/
rvalue.rs
750 lines (691 loc) · 32.5 KB
/
rvalue.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use llvm::{self, ValueRef};
use rustc::ty::{self, Ty};
use rustc::ty::cast::{CastTy, IntTy};
use rustc::ty::layout::Layout;
use rustc::mir::tcx::LvalueTy;
use rustc::mir;
use middle::lang_items::ExchangeMallocFnLangItem;
use asm;
use base;
use builder::Builder;
use callee::Callee;
use common::{self, val_ty, C_bool, C_null, C_uint};
use common::{C_integral};
use adt;
use machine;
use type_::Type;
use type_of;
use tvec;
use value::Value;
use Disr;
use super::MirContext;
use super::constant::const_scalar_checked_binop;
use super::operand::{OperandRef, OperandValue};
use super::lvalue::{LvalueRef};
impl<'a, 'tcx> MirContext<'a, 'tcx> {
pub fn trans_rvalue(&mut self,
bcx: Builder<'a, 'tcx>,
dest: LvalueRef<'tcx>,
rvalue: &mir::Rvalue<'tcx>)
-> Builder<'a, 'tcx>
{
debug!("trans_rvalue(dest.llval={:?}, rvalue={:?})",
Value(dest.llval), rvalue);
match *rvalue {
mir::Rvalue::Use(ref operand) => {
let tr_operand = self.trans_operand(&bcx, operand);
// FIXME: consider not copying constants through stack. (fixable by translating
// constants into OperandValue::Ref, why don’t we do that yet if we don’t?)
self.store_operand(&bcx, dest.llval, tr_operand, None);
bcx
}
mir::Rvalue::Cast(mir::CastKind::Unsize, ref source, cast_ty) => {
let cast_ty = self.monomorphize(&cast_ty);
if common::type_is_fat_ptr(bcx.ccx, cast_ty) {
// into-coerce of a thin pointer to a fat pointer - just
// use the operand path.
let (bcx, temp) = self.trans_rvalue_operand(bcx, rvalue);
self.store_operand(&bcx, dest.llval, temp, None);
return bcx;
}
// Unsize of a nontrivial struct. I would prefer for
// this to be eliminated by MIR translation, but
// `CoerceUnsized` can be passed by a where-clause,
// so the (generic) MIR may not be able to expand it.
let operand = self.trans_operand(&bcx, source);
let operand = operand.pack_if_pair(&bcx);
let llref = match operand.val {
OperandValue::Pair(..) => bug!(),
OperandValue::Immediate(llval) => {
// unsize from an immediate structure. We don't
// really need a temporary alloca here, but
// avoiding it would require us to have
// `coerce_unsized_into` use extractvalue to
// index into the struct, and this case isn't
// important enough for it.
debug!("trans_rvalue: creating ugly alloca");
let lltemp = bcx.alloca_ty(operand.ty, "__unsize_temp");
base::store_ty(&bcx, llval, lltemp, operand.ty);
lltemp
}
OperandValue::Ref(llref) => llref
};
base::coerce_unsized_into(&bcx, llref, operand.ty, dest.llval, cast_ty);
bcx
}
mir::Rvalue::Repeat(ref elem, ref count) => {
let tr_elem = self.trans_operand(&bcx, elem);
let size = count.value.as_u64(bcx.tcx().sess.target.uint_type);
let size = C_uint(bcx.ccx, size);
let base = base::get_dataptr(&bcx, dest.llval);
tvec::slice_for_each(&bcx, base, tr_elem.ty, size, |bcx, llslot| {
self.store_operand(bcx, llslot, tr_elem, None);
})
}
mir::Rvalue::Aggregate(ref kind, ref operands) => {
match *kind {
mir::AggregateKind::Adt(adt_def, variant_index, substs, active_field_index) => {
let disr = Disr::from(adt_def.variants[variant_index].disr_val);
let dest_ty = dest.ty.to_ty(bcx.tcx());
adt::trans_set_discr(&bcx, dest_ty, dest.llval, Disr::from(disr));
for (i, operand) in operands.iter().enumerate() {
let op = self.trans_operand(&bcx, operand);
// Do not generate stores and GEPis for zero-sized fields.
if !common::type_is_zero_size(bcx.ccx, op.ty) {
let mut val = LvalueRef::new_sized(dest.llval, dest.ty);
let field_index = active_field_index.unwrap_or(i);
val.ty = LvalueTy::Downcast {
adt_def: adt_def,
substs: self.monomorphize(&substs),
variant_index: disr.0 as usize,
};
let lldest_i = val.trans_field_ptr(&bcx, field_index);
self.store_operand(&bcx, lldest_i, op, None);
}
}
},
_ => {
// If this is a tuple or closure, we need to translate GEP indices.
let layout = bcx.ccx.layout_of(dest.ty.to_ty(bcx.tcx()));
let translation = if let Layout::Univariant { ref variant, .. } = *layout {
Some(&variant.memory_index)
} else {
None
};
for (i, operand) in operands.iter().enumerate() {
let op = self.trans_operand(&bcx, operand);
// Do not generate stores and GEPis for zero-sized fields.
if !common::type_is_zero_size(bcx.ccx, op.ty) {
// Note: perhaps this should be StructGep, but
// note that in some cases the values here will
// not be structs but arrays.
let i = if let Some(ref t) = translation {
t[i] as usize
} else {
i
};
let dest = bcx.gepi(dest.llval, &[0, i]);
self.store_operand(&bcx, dest, op, None);
}
}
}
}
bcx
}
mir::Rvalue::InlineAsm { ref asm, ref outputs, ref inputs } => {
let outputs = outputs.iter().map(|output| {
let lvalue = self.trans_lvalue(&bcx, output);
(lvalue.llval, lvalue.ty.to_ty(bcx.tcx()))
}).collect();
let input_vals = inputs.iter().map(|input| {
self.trans_operand(&bcx, input).immediate()
}).collect();
asm::trans_inline_asm(&bcx, asm, outputs, input_vals);
bcx
}
_ => {
assert!(rvalue_creates_operand(rvalue));
let (bcx, temp) = self.trans_rvalue_operand(bcx, rvalue);
self.store_operand(&bcx, dest.llval, temp, None);
bcx
}
}
}
pub fn trans_rvalue_operand(&mut self,
bcx: Builder<'a, 'tcx>,
rvalue: &mir::Rvalue<'tcx>)
-> (Builder<'a, 'tcx>, OperandRef<'tcx>)
{
assert!(rvalue_creates_operand(rvalue), "cannot trans {:?} to operand", rvalue);
match *rvalue {
mir::Rvalue::Cast(ref kind, ref source, cast_ty) => {
let operand = self.trans_operand(&bcx, source);
debug!("cast operand is {:?}", operand);
let cast_ty = self.monomorphize(&cast_ty);
let val = match *kind {
mir::CastKind::ReifyFnPointer => {
match operand.ty.sty {
ty::TyFnDef(def_id, substs, _) => {
OperandValue::Immediate(
Callee::def(bcx.ccx, def_id, substs)
.reify(bcx.ccx))
}
_ => {
bug!("{} cannot be reified to a fn ptr", operand.ty)
}
}
}
mir::CastKind::UnsafeFnPointer => {
// this is a no-op at the LLVM level
operand.val
}
mir::CastKind::Unsize => {
// unsize targets other than to a fat pointer currently
// can't be operands.
assert!(common::type_is_fat_ptr(bcx.ccx, cast_ty));
match operand.val {
OperandValue::Pair(lldata, llextra) => {
// unsize from a fat pointer - this is a
// "trait-object-to-supertrait" coercion, for
// example,
// &'a fmt::Debug+Send => &'a fmt::Debug,
// So we need to pointercast the base to ensure
// the types match up.
let llcast_ty = type_of::fat_ptr_base_ty(bcx.ccx, cast_ty);
let lldata = bcx.pointercast(lldata, llcast_ty);
OperandValue::Pair(lldata, llextra)
}
OperandValue::Immediate(lldata) => {
// "standard" unsize
let (lldata, llextra) = base::unsize_thin_ptr(&bcx, lldata,
operand.ty, cast_ty);
OperandValue::Pair(lldata, llextra)
}
OperandValue::Ref(_) => {
bug!("by-ref operand {:?} in trans_rvalue_operand",
operand);
}
}
}
mir::CastKind::Misc if common::type_is_fat_ptr(bcx.ccx, operand.ty) => {
let ll_cast_ty = type_of::immediate_type_of(bcx.ccx, cast_ty);
let ll_from_ty = type_of::immediate_type_of(bcx.ccx, operand.ty);
if let OperandValue::Pair(data_ptr, meta_ptr) = operand.val {
if common::type_is_fat_ptr(bcx.ccx, cast_ty) {
let ll_cft = ll_cast_ty.field_types();
let ll_fft = ll_from_ty.field_types();
let data_cast = bcx.pointercast(data_ptr, ll_cft[0]);
assert_eq!(ll_cft[1].kind(), ll_fft[1].kind());
OperandValue::Pair(data_cast, meta_ptr)
} else { // cast to thin-ptr
// Cast of fat-ptr to thin-ptr is an extraction of data-ptr and
// pointer-cast of that pointer to desired pointer type.
let llval = bcx.pointercast(data_ptr, ll_cast_ty);
OperandValue::Immediate(llval)
}
} else {
bug!("Unexpected non-Pair operand")
}
}
mir::CastKind::Misc => {
debug_assert!(common::type_is_immediate(bcx.ccx, cast_ty));
let r_t_in = CastTy::from_ty(operand.ty).expect("bad input type for cast");
let r_t_out = CastTy::from_ty(cast_ty).expect("bad output type for cast");
let ll_t_in = type_of::immediate_type_of(bcx.ccx, operand.ty);
let ll_t_out = type_of::immediate_type_of(bcx.ccx, cast_ty);
let llval = operand.immediate();
let l = bcx.ccx.layout_of(operand.ty);
let signed = if let Layout::CEnum { signed, min, max, .. } = *l {
if max > min {
// We want `table[e as usize]` to not
// have bound checks, and this is the most
// convenient place to put the `assume`.
base::call_assume(&bcx, bcx.icmp(
llvm::IntULE,
llval,
C_integral(common::val_ty(llval), max, false)
));
}
signed
} else {
operand.ty.is_signed()
};
let newval = match (r_t_in, r_t_out) {
(CastTy::Int(_), CastTy::Int(_)) => {
let srcsz = ll_t_in.int_width();
let dstsz = ll_t_out.int_width();
if srcsz == dstsz {
bcx.bitcast(llval, ll_t_out)
} else if srcsz > dstsz {
bcx.trunc(llval, ll_t_out)
} else if signed {
bcx.sext(llval, ll_t_out)
} else {
bcx.zext(llval, ll_t_out)
}
}
(CastTy::Float, CastTy::Float) => {
let srcsz = ll_t_in.float_width();
let dstsz = ll_t_out.float_width();
if dstsz > srcsz {
bcx.fpext(llval, ll_t_out)
} else if srcsz > dstsz {
bcx.fptrunc(llval, ll_t_out)
} else {
llval
}
}
(CastTy::Ptr(_), CastTy::Ptr(_)) |
(CastTy::FnPtr, CastTy::Ptr(_)) |
(CastTy::RPtr(_), CastTy::Ptr(_)) =>
bcx.pointercast(llval, ll_t_out),
(CastTy::Ptr(_), CastTy::Int(_)) |
(CastTy::FnPtr, CastTy::Int(_)) =>
bcx.ptrtoint(llval, ll_t_out),
(CastTy::Int(_), CastTy::Ptr(_)) =>
bcx.inttoptr(llval, ll_t_out),
(CastTy::Int(_), CastTy::Float) if signed =>
bcx.sitofp(llval, ll_t_out),
(CastTy::Int(_), CastTy::Float) =>
bcx.uitofp(llval, ll_t_out),
(CastTy::Float, CastTy::Int(IntTy::I)) =>
bcx.fptosi(llval, ll_t_out),
(CastTy::Float, CastTy::Int(_)) =>
bcx.fptoui(llval, ll_t_out),
_ => bug!("unsupported cast: {:?} to {:?}", operand.ty, cast_ty)
};
OperandValue::Immediate(newval)
}
};
let operand = OperandRef {
val: val,
ty: cast_ty
};
(bcx, operand)
}
mir::Rvalue::Ref(_, bk, ref lvalue) => {
let tr_lvalue = self.trans_lvalue(&bcx, lvalue);
let ty = tr_lvalue.ty.to_ty(bcx.tcx());
let ref_ty = bcx.tcx().mk_ref(
bcx.tcx().mk_region(ty::ReErased),
ty::TypeAndMut { ty: ty, mutbl: bk.to_mutbl_lossy() }
);
// Note: lvalues are indirect, so storing the `llval` into the
// destination effectively creates a reference.
let operand = if bcx.ccx.shared().type_is_sized(ty) {
OperandRef {
val: OperandValue::Immediate(tr_lvalue.llval),
ty: ref_ty,
}
} else {
OperandRef {
val: OperandValue::Pair(tr_lvalue.llval,
tr_lvalue.llextra),
ty: ref_ty,
}
};
(bcx, operand)
}
mir::Rvalue::Len(ref lvalue) => {
let tr_lvalue = self.trans_lvalue(&bcx, lvalue);
let operand = OperandRef {
val: OperandValue::Immediate(tr_lvalue.len(bcx.ccx)),
ty: bcx.tcx().types.usize,
};
(bcx, operand)
}
mir::Rvalue::BinaryOp(op, ref lhs, ref rhs) => {
let lhs = self.trans_operand(&bcx, lhs);
let rhs = self.trans_operand(&bcx, rhs);
let llresult = if common::type_is_fat_ptr(bcx.ccx, lhs.ty) {
match (lhs.val, rhs.val) {
(OperandValue::Pair(lhs_addr, lhs_extra),
OperandValue::Pair(rhs_addr, rhs_extra)) => {
self.trans_fat_ptr_binop(&bcx, op,
lhs_addr, lhs_extra,
rhs_addr, rhs_extra,
lhs.ty)
}
_ => bug!()
}
} else {
self.trans_scalar_binop(&bcx, op,
lhs.immediate(), rhs.immediate(),
lhs.ty)
};
let operand = OperandRef {
val: OperandValue::Immediate(llresult),
ty: op.ty(bcx.tcx(), lhs.ty, rhs.ty),
};
(bcx, operand)
}
mir::Rvalue::CheckedBinaryOp(op, ref lhs, ref rhs) => {
let lhs = self.trans_operand(&bcx, lhs);
let rhs = self.trans_operand(&bcx, rhs);
let result = self.trans_scalar_checked_binop(&bcx, op,
lhs.immediate(), rhs.immediate(),
lhs.ty);
let val_ty = op.ty(bcx.tcx(), lhs.ty, rhs.ty);
let operand_ty = bcx.tcx().intern_tup(&[val_ty, bcx.tcx().types.bool]);
let operand = OperandRef {
val: result,
ty: operand_ty
};
(bcx, operand)
}
mir::Rvalue::UnaryOp(op, ref operand) => {
let operand = self.trans_operand(&bcx, operand);
let lloperand = operand.immediate();
let is_float = operand.ty.is_fp();
let llval = match op {
mir::UnOp::Not => bcx.not(lloperand),
mir::UnOp::Neg => if is_float {
bcx.fneg(lloperand)
} else {
bcx.neg(lloperand)
}
};
(bcx, OperandRef {
val: OperandValue::Immediate(llval),
ty: operand.ty,
})
}
mir::Rvalue::Box(content_ty) => {
let content_ty: Ty<'tcx> = self.monomorphize(&content_ty);
let llty = type_of::type_of(bcx.ccx, content_ty);
let llsize = machine::llsize_of(bcx.ccx, llty);
let align = type_of::align_of(bcx.ccx, content_ty);
let llalign = C_uint(bcx.ccx, align);
let llty_ptr = llty.ptr_to();
let box_ty = bcx.tcx().mk_box(content_ty);
// Allocate space:
let def_id = match bcx.tcx().lang_items.require(ExchangeMallocFnLangItem) {
Ok(id) => id,
Err(s) => {
bcx.sess().fatal(&format!("allocation of `{}` {}", box_ty, s));
}
};
let r = Callee::def(bcx.ccx, def_id, bcx.tcx().intern_substs(&[]))
.reify(bcx.ccx);
let val = bcx.pointercast(bcx.call(r, &[llsize, llalign], None), llty_ptr);
let operand = OperandRef {
val: OperandValue::Immediate(val),
ty: box_ty,
};
(bcx, operand)
}
mir::Rvalue::Use(ref operand) => {
let operand = self.trans_operand(&bcx, operand);
(bcx, operand)
}
mir::Rvalue::Repeat(..) |
mir::Rvalue::Aggregate(..) |
mir::Rvalue::InlineAsm { .. } => {
bug!("cannot generate operand from rvalue {:?}", rvalue);
}
}
}
pub fn trans_scalar_binop(&mut self,
bcx: &Builder<'a, 'tcx>,
op: mir::BinOp,
lhs: ValueRef,
rhs: ValueRef,
input_ty: Ty<'tcx>) -> ValueRef {
let is_float = input_ty.is_fp();
let is_signed = input_ty.is_signed();
let is_nil = input_ty.is_nil();
let is_bool = input_ty.is_bool();
match op {
mir::BinOp::Add => if is_float {
bcx.fadd(lhs, rhs)
} else {
bcx.add(lhs, rhs)
},
mir::BinOp::Sub => if is_float {
bcx.fsub(lhs, rhs)
} else {
bcx.sub(lhs, rhs)
},
mir::BinOp::Mul => if is_float {
bcx.fmul(lhs, rhs)
} else {
bcx.mul(lhs, rhs)
},
mir::BinOp::Div => if is_float {
bcx.fdiv(lhs, rhs)
} else if is_signed {
bcx.sdiv(lhs, rhs)
} else {
bcx.udiv(lhs, rhs)
},
mir::BinOp::Rem => if is_float {
bcx.frem(lhs, rhs)
} else if is_signed {
bcx.srem(lhs, rhs)
} else {
bcx.urem(lhs, rhs)
},
mir::BinOp::BitOr => bcx.or(lhs, rhs),
mir::BinOp::BitAnd => bcx.and(lhs, rhs),
mir::BinOp::BitXor => bcx.xor(lhs, rhs),
mir::BinOp::Shl => common::build_unchecked_lshift(bcx, lhs, rhs),
mir::BinOp::Shr => common::build_unchecked_rshift(bcx, input_ty, lhs, rhs),
mir::BinOp::Ne | mir::BinOp::Lt | mir::BinOp::Gt |
mir::BinOp::Eq | mir::BinOp::Le | mir::BinOp::Ge => if is_nil {
C_bool(bcx.ccx, match op {
mir::BinOp::Ne | mir::BinOp::Lt | mir::BinOp::Gt => false,
mir::BinOp::Eq | mir::BinOp::Le | mir::BinOp::Ge => true,
_ => unreachable!()
})
} else if is_float {
bcx.fcmp(
base::bin_op_to_fcmp_predicate(op.to_hir_binop()),
lhs, rhs
)
} else {
let (lhs, rhs) = if is_bool {
// FIXME(#36856) -- extend the bools into `i8` because
// LLVM's i1 comparisons are broken.
(bcx.zext(lhs, Type::i8(bcx.ccx)),
bcx.zext(rhs, Type::i8(bcx.ccx)))
} else {
(lhs, rhs)
};
bcx.icmp(
base::bin_op_to_icmp_predicate(op.to_hir_binop(), is_signed),
lhs, rhs
)
}
}
}
pub fn trans_fat_ptr_binop(&mut self,
bcx: &Builder<'a, 'tcx>,
op: mir::BinOp,
lhs_addr: ValueRef,
lhs_extra: ValueRef,
rhs_addr: ValueRef,
rhs_extra: ValueRef,
_input_ty: Ty<'tcx>)
-> ValueRef {
match op {
mir::BinOp::Eq => {
bcx.and(
bcx.icmp(llvm::IntEQ, lhs_addr, rhs_addr),
bcx.icmp(llvm::IntEQ, lhs_extra, rhs_extra)
)
}
mir::BinOp::Ne => {
bcx.or(
bcx.icmp(llvm::IntNE, lhs_addr, rhs_addr),
bcx.icmp(llvm::IntNE, lhs_extra, rhs_extra)
)
}
mir::BinOp::Le | mir::BinOp::Lt |
mir::BinOp::Ge | mir::BinOp::Gt => {
// a OP b ~ a.0 STRICT(OP) b.0 | (a.0 == b.0 && a.1 OP a.1)
let (op, strict_op) = match op {
mir::BinOp::Lt => (llvm::IntULT, llvm::IntULT),
mir::BinOp::Le => (llvm::IntULE, llvm::IntULT),
mir::BinOp::Gt => (llvm::IntUGT, llvm::IntUGT),
mir::BinOp::Ge => (llvm::IntUGE, llvm::IntUGT),
_ => bug!(),
};
bcx.or(
bcx.icmp(strict_op, lhs_addr, rhs_addr),
bcx.and(
bcx.icmp(llvm::IntEQ, lhs_addr, rhs_addr),
bcx.icmp(op, lhs_extra, rhs_extra)
)
)
}
_ => {
bug!("unexpected fat ptr binop");
}
}
}
pub fn trans_scalar_checked_binop(&mut self,
bcx: &Builder<'a, 'tcx>,
op: mir::BinOp,
lhs: ValueRef,
rhs: ValueRef,
input_ty: Ty<'tcx>) -> OperandValue {
// This case can currently arise only from functions marked
// with #[rustc_inherit_overflow_checks] and inlined from
// another crate (mostly core::num generic/#[inline] fns),
// while the current crate doesn't use overflow checks.
if !bcx.ccx.check_overflow() {
let val = self.trans_scalar_binop(bcx, op, lhs, rhs, input_ty);
return OperandValue::Pair(val, C_bool(bcx.ccx, false));
}
// First try performing the operation on constants, which
// will only succeed if both operands are constant.
// This is necessary to determine when an overflow Assert
// will always panic at runtime, and produce a warning.
if let Some((val, of)) = const_scalar_checked_binop(bcx.tcx(), op, lhs, rhs, input_ty) {
return OperandValue::Pair(val, C_bool(bcx.ccx, of));
}
let (val, of) = match op {
// These are checked using intrinsics
mir::BinOp::Add | mir::BinOp::Sub | mir::BinOp::Mul => {
let oop = match op {
mir::BinOp::Add => OverflowOp::Add,
mir::BinOp::Sub => OverflowOp::Sub,
mir::BinOp::Mul => OverflowOp::Mul,
_ => unreachable!()
};
let intrinsic = get_overflow_intrinsic(oop, bcx, input_ty);
let res = bcx.call(intrinsic, &[lhs, rhs], None);
(bcx.extract_value(res, 0),
bcx.extract_value(res, 1))
}
mir::BinOp::Shl | mir::BinOp::Shr => {
let lhs_llty = val_ty(lhs);
let rhs_llty = val_ty(rhs);
let invert_mask = common::shift_mask_val(&bcx, lhs_llty, rhs_llty, true);
let outer_bits = bcx.and(rhs, invert_mask);
let of = bcx.icmp(llvm::IntNE, outer_bits, C_null(rhs_llty));
let val = self.trans_scalar_binop(bcx, op, lhs, rhs, input_ty);
(val, of)
}
_ => {
bug!("Operator `{:?}` is not a checkable operator", op)
}
};
OperandValue::Pair(val, of)
}
}
pub fn rvalue_creates_operand(rvalue: &mir::Rvalue) -> bool {
match *rvalue {
mir::Rvalue::Ref(..) |
mir::Rvalue::Len(..) |
mir::Rvalue::Cast(..) | // (*)
mir::Rvalue::BinaryOp(..) |
mir::Rvalue::CheckedBinaryOp(..) |
mir::Rvalue::UnaryOp(..) |
mir::Rvalue::Box(..) |
mir::Rvalue::Use(..) =>
true,
mir::Rvalue::Repeat(..) |
mir::Rvalue::Aggregate(..) |
mir::Rvalue::InlineAsm { .. } =>
false,
}
// (*) this is only true if the type is suitable
}
#[derive(Copy, Clone)]
enum OverflowOp {
Add, Sub, Mul
}
fn get_overflow_intrinsic(oop: OverflowOp, bcx: &Builder, ty: Ty) -> ValueRef {
use syntax::ast::IntTy::*;
use syntax::ast::UintTy::*;
use rustc::ty::{TyInt, TyUint};
let tcx = bcx.tcx();
let new_sty = match ty.sty {
TyInt(Is) => match &tcx.sess.target.target.target_pointer_width[..] {
"16" => TyInt(I16),
"32" => TyInt(I32),
"64" => TyInt(I64),
_ => panic!("unsupported target word size")
},
TyUint(Us) => match &tcx.sess.target.target.target_pointer_width[..] {
"16" => TyUint(U16),
"32" => TyUint(U32),
"64" => TyUint(U64),
_ => panic!("unsupported target word size")
},
ref t @ TyUint(_) | ref t @ TyInt(_) => t.clone(),
_ => panic!("tried to get overflow intrinsic for op applied to non-int type")
};
let name = match oop {
OverflowOp::Add => match new_sty {
TyInt(I8) => "llvm.sadd.with.overflow.i8",
TyInt(I16) => "llvm.sadd.with.overflow.i16",
TyInt(I32) => "llvm.sadd.with.overflow.i32",
TyInt(I64) => "llvm.sadd.with.overflow.i64",
TyInt(I128) => "llvm.sadd.with.overflow.i128",
TyUint(U8) => "llvm.uadd.with.overflow.i8",
TyUint(U16) => "llvm.uadd.with.overflow.i16",
TyUint(U32) => "llvm.uadd.with.overflow.i32",
TyUint(U64) => "llvm.uadd.with.overflow.i64",
TyUint(U128) => "llvm.uadd.with.overflow.i128",
_ => unreachable!(),
},
OverflowOp::Sub => match new_sty {
TyInt(I8) => "llvm.ssub.with.overflow.i8",
TyInt(I16) => "llvm.ssub.with.overflow.i16",
TyInt(I32) => "llvm.ssub.with.overflow.i32",
TyInt(I64) => "llvm.ssub.with.overflow.i64",
TyInt(I128) => "llvm.ssub.with.overflow.i128",
TyUint(U8) => "llvm.usub.with.overflow.i8",
TyUint(U16) => "llvm.usub.with.overflow.i16",
TyUint(U32) => "llvm.usub.with.overflow.i32",
TyUint(U64) => "llvm.usub.with.overflow.i64",
TyUint(U128) => "llvm.usub.with.overflow.i128",
_ => unreachable!(),
},
OverflowOp::Mul => match new_sty {
TyInt(I8) => "llvm.smul.with.overflow.i8",
TyInt(I16) => "llvm.smul.with.overflow.i16",
TyInt(I32) => "llvm.smul.with.overflow.i32",
TyInt(I64) => "llvm.smul.with.overflow.i64",
TyInt(I128) => "llvm.smul.with.overflow.i128",
TyUint(U8) => "llvm.umul.with.overflow.i8",
TyUint(U16) => "llvm.umul.with.overflow.i16",
TyUint(U32) => "llvm.umul.with.overflow.i32",
TyUint(U64) => "llvm.umul.with.overflow.i64",
TyUint(U128) => "llvm.umul.with.overflow.i128",
_ => unreachable!(),
},
};
bcx.ccx.get_intrinsic(&name)
}