[llvm] dd0245e - [InstCombine] Relax one-use requirement for add iN (sext i1 X), (sext i1 Y) --> sext (X | Y) to iN (#90509)
via llvm-commits
llvm-commits at lists.llvm.org
Fri Jun 28 00:08:04 PDT 2024
Author: AtariDreams
Date: 2024-06-28T09:08:01+02:00
New Revision: dd0245e3d74955ace14c95d288abf72346ad52e8
URL: https://github.com/llvm/llvm-project/commit/dd0245e3d74955ace14c95d288abf72346ad52e8
DIFF: https://github.com/llvm/llvm-project/commit/dd0245e3d74955ace14c95d288abf72346ad52e8.diff
LOG: [InstCombine] Relax one-use requirement for add iN (sext i1 X), (sext i1 Y) --> sext (X | Y) to iN (#90509)
Since these remove instructions as long as at least one of X or Y is
one-use, we don't need to check one-use for both.
Added:
Modified:
llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
llvm/test/Transforms/InstCombine/add.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index 35425c5d0882e..bfe5db3547cd5 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -499,10 +499,10 @@ Value *InstCombinerImpl::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
}
// add iN (sext i1 X), (sext i1 Y) --> sext (X | Y) to iN
- // TODO: Relax the one-use checks because we are removing an instruction?
- if (match(I, m_Add(m_OneUse(m_SExt(m_Value(X))),
- m_OneUse(m_SExt(m_Value(Y))))) &&
- X->getType()->isIntOrIntVectorTy(1) && X->getType() == Y->getType()) {
+ if (match(I, m_Add(m_SExt(m_Value(X)), m_SExt(m_Value(Y)))) &&
+ X->getType()->isIntOrIntVectorTy(1) && X->getType() == Y->getType() &&
+ (I->getOperand(0)->hasOneUse() || I->getOperand(1)->hasOneUse())) {
+
// Truth table for inputs and output signbits:
// X:0 | X:1
// -----------
diff --git a/llvm/test/Transforms/InstCombine/add.ll b/llvm/test/Transforms/InstCombine/add.ll
index 239e14682c306..8b3ecaf25cd9d 100644
--- a/llvm/test/Transforms/InstCombine/add.ll
+++ b/llvm/test/Transforms/InstCombine/add.ll
@@ -1435,15 +1435,28 @@ define i32 @and31_add_sexts(i1 %x, i1 %y) {
ret i32 %r
}
-; Negative test - extra use
-
define i32 @lshr_add_use_sexts(i1 %x, i1 %y, ptr %p) {
; CHECK-LABEL: @lshr_add_use_sexts(
+; CHECK-NEXT: [[YS:%.*]] = sext i1 [[Y:%.*]] to i32
+; CHECK-NEXT: store i32 [[YS]], ptr [[P:%.*]], align 4
+; CHECK-NEXT: [[TMP1:%.*]] = or i1 [[X:%.*]], [[Y]]
+; CHECK-NEXT: [[R:%.*]] = zext i1 [[TMP1]] to i32
+; CHECK-NEXT: ret i32 [[R]]
+;
+ %xs = sext i1 %x to i32
+ %ys = sext i1 %y to i32
+ store i32 %ys, ptr %p
+ %sub = add i32 %xs, %ys
+ %r = lshr i32 %sub, 31
+ ret i32 %r
+}
+
+define i32 @lshr_add_use_sexts_2(i1 %x, i1 %y, ptr %p) {
+; CHECK-LABEL: @lshr_add_use_sexts_2(
; CHECK-NEXT: [[XS:%.*]] = sext i1 [[X:%.*]] to i32
; CHECK-NEXT: store i32 [[XS]], ptr [[P:%.*]], align 4
-; CHECK-NEXT: [[YS:%.*]] = sext i1 [[Y:%.*]] to i32
-; CHECK-NEXT: [[SUB:%.*]] = add nsw i32 [[XS]], [[YS]]
-; CHECK-NEXT: [[R:%.*]] = lshr i32 [[SUB]], 31
+; CHECK-NEXT: [[TMP1:%.*]] = or i1 [[X]], [[Y:%.*]]
+; CHECK-NEXT: [[R:%.*]] = zext i1 [[TMP1]] to i32
; CHECK-NEXT: ret i32 [[R]]
;
%xs = sext i1 %x to i32
@@ -1456,18 +1469,20 @@ define i32 @lshr_add_use_sexts(i1 %x, i1 %y, ptr %p) {
; Negative test - extra use
-define i32 @lshr_add_use2_sexts(i1 %x, i1 %y, ptr %p) {
-; CHECK-LABEL: @lshr_add_use2_sexts(
+declare void @use_sexts(i32, i32)
+
+define i32 @lshr_add_use_sexts_both(i1 %x, i1 %y) {
+; CHECK-LABEL: @lshr_add_use_sexts_both(
; CHECK-NEXT: [[XS:%.*]] = sext i1 [[X:%.*]] to i32
; CHECK-NEXT: [[YS:%.*]] = sext i1 [[Y:%.*]] to i32
-; CHECK-NEXT: store i32 [[YS]], ptr [[P:%.*]], align 4
+; CHECK-NEXT: call void @use_sexts(i32 [[XS]], i32 [[YS]])
; CHECK-NEXT: [[SUB:%.*]] = add nsw i32 [[XS]], [[YS]]
; CHECK-NEXT: [[R:%.*]] = lshr i32 [[SUB]], 31
; CHECK-NEXT: ret i32 [[R]]
;
%xs = sext i1 %x to i32
%ys = sext i1 %y to i32
- store i32 %ys, ptr %p
+ call void @use_sexts(i32 %xs, i32 %ys)
%sub = add i32 %xs, %ys
%r = lshr i32 %sub, 31
ret i32 %r
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