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[InstCombine] use m_APInt to allow icmp eq (and X, C1), C2 folds for splat constant vectors 

llvm-svn: 277762
This commit is contained in:
Sanjay Patel 2016-08-04 20:05:02 +00:00
parent d62d116add
commit d938e88e89
3 changed files with 14 additions and 23 deletions
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23
llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
View File

@ -176,12 +176,6 @@ static bool isSignTest(ICmpInst::Predicate &Pred, const ConstantInt *RHS) {
return false;
}
/// Return true if the constant is of the form 1+0+. This is the same as
/// lowones(~X).
static bool isHighOnes(const ConstantInt *CI) {
return (~CI->getValue() + 1).isPowerOf2();
}
/// Given a signed integer type and a set of known zero and one bits, compute
/// the maximum and minimum values that could have the specified known zero and
/// known one bits, returning them in Min/Max.
@ -2288,11 +2282,11 @@ Instruction *InstCombiner::foldICmpEqualityWithConstant(ICmpInst &ICI) {
}
break;
}
case Instruction::And:
// FIXME: Vectors are excluded by ConstantInt.
if (ConstantInt *BOC = dyn_cast<ConstantInt>(BOp1)) {
case Instruction::And: {
const APInt *BOC;
if (match(BOp1, m_APInt(BOC))) {
// If we have ((X & C) == C), turn it into ((X & C) != 0).
if (RHS == BOC && RHSV->isPowerOf2())
if (RHSV == BOC && RHSV->isPowerOf2())
return new ICmpInst(isICMP_NE ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE,
BO, Constant::getNullValue(RHS->getType()));
@ -2301,7 +2295,7 @@ Instruction *InstCombiner::foldICmpEqualityWithConstant(ICmpInst &ICI) {
break;
// Replace (and X, (1 << size(X)-1) != 0) with x s< 0
if (BOC->getValue().isSignBit()) {
if (BOC->isSignBit()) {
Constant *Zero = Constant::getNullValue(BOp0->getType());
ICmpInst::Predicate Pred =
isICMP_NE ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_SGE;
@ -2309,14 +2303,15 @@ Instruction *InstCombiner::foldICmpEqualityWithConstant(ICmpInst &ICI) {
}
// ((X & ~7) == 0) --> X < 8
if (*RHSV == 0 && isHighOnes(BOC)) {
Constant *NegX = ConstantExpr::getNeg(BOC);
if (*RHSV == 0 && (~(*BOC) + 1).isPowerOf2()) {
Constant *NegBOC = ConstantExpr::getNeg(cast<Constant>(BOp1));
ICmpInst::Predicate Pred =
isICMP_NE ? ICmpInst::ICMP_UGE : ICmpInst::ICMP_ULT;
return new ICmpInst(Pred, BOp0, NegX);
return new ICmpInst(Pred, BOp0, NegBOC);
}
}
break;
}
case Instruction::Mul:
if (*RHSV == 0 && BO->hasNoSignedWrap()) {
// FIXME: Vectors are excluded by ConstantInt.

8
llvm/test/Transforms/InstCombine/and.ll
View File

@ -196,11 +196,9 @@ define i1 @test18(i32 %A) {
ret i1 %C
}
; FIXME: Vectors should fold the same way.
define <2 x i1> @test18_vec(<2 x i32> %A) {
; CHECK-LABEL: @test18_vec(
; CHECK-NEXT: [[B:%.*]] = and <2 x i32> %A, <i32 -128, i32 -128>
; CHECK-NEXT: [[C:%.*]] = icmp ne <2 x i32> [[B]], zeroinitializer
; CHECK-NEXT: [[C:%.*]] = icmp ugt <2 x i32> %A, <i32 127, i32 127>
; CHECK-NEXT: ret <2 x i1> [[C]]
;
%B = and <2 x i32> %A, <i32 -128, i32 -128>
@ -218,11 +216,9 @@ define i1 @test18a(i8 %A) {
ret i1 %C
}
; FIXME: Vectors should fold the same way.
define <2 x i1> @test18a_vec(<2 x i8> %A) {
; CHECK-LABEL: @test18a_vec(
; CHECK-NEXT: [[B:%.*]] = and <2 x i8> %A, <i8 -2, i8 -2>
; CHECK-NEXT: [[C:%.*]] = icmp eq <2 x i8> [[B]], zeroinitializer
; CHECK-NEXT: [[C:%.*]] = icmp ult <2 x i8> %A, <i8 2, i8 2>
; CHECK-NEXT: ret <2 x i1> [[C]]
;
%B = and <2 x i8> %A, <i8 -2, i8 -2>

6
llvm/test/Transforms/InstCombine/icmp.ll
View File

@ -205,11 +205,12 @@ define i1 @test19(i32 %x) {
}
; FIXME: Vectors should fold the same way.
define <2 x i1> @test19vec(<2 x i32> %x) {
; CHECK-LABEL: @test19vec(
; CHECK-NEXT: [[SHL:%.*]] = shl <2 x i32> <i32 1, i32 1>, %x
; CHECK-NEXT: [[AND:%.*]] = and <2 x i32> [[SHL]], <i32 8, i32 8>
; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i32> [[AND]], <i32 8, i32 8>
; CHECK-NEXT: [[CMP:%.*]] = icmp ne <2 x i32> [[AND]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%shl = shl <2 x i32> <i32 1, i32 1>, %x
@ -220,8 +221,7 @@ define <2 x i1> @test19vec(<2 x i32> %x) {
define <2 x i1> @cmp_and_signbit_vec(<2 x i3> %x) {
; CHECK-LABEL: @cmp_and_signbit_vec(
; CHECK-NEXT: [[AND:%.*]] = and <2 x i3> %x, <i3 -4, i3 -4>
; CHECK-NEXT: [[CMP:%.*]] = icmp ne <2 x i3> [[AND]], zeroinitializer
; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i3> %x, zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%and = and <2 x i3> %x, <i3 4, i3 4>