[llvm] ee3a260 - [InstCombine] support fold select(X|Y,X|Y,X) to X|Y
Congcong Cai via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 17 13:07:22 PDT 2023
Author: Congcong Cai
Date: 2023-04-17T22:07:01+02:00
New Revision: ee3a260e78474b4499fc98737923ebb7df6eada8
URL: https://github.com/llvm/llvm-project/commit/ee3a260e78474b4499fc98737923ebb7df6eada8
DIFF: https://github.com/llvm/llvm-project/commit/ee3a260e78474b4499fc98737923ebb7df6eada8.diff
LOG: [InstCombine] support fold select(X|Y,X|Y,X) to X|Y
Fixed: https://github.com/llvm/llvm-project/issues/62113
Add addtional check in `visitSelectInst` to:
1. match `select(X|Y==0, X, X|Y)` and replaced with `X|Y`
2. match `select(X&Y==-1, X, X&Y)` and replaced with `X&Y`
alive proof:
https://alive2.llvm.org/ce/z/4qHmv-
https://alive2.llvm.org/ce/z/c2MBGy
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D148275
Added:
Modified:
llvm/lib/Analysis/InstructionSimplify.cpp
llvm/test/Transforms/InstSimplify/select_or_and.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 51f8de43e5c8..fb6a395eea08 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4582,6 +4582,21 @@ static Value *simplifySelectWithICmpCond(Value *CondVal, Value *TrueVal,
return FalseVal;
}
+ if (Pred == ICmpInst::Predicate::ICMP_EQ) {
+ Value *X;
+ Value *Y;
+ // select(X | Y == 0, X or Y, X | Y) -> X | Y
+ if (match(CondVal, m_ICmp(Pred, m_Specific(FalseVal), m_Zero())) &&
+ match(FalseVal, m_Or(m_Value(X), m_Value(Y))) &&
+ (TrueVal == X || TrueVal == Y))
+ return FalseVal;
+ // select(X & Y == -1, X or Y, X & Y) -> X & Y
+ if (match(CondVal, m_ICmp(Pred, m_Specific(FalseVal), m_AllOnes())) &&
+ match(FalseVal, m_And(m_Value(X), m_Value(Y))) &&
+ (TrueVal == X || TrueVal == Y))
+ return FalseVal;
+ }
+
return nullptr;
}
diff --git a/llvm/test/Transforms/InstSimplify/select_or_and.ll b/llvm/test/Transforms/InstSimplify/select_or_and.ll
index 599b783cfac2..2188d3fcb28d 100644
--- a/llvm/test/Transforms/InstSimplify/select_or_and.ll
+++ b/llvm/test/Transforms/InstSimplify/select_or_and.ll
@@ -5,9 +5,7 @@
define i32 @select_or_1(i32 %x, i32 %y) {
; CHECK-LABEL: @select_or_1(
; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[OR]], 0
-; CHECK-NEXT: [[RET:%.*]] = select i1 [[CMP]], i32 [[X]], i32 [[OR]]
-; CHECK-NEXT: ret i32 [[RET]]
+; CHECK-NEXT: ret i32 [[OR]]
;
%or = or i32 %y, %x
%cmp = icmp eq i32 %or, 0
@@ -19,9 +17,7 @@ define i32 @select_or_1(i32 %x, i32 %y) {
define i32 @select_or_2(i32 %x, i32 %y) {
; CHECK-LABEL: @select_or_2(
; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[OR]], 0
-; CHECK-NEXT: [[RET:%.*]] = select i1 [[CMP]], i32 [[Y]], i32 [[OR]]
-; CHECK-NEXT: ret i32 [[RET]]
+; CHECK-NEXT: ret i32 [[OR]]
;
%or = or i32 %y, %x
%cmp = icmp eq i32 %or, 0
@@ -33,9 +29,7 @@ define i32 @select_or_2(i32 %x, i32 %y) {
define i32 @select_or_3(i32 %x, i32 %y) {
; CHECK-LABEL: @select_or_3(
; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[OR]], 0
-; CHECK-NEXT: [[RET:%.*]] = select i1 [[CMP]], i32 [[OR]], i32 [[X]]
-; CHECK-NEXT: ret i32 [[RET]]
+; CHECK-NEXT: ret i32 [[OR]]
;
%or = or i32 %y, %x
%cmp = icmp ne i32 %or, 0
@@ -47,9 +41,7 @@ define i32 @select_or_3(i32 %x, i32 %y) {
define i32 @select_or_4(i32 %x, i32 %y) {
; CHECK-LABEL: @select_or_4(
; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[OR]], 0
-; CHECK-NEXT: [[RET:%.*]] = select i1 [[CMP]], i32 [[OR]], i32 [[Y]]
-; CHECK-NEXT: ret i32 [[RET]]
+; CHECK-NEXT: ret i32 [[OR]]
;
%or = or i32 %y, %x
%cmp = icmp ne i32 %or, 0
@@ -61,9 +53,7 @@ define i32 @select_or_4(i32 %x, i32 %y) {
define <4 x i32> @select_or_vec(<4 x i32> %x, <4 x i32> %y) {
; CHECK-LABEL: @select_or_vec(
; CHECK-NEXT: [[OR:%.*]] = or <4 x i32> [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne <4 x i32> [[OR]], zeroinitializer
-; CHECK-NEXT: [[RET:%.*]] = select <4 x i1> [[CMP]], <4 x i32> [[OR]], <4 x i32> [[Y]]
-; CHECK-NEXT: ret <4 x i32> [[RET]]
+; CHECK-NEXT: ret <4 x i32> [[OR]]
;
%or = or <4 x i32> %y, %x
%cmp = icmp ne <4 x i32> %or, zeroinitializer
@@ -115,9 +105,7 @@ define i32 @select_or_not_3(i32 %x, i32 %y) {
define i32 @select_and_1(i32 %x, i32 %y) {
; CHECK-LABEL: @select_and_1(
; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[AND]], -1
-; CHECK-NEXT: [[RET:%.*]] = select i1 [[CMP]], i32 [[X]], i32 [[AND]]
-; CHECK-NEXT: ret i32 [[RET]]
+; CHECK-NEXT: ret i32 [[AND]]
;
%and = and i32 %y, %x
%cmp = icmp eq i32 %and, -1
@@ -129,9 +117,7 @@ define i32 @select_and_1(i32 %x, i32 %y) {
define i32 @select_and_2(i32 %x, i32 %y) {
; CHECK-LABEL: @select_and_2(
; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[AND]], -1
-; CHECK-NEXT: [[RET:%.*]] = select i1 [[CMP]], i32 [[Y]], i32 [[AND]]
-; CHECK-NEXT: ret i32 [[RET]]
+; CHECK-NEXT: ret i32 [[AND]]
;
%and = and i32 %y, %x
%cmp = icmp eq i32 %and, -1
@@ -144,9 +130,7 @@ define i32 @select_and_2(i32 %x, i32 %y) {
define i32 @select_and_3(i32 %x, i32 %y) {
; CHECK-LABEL: @select_and_3(
; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[AND]], -1
-; CHECK-NEXT: [[RET:%.*]] = select i1 [[CMP]], i32 [[AND]], i32 [[X]]
-; CHECK-NEXT: ret i32 [[RET]]
+; CHECK-NEXT: ret i32 [[AND]]
;
%and = and i32 %y, %x
%cmp = icmp ne i32 %and, -1
@@ -158,9 +142,7 @@ define i32 @select_and_3(i32 %x, i32 %y) {
define i32 @select_and_4(i32 %x, i32 %y) {
; CHECK-LABEL: @select_and_4(
; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[AND]], -1
-; CHECK-NEXT: [[RET:%.*]] = select i1 [[CMP]], i32 [[AND]], i32 [[Y]]
-; CHECK-NEXT: ret i32 [[RET]]
+; CHECK-NEXT: ret i32 [[AND]]
;
%and = and i32 %y, %x
%cmp = icmp ne i32 %and, -1
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