[llvm] r310889 - Recommit r310869, "[InstSimplify][InstCombine] Modify the interface of decomposeBitTestICmp and use it in the InstSimplify"
Craig Topper via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 14 14:39:51 PDT 2017
Author: ctopper
Date: Mon Aug 14 14:39:51 2017
New Revision: 310889
URL: http://llvm.org/viewvc/llvm-project?rev=310889&view=rev
Log:
Recommit r310869, "[InstSimplify][InstCombine] Modify the interface of decomposeBitTestICmp and use it in the InstSimplify"
This recommits r310869, with the moved files and no extra changes.
Original commit message:
This addresses a fixme in InstSimplify about using decomposeBitTest. This also fixes InstSimplify to handle ugt and ult compares too.
I've modified the interface a little to return only the APInt version of the mask that InstSimplify needs. InstCombine now has a small wrapper routine to create a Constant out of it. I've also dropped the returning of 0 since InstSimplify doesn't need that. So InstCombine creates a zero constant itself.
I also had to make decomposeBitTest support vectors since InstSimplify needs that.
As InstSimplify can't use something from the Transforms library, I've moved the CmpInstAnalysis code to the Analysis library.
Differential Revision: https://reviews.llvm.org/D36593
Added:
llvm/trunk/include/llvm/Analysis/CmpInstAnalysis.h (contents, props changed)
- copied, changed from r310888, llvm/trunk/include/llvm/Transforms/Utils/CmpInstAnalysis.h
llvm/trunk/lib/Analysis/CmpInstAnalysis.cpp (contents, props changed)
- copied, changed from r310888, llvm/trunk/lib/Transforms/Utils/CmpInstAnalysis.cpp
Removed:
llvm/trunk/include/llvm/Transforms/Utils/CmpInstAnalysis.h
llvm/trunk/lib/Transforms/Utils/CmpInstAnalysis.cpp
Modified:
llvm/trunk/lib/Analysis/CMakeLists.txt
llvm/trunk/lib/Analysis/InstructionSimplify.cpp
llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
llvm/trunk/lib/Transforms/Utils/CMakeLists.txt
llvm/trunk/test/Transforms/InstSimplify/select.ll
Copied: llvm/trunk/include/llvm/Analysis/CmpInstAnalysis.h (from r310888, llvm/trunk/include/llvm/Transforms/Utils/CmpInstAnalysis.h)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/CmpInstAnalysis.h?p2=llvm/trunk/include/llvm/Analysis/CmpInstAnalysis.h&p1=llvm/trunk/include/llvm/Transforms/Utils/CmpInstAnalysis.h&r1=310888&r2=310889&rev=310889&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/CmpInstAnalysis.h (original)
+++ llvm/trunk/include/llvm/Analysis/CmpInstAnalysis.h Mon Aug 14 14:39:51 2017
@@ -12,8 +12,8 @@
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_TRANSFORMS_UTILS_CMPINSTANALYSIS_H
-#define LLVM_TRANSFORMS_UTILS_CMPINSTANALYSIS_H
+#ifndef LLVM_ANALYSIS_CMPINSTANALYSIS_H
+#define LLVM_ANALYSIS_CMPINSTANALYSIS_H
#include "llvm/IR/InstrTypes.h"
@@ -60,10 +60,11 @@ namespace llvm {
/// equality comparison (which is signless).
bool PredicatesFoldable(CmpInst::Predicate p1, CmpInst::Predicate p2);
- /// Decompose an icmp into the form ((X & Y) pred Z) if possible. The returned
- /// predicate is either == or !=. Returns false if decomposition fails.
- bool decomposeBitTestICmp(const ICmpInst *I, CmpInst::Predicate &Pred,
- Value *&X, Value *&Y, Value *&Z);
+ /// Decompose an icmp into the form ((X & Mask) pred 0) if possible. The
+ /// returned predicate is either == or !=. Returns false if decomposition
+ /// fails.
+ bool decomposeBitTestICmp(Value *LHS, Value *RHS, CmpInst::Predicate &Pred,
+ Value *&X, APInt &Mask);
} // end namespace llvm
Propchange: llvm/trunk/include/llvm/Analysis/CmpInstAnalysis.h
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Propchange: llvm/trunk/include/llvm/Analysis/CmpInstAnalysis.h
------------------------------------------------------------------------------
svn:keywords = "Author Date Id Rev URL"
Propchange: llvm/trunk/include/llvm/Analysis/CmpInstAnalysis.h
------------------------------------------------------------------------------
svn:mime-type = text/plain
Removed: llvm/trunk/include/llvm/Transforms/Utils/CmpInstAnalysis.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/CmpInstAnalysis.h?rev=310888&view=auto
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/CmpInstAnalysis.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/CmpInstAnalysis.h (removed)
@@ -1,70 +0,0 @@
-//===-- CmpInstAnalysis.h - Utils to help fold compare insts ----*- C++ -*-===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file holds routines to help analyse compare instructions
-// and fold them into constants or other compare instructions
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_TRANSFORMS_UTILS_CMPINSTANALYSIS_H
-#define LLVM_TRANSFORMS_UTILS_CMPINSTANALYSIS_H
-
-#include "llvm/IR/InstrTypes.h"
-
-namespace llvm {
- class ICmpInst;
- class Value;
-
- /// Encode a icmp predicate into a three bit mask. These bits are carefully
- /// arranged to allow folding of expressions such as:
- ///
- /// (A < B) | (A > B) --> (A != B)
- ///
- /// Note that this is only valid if the first and second predicates have the
- /// same sign. It is illegal to do: (A u< B) | (A s> B)
- ///
- /// Three bits are used to represent the condition, as follows:
- /// 0 A > B
- /// 1 A == B
- /// 2 A < B
- ///
- /// <=> Value Definition
- /// 000 0 Always false
- /// 001 1 A > B
- /// 010 2 A == B
- /// 011 3 A >= B
- /// 100 4 A < B
- /// 101 5 A != B
- /// 110 6 A <= B
- /// 111 7 Always true
- ///
- unsigned getICmpCode(const ICmpInst *ICI, bool InvertPred = false);
-
- /// This is the complement of getICmpCode, which turns an opcode and two
- /// operands into either a constant true or false, or the predicate for a new
- /// ICmp instruction. The sign is passed in to determine which kind of
- /// predicate to use in the new icmp instruction.
- /// Non-NULL return value will be a true or false constant.
- /// NULL return means a new ICmp is needed. The predicate for which is output
- /// in NewICmpPred.
- Value *getICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS,
- CmpInst::Predicate &NewICmpPred);
-
- /// Return true if both predicates match sign or if at least one of them is an
- /// equality comparison (which is signless).
- bool PredicatesFoldable(CmpInst::Predicate p1, CmpInst::Predicate p2);
-
- /// Decompose an icmp into the form ((X & Y) pred Z) if possible. The returned
- /// predicate is either == or !=. Returns false if decomposition fails.
- bool decomposeBitTestICmp(const ICmpInst *I, CmpInst::Predicate &Pred,
- Value *&X, Value *&Y, Value *&Z);
-
-} // end namespace llvm
-
-#endif
Modified: llvm/trunk/lib/Analysis/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/CMakeLists.txt?rev=310889&r1=310888&r2=310889&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/CMakeLists.txt (original)
+++ llvm/trunk/lib/Analysis/CMakeLists.txt Mon Aug 14 14:39:51 2017
@@ -18,6 +18,7 @@ add_llvm_library(LLVMAnalysis
CallGraphSCCPass.cpp
CallPrinter.cpp
CaptureTracking.cpp
+ CmpInstAnalysis.cpp
CostModel.cpp
CodeMetrics.cpp
ConstantFolding.cpp
Copied: llvm/trunk/lib/Analysis/CmpInstAnalysis.cpp (from r310888, llvm/trunk/lib/Transforms/Utils/CmpInstAnalysis.cpp)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/CmpInstAnalysis.cpp?p2=llvm/trunk/lib/Analysis/CmpInstAnalysis.cpp&p1=llvm/trunk/lib/Transforms/Utils/CmpInstAnalysis.cpp&r1=310888&r2=310889&rev=310889&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/CmpInstAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/CmpInstAnalysis.cpp Mon Aug 14 14:39:51 2017
@@ -12,9 +12,10 @@
//
//===----------------------------------------------------------------------===//
-#include "llvm/Transforms/Utils/CmpInstAnalysis.h"
+#include "llvm/Analysis/CmpInstAnalysis.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Instructions.h"
+#include "llvm/IR/PatternMatch.h"
using namespace llvm;
@@ -63,46 +64,46 @@ bool llvm::PredicatesFoldable(ICmpInst::
(CmpInst::isSigned(p2) && ICmpInst::isEquality(p1));
}
-bool llvm::decomposeBitTestICmp(const ICmpInst *I, CmpInst::Predicate &Pred,
- Value *&X, Value *&Y, Value *&Z) {
- ConstantInt *C = dyn_cast<ConstantInt>(I->getOperand(1));
- if (!C)
+bool llvm::decomposeBitTestICmp(Value *LHS, Value *RHS,
+ CmpInst::Predicate &Pred,
+ Value *&X, APInt &Mask) {
+ const APInt *C;
+ if (!match(RHS, PatternMatch::m_APInt(C)))
return false;
- switch (I->getPredicate()) {
+ switch (Pred) {
default:
return false;
case ICmpInst::ICMP_SLT:
// X < 0 is equivalent to (X & SignMask) != 0.
- if (!C->isZero())
+ if (!C->isNullValue())
return false;
- Y = ConstantInt::get(I->getContext(), APInt::getSignMask(C->getBitWidth()));
+ Mask = APInt::getSignMask(C->getBitWidth());
Pred = ICmpInst::ICMP_NE;
break;
case ICmpInst::ICMP_SGT:
// X > -1 is equivalent to (X & SignMask) == 0.
- if (!C->isMinusOne())
+ if (!C->isAllOnesValue())
return false;
- Y = ConstantInt::get(I->getContext(), APInt::getSignMask(C->getBitWidth()));
+ Mask = APInt::getSignMask(C->getBitWidth());
Pred = ICmpInst::ICMP_EQ;
break;
case ICmpInst::ICMP_ULT:
// X <u 2^n is equivalent to (X & ~(2^n-1)) == 0.
- if (!C->getValue().isPowerOf2())
+ if (!C->isPowerOf2())
return false;
- Y = ConstantInt::get(I->getContext(), -C->getValue());
+ Mask = -*C;
Pred = ICmpInst::ICMP_EQ;
break;
case ICmpInst::ICMP_UGT:
// X >u 2^n-1 is equivalent to (X & ~(2^n-1)) != 0.
- if (!(C->getValue() + 1).isPowerOf2())
+ if (!(*C + 1).isPowerOf2())
return false;
- Y = ConstantInt::get(I->getContext(), ~C->getValue());
+ Mask = ~*C;
Pred = ICmpInst::ICMP_NE;
break;
}
- X = I->getOperand(0);
- Z = ConstantInt::getNullValue(C->getType());
+ X = LHS;
return true;
}
Propchange: llvm/trunk/lib/Analysis/CmpInstAnalysis.cpp
------------------------------------------------------------------------------
svn:eol-style = native
Propchange: llvm/trunk/lib/Analysis/CmpInstAnalysis.cpp
------------------------------------------------------------------------------
svn:keywords = "Author Date Id Rev URL"
Propchange: llvm/trunk/lib/Analysis/CmpInstAnalysis.cpp
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svn:mime-type = text/plain
Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=310889&r1=310888&r2=310889&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
+++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Mon Aug 14 14:39:51 2017
@@ -23,6 +23,7 @@
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CaptureTracking.h"
+#include "llvm/Analysis/CmpInstAnalysis.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/LoopAnalysisManager.h"
#include "llvm/Analysis/MemoryBuiltins.h"
@@ -3620,32 +3621,29 @@ static Value *simplifySelectBitTest(Valu
/// An alternative way to test if a bit is set or not uses sgt/slt instead of
/// eq/ne.
-static Value *simplifySelectWithFakeICmpEq(Value *CmpLHS, Value *TrueVal,
- Value *FalseVal,
- bool TrueWhenUnset) {
+static Value *simplifySelectWithFakeICmpEq(Value *CmpLHS, Value *CmpRHS,
+ ICmpInst::Predicate Pred,
+ Value *TrueVal, Value *FalseVal) {
+ Value *X;
+ APInt Mask;
+ if (!decomposeBitTestICmp(CmpLHS, CmpRHS, Pred, X, Mask))
+ return nullptr;
+
unsigned BitWidth = TrueVal->getType()->getScalarSizeInBits();
if (!BitWidth)
return nullptr;
- APInt MinSignedValue;
- Value *X;
- if (match(CmpLHS, m_Trunc(m_Value(X))) && (X == TrueVal || X == FalseVal)) {
+ Value *ExtX;
+ if (match(X, m_Trunc(m_Value(ExtX))) &&
+ (ExtX == TrueVal || ExtX == FalseVal)) {
// icmp slt (trunc X), 0 <--> icmp ne (and X, C), 0
// icmp sgt (trunc X), -1 <--> icmp eq (and X, C), 0
- unsigned DestSize = CmpLHS->getType()->getScalarSizeInBits();
- MinSignedValue = APInt::getSignedMinValue(DestSize).zext(BitWidth);
- } else {
- // icmp slt X, 0 <--> icmp ne (and X, C), 0
- // icmp sgt X, -1 <--> icmp eq (and X, C), 0
- X = CmpLHS;
- MinSignedValue = APInt::getSignedMinValue(BitWidth);
+ X = ExtX;
+ Mask = Mask.zext(BitWidth);
}
- if (Value *V = simplifySelectBitTest(TrueVal, FalseVal, X, &MinSignedValue,
- TrueWhenUnset))
- return V;
-
- return nullptr;
+ return simplifySelectBitTest(TrueVal, FalseVal, X, &Mask,
+ Pred == ICmpInst::ICMP_EQ);
}
/// Try to simplify a select instruction when its condition operand is an
@@ -3658,9 +3656,6 @@ static Value *simplifySelectWithICmpCond
if (!match(CondVal, m_ICmp(Pred, m_Value(CmpLHS), m_Value(CmpRHS))))
return nullptr;
- // FIXME: This code is nearly duplicated in InstCombine. Using/refactoring
- // decomposeBitTestICmp() might help.
- // FIXME this should support ICMP_SLE/SGE forms as well
if (ICmpInst::isEquality(Pred) && match(CmpRHS, m_Zero())) {
Value *X;
const APInt *Y;
@@ -3668,18 +3663,13 @@ static Value *simplifySelectWithICmpCond
if (Value *V = simplifySelectBitTest(TrueVal, FalseVal, X, Y,
Pred == ICmpInst::ICMP_EQ))
return V;
- } else if (Pred == ICmpInst::ICMP_SLT && match(CmpRHS, m_Zero())) {
- // Comparing signed-less-than 0 checks if the sign bit is set.
- if (Value *V = simplifySelectWithFakeICmpEq(CmpLHS, TrueVal, FalseVal,
- false))
- return V;
- } else if (Pred == ICmpInst::ICMP_SGT && match(CmpRHS, m_AllOnes())) {
- // Comparing signed-greater-than -1 checks if the sign bit is not set.
- if (Value *V = simplifySelectWithFakeICmpEq(CmpLHS, TrueVal, FalseVal,
- true))
- return V;
}
+ // Check for other compares that behave like bit test.
+ if (Value *V = simplifySelectWithFakeICmpEq(CmpLHS, CmpRHS, Pred,
+ TrueVal, FalseVal))
+ return V;
+
if (CondVal->hasOneUse()) {
const APInt *C;
if (match(CmpRHS, m_APInt(C))) {
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp?rev=310889&r1=310888&r2=310889&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp Mon Aug 14 14:39:51 2017
@@ -12,11 +12,11 @@
//===----------------------------------------------------------------------===//
#include "InstCombineInternal.h"
+#include "llvm/Analysis/CmpInstAnalysis.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/PatternMatch.h"
-#include "llvm/Transforms/Utils/CmpInstAnalysis.h"
#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;
using namespace PatternMatch;
@@ -292,6 +292,18 @@ static unsigned conjugateICmpMask(unsign
return NewMask;
}
+// Adapts the external decomposeBitTestICmp for local use.
+static bool decomposeBitTestICmp(Value *LHS, Value *RHS, CmpInst::Predicate &Pred,
+ Value *&X, Value *&Y, Value *&Z) {
+ APInt Mask;
+ if (!llvm::decomposeBitTestICmp(LHS, RHS, Pred, X, Mask))
+ return false;
+
+ Y = ConstantInt::get(LHS->getType(), Mask);
+ Z = ConstantInt::get(RHS->getType(), 0);
+ return true;
+}
+
/// Handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E).
/// Return the set of pattern classes (from MaskedICmpType) that both LHS and
/// RHS satisfy.
@@ -316,7 +328,7 @@ static unsigned getMaskedTypeForICmpPair
Value *L2 = LHS->getOperand(1);
Value *L11, *L12, *L21, *L22;
// Check whether the icmp can be decomposed into a bit test.
- if (decomposeBitTestICmp(LHS, PredL, L11, L12, L2)) {
+ if (decomposeBitTestICmp(L1, L2, PredL, L11, L12, L2)) {
L21 = L22 = L1 = nullptr;
} else {
// Look for ANDs in the LHS icmp.
@@ -347,7 +359,7 @@ static unsigned getMaskedTypeForICmpPair
Value *R2 = RHS->getOperand(1);
Value *R11, *R12;
bool Ok = false;
- if (decomposeBitTestICmp(RHS, PredR, R11, R12, R2)) {
+ if (decomposeBitTestICmp(R1, R2, PredR, R11, R12, R2)) {
if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
A = R11;
D = R12;
Modified: llvm/trunk/lib/Transforms/Utils/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/CMakeLists.txt?rev=310889&r1=310888&r2=310889&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/CMakeLists.txt (original)
+++ llvm/trunk/lib/Transforms/Utils/CMakeLists.txt Mon Aug 14 14:39:51 2017
@@ -7,7 +7,6 @@ add_llvm_library(LLVMTransformUtils
BypassSlowDivision.cpp
CloneFunction.cpp
CloneModule.cpp
- CmpInstAnalysis.cpp
CodeExtractor.cpp
CtorUtils.cpp
DemoteRegToStack.cpp
Removed: llvm/trunk/lib/Transforms/Utils/CmpInstAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/CmpInstAnalysis.cpp?rev=310888&view=auto
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/CmpInstAnalysis.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/CmpInstAnalysis.cpp (removed)
@@ -1,108 +0,0 @@
-//===- CmpInstAnalysis.cpp - Utils to help fold compares ---------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file holds routines to help analyse compare instructions
-// and fold them into constants or other compare instructions
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Transforms/Utils/CmpInstAnalysis.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/Instructions.h"
-
-using namespace llvm;
-
-unsigned llvm::getICmpCode(const ICmpInst *ICI, bool InvertPred) {
- ICmpInst::Predicate Pred = InvertPred ? ICI->getInversePredicate()
- : ICI->getPredicate();
- switch (Pred) {
- // False -> 0
- case ICmpInst::ICMP_UGT: return 1; // 001
- case ICmpInst::ICMP_SGT: return 1; // 001
- case ICmpInst::ICMP_EQ: return 2; // 010
- case ICmpInst::ICMP_UGE: return 3; // 011
- case ICmpInst::ICMP_SGE: return 3; // 011
- case ICmpInst::ICMP_ULT: return 4; // 100
- case ICmpInst::ICMP_SLT: return 4; // 100
- case ICmpInst::ICMP_NE: return 5; // 101
- case ICmpInst::ICMP_ULE: return 6; // 110
- case ICmpInst::ICMP_SLE: return 6; // 110
- // True -> 7
- default:
- llvm_unreachable("Invalid ICmp predicate!");
- }
-}
-
-Value *llvm::getICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS,
- CmpInst::Predicate &NewICmpPred) {
- switch (Code) {
- default: llvm_unreachable("Illegal ICmp code!");
- case 0: // False.
- return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
- case 1: NewICmpPred = Sign ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT; break;
- case 2: NewICmpPred = ICmpInst::ICMP_EQ; break;
- case 3: NewICmpPred = Sign ? ICmpInst::ICMP_SGE : ICmpInst::ICMP_UGE; break;
- case 4: NewICmpPred = Sign ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT; break;
- case 5: NewICmpPred = ICmpInst::ICMP_NE; break;
- case 6: NewICmpPred = Sign ? ICmpInst::ICMP_SLE : ICmpInst::ICMP_ULE; break;
- case 7: // True.
- return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 1);
- }
- return nullptr;
-}
-
-bool llvm::PredicatesFoldable(ICmpInst::Predicate p1, ICmpInst::Predicate p2) {
- return (CmpInst::isSigned(p1) == CmpInst::isSigned(p2)) ||
- (CmpInst::isSigned(p1) && ICmpInst::isEquality(p2)) ||
- (CmpInst::isSigned(p2) && ICmpInst::isEquality(p1));
-}
-
-bool llvm::decomposeBitTestICmp(const ICmpInst *I, CmpInst::Predicate &Pred,
- Value *&X, Value *&Y, Value *&Z) {
- ConstantInt *C = dyn_cast<ConstantInt>(I->getOperand(1));
- if (!C)
- return false;
-
- switch (I->getPredicate()) {
- default:
- return false;
- case ICmpInst::ICMP_SLT:
- // X < 0 is equivalent to (X & SignMask) != 0.
- if (!C->isZero())
- return false;
- Y = ConstantInt::get(I->getContext(), APInt::getSignMask(C->getBitWidth()));
- Pred = ICmpInst::ICMP_NE;
- break;
- case ICmpInst::ICMP_SGT:
- // X > -1 is equivalent to (X & SignMask) == 0.
- if (!C->isMinusOne())
- return false;
- Y = ConstantInt::get(I->getContext(), APInt::getSignMask(C->getBitWidth()));
- Pred = ICmpInst::ICMP_EQ;
- break;
- case ICmpInst::ICMP_ULT:
- // X <u 2^n is equivalent to (X & ~(2^n-1)) == 0.
- if (!C->getValue().isPowerOf2())
- return false;
- Y = ConstantInt::get(I->getContext(), -C->getValue());
- Pred = ICmpInst::ICMP_EQ;
- break;
- case ICmpInst::ICMP_UGT:
- // X >u 2^n-1 is equivalent to (X & ~(2^n-1)) != 0.
- if (!(C->getValue() + 1).isPowerOf2())
- return false;
- Y = ConstantInt::get(I->getContext(), ~C->getValue());
- Pred = ICmpInst::ICMP_NE;
- break;
- }
-
- X = I->getOperand(0);
- Z = ConstantInt::getNullValue(C->getType());
- return true;
-}
Modified: llvm/trunk/test/Transforms/InstSimplify/select.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/select.ll?rev=310889&r1=310888&r2=310889&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstSimplify/select.ll (original)
+++ llvm/trunk/test/Transforms/InstSimplify/select.ll Mon Aug 14 14:39:51 2017
@@ -160,13 +160,10 @@ define <2 x i8> @test11vec(<2 x i8> %X)
ret <2 x i8> %sel
}
-; TODO: we should be able to simplify this
define i32 @test12(i32 %X) {
; CHECK-LABEL: @test12(
-; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[X:%.*]], 4
-; CHECK-NEXT: [[AND:%.*]] = and i32 [[X]], 3
-; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[X]], i32 [[AND]]
-; CHECK-NEXT: ret i32 [[COND]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], 3
+; CHECK-NEXT: ret i32 [[AND]]
;
%cmp = icmp ult i32 %X, 4
%and = and i32 %X, 3
@@ -189,13 +186,10 @@ define i32 @test12noncanon(i32 %X) {
ret i32 %cond
}
-; TODO: we should be able to simplify this
define i32 @test13(i32 %X) {
; CHECK-LABEL: @test13(
-; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i32 [[X:%.*]], 3
-; CHECK-NEXT: [[AND:%.*]] = and i32 [[X]], 3
-; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[AND]], i32 [[X]]
-; CHECK-NEXT: ret i32 [[COND]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], 3
+; CHECK-NEXT: ret i32 [[AND]]
;
%cmp = icmp ugt i32 %X, 3
%and = and i32 %X, 3
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