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 pub fn codegen_intrinsic_call<'a, 'tcx: 'a>(
  62     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
  63     def_id: DefId,
  64     substs: &'tcx Substs,
  65     args: Vec<CValue<'tcx>>,
  66     destination: Option<(CPlace<'tcx>, BasicBlock)>,
  67 ) {
  68     let intrinsic = fx.tcx.item_name(def_id).as_str();
  69     let intrinsic = &intrinsic[..];
  70
  71     let ret = match destination {
  72         Some((place, _)) => place,
  73         None => {
  74             // Insert non returning intrinsics here
  75             match intrinsic {
  76                 "abort" => {
  77                     fx.bcx.ins().trap(TrapCode::User(!0 - 1));
  78                 }
  79                 "unreachable" => {
  80                     fx.bcx.ins().trap(TrapCode::User(!0 - 1));
  81                 }
  82                 _ => unimplemented!("unsupported instrinsic {}", intrinsic),
  83             }
  84             return;
  85         }
  86     };
  87
  88     let u64_layout = fx.layout_of(fx.tcx.types.u64);
  89     let usize_layout = fx.layout_of(fx.tcx.types.usize);
  90
  91     intrinsic_match! {
  92         fx, intrinsic, substs, args,
  93
  94         assume, (c _a) {};
  95         arith_offset, (v base, v offset) {
  96             let res = fx.bcx.ins().iadd(base, offset);
  97             let res = CValue::ByVal(res, ret.layout());
  98             ret.write_cvalue(fx, res);
  99         };
 100         likely | unlikely, (c a) {
 101             ret.write_cvalue(fx, a);
 102         };
 103         copy | copy_nonoverlapping, <elem_ty> (v src, v dst, v count) {
 104             let elem_size: u64 = fx.layout_of(elem_ty).size.bytes();
 105             let elem_size = fx
 106                 .bcx
 107                 .ins()
 108                 .iconst(fx.module.pointer_type(), elem_size as i64);
 109             assert_eq!(args.len(), 3);
 110             let byte_amount = fx.bcx.ins().imul(count, elem_size);
 111
 112             if intrinsic.ends_with("_nonoverlapping") {
 113                 fx.bcx.call_memcpy(fx.isa, dst, src, byte_amount);
 114             } else {
 115                 fx.bcx.call_memmove(fx.isa, dst, src, byte_amount);
 116             }
 117         };
 118         discriminant_value, (c val) {
 119             let discr = crate::base::trans_get_discriminant(fx, val, ret.layout());
 120             ret.write_cvalue(fx, discr);
 121         };
 122         size_of, <T> () {
 123             let size_of = fx.layout_of(T).size.bytes();
 124             let size_of = CValue::const_val(fx, usize_layout.ty, size_of as i64);
 125             ret.write_cvalue(fx, size_of);
 126         };
 127         size_of_val, <T> (c ptr) {
 128             let layout = fx.layout_of(T);
 129             let size = match &layout.ty.sty {
 130                 _ if !layout.is_unsized() => fx
 131                     .bcx
 132                     .ins()
 133                     .iconst(fx.module.pointer_type(), layout.size.bytes() as i64),
 134                 ty::Slice(elem) => {
 135                     let len = ptr.load_value_pair(fx).1;
 136                     let elem_size = fx.layout_of(elem).size.bytes();
 137                     fx.bcx.ins().imul_imm(len, elem_size as i64)
 138                 }
 139                 ty::Dynamic(..) => crate::vtable::size_of_obj(fx, ptr),
 140                 ty => bug!("size_of_val for unknown unsized type {:?}", ty),
 141             };
 142             ret.write_cvalue(fx, CValue::ByVal(size, usize_layout));
 143         };
 144         min_align_of, <T> () {
 145             let min_align = fx.layout_of(T).align.abi();
 146             let min_align = CValue::const_val(fx, usize_layout.ty, min_align as i64);
 147             ret.write_cvalue(fx, min_align);
 148         };
 149         min_align_of_val, <T> (c ptr) {
 150             let layout = fx.layout_of(T);
 151             let align = match &layout.ty.sty {
 152                 _ if !layout.is_unsized() => fx
 153                     .bcx
 154                     .ins()
 155                     .iconst(fx.module.pointer_type(), layout.align.abi() as i64),
 156                 ty::Slice(elem) => {
 157                     let align = fx.layout_of(elem).align.abi() as i64;
 158                     fx.bcx.ins().iconst(fx.module.pointer_type(), align)
 159                 }
 160                 ty::Dynamic(..) => crate::vtable::min_align_of_obj(fx, ptr),
 161                 ty => unimplemented!("min_align_of_val for {:?}", ty),
 162             };
 163             ret.write_cvalue(fx, CValue::ByVal(align, usize_layout));
 164         };
 165         type_id, <T> () {
 166             let type_id = fx.tcx.type_id_hash(T);
 167             let type_id = CValue::const_val(fx, u64_layout.ty, type_id as i64);
 168             ret.write_cvalue(fx, type_id);
 169         };
 170         _ if intrinsic.starts_with("unchecked_"), (c x, c y) {
 171             let bin_op = match intrinsic {
 172                 "unchecked_div" => BinOp::Div,
 173                 "unchecked_rem" => BinOp::Rem,
 174                 "unchecked_shl" => BinOp::Shl,
 175                 "unchecked_shr" => BinOp::Shr,
 176                 _ => unimplemented!("intrinsic {}", intrinsic),
 177             };
 178             let res = match ret.layout().ty.sty {
 179                 ty::Uint(_) => crate::base::trans_int_binop(
 180                     fx,
 181                     bin_op,
 182                     x,
 183                     y,
 184                     ret.layout().ty,
 185                     false,
 186                 ),
 187                 ty::Int(_) => crate::base::trans_int_binop(
 188                     fx,
 189                     bin_op,
 190                     x,
 191                     y,
 192                     ret.layout().ty,
 193                     true,
 194                 ),
 195                 _ => panic!(),
 196             };
 197             ret.write_cvalue(fx, res);
 198         };
 199         _ if intrinsic.ends_with("_with_overflow"), <T> (c x, c y) {
 200             assert_eq!(x.layout().ty, y.layout().ty);
 201             let bin_op = match intrinsic {
 202                 "add_with_overflow" => BinOp::Add,
 203                 "sub_with_overflow" => BinOp::Sub,
 204                 "mul_with_overflow" => BinOp::Mul,
 205                 _ => unimplemented!("intrinsic {}", intrinsic),
 206             };
 207             let res = match T.sty {
 208                 ty::Uint(_) => crate::base::trans_checked_int_binop(
 209                     fx,
 210                     bin_op,
 211                     x,
 212                     y,
 213                     ret.layout().ty,
 214                     false,
 215                 ),
 216                 ty::Int(_) => crate::base::trans_checked_int_binop(
 217                     fx,
 218                     bin_op,
 219                     x,
 220                     y,
 221                     ret.layout().ty,
 222                     true,
 223                 ),
 224                 _ => panic!(),
 225             };
 226             ret.write_cvalue(fx, res);
 227         };
 228         _ if intrinsic.starts_with("overflowing_"), <T> (c x, c y) {
 229             assert_eq!(x.layout().ty, y.layout().ty);
 230             let bin_op = match intrinsic {
 231                 "overflowing_add" => BinOp::Add,
 232                 "overflowing_sub" => BinOp::Sub,
 233                 "overflowing_mul" => BinOp::Mul,
 234                 _ => unimplemented!("intrinsic {}", intrinsic),
 235             };
 236             let res = match T.sty {
 237                 ty::Uint(_) => crate::base::trans_int_binop(
 238                     fx,
 239                     bin_op,
 240                     x,
 241                     y,
 242                     ret.layout().ty,
 243                     false,
 244                 ),
 245                 ty::Int(_) => crate::base::trans_int_binop(
 246                     fx,
 247                     bin_op,
 248                     x,
 249                     y,
 250                     ret.layout().ty,
 251                     true,
 252                 ),
 253                 _ => panic!(),
 254             };
 255             ret.write_cvalue(fx, res);
 256         };
 257         offset, (v base, v offset) {
 258             let res = fx.bcx.ins().iadd(base, offset);
 259             ret.write_cvalue(fx, CValue::ByVal(res, args[0].layout()));
 260         };
 261         transmute, <src_ty, dst_ty> (c from) {
 262             assert_eq!(from.layout().ty, src_ty);
 263             let addr = from.force_stack(fx);
 264             let dst_layout = fx.layout_of(dst_ty);
 265             ret.write_cvalue(fx, CValue::ByRef(addr, dst_layout))
 266         };
 267         init, <T> () {
 268             let layout = fx.layout_of(T);
 269             let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 270                 kind: StackSlotKind::ExplicitSlot,
 271                 size: layout.size.bytes() as u32,
 272                 offset: None,
 273             });
 274             let addr = fx.bcx.ins().stack_addr(pointer_ty(fx.tcx), stack_slot, 0);
 275             let zero_val = fx.bcx.ins().iconst(types::I8, 0);
 276             let len_val = fx.bcx.ins().iconst(pointer_ty(fx.tcx), layout.size.bytes() as i64);
 277             fx.bcx.call_memset(fx.isa, addr, zero_val, len_val);
 278
 279             let uninit_place = CPlace::from_stack_slot(fx, stack_slot, T);
 280             let uninit_val = uninit_place.to_cvalue(fx);
 281             ret.write_cvalue(fx, uninit_val);
 282         };
 283         uninit, <T> () {
 284             let layout = fx.layout_of(T);
 285             let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 286                 kind: StackSlotKind::ExplicitSlot,
 287                 size: layout.size.bytes() as u32,
 288                 offset: None,
 289             });
 290
 291             let uninit_place = CPlace::from_stack_slot(fx, stack_slot, T);
 292             let uninit_val = uninit_place.to_cvalue(fx);
 293             ret.write_cvalue(fx, uninit_val);
 294         };
 295         ctlz | ctlz_nonzero, <T> (v arg) {
 296             let res = CValue::ByVal(fx.bcx.ins().clz(arg), fx.layout_of(T));
 297             ret.write_cvalue(fx, res);
 298         };
 299         cttz | cttz_nonzero, <T> (v arg) {
 300             let res = CValue::ByVal(fx.bcx.ins().clz(arg), fx.layout_of(T));
 301             ret.write_cvalue(fx, res);
 302         };
 303         ctpop, <T> (v arg) {
 304             let res = CValue::ByVal(fx.bcx.ins().popcnt(arg), fx.layout_of(T));
 305             ret.write_cvalue(fx, res);
 306         };
 307         bitreverse, <T> (v arg) {
 308             let res = CValue::ByVal(fx.bcx.ins().bitrev(arg), fx.layout_of(T));
 309             ret.write_cvalue(fx, res);
 310         };
 311         needs_drop, <T> () {
 312             let needs_drop = if T.needs_drop(fx.tcx, ParamEnv::reveal_all()) {
 313                 1
 314             } else {
 315                 0
 316             };
 317             let needs_drop = CValue::const_val(fx, fx.tcx.types.bool, needs_drop);
 318             ret.write_cvalue(fx, needs_drop);
 319         };
 320         _ if intrinsic.starts_with("atomic_fence"), () {};
 321         _ if intrinsic.starts_with("atomic_singlethreadfence"), () {};
 322         _ if intrinsic.starts_with("atomic_load"), (c ptr) {
 323             let inner_layout =
 324                 fx.layout_of(ptr.layout().ty.builtin_deref(true).unwrap().ty);
 325             let val = CValue::ByRef(ptr.load_value(fx), inner_layout);
 326             ret.write_cvalue(fx, val);
 327         };
 328         _ if intrinsic.starts_with("atomic_store"), (v ptr, c val) {
 329             let dest = CPlace::Addr(ptr, None, val.layout());
 330             dest.write_cvalue(fx, val);
 331         };
 332         _ if intrinsic.starts_with("atomic_xadd"), <T> (v ptr, v amount) {
 333             let clif_ty = fx.cton_type(T).unwrap();
 334             let old = fx.bcx.ins().load(clif_ty, MemFlags::new(), ptr, 0);
 335             let new = fx.bcx.ins().iadd(old, amount);
 336             fx.bcx.ins().store(MemFlags::new(), new, ptr, 0);
 337             ret.write_cvalue(fx, CValue::ByVal(old, fx.layout_of(T)));
 338         };
 339         _ if intrinsic.starts_with("atomic_xsub"), <T> (v ptr, v amount) {
 340             let clif_ty = fx.cton_type(T).unwrap();
 341             let old = fx.bcx.ins().load(clif_ty, MemFlags::new(), ptr, 0);
 342             let new = fx.bcx.ins().isub(old, amount);
 343             fx.bcx.ins().store(MemFlags::new(), new, ptr, 0);
 344             ret.write_cvalue(fx, CValue::ByVal(old, fx.layout_of(T)));
 345         };
 346     }
 347
 348     if let Some((_, dest)) = destination {
 349         let ret_ebb = fx.get_ebb(dest);
 350         fx.bcx.ins().jump(ret_ebb, &[]);
 351     } else {
 352         fx.bcx.ins().trap(TrapCode::User(!0));
 353     }
 354 }