[InstCombine] handle zero constant vectors for LE/GE comparisons too

Enhancement to: http://reviews.llvm.org/rL269426
With discussion in: http://reviews.llvm.org/D17859

This should complete the fixes for: PR26701, PR26819:
https://llvm.org/bugs/show_bug.cgi?id=26701
https://llvm.org/bugs/show_bug.cgi?id=26819
 

llvm-svn: 269439
This commit is contained in:
Sanjay Patel 2016-05-13 17:28:12 +00:00
parent 27dba61ff3
commit 0c8f3f9332
2 changed files with 40 additions and 2 deletions

View File

@ -3130,8 +3130,9 @@ static ICmpInst *canonicalizeCmpWithConstant(ICmpInst &I,
}
// The usual vector types are ConstantDataVector. Exotic vector types are
// ConstantVector. They both derive from Constant.
if (isa<ConstantDataVector>(Op1) || isa<ConstantVector>(Op1)) {
// ConstantVector. Zeros are special. They all derive from Constant.
if (isa<ConstantDataVector>(Op1) || isa<ConstantVector>(Op1) ||
isa<ConstantAggregateZero>(Op1)) {
Constant *Op1C = cast<Constant>(Op1);
Type *Op1Type = Op1->getType();
unsigned NumElts = Op1Type->getVectorNumElements();

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@ -42,6 +42,43 @@ define <2 x i1> @ule(<2 x i8> %x) {
ret <2 x i1> %cmp
}
; Zeros are special: they're ConstantAggregateZero.
define <2 x i1> @sge_zero(<2 x i8> %x) {
; CHECK-LABEL: @sge_zero(
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <2 x i8> %x, <i8 -1, i8 -1>
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%cmp = icmp sge <2 x i8> %x, <i8 0, i8 0>
ret <2 x i1> %cmp
}
define <2 x i1> @uge_zero(<2 x i8> %x) {
; CHECK-LABEL: @uge_zero(
; CHECK-NEXT: ret <2 x i1> <i1 true, i1 true>
;
%cmp = icmp uge <2 x i8> %x, <i8 0, i8 0>
ret <2 x i1> %cmp
}
define <2 x i1> @sle_zero(<2 x i8> %x) {
; CHECK-LABEL: @sle_zero(
; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i8> %x, <i8 1, i8 1>
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%cmp = icmp sle <2 x i8> %x, <i8 0, i8 0>
ret <2 x i1> %cmp
}
define <2 x i1> @ule_zero(<2 x i8> %x) {
; CHECK-LABEL: @ule_zero(
; CHECK-NEXT: [[CMP:%.*]] = icmp ult <2 x i8> %x, <i8 1, i8 1>
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%cmp = icmp ule <2 x i8> %x, <i8 0, i8 0>
ret <2 x i1> %cmp
}
; Weird types are ConstantVectors, not ConstantDataVectors. For an i3 type:
; Signed min = -4
; Unsigned min = 0