src/intrinsics.rs

   1 use crate::prelude::*;
   2
   3 macro_rules! intrinsic_pat {
   4     (_) => {
   5         _
   6     };
   7     ($name:ident) => {
   8         stringify!($name)
   9     }
  10 }
  11
  12 macro_rules! intrinsic_arg {
  13     (c $fx:expr, $arg:ident) => {
  14         $arg
  15     };
  16     (v $fx:expr, $arg:ident) => {
  17         $arg.load_scalar($fx)
  18     };
  19 }
  20
  21 macro_rules! intrinsic_substs {
  22     ($substs:expr, $index:expr,) => {};
  23     ($substs:expr, $index:expr, $first:ident $(,$rest:ident)*) => {
  24         let $first = $substs.type_at($index);
  25         intrinsic_substs!($substs, $index+1, $($rest),*);
  26     };
  27 }
  28
  29 macro_rules! intrinsic_match {
  30     ($fx:expr, $intrinsic:expr, $substs:expr, $args:expr, $(
  31         $($name:tt)|+ $(if $cond:expr)?, $(<$($subst:ident),*>)? ($($a:ident $arg:ident),*) $content:block;
  32     )*) => {
  33         match $intrinsic {
  34             $(
  35                 $(intrinsic_pat!($name))|* $(if $cond)? => {
  36                     #[allow(unused_parens, non_snake_case)]
  37                     {
  38                         $(
  39                             intrinsic_substs!($substs, 0, $($subst),*);
  40                         )?
  41                         if let [$($arg),*] = *$args {
  42                             let ($($arg),*) = (
  43                                 $(intrinsic_arg!($a $fx, $arg)),*
  44                             );
  45                             #[warn(unused_parens, non_snake_case)]
  46                             {
  47                                 $content
  48                             }
  49                         } else {
  50                             bug!("wrong number of args for intrinsic {:?}", $intrinsic);
  51                         }
  52                     }
  53                 }
  54             )*
  55             _ => unimpl!("unsupported intrinsic {}", $intrinsic),
  56         }
  57     };
  58 }
  59
  60 macro_rules! atomic_binop_return_old {
  61     ($fx:expr, $op:ident<$T:ident>($ptr:ident, $src:ident) -> $ret:ident) => {
  62         let clif_ty = $fx.clif_type($T).unwrap();
  63         let old = $fx.bcx.ins().load(clif_ty, MemFlags::new(), $ptr, 0);
  64         let new = $fx.bcx.ins().band(old, $src);
  65         $fx.bcx.ins().store(MemFlags::new(), new, $ptr, 0);
  66         $ret.write_cvalue($fx, CValue::ByVal(old, $fx.layout_of($T)));
  67     };
  68 }
  69
  70 macro_rules! atomic_minmax {
  71     ($fx:expr, $cc:expr, <$T:ident> ($ptr:ident, $src:ident) -> $ret:ident) => {
  72         // Read old
  73         let clif_ty = $fx.clif_type($T).unwrap();
  74         let old = $fx.bcx.ins().load(clif_ty, MemFlags::new(), $ptr, 0);
  75
  76         // Compare
  77         let is_eq = $fx.bcx.ins().icmp(IntCC::SignedGreaterThan, old, $src);
  78         let new = crate::common::codegen_select(&mut $fx.bcx, is_eq, old, $src);
  79
  80         // Write new
  81         $fx.bcx.ins().store(MemFlags::new(), new, $ptr, 0);
  82
  83         let ret_val = CValue::ByVal(old, $ret.layout());
  84         $ret.write_cvalue($fx, ret_val);
  85     };
  86 }
  87
  88 pub fn codegen_intrinsic_call<'a, 'tcx: 'a>(
  89     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
  90     def_id: DefId,
  91     substs: &'tcx Substs,
  92     args: Vec<CValue<'tcx>>,
  93     destination: Option<(CPlace<'tcx>, BasicBlock)>,
  94 ) {
  95     let intrinsic = fx.tcx.item_name(def_id).as_str();
  96     let intrinsic = &intrinsic[..];
  97
  98     let ret = match destination {
  99         Some((place, _)) => place,
 100         None => {
 101             // Insert non returning intrinsics here
 102             match intrinsic {
 103                 "abort" => {
 104                     trap_panic(&mut fx.bcx);
 105                 }
 106                 "unreachable" => {
 107                     trap_unreachable(&mut fx.bcx);
 108                 }
 109                 _ => unimplemented!("unsupported instrinsic {}", intrinsic),
 110             }
 111             return;
 112         }
 113     };
 114
 115     let u64_layout = fx.layout_of(fx.tcx.types.u64);
 116     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 117
 118     intrinsic_match! {
 119         fx, intrinsic, substs, args,
 120
 121         assume, (c _a) {};
 122         likely | unlikely, (c a) {
 123             ret.write_cvalue(fx, a);
 124         };
 125         breakpoint, () {
 126             fx.bcx.ins().debugtrap();
 127         };
 128         copy | copy_nonoverlapping, <elem_ty> (v src, v dst, v count) {
 129             let elem_size: u64 = fx.layout_of(elem_ty).size.bytes();
 130             let elem_size = fx
 131                 .bcx
 132                 .ins()
 133                 .iconst(fx.pointer_type, elem_size as i64);
 134             assert_eq!(args.len(), 3);
 135             let byte_amount = fx.bcx.ins().imul(count, elem_size);
 136
 137             if intrinsic.ends_with("_nonoverlapping") {
 138                 fx.bcx.call_memcpy(fx.module.target_config(), dst, src, byte_amount);
 139             } else {
 140                 fx.bcx.call_memmove(fx.module.target_config(), dst, src, byte_amount);
 141             }
 142         };
 143         discriminant_value, (c val) {
 144             let discr = crate::base::trans_get_discriminant(fx, val, ret.layout());
 145             ret.write_cvalue(fx, discr);
 146         };
 147         size_of, <T> () {
 148             let size_of = fx.layout_of(T).size.bytes();
 149             let size_of = CValue::const_val(fx, usize_layout.ty, size_of as i64);
 150             ret.write_cvalue(fx, size_of);
 151         };
 152         size_of_val, <T> (c ptr) {
 153             let layout = fx.layout_of(T);
 154             let size = if layout.is_unsized() {
 155                 let (_ptr, info) = ptr.load_value_pair(fx);
 156                 let (size, _align) = crate::unsize::size_and_align_of_dst(fx, layout.ty, info);
 157                 size
 158             } else {
 159                 fx
 160                     .bcx
 161                     .ins()
 162                     .iconst(fx.pointer_type, layout.size.bytes() as i64)
 163             };
 164             ret.write_cvalue(fx, CValue::ByVal(size, usize_layout));
 165         };
 166         min_align_of, <T> () {
 167             let min_align = fx.layout_of(T).align.abi.bytes();
 168             let min_align = CValue::const_val(fx, usize_layout.ty, min_align as i64);
 169             ret.write_cvalue(fx, min_align);
 170         };
 171         min_align_of_val, <T> (c ptr) {
 172             let layout = fx.layout_of(T);
 173             let align = if layout.is_unsized() {
 174                 let (_ptr, info) = ptr.load_value_pair(fx);
 175                 let (_size, align) = crate::unsize::size_and_align_of_dst(fx, layout.ty, info);
 176                 align
 177             } else {
 178                 fx
 179                     .bcx
 180                     .ins()
 181                     .iconst(fx.pointer_type, layout.align.abi.bytes() as i64)
 182             };
 183             ret.write_cvalue(fx, CValue::ByVal(align, usize_layout));
 184         };
 185         type_id, <T> () {
 186             let type_id = fx.tcx.type_id_hash(T);
 187             let type_id = CValue::const_val(fx, u64_layout.ty, type_id as i64);
 188             ret.write_cvalue(fx, type_id);
 189         };
 190         _ if intrinsic.starts_with("unchecked_") || intrinsic == "exact_div", (c x, c y) {
 191             let bin_op = match intrinsic {
 192                 "unchecked_div" | "exact_div" => BinOp::Div,
 193                 "unchecked_rem" => BinOp::Rem,
 194                 "unchecked_shl" => BinOp::Shl,
 195                 "unchecked_shr" => BinOp::Shr,
 196                 _ => unimplemented!("intrinsic {}", intrinsic),
 197             };
 198             let res = match ret.layout().ty.sty {
 199                 ty::Uint(_) => crate::base::trans_int_binop(
 200                     fx,
 201                     bin_op,
 202                     x,
 203                     y,
 204                     ret.layout().ty,
 205                     false,
 206                 ),
 207                 ty::Int(_) => crate::base::trans_int_binop(
 208                     fx,
 209                     bin_op,
 210                     x,
 211                     y,
 212                     ret.layout().ty,
 213                     true,
 214                 ),
 215                 _ => panic!(),
 216             };
 217             ret.write_cvalue(fx, res);
 218         };
 219         _ if intrinsic.ends_with("_with_overflow"), <T> (c x, c y) {
 220             assert_eq!(x.layout().ty, y.layout().ty);
 221             let bin_op = match intrinsic {
 222                 "add_with_overflow" => BinOp::Add,
 223                 "sub_with_overflow" => BinOp::Sub,
 224                 "mul_with_overflow" => BinOp::Mul,
 225                 _ => unimplemented!("intrinsic {}", intrinsic),
 226             };
 227             let res = match T.sty {
 228                 ty::Uint(_) => crate::base::trans_checked_int_binop(
 229                     fx,
 230                     bin_op,
 231                     x,
 232                     y,
 233                     ret.layout().ty,
 234                     false,
 235                 ),
 236                 ty::Int(_) => crate::base::trans_checked_int_binop(
 237                     fx,
 238                     bin_op,
 239                     x,
 240                     y,
 241                     ret.layout().ty,
 242                     true,
 243                 ),
 244                 _ => panic!(),
 245             };
 246             ret.write_cvalue(fx, res);
 247         };
 248         _ if intrinsic.starts_with("overflowing_"), <T> (c x, c y) {
 249             assert_eq!(x.layout().ty, y.layout().ty);
 250             let bin_op = match intrinsic {
 251                 "overflowing_add" => BinOp::Add,
 252                 "overflowing_sub" => BinOp::Sub,
 253                 "overflowing_mul" => BinOp::Mul,
 254                 _ => unimplemented!("intrinsic {}", intrinsic),
 255             };
 256             let res = match T.sty {
 257                 ty::Uint(_) => crate::base::trans_int_binop(
 258                     fx,
 259                     bin_op,
 260                     x,
 261                     y,
 262                     ret.layout().ty,
 263                     false,
 264                 ),
 265                 ty::Int(_) => crate::base::trans_int_binop(
 266                     fx,
 267                     bin_op,
 268                     x,
 269                     y,
 270                     ret.layout().ty,
 271                     true,
 272                 ),
 273                 _ => panic!(),
 274             };
 275             ret.write_cvalue(fx, res);
 276         };
 277         rotate_left, <T>(v x, v y) {
 278             let layout = fx.layout_of(T);
 279             let res = fx.bcx.ins().rotl(x, y);
 280             ret.write_cvalue(fx, CValue::ByVal(res, layout));
 281         };
 282         rotate_right, <T>(v x, v y) {
 283             let layout = fx.layout_of(T);
 284             let res = fx.bcx.ins().rotr(x, y);
 285             ret.write_cvalue(fx, CValue::ByVal(res, layout));
 286         };
 287
 288         // The only difference between offset and arith_offset is regarding UB. Because Cranelift
 289         // doesn't have UB both are codegen'ed the same way
 290         offset | arith_offset, (c base, v offset) {
 291             let pointee_ty = base.layout().ty.builtin_deref(true).unwrap().ty;
 292             let pointee_size = fx.layout_of(pointee_ty).size.bytes();
 293             let ptr_diff = fx.bcx.ins().imul_imm(offset, pointee_size as i64);
 294             let base_val = base.load_scalar(fx);
 295             let res = fx.bcx.ins().iadd(base_val, ptr_diff);
 296             ret.write_cvalue(fx, CValue::ByVal(res, args[0].layout()));
 297         };
 298
 299         transmute, <src_ty, dst_ty> (c from) {
 300             assert_eq!(from.layout().ty, src_ty);
 301             let addr = from.force_stack(fx);
 302             let dst_layout = fx.layout_of(dst_ty);
 303             ret.write_cvalue(fx, CValue::ByRef(addr, dst_layout))
 304         };
 305         init, <T> () {
 306             let layout = fx.layout_of(T);
 307             let inited_place = CPlace::new_stack_slot(fx, T);
 308             let addr = inited_place.to_addr(fx);
 309             let zero_val = fx.bcx.ins().iconst(types::I8, 0);
 310             let len_val = fx.bcx.ins().iconst(pointer_ty(fx.tcx), layout.size.bytes() as i64);
 311             fx.bcx.call_memset(fx.module.target_config(), addr, zero_val, len_val);
 312
 313             let inited_val = inited_place.to_cvalue(fx);
 314             ret.write_cvalue(fx, inited_val);
 315         };
 316         write_bytes, (c dst, v val, v count) {
 317             let pointee_ty = dst.layout().ty.builtin_deref(true).unwrap().ty;
 318             let pointee_size = fx.layout_of(pointee_ty).size.bytes();
 319             let count = fx.bcx.ins().imul_imm(count, pointee_size as i64);
 320             let dst_ptr = dst.load_scalar(fx);
 321             fx.bcx.call_memset(fx.module.target_config(), dst_ptr, val, count);
 322         };
 323         uninit, <T> () {
 324             let uninit_place = CPlace::new_stack_slot(fx, T);
 325             let uninit_val = uninit_place.to_cvalue(fx);
 326             ret.write_cvalue(fx, uninit_val);
 327         };
 328         ctlz | ctlz_nonzero, <T> (v arg) {
 329             let res = CValue::ByVal(fx.bcx.ins().clz(arg), fx.layout_of(T));
 330             ret.write_cvalue(fx, res);
 331         };
 332         cttz | cttz_nonzero, <T> (v arg) {
 333             let res = CValue::ByVal(fx.bcx.ins().ctz(arg), fx.layout_of(T));
 334             ret.write_cvalue(fx, res);
 335         };
 336         ctpop, <T> (v arg) {
 337             let res = CValue::ByVal(fx.bcx.ins().popcnt(arg), fx.layout_of(T));
 338             ret.write_cvalue(fx, res);
 339         };
 340         bitreverse, <T> (v arg) {
 341             let res = CValue::ByVal(fx.bcx.ins().bitrev(arg), fx.layout_of(T));
 342             ret.write_cvalue(fx, res);
 343         };
 344         needs_drop, <T> () {
 345             let needs_drop = if T.needs_drop(fx.tcx, ParamEnv::reveal_all()) {
 346                 1
 347             } else {
 348                 0
 349             };
 350             let needs_drop = CValue::const_val(fx, fx.tcx.types.bool, needs_drop);
 351             ret.write_cvalue(fx, needs_drop);
 352         };
 353         panic_if_uninhabited, <T> () {
 354             if fx.layout_of(T).abi.is_uninhabited() {
 355                 crate::trap::trap_panic(&mut fx.bcx);
 356                 return;
 357             }
 358         };
 359
 360         _ if intrinsic.starts_with("atomic_fence"), () {};
 361         _ if intrinsic.starts_with("atomic_singlethreadfence"), () {};
 362         _ if intrinsic.starts_with("atomic_load"), (c ptr) {
 363             let inner_layout =
 364                 fx.layout_of(ptr.layout().ty.builtin_deref(true).unwrap().ty);
 365             let val = CValue::ByRef(ptr.load_scalar(fx), inner_layout);
 366             ret.write_cvalue(fx, val);
 367         };
 368         _ if intrinsic.starts_with("atomic_store"), (v ptr, c val) {
 369             let dest = CPlace::Addr(ptr, None, val.layout());
 370             dest.write_cvalue(fx, val);
 371         };
 372         _ if intrinsic.starts_with("atomic_xchg"), <T> (v ptr, c src) {
 373             // Read old
 374             let clif_ty = fx.clif_type(T).unwrap();
 375             let old = fx.bcx.ins().load(clif_ty, MemFlags::new(), ptr, 0);
 376             ret.write_cvalue(fx, CValue::ByVal(old, fx.layout_of(T)));
 377
 378             // Write new
 379             let dest = CPlace::Addr(ptr, None, src.layout());
 380             dest.write_cvalue(fx, src);
 381         };
 382         _ if intrinsic.starts_with("atomic_cxchg"), <T> (v ptr, v test_old, v new) { // both atomic_cxchg_* and atomic_cxchgweak_*
 383             // Read old
 384             let clif_ty = fx.clif_type(T).unwrap();
 385             let old = fx.bcx.ins().load(clif_ty, MemFlags::new(), ptr, 0);
 386
 387             // Compare
 388             let is_eq = fx.bcx.ins().icmp(IntCC::Equal, old, test_old);
 389             let new = crate::common::codegen_select(&mut fx.bcx, is_eq, old, new); // Keep old if not equal to test_old
 390
 391             // Write new
 392             fx.bcx.ins().store(MemFlags::new(), new, ptr, 0);
 393
 394             let ret_val = CValue::ByValPair(old, fx.bcx.ins().bint(types::I8, is_eq), ret.layout());
 395             ret.write_cvalue(fx, ret_val);
 396         };
 397
 398         _ if intrinsic.starts_with("atomic_xadd"), <T> (v ptr, v amount) {
 399             atomic_binop_return_old! (fx, iadd<T>(ptr, amount) -> ret);
 400         };
 401         _ if intrinsic.starts_with("atomic_xsub"), <T> (v ptr, v amount) {
 402             atomic_binop_return_old! (fx, isub<T>(ptr, amount) -> ret);
 403         };
 404         _ if intrinsic.starts_with("atomic_and"), <T> (v ptr, v src) {
 405             atomic_binop_return_old! (fx, band<T>(ptr, src) -> ret);
 406         };
 407         _ if intrinsic.starts_with("atomic_nand"), <T> (v ptr, v src) {
 408             atomic_binop_return_old! (fx, bnand<T>(ptr, src) -> ret);
 409         };
 410         _ if intrinsic.starts_with("atomic_or"), <T> (v ptr, v src) {
 411             atomic_binop_return_old! (fx, bor<T>(ptr, src) -> ret);
 412         };
 413         _ if intrinsic.starts_with("atomic_xor"), <T> (v ptr, v src) {
 414             atomic_binop_return_old! (fx, bxor<T>(ptr, src) -> ret);
 415         };
 416
 417         _ if intrinsic.starts_with("atomic_max"), <T> (v ptr, v src) {
 418             atomic_minmax!(fx, IntCC::SignedGreaterThan, <T> (ptr, src) -> ret);
 419         };
 420         _ if intrinsic.starts_with("atomic_umax"), <T> (v ptr, v src) {
 421             atomic_minmax!(fx, IntCC::UnsignedGreaterThan, <T> (ptr, src) -> ret);
 422         };
 423         _ if intrinsic.starts_with("atomic_min"), <T> (v ptr, v src) {
 424             atomic_minmax!(fx, IntCC::SignedLessThan, <T> (ptr, src) -> ret);
 425         };
 426         _ if intrinsic.starts_with("atomic_umin"), <T> (v ptr, v src) {
 427             atomic_minmax!(fx, IntCC::UnsignedLessThan, <T> (ptr, src) -> ret);
 428         };
 429     }
 430
 431     if let Some((_, dest)) = destination {
 432         let ret_ebb = fx.get_ebb(dest);
 433         fx.bcx.ins().jump(ret_ebb, &[]);
 434     } else {
 435         trap_unreachable(&mut fx.bcx);
 436     }
 437 }