LLVM  14.0.0git
OverflowInstAnalysis.h
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1 //===-- OverflowInstAnalysis.h - Utils to fold overflow insts ----*- C++ -*-==//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file holds routines to help analyse overflow instructions
10 // and fold them into constants or other overflow instructions
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_ANALYSIS_OVERFLOWINSTANALYSIS_H
15 #define LLVM_ANALYSIS_OVERFLOWINSTANALYSIS_H
16 
17 #include "llvm/IR/InstrTypes.h"
18 
19 namespace llvm {
20 class Value;
21 class Use;
22 
23 /// Match one of the patterns up to the select/logic op:
24 /// %Op0 = icmp ne i4 %X, 0
25 /// %Agg = call { i4, i1 } @llvm.[us]mul.with.overflow.i4(i4 %X, i4 %Y)
26 /// %Op1 = extractvalue { i4, i1 } %Agg, 1
27 /// %ret = select i1 %Op0, i1 %Op1, i1 false / %ret = and i1 %Op0, %Op1
28 ///
29 /// %Op0 = icmp eq i4 %X, 0
30 /// %Agg = call { i4, i1 } @llvm.[us]mul.with.overflow.i4(i4 %X, i4 %Y)
31 /// %NotOp1 = extractvalue { i4, i1 } %Agg, 1
32 /// %Op1 = xor i1 %NotOp1, true
33 /// %ret = select i1 %Op0, i1 true, i1 %Op1 / %ret = or i1 %Op0, %Op1
34 ///
35 /// Callers are expected to align that with the operands of the select/logic.
36 /// IsAnd is set to true if the Op0 and Op1 are used as the first pattern.
37 /// If Op0 and Op1 match one of the patterns above, return true and fill Y's
38 /// use.
39 
40 bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd,
41  Use *&Y);
42 bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd);
43 } // end namespace llvm
44 
45 #endif
llvm
This file implements support for optimizing divisions by a constant.
Definition: AllocatorList.h:23
llvm::isCheckForZeroAndMulWithOverflow
bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd, Use *&Y)
Match one of the patterns up to the select/logic op: Op0 = icmp ne i4 X, 0 Agg = call { i4,...
Definition: OverflowInstAnalysis.cpp:22
InstrTypes.h
Y
static GCMetadataPrinterRegistry::Add< OcamlGCMetadataPrinter > Y("ocaml", "ocaml 3.10-compatible collector")
llvm::TargetStackID::Value
Value
Definition: TargetFrameLowering.h:27