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[InstCombine] use m_APInt to allow icmp X, C folds for splat constant vectors 

isSignBitCheck could be changed to take a pointer param to avoid the 'UnusedBit' ugliness.

llvm-svn: 281231
This commit is contained in:
Sanjay Patel 2016-09-12 16:25:41 +00:00
parent e58e0e3fe3
commit f5887f1fbd
3 changed files with 6 additions and 7 deletions
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5
llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
View File

@ -3153,9 +3153,10 @@ Instruction *InstCombiner::foldICmpUsingKnownBits(ICmpInst &I) {
// If this is a normal comparison, it demands all bits. If it is a sign bit
// comparison, it only demands the sign bit.
bool IsSignBit = false;
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
const APInt *CmpC;
if (match(Op1, m_APInt(CmpC))) {
bool UnusedBit;
IsSignBit = isSignBitCheck(Pred, CI->getValue(), UnusedBit);
IsSignBit = isSignBitCheck(Pred, *CmpC, UnusedBit);
}
APInt Op0KnownZero(BitWidth, 0), Op0KnownOne(BitWidth, 0);

4
llvm/test/Transforms/InstCombine/shift.ll
View File

@ -628,11 +628,9 @@ define i1 @test35(i32 %X) {
ret i1 %tmp2
}
; FIXME: Vectors should fold the same way.
define <2 x i1> @test35vec(<2 x i32> %X) {
; CHECK-LABEL: @test35vec(
; CHECK-NEXT: [[TMP1:%.*]] = ashr <2 x i32> %X, <i32 7, i32 7>
; CHECK-NEXT: [[TMP2:%.*]] = icmp slt <2 x i32> [[TMP1]], zeroinitializer
; CHECK-NEXT: [[TMP2:%.*]] = icmp slt <2 x i32> %X, zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[TMP2]]
;
%tmp1 = ashr <2 x i32> %X, <i32 7, i32 7>

4
llvm/test/Transforms/InstCombine/vec_sext.ll
View File

@ -3,8 +3,8 @@
define <4 x i32> @psignd_3(<4 x i32> %a, <4 x i32> %b) {
; CHECK-LABEL: @psignd_3(
; CHECK-NEXT: [[B_LOBIT:%.*]] = ashr <4 x i32> %b, <i32 31, i32 31, i32 31, i32 31>
; CHECK-NEXT: [[SUB:%.*]] = sub nsw <4 x i32> zeroinitializer, %a
; CHECK-NEXT: [[B_LOBIT:%.*]] = ashr <4 x i32> %b, <i32 31, i32 31, i32 31, i32 31>
; CHECK-NEXT: [[T1:%.*]] = xor <4 x i32> [[B_LOBIT]], <i32 -1, i32 -1, i32 -1, i32 -1>
; CHECK-NEXT: [[T2:%.*]] = and <4 x i32> %a, [[T1]]
; CHECK-NEXT: [[T3:%.*]] = and <4 x i32> [[B_LOBIT]], [[SUB]]
@ -25,8 +25,8 @@ define <4 x i32> @psignd_3(<4 x i32> %a, <4 x i32> %b) {
define <4 x i32> @test1(<4 x i32> %a, <4 x i32> %b) {
; CHECK-LABEL: @test1(
; CHECK-NEXT: [[B_LOBIT:%.*]] = ashr <4 x i32> %b, <i32 31, i32 31, i32 31, i32 31>
; CHECK-NEXT: [[SUB:%.*]] = sub nsw <4 x i32> zeroinitializer, %a
; CHECK-NEXT: [[B_LOBIT:%.*]] = ashr <4 x i32> %b, <i32 31, i32 31, i32 31, i32 31>
; CHECK-NEXT: [[B_LOBIT_NOT:%.*]] = xor <4 x i32> [[B_LOBIT]], <i32 -1, i32 -1, i32 -1, i32 -1>
; CHECK-NEXT: [[T2:%.*]] = and <4 x i32> [[B_LOBIT]], %a
; CHECK-NEXT: [[T3:%.*]] = and <4 x i32> [[B_LOBIT_NOT]], [[SUB]]