CValue::ByValPair(old, fx.bcx.ins().bint(types::I8, is_eq), ret.layout());
 387             ret.write_cvalue(fx, ret_val);
 388         };
 389
 390         _ if intrinsic.starts_with("atomic_xadd"), <T> (v ptr, v amount) {
 391             atomic_binop_return_old! (fx, iadd<T>(ptr, amount) -> ret);
 392         };
 393         _ if intrinsic.starts_with("atomic_xsub"), <T> (v ptr, v amount) {
 394             atomic_binop_return_old! (fx, isub<T>(ptr, amount) -> ret);
 395         };
 396         _ if intrinsic.starts_with("atomic_and"), <T> (v ptr, v src) {
 397             atomic_binop_return_old! (fx, band<T>(ptr, src) -> ret);
 398         };
 399         _ if intrinsic.starts_with("atomic_nand"), <T> (v ptr, v src) {
 400             atomic_binop_return_old! (fx, bnand<T>(ptr, src) -> ret);
 401         };
 402         _ if intrinsic.starts_with("atomic_or"), <T> (v ptr, v src) {
 403             atomic_binop_return_old! (fx, bor<T>(ptr, src) -> ret);
 404         };
 405         _ if intrinsic.starts_with("atomic_xor"), <T> (v ptr, v src) {
 406             atomic_binop_return_old! (fx, bxor<T>(ptr, src) -> ret);
 407         };
 408
 409         _ if intrinsic.starts_with("atomic_max"), <T> (v ptr, v src) {
 410             atomic_minmax!(fx, IntCC::SignedGreaterThan, <T> (ptr, src) -> ret);
 411         };
 412         _ if intrinsic.starts_with("atomic_umax"), <T> (v ptr, v src) {
 413             atomic_minmax!(fx, IntCC::UnsignedGreaterThan, <T> (ptr, src) -> ret);
 414         };
 415         _ if intrinsic.starts_with("atomic_min"), <T> (v ptr, v src) {
 416             atomic_minmax!(fx, IntCC::SignedLessThan, <T> (ptr, src) -> ret);
 417         };
 418         _ if intrinsic.starts_with("atomic_umin"), <T> (v ptr, v src) {
 419             atomic_minmax!(fx, IntCC::UnsignedLessThan, <T> (ptr, src) -> ret);
 420         };
 421     }
 422
 423     if let Some((_, dest)) = destination {
 424         let ret_ebb = fx.get_ebb(dest);
 425         fx.bcx.ins().jump(ret_ebb, &[]);
 426     } else {
 427         fx.bcx.ins().trap(TrapCode::User(!0));
 428     }
 429 }