From: David Bolvansky <david.bolvansky@gmail.com>
Date: Tue, 31 Jul 2018 14:17:15 +0000 (+0000)
Subject: [InstSimplify] Fold another Select with And/Or pattern
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f241788fa53efc925312f5eb1b2630f76675e2f5;p=llvm

[InstSimplify] Fold another Select with And/Or pattern

Summary: Proof: https://rise4fun.com/Alive/L5J

Reviewers: lebedev.ri, spatel

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D49975

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338383 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index 607ec382074..6ebae37a6a8 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -65,13 +65,6 @@ static Value *SimplifyCastInst(unsigned, Value *, Type *,
 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;
@@ -80,7 +73,7 @@ static Value *foldSelectWithBinaryOp(Value *Cond, Value *TrueVal,
   else
     return nullptr;
 
-  CmpInst::Predicate ExpectedPred;
+  CmpInst::Predicate ExpectedPred, Pred1, Pred2;
   if (BinOpCode == BinaryOperator::Or) {
     ExpectedPred = ICmpInst::ICMP_NE;
   } else if (BinOpCode == BinaryOperator::And) {
@@ -88,15 +81,30 @@ static Value *foldSelectWithBinaryOp(Value *Cond, Value *TrueVal,
   } 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()))) ||
+  // %A = icmp eq %TV, %FV
+  // %B = icmp eq %X, %Y (and one of these is a select operand)
+  // %C = and %A, %B
+  // %D = select %C, %TV, %FV
+  // -->
+  // %FV
+
+  // %A = icmp ne %TV, %FV
+  // %B = icmp ne %X, %Y (and one of these is a select operand)
+  // %C = or %A, %B
+  // %D = select %C, %TV, %FV
+  // -->
+  // %TV
+  Value *X, *Y;
+  if (!match(Cond, m_c_BinOp(m_c_ICmp(Pred1, m_Specific(TrueVal),
+                                      m_Specific(FalseVal)),
+                             m_ICmp(Pred2, m_Value(X), m_Value(Y)))) ||
       Pred1 != Pred2 || Pred1 != ExpectedPred)
     return nullptr;
 
-  return BinOpCode == BinaryOperator::Or ? TrueVal : FalseVal;
+  if (X == TrueVal || X == FalseVal || Y == TrueVal || Y == FalseVal)
+    return BinOpCode == BinaryOperator::Or ? TrueVal : FalseVal;
+
+  return nullptr;
 }
 
 /// For a boolean type or a vector of boolean type, return false or a vector
diff --git a/test/Transforms/InstSimplify/select-and-cmp.ll b/test/Transforms/InstSimplify/select-and-cmp.ll
index 23eed4c2681..7153972c79c 100644
--- a/test/Transforms/InstSimplify/select-and-cmp.ll
+++ b/test/Transforms/InstSimplify/select-and-cmp.ll
@@ -36,11 +36,7 @@ define i32 @select_and_icmp2(i32 %x, i32 %y, i32 %z) {
 
 define i32 @select_and_icmp_alt(i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @select_and_icmp_alt(
-; 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 [[X]], i32 [[Z]]
-; CHECK-NEXT:    ret i32 [[D]]
+; CHECK-NEXT:    ret i32 [[Z:%.*]]
 ;
   %A = icmp eq i32 %x, %z
   %B = icmp eq i32 %y, %z
@@ -51,11 +47,7 @@ define i32 @select_and_icmp_alt(i32 %x, i32 %y, i32 %z) {
 
 define i32 @select_and_icmp_alt2(i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @select_and_icmp_alt2(
-; 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 [[Y]], i32 [[Z]]
-; CHECK-NEXT:    ret i32 [[D]]
+; CHECK-NEXT:    ret i32 [[Z:%.*]]
 ;
   %A = icmp eq i32 %x, %z
   %B = icmp eq i32 %y, %z
@@ -66,11 +58,7 @@ define i32 @select_and_icmp_alt2(i32 %x, i32 %y, i32 %z) {
 
 define i32 @select_and_icmp_inv_alt(i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @select_and_icmp_inv_alt(
-; 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 [[X]], i32 [[Z]]
-; CHECK-NEXT:    ret i32 [[D]]
+; CHECK-NEXT:    ret i32 [[Z:%.*]]
 ;
   %A = icmp eq i32 %z, %x
   %B = icmp eq i32 %z, %y
@@ -81,11 +69,7 @@ define i32 @select_and_icmp_inv_alt(i32 %x, i32 %y, i32 %z) {
 
 define i32 @select_and_inv_icmp_alt(i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @select_and_inv_icmp_alt(
-; 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 [[X]], i32 [[Z]]
-; CHECK-NEXT:    ret i32 [[D]]
+; CHECK-NEXT:    ret i32 [[Z:%.*]]
 ;
   %A = icmp eq i32 %x, %z
   %B = icmp eq i32 %y, %z
@@ -107,11 +91,7 @@ define i32 @select_and_inv_icmp(i32 %x, i32 %y, i32 %z) {
 
 define <2 x i8> @select_and_icmp_alt_vec(<2 x i8> %x, <2 x i8> %y, <2 x i8> %z) {
 ; CHECK-LABEL: @select_and_icmp_alt_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> [[X]], <2 x i8> [[Z]]
-; CHECK-NEXT:    ret <2 x i8> [[D]]
+; CHECK-NEXT:    ret <2 x i8> [[Z:%.*]]
 ;
   %A = icmp eq <2 x i8> %x, %z
   %B = icmp eq <2 x i8> %y, %z
diff --git a/test/Transforms/InstSimplify/select-or-cmp.ll b/test/Transforms/InstSimplify/select-or-cmp.ll
index 1810beb2371..ea29bff7d1c 100644
--- a/test/Transforms/InstSimplify/select-or-cmp.ll
+++ b/test/Transforms/InstSimplify/select-or-cmp.ll
@@ -36,11 +36,7 @@ define i32 @select_or_icmp2(i32 %x, i32 %y, i32 %z) {
 
 define i32 @select_or_icmp_alt(i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @select_or_icmp_alt(
-; 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 [[X]], i32 [[Z]]
-; CHECK-NEXT:    ret i32 [[D]]
+; CHECK-NEXT:    ret i32 [[X:%.*]]
 ;
   %A = icmp ne i32 %x, %z
   %B = icmp ne i32 %y, %z
@@ -51,11 +47,7 @@ define i32 @select_or_icmp_alt(i32 %x, i32 %y, i32 %z) {
 
 define i32 @select_or_icmp_alt2(i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @select_or_icmp_alt2(
-; 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 [[Y]], i32 [[Z]]
-; CHECK-NEXT:    ret i32 [[D]]
+; CHECK-NEXT:    ret i32 [[Y:%.*]]
 ;
   %A = icmp ne i32 %x, %z
   %B = icmp ne i32 %y, %z
@@ -66,11 +58,7 @@ define i32 @select_or_icmp_alt2(i32 %x, i32 %y, i32 %z) {
 
 define i32 @select_or_icmp_inv_alt(i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @select_or_icmp_inv_alt(
-; 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 [[X]], i32 [[Z]]
-; CHECK-NEXT:    ret i32 [[D]]
+; CHECK-NEXT:    ret i32 [[X:%.*]]
 ;
   %A = icmp ne i32 %z, %x
   %B = icmp ne i32 %z, %y
@@ -81,11 +69,7 @@ define i32 @select_or_icmp_inv_alt(i32 %x, i32 %y, i32 %z) {
 
 define i32 @select_or_inv_icmp_alt(i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @select_or_inv_icmp_alt(
-; CHECK-NEXT:    [[A:%.*]] = icmp ne i32 [[Z:%.*]], [[X:%.*]]
-; CHECK-NEXT:    [[B:%.*]] = icmp ne i32 [[Z]], [[Y:%.*]]
-; CHECK-NEXT:    [[C:%.*]] = or i1 [[B]], [[A]]
-; CHECK-NEXT:    [[D:%.*]] = select i1 [[C]], i32 [[X]], i32 [[Z]]
-; CHECK-NEXT:    ret i32 [[D]]
+; CHECK-NEXT:    ret i32 [[X:%.*]]
 ;
   %A = icmp ne i32 %z, %x
   %B = icmp ne i32 %z, %y
@@ -96,11 +80,7 @@ define i32 @select_or_inv_icmp_alt(i32 %x, i32 %y, i32 %z) {
 
 define <2 x i8> @select_or_icmp_alt_vec(<2 x i8> %x, <2 x i8> %y, <2 x i8> %z) {
 ; CHECK-LABEL: @select_or_icmp_alt_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> [[X]], <2 x i8> [[Z]]
-; CHECK-NEXT:    ret <2 x i8> [[D]]
+; CHECK-NEXT:    ret <2 x i8> [[X:%.*]]
 ;
   %A = icmp ne <2 x i8> %x, %z
   %B = icmp ne <2 x i8> %y, %z