[llvm] 1fd4d91 - [InstSimplify] Fold !(X || Y) && X --> false
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Tue Nov 29 06:45:42 PST 2022
Author: chenglin.bi
Date: 2022-11-29T22:45:24+08:00
New Revision: 1fd4d91fa6637c2edcbd9f6434db6d9dadcea0df
URL: https://github.com/llvm/llvm-project/commit/1fd4d91fa6637c2edcbd9f6434db6d9dadcea0df
DIFF: https://github.com/llvm/llvm-project/commit/1fd4d91fa6637c2edcbd9f6434db6d9dadcea0df.diff
LOG: [InstSimplify] Fold !(X || Y) && X --> false
!(X || Y) && X --> false
https://alive2.llvm.org/ce/z/693Jgv
Fix: [56654](https://github.com/llvm/llvm-project/issues/56654)
Fix: [56780](https://github.com/llvm/llvm-project/issues/56780)
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D138853
Added:
Modified:
llvm/lib/Analysis/InstructionSimplify.cpp
llvm/test/Transforms/InstSimplify/select-logical.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 6bb0b94fd1930..419a344c42fa3 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4562,6 +4562,10 @@ static Value *simplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
Value *X, *Y;
if (match(FalseVal, m_ZeroInt())) {
+ // !(X || Y) && X --> false (commuted 2 ways)
+ if (match(Cond, m_Not(m_c_LogicalOr(m_Specific(TrueVal), m_Value()))))
+ return ConstantInt::getFalse(Cond->getType());
+
// (X || Y) && (X || !Y) --> X (commuted 8 ways)
if (match(Cond, m_c_LogicalOr(m_Value(X), m_Not(m_Value(Y)))) &&
match(TrueVal, m_c_LogicalOr(m_Specific(X), m_Specific(Y))))
diff --git a/llvm/test/Transforms/InstSimplify/select-logical.ll b/llvm/test/Transforms/InstSimplify/select-logical.ll
index 61c108fa206a1..f4ec5b1f2f657 100644
--- a/llvm/test/Transforms/InstSimplify/select-logical.ll
+++ b/llvm/test/Transforms/InstSimplify/select-logical.ll
@@ -127,10 +127,7 @@ define i1 @logical_and_of_or_no_common_op(i1 %x, i1 %y, i1 %z) {
define i1 @or_not_and(i1 %x, i1 %y) {
; CHECK-LABEL: @or_not_and(
-; CHECK-NEXT: [[L_AND:%.*]] = or i1 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor i1 [[L_AND]], true
-; CHECK-NEXT: [[R:%.*]] = select i1 [[NOT]], i1 [[X]], i1 false
-; CHECK-NEXT: ret i1 [[R]]
+; CHECK-NEXT: ret i1 false
;
%l.and = or i1 %x, %y
%not = xor i1 %l.and, true
@@ -142,10 +139,7 @@ define i1 @or_not_and(i1 %x, i1 %y) {
define <2 x i1> @or_not_and_vector(<2 x i1> %x, <2 x i1> %y) {
; CHECK-LABEL: @or_not_and_vector(
-; CHECK-NEXT: [[L_AND:%.*]] = or <2 x i1> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor <2 x i1> [[L_AND]], <i1 true, i1 true>
-; CHECK-NEXT: [[R:%.*]] = select <2 x i1> [[NOT]], <2 x i1> [[X]], <2 x i1> zeroinitializer
-; CHECK-NEXT: ret <2 x i1> [[R]]
+; CHECK-NEXT: ret <2 x i1> zeroinitializer
;
%l.and = or <2 x i1> %x, %y
%not = xor <2 x i1> %l.and, <i1 true, i1 true>
@@ -157,10 +151,7 @@ define <2 x i1> @or_not_and_vector(<2 x i1> %x, <2 x i1> %y) {
define <2 x i1> @or_not_and_vector_poison1(<2 x i1> %x, <2 x i1> %y) {
; CHECK-LABEL: @or_not_and_vector_poison1(
-; CHECK-NEXT: [[L_AND:%.*]] = or <2 x i1> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor <2 x i1> [[L_AND]], <i1 poison, i1 true>
-; CHECK-NEXT: [[R:%.*]] = select <2 x i1> [[NOT]], <2 x i1> [[X]], <2 x i1> zeroinitializer
-; CHECK-NEXT: ret <2 x i1> [[R]]
+; CHECK-NEXT: ret <2 x i1> zeroinitializer
;
%l.and = or <2 x i1> %x, %y
%not = xor <2 x i1> %l.and, <i1 poison, i1 true>
@@ -172,10 +163,7 @@ define <2 x i1> @or_not_and_vector_poison1(<2 x i1> %x, <2 x i1> %y) {
define <2 x i1> @or_not_and_vector_poison2(<2 x i1> %x, <2 x i1> %y) {
; CHECK-LABEL: @or_not_and_vector_poison2(
-; CHECK-NEXT: [[L_AND:%.*]] = or <2 x i1> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor <2 x i1> [[L_AND]], <i1 true, i1 true>
-; CHECK-NEXT: [[R:%.*]] = select <2 x i1> [[NOT]], <2 x i1> [[X]], <2 x i1> <i1 poison, i1 false>
-; CHECK-NEXT: ret <2 x i1> [[R]]
+; CHECK-NEXT: ret <2 x i1> zeroinitializer
;
%l.and = or <2 x i1> %x, %y
%not = xor <2 x i1> %l.and, <i1 true, i1 true>
@@ -188,10 +176,7 @@ define <2 x i1> @or_not_and_vector_poison2(<2 x i1> %x, <2 x i1> %y) {
define i1 @logical_or_not_and(i1 %x, i1 %y) {
; CHECK-LABEL: @logical_or_not_and(
-; CHECK-NEXT: [[L_AND:%.*]] = select i1 [[X:%.*]], i1 true, i1 [[Y:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor i1 [[L_AND]], true
-; CHECK-NEXT: [[R:%.*]] = select i1 [[NOT]], i1 [[X]], i1 false
-; CHECK-NEXT: ret i1 [[R]]
+; CHECK-NEXT: ret i1 false
;
%l.and = select i1 %x, i1 true, i1 %y
%not = xor i1 %l.and, true
@@ -202,12 +187,9 @@ define i1 @logical_or_not_and(i1 %x, i1 %y) {
; !(X || Y) && Y --> false
-define i1 @logical_or_not_and_comute_or(i1 %x, i1 %y) {
-; CHECK-LABEL: @logical_or_not_and_comute_or(
-; CHECK-NEXT: [[L_AND:%.*]] = select i1 [[X:%.*]], i1 true, i1 [[Y:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor i1 [[L_AND]], true
-; CHECK-NEXT: [[R:%.*]] = select i1 [[NOT]], i1 [[Y]], i1 false
-; CHECK-NEXT: ret i1 [[R]]
+define i1 @logical_or_not_and_commute_or(i1 %x, i1 %y) {
+; CHECK-LABEL: @logical_or_not_and_commute_or(
+; CHECK-NEXT: ret i1 false
;
%l.and = select i1 %x, i1 true, i1 %y
%not = xor i1 %l.and, true
@@ -219,10 +201,7 @@ define i1 @logical_or_not_and_comute_or(i1 %x, i1 %y) {
define <3 x i1> @logical_or_not_and_vector1(<3 x i1> %x, <3 x i1> %y) {
; CHECK-LABEL: @logical_or_not_and_vector1(
-; CHECK-NEXT: [[L_AND:%.*]] = select <3 x i1> [[X:%.*]], <3 x i1> <i1 true, i1 true, i1 true>, <3 x i1> [[Y:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor <3 x i1> [[L_AND]], <i1 true, i1 true, i1 true>
-; CHECK-NEXT: [[R:%.*]] = select <3 x i1> [[NOT]], <3 x i1> [[X]], <3 x i1> zeroinitializer
-; CHECK-NEXT: ret <3 x i1> [[R]]
+; CHECK-NEXT: ret <3 x i1> zeroinitializer
;
%l.and = select <3 x i1> %x, <3 x i1> <i1 true, i1 true, i1 true>, <3 x i1> %y
%not = xor <3 x i1> %l.and, <i1 true, i1 true, i1 true>
@@ -230,18 +209,19 @@ define <3 x i1> @logical_or_not_and_vector1(<3 x i1> %x, <3 x i1> %y) {
ret <3 x i1> %r
}
+; TODO: this could transform to false
; vector case !(X || Y) && X --> false
define <3 x i1> @logical_or_not_and_vector1_poison1(<3 x i1> %x, <3 x i1> %y) {
; CHECK-LABEL: @logical_or_not_and_vector1_poison1(
; CHECK-NEXT: [[L_AND:%.*]] = select <3 x i1> [[X:%.*]], <3 x i1> <i1 true, i1 true, i1 poison>, <3 x i1> [[Y:%.*]]
; CHECK-NEXT: [[NOT:%.*]] = xor <3 x i1> [[L_AND]], <i1 true, i1 true, i1 true>
-; CHECK-NEXT: [[R:%.*]] = select <3 x i1> [[NOT]], <3 x i1> [[X]], <3 x i1> <i1 true, i1 false, i1 false>
+; CHECK-NEXT: [[R:%.*]] = select <3 x i1> [[NOT]], <3 x i1> [[X]], <3 x i1> zeroinitializer
; CHECK-NEXT: ret <3 x i1> [[R]]
;
%l.and = select <3 x i1> %x, <3 x i1> <i1 true, i1 true, i1 poison>, <3 x i1> %y
%not = xor <3 x i1> %l.and, <i1 true, i1 true, i1 true>
- %r = select <3 x i1> %not, <3 x i1> %x, <3 x i1> <i1 true, i1 false, i1 false>
+ %r = select <3 x i1> %not, <3 x i1> %x, <3 x i1> <i1 false, i1 false, i1 false>
ret <3 x i1> %r
}
@@ -249,10 +229,7 @@ define <3 x i1> @logical_or_not_and_vector1_poison1(<3 x i1> %x, <3 x i1> %y) {
define <3 x i1> @logical_or_not_and_vector1_poison2(<3 x i1> %x, <3 x i1> %y) {
; CHECK-LABEL: @logical_or_not_and_vector1_poison2(
-; CHECK-NEXT: [[L_AND:%.*]] = select <3 x i1> [[X:%.*]], <3 x i1> <i1 true, i1 true, i1 true>, <3 x i1> [[Y:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor <3 x i1> [[L_AND]], <i1 true, i1 poison, i1 true>
-; CHECK-NEXT: [[R:%.*]] = select <3 x i1> [[NOT]], <3 x i1> [[X]], <3 x i1> zeroinitializer
-; CHECK-NEXT: ret <3 x i1> [[R]]
+; CHECK-NEXT: ret <3 x i1> zeroinitializer
;
%l.and = select <3 x i1> %x, <3 x i1> <i1 true, i1 true, i1 true>, <3 x i1> %y
%not = xor <3 x i1> %l.and, <i1 true, i1 poison, i1 true>
@@ -264,10 +241,7 @@ define <3 x i1> @logical_or_not_and_vector1_poison2(<3 x i1> %x, <3 x i1> %y) {
define <3 x i1> @logical_or_not_and_vector1_poison3(<3 x i1> %x, <3 x i1> %y) {
; CHECK-LABEL: @logical_or_not_and_vector1_poison3(
-; CHECK-NEXT: [[L_AND:%.*]] = select <3 x i1> [[X:%.*]], <3 x i1> <i1 true, i1 true, i1 true>, <3 x i1> [[Y:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor <3 x i1> [[L_AND]], <i1 true, i1 true, i1 true>
-; CHECK-NEXT: [[R:%.*]] = select <3 x i1> [[NOT]], <3 x i1> [[X]], <3 x i1> <i1 poison, i1 false, i1 false>
-; CHECK-NEXT: ret <3 x i1> [[R]]
+; CHECK-NEXT: ret <3 x i1> zeroinitializer
;
%l.and = select <3 x i1> %x, <3 x i1> <i1 true, i1 true, i1 true>, <3 x i1> %y
%not = xor <3 x i1> %l.and, <i1 true, i1 true, i1 true>
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