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         arith_offset, (v base, v offset) {
 123             let res = fx.bcx.ins().iadd(base, offset);
 124             let res = CValue::ByVal(res, ret.layout());
 125             ret.write_cvalue(fx, res);
 126         };
 127         likely | unlikely, (c a) {
 128             ret.write_cvalue(fx, a);
 129         };
 130         copy | copy_nonoverlapping, <elem_ty> (v src, v dst, v count) {
 131             let elem_size: u64 = fx.layout_of(elem_ty).size.bytes();
 132             let elem_size = fx
 133                 .bcx
 134                 .ins()
 135                 .iconst(fx.pointer_type, elem_size as i64);
 136             assert_eq!(args.len(), 3);
 137             let byte_amount = fx.bcx.ins().imul(count, elem_size);
 138
 139             if intrinsic.ends_with("_nonoverlapping") {
 140                 fx.bcx.call_memcpy(fx.module.target_config(), dst, src, byte_amount);
 141             } else {
 142                 fx.bcx.call_memmove(fx.module.target_config(), dst, src, byte_amount);
 143             }
 144         };
 145         discriminant_value, (c val) {
 146             let discr = crate::base::trans_get_discriminant(fx, val, ret.layout());
 147             ret.write_cvalue(fx, discr);
 148         };
 149         size_of, <T> () {
 150             let size_of = fx.layout_of(T).size.bytes();
 151             let size_of = CValue::const_val(fx, usize_layout.ty, size_of as i64);
 152             ret.write_cvalue(fx, size_of);
 153         };
 154         size_of_val, <T> (c ptr) {
 155             let layout = fx.layout_of(T);
 156             let size = if layout.is_unsized() {
 157                 let (_ptr, info) = ptr.load_value_pair(fx);
 158                 let (size, _align) = crate::unsize::size_and_align_of_dst(fx, layout.ty, info);
 159                 size
 160             } else {
 161                 fx
 162                     .bcx
 163                     .ins()
 164                     .iconst(fx.pointer_type, layout.size.bytes() as i64)
 165             };
 166             ret.write_cvalue(fx, CValue::ByVal(size, usize_layout));
 167         };
 168         min_align_of, <T> () {
 169             let min_align = fx.layout_of(T).align.abi.bytes();
 170             let min_align = CValue::const_val(fx, usize_layout.ty, min_align as i64);
 171             ret.write_cvalue(fx, min_align);
 172         };
 173         min_align_of_val, <T> (c ptr) {
 174             let layout = fx.layout_of(T);
 175             let align = if layout.is_unsized() {
 176                 let (_ptr, info) = ptr.load_value_pair(fx);
 177                 let (_size, align) = crate::unsize::size_and_align_of_dst(fx, layout.ty, info);
 178                 align
 179             } else {
 180                 fx
 181                     .bcx
 182                     .ins()
 183                     .iconst(fx.pointer_type, layout.align.abi.bytes() as i64)
 184             };
 185             ret.write_cvalue(fx, CValue::ByVal(align, usize_layout));
 186         };
 187         type_id, <T> () {
 188             let type_id = fx.tcx.type_id_hash(T);
 189             let type_id = CValue::const_val(fx, u64_layout.ty, type_id as i64);
 190             ret.write_cvalue(fx, type_id);
 191         };
 192         _ if intrinsic.starts_with("unchecked_") || intrinsic == "exact_div", (c x, c y) {
 193             let bin_op = match intrinsic {
 194                 "unchecked_div" | "exact_div" => BinOp::Div,
 195                 "unchecked_rem" => BinOp::Rem,
 196                 "unchecked_shl" => BinOp::Shl,
 197                 "unchecked_shr" => BinOp::Shr,
 198                 _ => unimplemented!("intrinsic {}", intrinsic),
 199             };
 200             let res = match ret.layout().ty.sty {
 201                 ty::Uint(_) => crate::base::trans_int_binop(
 202                     fx,
 203                     bin_op,
 204                     x,
 205                     y,
 206                     ret.layout().ty,
 207                     false,
 208                 ),
 209                 ty::Int(_) => crate::base::trans_int_binop(
 210                     fx,
 211                     bin_op,
 212                     x,
 213                     y,
 214                     ret.layout().ty,
 215                     true,
 216                 ),
 217                 _ => panic!(),
 218             };
 219             ret.write_cvalue(fx, res);
 220         };
 221         _ if intrinsic.ends_with("_with_overflow"), <T> (c x, c y) {
 222             assert_eq!(x.layout().ty, y.layout().ty);
 223             let bin_op = match intrinsic {
 224                 "add_with_overflow" => BinOp::Add,
 225                 "sub_with_overflow" => BinOp::Sub,
 226                 "mul_with_overflow" => BinOp::Mul,
 227                 _ => unimplemented!("intrinsic {}", intrinsic),
 228             };
 229             let res = match T.sty {
 230                 ty::Uint(_) => crate::base::trans_checked_int_binop(
 231                     fx,
 232                     bin_op,
 233                     x,
 234                     y,
 235                     ret.layout().ty,
 236                     false,
 237                 ),
 238                 ty::Int(_) => crate::base::trans_checked_int_binop(
 239                     fx,
 240                     bin_op,
 241                     x,
 242                     y,
 243                     ret.layout().ty,
 244                     true,
 245                 ),
 246                 _ => panic!(),
 247             };
 248             ret.write_cvalue(fx, res);
 249         };
 250         _ if intrinsic.starts_with("overflowing_"), <T> (c x, c y) {
 251             assert_eq!(x.layout().ty, y.layout().ty);
 252             let bin_op = match intrinsic {
 253                 "overflowing_add" => BinOp::Add,
 254                 "overflowing_sub" => BinOp::Sub,
 255                 "overflowing_mul" => BinOp::Mul,
 256                 _ => unimplemented!("intrinsic {}", intrinsic),
 257             };
 258             let res = match T.sty {
 259                 ty::Uint(_) => crate::base::trans_int_binop(
 260                     fx,
 261                     bin_op,
 262                     x,
 263                     y,
 264                     ret.layout().ty,
 265                     false,
 266                 ),
 267                 ty::Int(_) => crate::base::trans_int_binop(
 268                     fx,
 269                     bin_op,
 270                     x,
 271                     y,
 272                     ret.layout().ty,
 273                     true,
 274                 ),
 275                 _ => panic!(),
 276             };
 277             ret.write_cvalue(fx, res);
 278         };
 279         rotate_left, <T>(v x, v y) {
 280             let layout = fx.layout_of(T);
 281             let res = fx.bcx.ins().rotl(x, y);
 282             ret.write_cvalue(fx, CValue::ByVal(res, layout));
 283         };
 284         rotate_right, <T>(v x, v y) {
 285             let layout = fx.layout_of(T);
 286             let res = fx.bcx.ins().rotr(x, y);
 287             ret.write_cvalue(fx, CValue::ByVal(res, layout));
 288         };
 289         offset, (v base, v offset) {
 290             let res = fx.bcx.ins().iadd(base, offset);
 291             ret.write_cvalue(fx, CValue::ByVal(res, args[0].layout()));
 292         };
 293         transmute, <src_ty, dst_ty> (c from) {
 294             assert_eq!(from.layout().ty, src_ty);
 295             let addr = from.force_stack(fx);
 296             let dst_layout = fx.layout_of(dst_ty);
 297             ret.write_cvalue(fx, CValue::ByRef(addr, dst_layout))
 298         };
 299         init, <T> () {
 300             let layout = fx.layout_of(T);
 301             let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 302                 kind: StackSlotKind::ExplicitSlot,
 303                 size: layout.size.bytes() as u32,
 304                 offset: None,
 305             });
 306             let addr = fx.bcx.ins().stack_addr(pointer_ty(fx.tcx), stack_slot, 0);
 307             let zero_val = fx.bcx.ins().iconst(types::I8, 0);
 308             let len_val = fx.bcx.ins().iconst(pointer_ty(fx.tcx), layout.size.bytes() as i64);
 309             fx.bcx.call_memset(fx.module.target_config(), addr, zero_val, len_val);
 310
 311             let uninit_place = CPlace::from_stack_slot(fx, stack_slot, T);
 312             let uninit_val = uninit_place.to_cvalue(fx);
 313             ret.write_cvalue(fx, uninit_val);
 314         };
 315         write_bytes, (v dst, v val, v count) {
 316             fx.bcx.call_memset(fx.module.target_config(), dst, val, count);
 317         };
 318         uninit, <T> () {
 319             let layout = fx.layout_of(T);
 320             let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 321                 kind: StackSlotKind::ExplicitSlot,
 322                 size: layout.size.bytes() as u32,
 323                 offset: None,
 324             });
 325
 326             let uninit_place = CPlace::from_stack_slot(fx, stack_slot, T);
 327             let uninit_val = uninit_place.to_cvalue(fx);
 328             ret.write_cvalue(fx, uninit_val);
 329         };
 330         ctlz | ctlz_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         cttz | cttz_nonzero, <T> (v arg) {
 335             let res = CValue::ByVal(fx.bcx.ins().clz(arg), fx.layout_of(T));
 336             ret.write_cvalue(fx, res);
 337         };
 338         ctpop, <T> (v arg) {
 339             let res = CValue::ByVal(fx.bcx.ins().popcnt(arg), fx.layout_of(T));
 340             ret.write_cvalue(fx, res);
 341         };
 342         bitreverse, <T> (v arg) {
 343             let res = CValue::ByVal(fx.bcx.ins().bitrev(arg), fx.layout_of(T));
 344             ret.write_cvalue(fx, res);
 345         };
 346         needs_drop, <T> () {
 347             let needs_drop = if T.needs_drop(fx.tcx, ParamEnv::reveal_all()) {
 348                 1
 349             } else {
 350                 0
 351             };
 352             let needs_drop = CValue::const_val(fx, fx.tcx.types.bool, needs_drop);
 353             ret.write_cvalue(fx, needs_drop);
 354         };
 355
 356         _ if intrinsic.starts_with("atomic_fence"), () {};
 357         _ if intrinsic.starts_with("atomic_singlethreadfence"), () {};
 358         _ if intrinsic.starts_with("atomic_load"), (c ptr) {
 359             let inner_layout =
 360                 fx.layout_of(ptr.layout().ty.builtin_deref(true).unwrap().ty);
 361             let val = CValue::ByRef(ptr.load_scalar(fx), inner_layout);
 362             ret.write_cvalue(fx, val);
 363         };
 364         _ if intrinsic.starts_with("atomic_store"), (v ptr, c val) {
 365             let dest = CPlace::Addr(ptr, None, val.layout());
 366             dest.write_cvalue(fx, val);
 367         };
 368         _ if intrinsic.starts_with("atomic_xchg"), <T> (v ptr, c src) {
 369             // Read old
 370             let clif_ty = fx.clif_type(T).unwrap();
 371             let old = fx.bcx.ins().load(clif_ty, MemFlags::new(), ptr, 0);
 372             ret.write_cvalue(fx, CValue::ByVal(old, fx.layout_of(T)));
 373
 374             // Write new
 375             let dest = CPlace::Addr(ptr, None, src.layout());
 376             dest.write_cvalue(fx, src);
 377         };
 378         _ if intrinsic.starts_with("atomic_cxchg"), <T> (v ptr, v test_old, v new) { // both atomic_cxchg_* and atomic_cxchgweak_*
 379             // Read old
 380             let clif_ty = fx.clif_type(T).unwrap();
 381             let old = fx.bcx.ins().load(clif_ty, MemFlags::new(), ptr, 0);
 382
 383             // Compare
 384             let is_eq = fx.bcx.ins().icmp(IntCC::Equal, old, test_old);
 385             let new = crate::common::codegen_select(&mut fx.bcx, is_eq, old, new); // Keep old if not equal to test_old
 386
 387             // Write new
 388             fx.bcx.ins().store(MemFlags::new(), new, ptr, 0);
 389
 390             let ret_val = CValue::ByValPair(old, fx.bcx.ins().bint(types::I8, is_eq), ret.layout());
 391             ret.write_cvalue(fx, ret_val);
 392         };
 393
 394         _ if intrinsic.starts_with("atomic_xadd"), <T> (v ptr, v amount) {
 395             atomic_binop_return_old! (fx, iadd<T>(ptr, amount) -> ret);
 396         };
 397         _ if intrinsic.starts_with("atomic_xsub"), <T> (v ptr, v amount) {
 398             atomic_binop_return_old! (fx, isub<T>(ptr, amount) -> ret);
 399         };
 400         _ if intrinsic.starts_with("atomic_and"), <T> (v ptr, v src) {
 401             atomic_binop_return_old! (fx, band<T>(ptr, src) -> ret);
 402         };
 403         _ if intrinsic.starts_with("atomic_nand"), <T> (v ptr, v src) {
 404             atomic_binop_return_old! (fx, bnand<T>(ptr, src) -> ret);
 405         };
 406         _ if intrinsic.starts_with("atomic_or"), <T> (v ptr, v src) {
 407             atomic_binop_return_old! (fx, bor<T>(ptr, src) -> ret);
 408         };
 409         _ if intrinsic.starts_with("atomic_xor"), <T> (v ptr, v src) {
 410             atomic_binop_return_old! (fx, bxor<T>(ptr, src) -> ret);
 411         };
 412
 413         _ if intrinsic.starts_with("atomic_max"), <T> (v ptr, v src) {
 414             atomic_minmax!(fx, IntCC::SignedGreaterThan, <T> (ptr, src) -> ret);
 415         };
 416         _ if intrinsic.starts_with("atomic_umax"), <T> (v ptr, v src) {
 417             atomic_minmax!(fx, IntCC::UnsignedGreaterThan, <T> (ptr, src) -> ret);
 418         };
 419         _ if intrinsic.starts_with("atomic_min"), <T> (v ptr, v src) {
 420             atomic_minmax!(fx, IntCC::SignedLessThan, <T> (ptr, src) -> ret);
 421         };
 422         _ if intrinsic.starts_with("atomic_umin"), <T> (v ptr, v src) {
 423             atomic_minmax!(fx, IntCC::UnsignedLessThan, <T> (ptr, src) -> ret);
 424         };
 425     }
 426
 427     if let Some((_, dest)) = destination {
 428         let ret_ebb = fx.get_ebb(dest);
 429         fx.bcx.ins().jump(ret_ebb, &[]);
 430     } else {
 431         trap_unreachable(&mut fx.bcx);
 432     }
 433 }