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[InstCombine] use m_APInt to allow icmp (udiv X, Y), C folds for spla…
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…t constant vectors

This is a sibling of:
https://reviews.llvm.org/rL278859
https://reviews.llvm.org/rL278935
https://reviews.llvm.org/rL278945
https://reviews.llvm.org/rL279066
https://reviews.llvm.org/rL279077


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279101 91177308-0d34-0410-b5e6-96231b3b80d8
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@rotateright
rotateright committed Aug 18, 2016
1 parent bb5b5bc commit 030db64
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Showing 2 changed files with 27 additions and 34 deletions.
38 changes: 20 additions & 18 deletions lib/Transforms/InstCombine/InstCombineCompares.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2105,24 +2105,26 @@ Instruction *InstCombiner::foldICmpShrConstant(ICmpInst &ICI, Instruction *LHSI,
Instruction *InstCombiner::foldICmpUDivConstant(ICmpInst &Cmp,
Instruction *UDiv,
const APInt *C) {
// FIXME: This check restricts all folds under here to scalar types.
if (ConstantInt *DivLHS = dyn_cast<ConstantInt>(UDiv->getOperand(0))) {
Value *X = UDiv->getOperand(1);
const APInt &C2 = DivLHS->getValue();
assert(C2 != 0 && "udiv 0, X should have been simplified already.");
// (icmp ugt (udiv C2, X), C1) -> (icmp ule X, C2/(C1+1))
if (Cmp.getPredicate() == ICmpInst::ICMP_UGT) {
assert(!C->isMaxValue() &&
"icmp ugt X, UINT_MAX should have been simplified already.");
return new ICmpInst(ICmpInst::ICMP_ULE, X,
ConstantInt::get(X->getType(), C2.udiv(*C + 1)));
}
// (icmp ult (udiv C2, X), C1) -> (icmp ugt X, C2/C1)
if (Cmp.getPredicate() == ICmpInst::ICMP_ULT) {
assert(C != 0 && "icmp ult X, 0 should have been simplified already.");
return new ICmpInst(ICmpInst::ICMP_UGT, X,
ConstantInt::get(X->getType(), C2.udiv(*C)));
}
const APInt *C2;
if (!match(UDiv->getOperand(0), m_APInt(C2)))
return nullptr;

assert(C2 != 0 && "udiv 0, X should have been simplified already.");

// (icmp ugt (udiv C2, Y), C) -> (icmp ule Y, C2/(C+1))
Value *Y = UDiv->getOperand(1);
if (Cmp.getPredicate() == ICmpInst::ICMP_UGT) {
assert(!C->isMaxValue() &&
"icmp ugt X, UINT_MAX should have been simplified already.");
return new ICmpInst(ICmpInst::ICMP_ULE, Y,
ConstantInt::get(Y->getType(), C2->udiv(*C + 1)));
}

// (icmp ult (udiv C2, Y), C) -> (icmp ugt Y, C2/C)
if (Cmp.getPredicate() == ICmpInst::ICMP_ULT) {
assert(C != 0 && "icmp ult X, 0 should have been simplified already.");
return new ICmpInst(ICmpInst::ICMP_UGT, Y,
ConstantInt::get(Y->getType(), C2->udiv(*C)));
}

return nullptr;
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23 changes: 7 additions & 16 deletions test/Transforms/InstCombine/compare-udiv.ll
View file
Original file line number Diff line number Diff line change
Expand Up @@ -148,12 +148,9 @@ define i1 @test8(i32 %d) {
ret i1 %cmp1
}

; FIXME: Vectors should get the same folds as scalars for all tests.

define <2 x i1> @test8vec(<2 x i32> %d) {
; CHECK-LABEL: @test8vec(
; CHECK-NEXT: [[DIV:%.*]] = udiv <2 x i32> <i32 4, i32 4>, %d
; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt <2 x i32> [[DIV]], <i32 3, i32 3>
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult <2 x i32> %d, <i32 2, i32 2>
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%div = udiv <2 x i32> <i32 4, i32 4>, %d
Expand All @@ -173,8 +170,7 @@ define i1 @test9(i32 %d) {

define <2 x i1> @test9vec(<2 x i32> %d) {
; CHECK-LABEL: @test9vec(
; CHECK-NEXT: [[DIV:%.*]] = udiv <2 x i32> <i32 4, i32 4>, %d
; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt <2 x i32> [[DIV]], <i32 2, i32 2>
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult <2 x i32> %d, <i32 2, i32 2>
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%div = udiv <2 x i32> <i32 4, i32 4>, %d
Expand All @@ -194,8 +190,7 @@ define i1 @test10(i32 %d) {

define <2 x i1> @test10vec(<2 x i32> %d) {
; CHECK-LABEL: @test10vec(
; CHECK-NEXT: [[DIV:%.*]] = udiv <2 x i32> <i32 4, i32 4>, %d
; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt <2 x i32> [[DIV]], <i32 1, i32 1>
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult <2 x i32> %d, <i32 3, i32 3>
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%div = udiv <2 x i32> <i32 4, i32 4>, %d
Expand All @@ -215,8 +210,7 @@ define i1 @test11(i32 %d) {

define <2 x i1> @test11vec(<2 x i32> %d) {
; CHECK-LABEL: @test11vec(
; CHECK-NEXT: [[DIV:%.*]] = udiv <2 x i32> <i32 4, i32 4>, %d
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult <2 x i32> [[DIV]], <i32 1, i32 1>
; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt <2 x i32> %d, <i32 4, i32 4>
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%div = udiv <2 x i32> <i32 4, i32 4>, %d
Expand All @@ -236,8 +230,7 @@ define i1 @test12(i32 %d) {

define <2 x i1> @test12vec(<2 x i32> %d) {
; CHECK-LABEL: @test12vec(
; CHECK-NEXT: [[DIV:%.*]] = udiv <2 x i32> <i32 4, i32 4>, %d
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult <2 x i32> [[DIV]], <i32 2, i32 2>
; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt <2 x i32> %d, <i32 2, i32 2>
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%div = udiv <2 x i32> <i32 4, i32 4>, %d
Expand All @@ -257,8 +250,7 @@ define i1 @test13(i32 %d) {

define <2 x i1> @test13vec(<2 x i32> %d) {
; CHECK-LABEL: @test13vec(
; CHECK-NEXT: [[DIV:%.*]] = udiv <2 x i32> <i32 4, i32 4>, %d
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult <2 x i32> [[DIV]], <i32 3, i32 3>
; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt <2 x i32> %d, <i32 1, i32 1>
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%div = udiv <2 x i32> <i32 4, i32 4>, %d
Expand All @@ -278,8 +270,7 @@ define i1 @test14(i32 %d) {

define <2 x i1> @test14vec(<2 x i32> %d) {
; CHECK-LABEL: @test14vec(
; CHECK-NEXT: [[DIV:%.*]] = udiv <2 x i32> <i32 4, i32 4>, %d
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult <2 x i32> [[DIV]], <i32 4, i32 4>
; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt <2 x i32> %d, <i32 1, i32 1>
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%div = udiv <2 x i32> <i32 4, i32 4>, %d
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