[llvm] [InstCombine] Fold `select Cond, not X, X` into `Cond ^ X` (PR #93591)
Yingwei Zheng via llvm-commits
llvm-commits at lists.llvm.org
Tue Jun 4 05:03:17 PDT 2024
https://github.com/dtcxzyw updated https://github.com/llvm/llvm-project/pull/93591
>From 6af4194de2e315a680e18d29fc7095d97232856a Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Wed, 29 May 2024 01:47:07 +0800
Subject: [PATCH 1/4] [InstCombine] Add pre-commit tests. NFC.
---
.../test/Transforms/InstCombine/select-cmp.ll | 91 +++++++++++++++++++
1 file changed, 91 insertions(+)
diff --git a/llvm/test/Transforms/InstCombine/select-cmp.ll b/llvm/test/Transforms/InstCombine/select-cmp.ll
index 711fac542179f..2d399245c7c70 100644
--- a/llvm/test/Transforms/InstCombine/select-cmp.ll
+++ b/llvm/test/Transforms/InstCombine/select-cmp.ll
@@ -345,4 +345,95 @@ define i1 @icmp_no_common(i1 %c, i8 %x, i8 %y, i8 %z) {
ret i1 %r
}
+define i1 @test_select_inverse_eq(i64 %x, i1 %y) {
+; CHECK-LABEL: @test_select_inverse_eq(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ne i64 [[X:%.*]], 0
+; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i64 [[X]], 0
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[Y:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: ret i1 [[SEL]]
+;
+ %cmp1 = icmp ne i64 %x, 0
+ %cmp2 = icmp eq i64 %x, 0
+ %sel = select i1 %y, i1 %cmp1, i1 %cmp2
+ ret i1 %sel
+}
+
+define i1 @test_select_inverse_signed(i64 %x, i1 %y) {
+; CHECK-LABEL: @test_select_inverse_signed(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i64 [[X:%.*]], -1
+; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i64 [[X]], 0
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[Y:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: ret i1 [[SEL]]
+;
+ %cmp1 = icmp sgt i64 %x, -1
+ %cmp2 = icmp slt i64 %x, 0
+ %sel = select i1 %y, i1 %cmp1, i1 %cmp2
+ ret i1 %sel
+}
+
+define i1 @test_select_inverse_unsigned(i64 %x, i1 %y) {
+; CHECK-LABEL: @test_select_inverse_unsigned(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i64 [[X:%.*]], 11
+; CHECK-NEXT: [[CMP2:%.*]] = icmp ugt i64 [[X]], 10
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[Y:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: ret i1 [[SEL]]
+;
+ %cmp1 = icmp ult i64 %x, 11
+ %cmp2 = icmp ugt i64 %x, 10
+ %sel = select i1 %y, i1 %cmp1, i1 %cmp2
+ ret i1 %sel
+}
+
+define i1 @test_select_inverse_eq_ptr(ptr %x, i1 %y) {
+; CHECK-LABEL: @test_select_inverse_eq_ptr(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp eq ptr [[X:%.*]], null
+; CHECK-NEXT: [[CMP2:%.*]] = icmp ne ptr [[X]], null
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[Y:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: ret i1 [[SEL]]
+;
+ %cmp1 = icmp eq ptr %x, null
+ %cmp2 = icmp ne ptr %x, null
+ %sel = select i1 %y, i1 %cmp1, i1 %cmp2
+ ret i1 %sel
+}
+
+define i1 @test_select_inverse_fail(i64 %x, i1 %y) {
+; CHECK-LABEL: @test_select_inverse_fail(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i64 [[X:%.*]], 0
+; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i64 [[X]], 0
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[Y:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: ret i1 [[SEL]]
+;
+ %cmp1 = icmp sgt i64 %x, 0
+ %cmp2 = icmp slt i64 %x, 0
+ %sel = select i1 %y, i1 %cmp1, i1 %cmp2
+ ret i1 %sel
+}
+
+define <2 x i1> @test_select_inverse_vec(<2 x i64> %x, <2 x i1> %y) {
+; CHECK-LABEL: @test_select_inverse_vec(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ne <2 x i64> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: [[CMP2:%.*]] = icmp eq <2 x i64> [[X]], zeroinitializer
+; CHECK-NEXT: [[SEL:%.*]] = select <2 x i1> [[Y:%.*]], <2 x i1> [[CMP1]], <2 x i1> [[CMP2]]
+; CHECK-NEXT: ret <2 x i1> [[SEL]]
+;
+ %cmp1 = icmp ne <2 x i64> %x, zeroinitializer
+ %cmp2 = icmp eq <2 x i64> %x, zeroinitializer
+ %sel = select <2 x i1> %y, <2 x i1> %cmp1, <2 x i1> %cmp2
+ ret <2 x i1> %sel
+}
+
+define <2 x i1> @test_select_inverse_vec_fail(<2 x i64> %x, i1 %y) {
+; CHECK-LABEL: @test_select_inverse_vec_fail(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ne <2 x i64> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: [[CMP2:%.*]] = icmp eq <2 x i64> [[X]], zeroinitializer
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[Y:%.*]], <2 x i1> [[CMP1]], <2 x i1> [[CMP2]]
+; CHECK-NEXT: ret <2 x i1> [[SEL]]
+;
+ %cmp1 = icmp ne <2 x i64> %x, zeroinitializer
+ %cmp2 = icmp eq <2 x i64> %x, zeroinitializer
+ %sel = select i1 %y, <2 x i1> %cmp1, <2 x i1> %cmp2
+ ret <2 x i1> %sel
+}
+
declare void @use(i1)
>From c7fb076906dff0f140462c093571e7f555d1271e Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Wed, 29 May 2024 01:55:40 +0800
Subject: [PATCH 2/4] [InstCombine] Fold `select Cond, not X, X` into `Cond ^
X`
---
.../InstCombine/InstCombineSelect.cpp | 34 +++++++++++++++++++
.../test/Transforms/InstCombine/select-cmp.ll | 25 ++++++--------
2 files changed, 44 insertions(+), 15 deletions(-)
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index a3ddb402bf662..011b1c2e09c03 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -3502,6 +3502,34 @@ static bool matchFMulByZeroIfResultEqZero(InstCombinerImpl &IC, Value *Cmp0,
return false;
}
+/// Return true iff:
+/// 1. X is poison implies Y is poison.
+/// 2. X is true implies Y is false.
+/// 3. X is false implies Y is true.
+/// Otherwise, return false.
+static bool isKnownInversion(Value *X, Value *Y) {
+ // Handle X = icmp pred V, C1, Y = icmp pred V, C2.
+ Value *V;
+ Constant *C1, *C2;
+ ICmpInst::Predicate Pred1, Pred2;
+ if (!match(X, m_ICmp(Pred1, m_Value(V), m_Constant(C1))) ||
+ !match(Y, m_ICmp(Pred2, m_Specific(V), m_Constant(C2))))
+ return false;
+
+ if (C1 == C2)
+ return Pred1 == ICmpInst::getInversePredicate(Pred2);
+
+ // Try to infer the relationship from constant ranges.
+ const APInt *RHSC1, *RHSC2;
+ if (!match(C1, m_APInt(RHSC1)) || !match(C2, m_APInt(RHSC2)))
+ return false;
+
+ const auto CR1 = ConstantRange::makeExactICmpRegion(Pred1, *RHSC1);
+ const auto CR2 = ConstantRange::makeExactICmpRegion(Pred2, *RHSC2);
+
+ return CR1.inverse() == CR2;
+}
+
Instruction *InstCombinerImpl::visitSelectInst(SelectInst &SI) {
Value *CondVal = SI.getCondition();
Value *TrueVal = SI.getTrueValue();
@@ -3996,5 +4024,11 @@ Instruction *InstCombinerImpl::visitSelectInst(SelectInst &SI) {
}
}
+ // select Cond, !X, X -> xor Cond, X
+ // Note: We don't fold select Cond, Y, X -> X (iff X->Y & !X->!Y) here as
+ // it indicates that these two patterns should be canonicalized.
+ if (CondVal->getType() == SI.getType() && isKnownInversion(FalseVal, TrueVal))
+ return BinaryOperator::CreateXor(CondVal, FalseVal);
+
return nullptr;
}
diff --git a/llvm/test/Transforms/InstCombine/select-cmp.ll b/llvm/test/Transforms/InstCombine/select-cmp.ll
index 2d399245c7c70..8609bc5041ad8 100644
--- a/llvm/test/Transforms/InstCombine/select-cmp.ll
+++ b/llvm/test/Transforms/InstCombine/select-cmp.ll
@@ -347,9 +347,8 @@ define i1 @icmp_no_common(i1 %c, i8 %x, i8 %y, i8 %z) {
define i1 @test_select_inverse_eq(i64 %x, i1 %y) {
; CHECK-LABEL: @test_select_inverse_eq(
-; CHECK-NEXT: [[CMP1:%.*]] = icmp ne i64 [[X:%.*]], 0
-; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i64 [[X]], 0
-; CHECK-NEXT: [[SEL:%.*]] = select i1 [[Y:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i64 [[X:%.*]], 0
+; CHECK-NEXT: [[SEL:%.*]] = xor i1 [[CMP2]], [[Y:%.*]]
; CHECK-NEXT: ret i1 [[SEL]]
;
%cmp1 = icmp ne i64 %x, 0
@@ -360,9 +359,8 @@ define i1 @test_select_inverse_eq(i64 %x, i1 %y) {
define i1 @test_select_inverse_signed(i64 %x, i1 %y) {
; CHECK-LABEL: @test_select_inverse_signed(
-; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i64 [[X:%.*]], -1
-; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i64 [[X]], 0
-; CHECK-NEXT: [[SEL:%.*]] = select i1 [[Y:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i64 [[X:%.*]], 0
+; CHECK-NEXT: [[SEL:%.*]] = xor i1 [[CMP2]], [[Y:%.*]]
; CHECK-NEXT: ret i1 [[SEL]]
;
%cmp1 = icmp sgt i64 %x, -1
@@ -373,9 +371,8 @@ define i1 @test_select_inverse_signed(i64 %x, i1 %y) {
define i1 @test_select_inverse_unsigned(i64 %x, i1 %y) {
; CHECK-LABEL: @test_select_inverse_unsigned(
-; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i64 [[X:%.*]], 11
-; CHECK-NEXT: [[CMP2:%.*]] = icmp ugt i64 [[X]], 10
-; CHECK-NEXT: [[SEL:%.*]] = select i1 [[Y:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp ugt i64 [[X:%.*]], 10
+; CHECK-NEXT: [[SEL:%.*]] = xor i1 [[CMP2]], [[Y:%.*]]
; CHECK-NEXT: ret i1 [[SEL]]
;
%cmp1 = icmp ult i64 %x, 11
@@ -386,9 +383,8 @@ define i1 @test_select_inverse_unsigned(i64 %x, i1 %y) {
define i1 @test_select_inverse_eq_ptr(ptr %x, i1 %y) {
; CHECK-LABEL: @test_select_inverse_eq_ptr(
-; CHECK-NEXT: [[CMP1:%.*]] = icmp eq ptr [[X:%.*]], null
-; CHECK-NEXT: [[CMP2:%.*]] = icmp ne ptr [[X]], null
-; CHECK-NEXT: [[SEL:%.*]] = select i1 [[Y:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp ne ptr [[X:%.*]], null
+; CHECK-NEXT: [[SEL:%.*]] = xor i1 [[CMP2]], [[Y:%.*]]
; CHECK-NEXT: ret i1 [[SEL]]
;
%cmp1 = icmp eq ptr %x, null
@@ -412,9 +408,8 @@ define i1 @test_select_inverse_fail(i64 %x, i1 %y) {
define <2 x i1> @test_select_inverse_vec(<2 x i64> %x, <2 x i1> %y) {
; CHECK-LABEL: @test_select_inverse_vec(
-; CHECK-NEXT: [[CMP1:%.*]] = icmp ne <2 x i64> [[X:%.*]], zeroinitializer
-; CHECK-NEXT: [[CMP2:%.*]] = icmp eq <2 x i64> [[X]], zeroinitializer
-; CHECK-NEXT: [[SEL:%.*]] = select <2 x i1> [[Y:%.*]], <2 x i1> [[CMP1]], <2 x i1> [[CMP2]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp eq <2 x i64> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: [[SEL:%.*]] = xor <2 x i1> [[CMP2]], [[Y:%.*]]
; CHECK-NEXT: ret <2 x i1> [[SEL]]
;
%cmp1 = icmp ne <2 x i64> %x, zeroinitializer
>From 6d5cfb7998527d4b62b4a368c1a8c7affae25f74 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Tue, 4 Jun 2024 19:53:33 +0800
Subject: [PATCH 3/4] [InstCombine] Add more tests. NFC.
---
.../test/Transforms/InstCombine/select-cmp.ll | 52 +++++++++++++++++++
1 file changed, 52 insertions(+)
diff --git a/llvm/test/Transforms/InstCombine/select-cmp.ll b/llvm/test/Transforms/InstCombine/select-cmp.ll
index 8609bc5041ad8..2d12daca4b143 100644
--- a/llvm/test/Transforms/InstCombine/select-cmp.ll
+++ b/llvm/test/Transforms/InstCombine/select-cmp.ll
@@ -431,4 +431,56 @@ define <2 x i1> @test_select_inverse_vec_fail(<2 x i64> %x, i1 %y) {
ret <2 x i1> %sel
}
+define i1 @test_select_inverse_nonconst1(i64 %x, i64 %y, i1 %cond) {
+; CHECK-LABEL: @test_select_inverse_nonconst1(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ne i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i64 [[X]], [[Y]]
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: ret i1 [[SEL]]
+;
+ %cmp1 = icmp ne i64 %x, %y
+ %cmp2 = icmp eq i64 %x, %y
+ %sel = select i1 %cond, i1 %cmp1, i1 %cmp2
+ ret i1 %sel
+}
+
+define i1 @test_select_inverse_nonconst2(i64 %x, i64 %y, i1 %cond) {
+; CHECK-LABEL: @test_select_inverse_nonconst2(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ne i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i64 [[Y]], [[X]]
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: ret i1 [[SEL]]
+;
+ %cmp1 = icmp ne i64 %x, %y
+ %cmp2 = icmp eq i64 %y, %x
+ %sel = select i1 %cond, i1 %cmp1, i1 %cmp2
+ ret i1 %sel
+}
+
+define i1 @test_select_inverse_nonconst3(i64 %x, i64 %y, i1 %cond) {
+; CHECK-LABEL: @test_select_inverse_nonconst3(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp uge i64 [[X]], [[Y]]
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: ret i1 [[SEL]]
+;
+ %cmp1 = icmp ult i64 %x, %y
+ %cmp2 = icmp uge i64 %x, %y
+ %sel = select i1 %cond, i1 %cmp1, i1 %cmp2
+ ret i1 %sel
+}
+
+define i1 @test_select_inverse_nonconst4(i64 %x, i64 %y, i64 %z, i1 %cond) {
+; CHECK-LABEL: @test_select_inverse_nonconst4(
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp uge i64 [[Z:%.*]], [[Y]]
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: ret i1 [[SEL]]
+;
+ %cmp1 = icmp ult i64 %x, %y
+ %cmp2 = icmp uge i64 %z, %y
+ %sel = select i1 %cond, i1 %cmp1, i1 %cmp2
+ ret i1 %sel
+}
+
declare void @use(i1)
>From dab70ac2f2e4f3d2bac92585c32dc6aeb0200b25 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Tue, 4 Jun 2024 20:02:40 +0800
Subject: [PATCH 4/4] [InstCombine] Address review comments.
---
.../Transforms/InstCombine/InstCombineSelect.cpp | 13 ++++++-------
llvm/test/Transforms/InstCombine/select-cmp.ll | 15 ++++++---------
2 files changed, 12 insertions(+), 16 deletions(-)
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 011b1c2e09c03..d62a8ef51923f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -3508,20 +3508,19 @@ static bool matchFMulByZeroIfResultEqZero(InstCombinerImpl &IC, Value *Cmp0,
/// 3. X is false implies Y is true.
/// Otherwise, return false.
static bool isKnownInversion(Value *X, Value *Y) {
- // Handle X = icmp pred V, C1, Y = icmp pred V, C2.
- Value *V;
- Constant *C1, *C2;
+ // Handle X = icmp pred A, B, Y = icmp pred A, C.
+ Value *A, *B, *C;
ICmpInst::Predicate Pred1, Pred2;
- if (!match(X, m_ICmp(Pred1, m_Value(V), m_Constant(C1))) ||
- !match(Y, m_ICmp(Pred2, m_Specific(V), m_Constant(C2))))
+ if (!match(X, m_ICmp(Pred1, m_Value(A), m_Value(B))) ||
+ !match(Y, m_c_ICmp(Pred2, m_Specific(A), m_Value(C))))
return false;
- if (C1 == C2)
+ if (B == C)
return Pred1 == ICmpInst::getInversePredicate(Pred2);
// Try to infer the relationship from constant ranges.
const APInt *RHSC1, *RHSC2;
- if (!match(C1, m_APInt(RHSC1)) || !match(C2, m_APInt(RHSC2)))
+ if (!match(B, m_APInt(RHSC1)) || !match(C, m_APInt(RHSC2)))
return false;
const auto CR1 = ConstantRange::makeExactICmpRegion(Pred1, *RHSC1);
diff --git a/llvm/test/Transforms/InstCombine/select-cmp.ll b/llvm/test/Transforms/InstCombine/select-cmp.ll
index 2d12daca4b143..4f75745643161 100644
--- a/llvm/test/Transforms/InstCombine/select-cmp.ll
+++ b/llvm/test/Transforms/InstCombine/select-cmp.ll
@@ -433,9 +433,8 @@ define <2 x i1> @test_select_inverse_vec_fail(<2 x i64> %x, i1 %y) {
define i1 @test_select_inverse_nonconst1(i64 %x, i64 %y, i1 %cond) {
; CHECK-LABEL: @test_select_inverse_nonconst1(
-; CHECK-NEXT: [[CMP1:%.*]] = icmp ne i64 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i64 [[X]], [[Y]]
-; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: [[SEL:%.*]] = xor i1 [[CMP2]], [[COND:%.*]]
; CHECK-NEXT: ret i1 [[SEL]]
;
%cmp1 = icmp ne i64 %x, %y
@@ -446,9 +445,8 @@ define i1 @test_select_inverse_nonconst1(i64 %x, i64 %y, i1 %cond) {
define i1 @test_select_inverse_nonconst2(i64 %x, i64 %y, i1 %cond) {
; CHECK-LABEL: @test_select_inverse_nonconst2(
-; CHECK-NEXT: [[CMP1:%.*]] = icmp ne i64 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i64 [[Y]], [[X]]
-; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i64 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[SEL:%.*]] = xor i1 [[CMP2]], [[COND:%.*]]
; CHECK-NEXT: ret i1 [[SEL]]
;
%cmp1 = icmp ne i64 %x, %y
@@ -459,9 +457,8 @@ define i1 @test_select_inverse_nonconst2(i64 %x, i64 %y, i1 %cond) {
define i1 @test_select_inverse_nonconst3(i64 %x, i64 %y, i1 %cond) {
; CHECK-LABEL: @test_select_inverse_nonconst3(
-; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i64 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT: [[CMP2:%.*]] = icmp uge i64 [[X]], [[Y]]
-; CHECK-NEXT: [[SEL:%.*]] = select i1 [[COND:%.*]], i1 [[CMP1]], i1 [[CMP2]]
+; CHECK-NEXT: [[CMP2:%.*]] = icmp uge i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: [[SEL:%.*]] = xor i1 [[CMP2]], [[COND:%.*]]
; CHECK-NEXT: ret i1 [[SEL]]
;
%cmp1 = icmp ult i64 %x, %y
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