[PATCH] D60396: [InstCombine] sdiv exact flag fixup
ChenZheng via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 8 05:06:29 PDT 2019
This revision was automatically updated to reflect the committed changes.
shchenz marked an inline comment as done.
Closed by commit rL357904: [InstCombine] sdiv exact flag fixup. (authored by shchenz, committed by ).
Changed prior to commit:
https://reviews.llvm.org/D60396?vs=194107&id=194116#toc
Repository:
rL LLVM
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D60396/new/
https://reviews.llvm.org/D60396
Files:
llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp
llvm/trunk/test/Transforms/InstCombine/div.ll
Index: llvm/trunk/test/Transforms/InstCombine/div.ll
===================================================================
--- llvm/trunk/test/Transforms/InstCombine/div.ll
+++ llvm/trunk/test/Transforms/InstCombine/div.ll
@@ -762,7 +762,7 @@
define i32 @test_exact_nsw_exact(i32 %x) {
; CHECK-LABEL: @test_exact_nsw_exact(
-; CHECK-NEXT: [[NEG:%.*]] = sdiv i32 [[X:%.*]], -3
+; CHECK-NEXT: [[NEG:%.*]] = sdiv exact i32 [[X:%.*]], -3
; CHECK-NEXT: ret i32 [[NEG]]
;
%div = sdiv exact i32 %x, 3
@@ -772,7 +772,7 @@
define <2 x i64> @test_exact_vec(<2 x i64> %x) {
; CHECK-LABEL: @test_exact_vec(
-; CHECK-NEXT: [[NEG:%.*]] = sdiv <2 x i64> [[X:%.*]], <i64 -3, i64 -4>
+; CHECK-NEXT: [[NEG:%.*]] = sdiv exact <2 x i64> [[X:%.*]], <i64 -3, i64 -4>
; CHECK-NEXT: ret <2 x i64> [[NEG]]
;
%div = sdiv exact <2 x i64> %x, <i64 3, i64 4>
@@ -782,7 +782,7 @@
define i32 @test_exact_nonsw_exact(i32 %x) {
; CHECK-LABEL: @test_exact_nonsw_exact(
-; CHECK-NEXT: [[NEG:%.*]] = sdiv i32 [[X:%.*]], -3
+; CHECK-NEXT: [[NEG:%.*]] = sdiv exact i32 [[X:%.*]], -3
; CHECK-NEXT: ret i32 [[NEG]]
;
%div = sdiv exact i32 %x, 3
@@ -806,7 +806,7 @@
; CHECK-NEXT: ret i32 [[NEG]]
;
%div = sdiv i32 %x, 3
- %neg = sub nsw i32 0, %div
+ %neg = sub i32 0, %div
ret i32 %neg
}
Index: llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp
===================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -1693,8 +1693,11 @@
// 0 - (X sdiv C) -> (X sdiv -C) provided the negation doesn't overflow.
if (match(Op1, m_SDiv(m_Value(X), m_Constant(C))) && match(Op0, m_Zero()) &&
- C->isNotMinSignedValue() && !C->isOneValue())
- return BinaryOperator::CreateSDiv(X, ConstantExpr::getNeg(C));
+ C->isNotMinSignedValue() && !C->isOneValue()) {
+ auto *BO = BinaryOperator::CreateSDiv(X, ConstantExpr::getNeg(C));
+ BO->setIsExact(cast<BinaryOperator>(Op1)->isExact());
+ return BO;
+ }
// 0 - (X << Y) -> (-X << Y) when X is freely negatable.
if (match(Op1, m_Shl(m_Value(X), m_Value(Y))) && match(Op0, m_Zero()))
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