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[InstCombine] Disable some portions of foldGEPICmp for GEPs that return a vector of pointers. Fix other portions. 

llvm-svn: 370114
This commit is contained in:
Craig Topper 2019-08-27 21:38:56 +00:00
parent c894c6c983
commit 5bbb604bb5
2 changed files with 41 additions and 11 deletions
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37
llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
View File

@ -832,6 +832,10 @@ getAsConstantIndexedAddress(Value *V, const DataLayout &DL) {
static Instruction *transformToIndexedCompare(GEPOperator *GEPLHS, Value *RHS,
ICmpInst::Predicate Cond,
const DataLayout &DL) {
// FIXME: Support vector of pointers.
if (GEPLHS->getType()->isVectorTy())
return nullptr;
if (!GEPLHS->hasAllConstantIndices())
return nullptr;
@ -882,7 +886,9 @@ Instruction *InstCombiner::foldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
RHS = RHS->stripPointerCasts();
Value *PtrBase = GEPLHS->getOperand(0);
if (PtrBase == RHS && GEPLHS->isInBounds()) {
// FIXME: Support vector pointer GEPs.
if (PtrBase == RHS && GEPLHS->isInBounds() &&
!GEPLHS->getType()->isVectorTy()) {
// ((gep Ptr, OFFSET) cmp Ptr) ---> (OFFSET cmp 0).
// This transformation (ignoring the base and scales) is valid because we
// know pointers can't overflow since the gep is inbounds. See if we can
@ -894,10 +900,12 @@ Instruction *InstCombiner::foldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
Offset = EmitGEPOffset(GEPLHS);
return new ICmpInst(ICmpInst::getSignedPredicate(Cond), Offset,
Constant::getNullValue(Offset->getType()));
} else if (GEPLHS->isInBounds() && ICmpInst::isEquality(Cond) &&
isa<Constant>(RHS) && cast<Constant>(RHS)->isNullValue() &&
!NullPointerIsDefined(I.getFunction(),
RHS->getType()->getPointerAddressSpace())) {
}
if (GEPLHS->isInBounds() && ICmpInst::isEquality(Cond) &&
isa<Constant>(RHS) && cast<Constant>(RHS)->isNullValue() &&
!NullPointerIsDefined(I.getFunction(),
RHS->getType()->getPointerAddressSpace())) {
// For most address spaces, an allocation can't be placed at null, but null
// itself is treated as a 0 size allocation in the in bounds rules. Thus,
// the only valid inbounds address derived from null, is null itself.
@ -945,11 +953,13 @@ Instruction *InstCombiner::foldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
// If we're comparing GEPs with two base pointers that only differ in type
// and both GEPs have only constant indices or just one use, then fold
// the compare with the adjusted indices.
// FIXME: Support vector of pointers.
if (GEPLHS->isInBounds() && GEPRHS->isInBounds() &&
(GEPLHS->hasAllConstantIndices() || GEPLHS->hasOneUse()) &&
(GEPRHS->hasAllConstantIndices() || GEPRHS->hasOneUse()) &&
PtrBase->stripPointerCasts() ==
GEPRHS->getOperand(0)->stripPointerCasts()) {
GEPRHS->getOperand(0)->stripPointerCasts() &&
!GEPLHS->getType()->isVectorTy()) {
Value *LOffset = EmitGEPOffset(GEPLHS);
Value *ROffset = EmitGEPOffset(GEPRHS);
@ -993,15 +1003,20 @@ Instruction *InstCombiner::foldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
unsigned DiffOperand = 0; // The operand that differs.
for (unsigned i = 1, e = GEPRHS->getNumOperands(); i != e; ++i)
if (GEPLHS->getOperand(i) != GEPRHS->getOperand(i)) {
if (GEPLHS->getOperand(i)->getType()->getPrimitiveSizeInBits() !=
GEPRHS->getOperand(i)->getType()->getPrimitiveSizeInBits()) {
Type *LHSType = GEPLHS->getOperand(i)->getType();
Type *RHSType = GEPRHS->getOperand(i)->getType();
// FIXME: Better support for vector of pointers.
if (LHSType->getPrimitiveSizeInBits() !=
RHSType->getPrimitiveSizeInBits() ||
(GEPLHS->getType()->isVectorTy() &&
(!LHSType->isVectorTy() || !RHSType->isVectorTy()))) {
// Irreconcilable differences.
NumDifferences = 2;
break;
} else {
if (NumDifferences++) break;
DiffOperand = i;
}
if (NumDifferences++) break;
DiffOperand = i;
}
if (NumDifferences == 0) // SAME GEP?

15
llvm/test/Transforms/InstCombine/getelementptr.ll
View File

@ -202,6 +202,21 @@ define <2 x i1> @test13_vector2(i64 %X, <2 x %S*> %P) nounwind {
ret <2 x i1> %C
}
; This is a test of icmp + shl nuw in disguise - 4611... is 0x3fff...
define <2 x i1> @test13_vector3(i64 %X, <2 x %S*> %P) nounwind {
; CHECK-LABEL: @test13_vector3(
; CHECK-NEXT: [[DOTSPLATINSERT:%.*]] = insertelement <2 x i64> undef, i64 [[X:%.*]], i32 0
; CHECK-NEXT: [[TMP1:%.*]] = shl nuw <2 x i64> [[DOTSPLATINSERT]], <i64 2, i64 undef>
; CHECK-NEXT: [[A_IDX:%.*]] = shufflevector <2 x i64> [[TMP1]], <2 x i64> undef, <2 x i32> zeroinitializer
; CHECK-NEXT: [[C:%.*]] = icmp eq <2 x i64> [[A_IDX]], <i64 4, i64 4>
; CHECK-NEXT: ret <2 x i1> [[C]]
;
%A = getelementptr inbounds %S, <2 x %S*> %P, <2 x i64> zeroinitializer, <2 x i32> <i32 1, i32 1>, i64 %X
%B = getelementptr inbounds %S, <2 x %S*> %P, <2 x i64> <i64 0, i64 0>, <2 x i32> <i32 1, i32 1>, i64 1
%C = icmp eq <2 x i32*> %A, %B
ret <2 x i1> %C
}
define i1 @test13_as1(i16 %X, %S addrspace(1)* %P) {
; CHECK-LABEL: @test13_as1(
; CHECK-NEXT: %C = icmp eq i16 %X, -1