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| author | Sanjay Patel <spatel@rotateright.com> | 2018-06-25 21:39:41 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2018-06-25 21:39:41 +0000 |
| commit | 6a96d90acd4ea15b18ab526966dcd4f1fe86754a (patch) | |
| tree | 203cbd58f3471d6ef99645d5f21c0fcefb5e27e7 | |
| parent | 46f9b8c333d641f5d386e21d0ca3cc34b8b90e34 (diff) | |
| download | bcm5719-llvm-6a96d90acd4ea15b18ab526966dcd4f1fe86754a.tar.gz bcm5719-llvm-6a96d90acd4ea15b18ab526966dcd4f1fe86754a.zip | |
[InstCombine] fold sdiv with sext bool divisor
llvm-svn: 335527
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 11 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/div.ll | 6 |
2 files changed, 9 insertions, 8 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index c2293f08309..326f499ed9f 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -1019,12 +1019,15 @@ Instruction *InstCombiner::visitSDiv(BinaryOperator &I) { return Common; Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); + Value *X; + // sdiv Op0, -1 --> -Op0 + // sdiv Op0, (sext i1 X) --> -Op0 (because if X is 0, the op is undefined) + if (match(Op1, m_AllOnes()) || + (match(Op1, m_SExt(m_Value(X))) && X->getType()->isIntOrIntVectorTy(1))) + return BinaryOperator::CreateNeg(Op0); + const APInt *Op1C; if (match(Op1, m_APInt(Op1C))) { - // sdiv X, -1 == -X - if (Op1C->isAllOnesValue()) - return BinaryOperator::CreateNeg(Op0); - // sdiv exact X, C --> ashr exact X, log2(C) if (I.isExact() && Op1C->isNonNegative() && Op1C->isPowerOf2()) { Value *ShAmt = ConstantInt::get(Op1->getType(), Op1C->exactLogBase2()); diff --git a/llvm/test/Transforms/InstCombine/div.ll b/llvm/test/Transforms/InstCombine/div.ll index 805eb466804..13f751d0d9c 100644 --- a/llvm/test/Transforms/InstCombine/div.ll +++ b/llvm/test/Transforms/InstCombine/div.ll @@ -48,8 +48,7 @@ define <2 x i64> @sdiv_by_minus1_vec_undef_elt(<2 x i64> %x) { define i32 @sdiv_by_sext_minus1(i1 %x, i32 %y) { ; CHECK-LABEL: @sdiv_by_sext_minus1( -; CHECK-NEXT: [[SEXT:%.*]] = sext i1 [[X:%.*]] to i32 -; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 [[Y:%.*]], [[SEXT]] +; CHECK-NEXT: [[DIV:%.*]] = sub i32 0, [[Y:%.*]] ; CHECK-NEXT: ret i32 [[DIV]] ; %sext = sext i1 %x to i32 @@ -59,8 +58,7 @@ define i32 @sdiv_by_sext_minus1(i1 %x, i32 %y) { define <2 x i32> @sdiv_by_sext_minus1_vec(<2 x i1> %x, <2 x i32> %y) { ; CHECK-LABEL: @sdiv_by_sext_minus1_vec( -; CHECK-NEXT: [[SEXT:%.*]] = sext <2 x i1> [[X:%.*]] to <2 x i32> -; CHECK-NEXT: [[DIV:%.*]] = sdiv <2 x i32> [[Y:%.*]], [[SEXT]] +; CHECK-NEXT: [[DIV:%.*]] = sub <2 x i32> zeroinitializer, [[Y:%.*]] ; CHECK-NEXT: ret <2 x i32> [[DIV]] ; %sext = sext <2 x i1> %x to <2 x i32> |
