[llvm] r338191 - [InstCombine] Fold Select with AND/OR condition
David Bolvansky via llvm-commits
llvm-commits at lists.llvm.org
Fri Jul 27 23:55:52 PDT 2018
Author: xbolva00
Date: Fri Jul 27 23:55:51 2018
New Revision: 338191
URL: http://llvm.org/viewvc/llvm-project?rev=338191&view=rev
Log:
[InstCombine] Fold Select with AND/OR condition
Summary:
Fold
```
%A = icmp ne i8 %X, %V1
%B = icmp ne i8 %X, %V2
%C = or i1 %A, %B
%D = select i1 %C, i8 %X, i8 %V1
ret i8 %D
=>
ret i8 %X
Fixes https://bugs.llvm.org/show_bug.cgi?id=38334
Proof: https://rise4fun.com/Alive/plI8
Reviewers: spatel, lebedev.ri
Reviewed By: lebedev.ri
Subscribers: craig.topper, llvm-commits
Differential Revision: https://reviews.llvm.org/D49919
Modified:
llvm/trunk/lib/Analysis/InstructionSimplify.cpp
llvm/trunk/test/Transforms/InstCombine/select-and-cmp.ll
llvm/trunk/test/Transforms/InstCombine/select-or-cmp.ll
Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=338191&r1=338190&r2=338191&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
+++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Fri Jul 27 23:55:51 2018
@@ -65,6 +65,40 @@ static Value *SimplifyCastInst(unsigned,
static Value *SimplifyGEPInst(Type *, ArrayRef<Value *>, const SimplifyQuery &,
unsigned);
+/// Fold
+/// %A = icmp ne/eq i8 %X, %V1
+/// %B = icmp ne/eq i8 %X, %V2
+/// %C = or/and i1 %A, %B
+/// %D = select i1 %C, i8 %X, i8 %V1
+/// To
+/// %X/%V1
+static Value *foldSelectWithBinaryOp(Value *Cond, Value *TrueVal,
+ Value *FalseVal) {
+ BinaryOperator::BinaryOps BinOpCode;
+ if (auto *BO = dyn_cast<BinaryOperator>(Cond))
+ BinOpCode = BO->getOpcode();
+ else
+ return nullptr;
+
+ CmpInst::Predicate ExpectedPred;
+ if (BinOpCode == BinaryOperator::Or) {
+ ExpectedPred = ICmpInst::ICMP_NE;
+ } else if (BinOpCode == BinaryOperator::And) {
+ ExpectedPred = ICmpInst::ICMP_EQ;
+ } else
+ return nullptr;
+
+ CmpInst::Predicate Pred1, Pred2;
+ if (!match(
+ Cond,
+ m_c_BinOp(m_c_ICmp(Pred1, m_Specific(TrueVal), m_Specific(FalseVal)),
+ m_c_ICmp(Pred2, m_Specific(TrueVal), m_Value()))) ||
+ Pred1 != Pred2 || Pred1 != ExpectedPred)
+ return nullptr;
+
+ return BinOpCode == BinaryOperator::Or ? TrueVal : FalseVal;
+}
+
/// For a boolean type or a vector of boolean type, return false or a vector
/// with every element false.
static Constant *getFalse(Type *Ty) {
@@ -3752,6 +3786,9 @@ static Value *SimplifySelectInst(Value *
simplifySelectWithICmpCond(Cond, TrueVal, FalseVal, Q, MaxRecurse))
return V;
+ if (Value *V = foldSelectWithBinaryOp(Cond, TrueVal, FalseVal))
+ return V;
+
return nullptr;
}
Modified: llvm/trunk/test/Transforms/InstCombine/select-and-cmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/select-and-cmp.ll?rev=338191&r1=338190&r2=338191&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/select-and-cmp.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/select-and-cmp.ll Fri Jul 27 23:55:51 2018
@@ -5,11 +5,7 @@ target triple = "x86_64-unknown-linux-gn
define i32 @select_and_icmp(i32 %x, i32 %y, i32 %z) {
; CHECK-LABEL: @select_and_icmp(
-; CHECK-NEXT: [[A:%.*]] = icmp eq i32 [[X:%.*]], [[Z:%.*]]
-; CHECK-NEXT: [[B:%.*]] = icmp eq i32 [[Y:%.*]], [[Z]]
-; CHECK-NEXT: [[C:%.*]] = and i1 [[A]], [[B]]
-; CHECK-NEXT: [[D:%.*]] = select i1 [[C]], i32 [[Z]], i32 [[X]]
-; CHECK-NEXT: ret i32 [[D]]
+; CHECK-NEXT: ret i32 [[X:%.*]]
;
%A = icmp eq i32 %x, %z
%B = icmp eq i32 %y, %z
@@ -20,11 +16,7 @@ define i32 @select_and_icmp(i32 %x, i32
define <2 x i8> @select_and_icmp_vec(<2 x i8> %x, <2 x i8> %y, <2 x i8> %z) {
; CHECK-LABEL: @select_and_icmp_vec(
-; CHECK-NEXT: [[A:%.*]] = icmp eq <2 x i8> [[X:%.*]], [[Z:%.*]]
-; CHECK-NEXT: [[B:%.*]] = icmp eq <2 x i8> [[Y:%.*]], [[Z]]
-; CHECK-NEXT: [[C:%.*]] = and <2 x i1> [[A]], [[B]]
-; CHECK-NEXT: [[D:%.*]] = select <2 x i1> [[C]], <2 x i8> [[Z]], <2 x i8> [[X]]
-; CHECK-NEXT: ret <2 x i8> [[D]]
+; CHECK-NEXT: ret <2 x i8> [[X:%.*]]
;
%A = icmp eq <2 x i8> %x, %z
%B = icmp eq <2 x i8> %y, %z
@@ -35,11 +27,7 @@ define <2 x i8> @select_and_icmp_vec(<2
define i32 @select_and_icmp2(i32 %x, i32 %y, i32 %z) {
; CHECK-LABEL: @select_and_icmp2(
-; CHECK-NEXT: [[A:%.*]] = icmp eq i32 [[X:%.*]], [[Z:%.*]]
-; CHECK-NEXT: [[B:%.*]] = icmp eq i32 [[Y:%.*]], [[Z]]
-; CHECK-NEXT: [[C:%.*]] = and i1 [[A]], [[B]]
-; CHECK-NEXT: [[D:%.*]] = select i1 [[C]], i32 [[Z]], i32 [[Y]]
-; CHECK-NEXT: ret i32 [[D]]
+; CHECK-NEXT: ret i32 [[Y:%.*]]
;
%A = icmp eq i32 %x, %z
%B = icmp eq i32 %y, %z
@@ -50,11 +38,7 @@ define i32 @select_and_icmp2(i32 %x, i32
define i32 @select_and_inv_icmp(i32 %x, i32 %y, i32 %z) {
; CHECK-LABEL: @select_and_inv_icmp(
-; CHECK-NEXT: [[A:%.*]] = icmp eq i32 [[X:%.*]], [[Z:%.*]]
-; CHECK-NEXT: [[B:%.*]] = icmp eq i32 [[Y:%.*]], [[Z]]
-; CHECK-NEXT: [[C:%.*]] = and i1 [[B]], [[A]]
-; CHECK-NEXT: [[D:%.*]] = select i1 [[C]], i32 [[Z]], i32 [[X]]
-; CHECK-NEXT: ret i32 [[D]]
+; CHECK-NEXT: ret i32 [[X:%.*]]
;
%A = icmp eq i32 %x, %z
%B = icmp eq i32 %y, %z
@@ -65,11 +49,7 @@ define i32 @select_and_inv_icmp(i32 %x,
define i32 @select_and_icmp_inv(i32 %x, i32 %y, i32 %z) {
; CHECK-LABEL: @select_and_icmp_inv(
-; CHECK-NEXT: [[A:%.*]] = icmp eq i32 [[Z:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[B:%.*]] = icmp eq i32 [[Z]], [[Y:%.*]]
-; CHECK-NEXT: [[C:%.*]] = and i1 [[A]], [[B]]
-; CHECK-NEXT: [[D:%.*]] = select i1 [[C]], i32 [[Z]], i32 [[X]]
-; CHECK-NEXT: ret i32 [[D]]
+; CHECK-NEXT: ret i32 [[X:%.*]]
;
%A = icmp eq i32 %z, %x
%B = icmp eq i32 %z, %y
Modified: llvm/trunk/test/Transforms/InstCombine/select-or-cmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/select-or-cmp.ll?rev=338191&r1=338190&r2=338191&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/select-or-cmp.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/select-or-cmp.ll Fri Jul 27 23:55:51 2018
@@ -5,11 +5,7 @@ target triple = "x86_64-unknown-linux-gn
define i32 @select_or_icmp(i32 %x, i32 %y, i32 %z) {
; CHECK-LABEL: @select_or_icmp(
-; CHECK-NEXT: [[A:%.*]] = icmp ne i32 [[X:%.*]], [[Z:%.*]]
-; CHECK-NEXT: [[B:%.*]] = icmp ne i32 [[Y:%.*]], [[Z]]
-; CHECK-NEXT: [[C:%.*]] = or i1 [[A]], [[B]]
-; CHECK-NEXT: [[D:%.*]] = select i1 [[C]], i32 [[Z]], i32 [[X]]
-; CHECK-NEXT: ret i32 [[D]]
+; CHECK-NEXT: ret i32 [[Z:%.*]]
;
%A = icmp ne i32 %x, %z
%B = icmp ne i32 %y, %z
@@ -20,11 +16,7 @@ define i32 @select_or_icmp(i32 %x, i32 %
define <2 x i8> @select_or_icmp_vec(<2 x i8> %x, <2 x i8> %y, <2 x i8> %z) {
; CHECK-LABEL: @select_or_icmp_vec(
-; CHECK-NEXT: [[A:%.*]] = icmp ne <2 x i8> [[X:%.*]], [[Z:%.*]]
-; CHECK-NEXT: [[B:%.*]] = icmp ne <2 x i8> [[Y:%.*]], [[Z]]
-; CHECK-NEXT: [[C:%.*]] = or <2 x i1> [[A]], [[B]]
-; CHECK-NEXT: [[D:%.*]] = select <2 x i1> [[C]], <2 x i8> [[Z]], <2 x i8> [[X]]
-; CHECK-NEXT: ret <2 x i8> [[D]]
+; CHECK-NEXT: ret <2 x i8> [[Z:%.*]]
;
%A = icmp ne <2 x i8> %x, %z
%B = icmp ne <2 x i8> %y, %z
@@ -35,11 +27,7 @@ define <2 x i8> @select_or_icmp_vec(<2 x
define i32 @select_or_icmp2(i32 %x, i32 %y, i32 %z) {
; CHECK-LABEL: @select_or_icmp2(
-; CHECK-NEXT: [[A:%.*]] = icmp ne i32 [[X:%.*]], [[Z:%.*]]
-; CHECK-NEXT: [[B:%.*]] = icmp ne i32 [[Y:%.*]], [[Z]]
-; CHECK-NEXT: [[C:%.*]] = or i1 [[A]], [[B]]
-; CHECK-NEXT: [[D:%.*]] = select i1 [[C]], i32 [[Z]], i32 [[Y]]
-; CHECK-NEXT: ret i32 [[D]]
+; CHECK-NEXT: ret i32 [[Z:%.*]]
;
%A = icmp ne i32 %x, %z
%B = icmp ne i32 %y, %z
@@ -50,11 +38,7 @@ define i32 @select_or_icmp2(i32 %x, i32
define i32 @select_or_inv_icmp(i32 %x, i32 %y, i32 %z) {
; CHECK-LABEL: @select_or_inv_icmp(
-; CHECK-NEXT: [[A:%.*]] = icmp ne i32 [[X:%.*]], [[Z:%.*]]
-; CHECK-NEXT: [[B:%.*]] = icmp ne i32 [[Y:%.*]], [[Z]]
-; CHECK-NEXT: [[C:%.*]] = or i1 [[B]], [[A]]
-; CHECK-NEXT: [[D:%.*]] = select i1 [[C]], i32 [[Z]], i32 [[X]]
-; CHECK-NEXT: ret i32 [[D]]
+; CHECK-NEXT: ret i32 [[Z:%.*]]
;
%A = icmp ne i32 %x, %z
%B = icmp ne i32 %y, %z
@@ -65,11 +49,7 @@ define i32 @select_or_inv_icmp(i32 %x, i
define i32 @select_or_icmp_inv(i32 %x, i32 %y, i32 %z) {
; CHECK-LABEL: @select_or_icmp_inv(
-; CHECK-NEXT: [[A:%.*]] = icmp ne i32 [[Z:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[B:%.*]] = icmp ne i32 [[Z]], [[Y:%.*]]
-; CHECK-NEXT: [[C:%.*]] = or i1 [[A]], [[B]]
-; CHECK-NEXT: [[D:%.*]] = select i1 [[C]], i32 [[Z]], i32 [[X]]
-; CHECK-NEXT: ret i32 [[D]]
+; CHECK-NEXT: ret i32 [[Z:%.*]]
;
%A = icmp ne i32 %z, %x
%B = icmp ne i32 %z, %y
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