[llvm] r300439 - [InstCombine] Simplify 1/X for vectors.
Craig Topper via llvm-commits
llvm-commits at lists.llvm.org
Sun Apr 16 20:41:47 PDT 2017
Author: ctopper
Date: Sun Apr 16 22:41:47 2017
New Revision: 300439
URL: http://llvm.org/viewvc/llvm-project?rev=300439&view=rev
Log:
[InstCombine] Simplify 1/X for vectors.
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
llvm/trunk/test/Transforms/InstCombine/div.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp?rev=300439&r1=300438&r2=300439&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp Sun Apr 16 22:41:47 2017
@@ -944,22 +944,21 @@ Instruction *InstCombiner::commonIDivTra
}
}
- if (ConstantInt *One = dyn_cast<ConstantInt>(Op0)) {
- if (One->isOne() && !I.getType()->isIntegerTy(1)) {
- bool isSigned = I.getOpcode() == Instruction::SDiv;
- if (isSigned) {
- // If Op1 is 0 then it's undefined behaviour, if Op1 is 1 then the
- // result is one, if Op1 is -1 then the result is minus one, otherwise
- // it's zero.
- Value *Inc = Builder->CreateAdd(Op1, One);
- Value *Cmp = Builder->CreateICmpULT(
- Inc, ConstantInt::get(I.getType(), 3));
- return SelectInst::Create(Cmp, Op1, ConstantInt::get(I.getType(), 0));
- } else {
- // If Op1 is 0 then it's undefined behaviour. If Op1 is 1 then the
- // result is one, otherwise it's zero.
- return new ZExtInst(Builder->CreateICmpEQ(Op1, One), I.getType());
- }
+ if (match(Op0, m_One())) {
+ assert(!I.getType()->getScalarType()->isIntegerTy(1) &&
+ "i1 divide not removed?");
+ if (I.getOpcode() == Instruction::SDiv) {
+ // If Op1 is 0 then it's undefined behaviour, if Op1 is 1 then the
+ // result is one, if Op1 is -1 then the result is minus one, otherwise
+ // it's zero.
+ Value *Inc = Builder->CreateAdd(Op1, Op0);
+ Value *Cmp = Builder->CreateICmpULT(
+ Inc, ConstantInt::get(I.getType(), 3));
+ return SelectInst::Create(Cmp, Op1, ConstantInt::get(I.getType(), 0));
+ } else {
+ // If Op1 is 0 then it's undefined behaviour. If Op1 is 1 then the
+ // result is one, otherwise it's zero.
+ return new ZExtInst(Builder->CreateICmpEQ(Op1, Op0), I.getType());
}
}
Modified: llvm/trunk/test/Transforms/InstCombine/div.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/div.ll?rev=300439&r1=300438&r2=300439&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/div.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/div.ll Sun Apr 16 22:41:47 2017
@@ -227,7 +227,8 @@ define i32 @test19(i32 %x) {
define <2 x i32> @test19vec(<2 x i32> %x) {
; CHECK-LABEL: @test19vec(
-; CHECK-NEXT: [[A:%.*]] = udiv <2 x i32> <i32 1, i32 1>, [[X:%.*]]
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq <2 x i32> [[X:%.*]], <i32 1, i32 1>
+; CHECK-NEXT: [[A:%.*]] = zext <2 x i1> [[TMP1]] to <2 x i32>
; CHECK-NEXT: ret <2 x i32> [[A]]
;
%A = udiv <2 x i32> <i32 1, i32 1>, %x
@@ -247,7 +248,9 @@ define i32 @test20(i32 %x) {
define <2 x i32> @test20vec(<2 x i32> %x) {
; CHECK-LABEL: @test20vec(
-; CHECK-NEXT: [[A:%.*]] = sdiv <2 x i32> <i32 1, i32 1>, [[X:%.*]]
+; CHECK-NEXT: [[TMP1:%.*]] = add <2 x i32> [[X:%.*]], <i32 1, i32 1>
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ult <2 x i32> [[TMP1]], <i32 3, i32 3>
+; CHECK-NEXT: [[A:%.*]] = select <2 x i1> [[TMP2]], <2 x i32> [[X]], <2 x i32> zeroinitializer
; CHECK-NEXT: ret <2 x i32> [[A]]
;
%A = sdiv <2 x i32> <i32 1, i32 1>, %x
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