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
llvm-svn: 310889
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index dfc2ea3..8f0254f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -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 @@
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 @@
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 @@
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;
diff --git a/llvm/lib/Transforms/Utils/CMakeLists.txt b/llvm/lib/Transforms/Utils/CMakeLists.txt
index 83bc05d..8561ec7 100644
--- a/llvm/lib/Transforms/Utils/CMakeLists.txt
+++ b/llvm/lib/Transforms/Utils/CMakeLists.txt
@@ -7,7 +7,6 @@
BypassSlowDivision.cpp
CloneFunction.cpp
CloneModule.cpp
- CmpInstAnalysis.cpp
CodeExtractor.cpp
CtorUtils.cpp
DemoteRegToStack.cpp
diff --git a/llvm/lib/Transforms/Utils/CmpInstAnalysis.cpp b/llvm/lib/Transforms/Utils/CmpInstAnalysis.cpp
deleted file mode 100644
index d9294c4..0000000
--- a/llvm/lib/Transforms/Utils/CmpInstAnalysis.cpp
+++ /dev/null
@@ -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;
-}