RPCS3/llvm
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm.git synced 2025-02-23 12:11:58 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

[InstCombine] use m_APInt for div --> ashr fold

Browse Source 
The APInt matcher works with splat vectors, so we get this fold for vectors too.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273897 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Sanjay Patel 2016-06-27 17:25:57 +00:00
parent 0c5a6a8955
commit d96514bcfe
2 changed files with 15 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
View File

@ -1143,14 +1143,12 @@ Instruction *InstCombiner::visitSDiv(BinaryOperator &I) {
if (match(Op1, m_AllOnes()))
return BinaryOperator::CreateNeg(Op0);
if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
// sdiv X, C --> ashr exact X, log2(C)
if (I.isExact() && RHS->getValue().isNonNegative() &&
RHS->getValue().isPowerOf2()) {
Value *ShAmt = llvm::ConstantInt::get(RHS->getType(),
RHS->getValue().exactLogBase2());
return BinaryOperator::CreateExactAShr(Op0, ShAmt, I.getName());
}
// sdiv exact X, C --> ashr exact X, log2(C)
const APInt *Op1C;
if (match(Op1, m_APInt(Op1C)) && I.isExact() && Op1C->isNonNegative() &&
Op1C->isPowerOf2()) {
Value *ShAmt = ConstantInt::get(Op1->getType(), Op1C->exactLogBase2());
return BinaryOperator::CreateExactAShr(Op0, ShAmt, I.getName());
}
if (Constant *RHS = dyn_cast<Constant>(Op1)) {

9
test/Transforms/InstCombine/exact.ll
View File

@ -19,6 +19,15 @@ define i32 @sdiv2(i32 %x) {
ret i32 %y
}
define <2 x i32> @sdiv2_vec(<2 x i32> %x) {
; CHECK-LABEL: @sdiv2_vec(
; CHECK-NEXT: [[Y:%.*]] = ashr exact <2 x i32> %x, <i32 7, i32 7>
; CHECK-NEXT: ret <2 x i32> [[Y]]
;
%y = sdiv exact <2 x i32> %x, <i32 128, i32 128>
ret <2 x i32> %y
}
define i32 @sdiv3(i32 %x) {
; CHECK-LABEL: @sdiv3(
; CHECK-NEXT: [[Y:%.*]] = srem i32 %x, 3