From a7a5d25155b35a5133422d01989983c13ac8c4a7 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333@gmail.com>
Date: Thu, 9 Jan 2025 20:25:12 +0800
Subject: [PATCH 1/2] [InstCombine] Add pre-commit tests. NFC.

---
 llvm/test/Transforms/InstCombine/icmp-mul.ll | 34 ++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/llvm/test/Transforms/InstCombine/icmp-mul.ll b/llvm/test/Transforms/InstCombine/icmp-mul.ll
index 49e1e11fe6c36..313fb3bba41f1 100644
--- a/llvm/test/Transforms/InstCombine/icmp-mul.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-mul.ll
@@ -3,6 +3,7 @@
 
 declare void @llvm.assume(i1)
 declare void @use(i8)
+declare void @use32(i32)
 declare void @usev2xi8(<2 x i8>)
 
 
@@ -780,6 +781,39 @@ define i1 @eq_mul_constants_with_tz(i32 %x, i32 %y) {
   ret i1 %C
 }
 
+define i1 @eq_mul_constants_with_tz_extra_use1(i32 %x, i32 %y) {
+; CHECK-LABEL: @eq_mul_constants_with_tz_extra_use1(
+; CHECK-NEXT:    [[A:%.*]] = mul i32 [[X:%.*]], 12
+; CHECK-NEXT:    call void @use32(i32 [[A]])
+; CHECK-NEXT:    [[TMP1:%.*]] = xor i32 [[X]], [[Y:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = and i32 [[TMP1]], 1073741823
+; CHECK-NEXT:    [[C:%.*]] = icmp ne i32 [[TMP2]], 0
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %A = mul i32 %x, 12
+  call void @use32(i32 %A)
+  %B = mul i32 %y, 12
+  %C = icmp ne i32 %A, %B
+  ret i1 %C
+}
+
+define i1 @eq_mul_constants_with_tz_extra_use2(i32 %x, i32 %y) {
+; CHECK-LABEL: @eq_mul_constants_with_tz_extra_use2(
+; CHECK-NEXT:    [[A:%.*]] = mul i32 [[X:%.*]], 12
+; CHECK-NEXT:    call void @use32(i32 [[A]])
+; CHECK-NEXT:    [[B:%.*]] = mul i32 [[Y:%.*]], 12
+; CHECK-NEXT:    call void @use32(i32 [[B]])
+; CHECK-NEXT:    [[C:%.*]] = icmp ne i32 [[A]], [[B]]
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %A = mul i32 %x, 12
+  call void @use32(i32 %A)
+  %B = mul i32 %y, 12
+  call void @use32(i32 %B)
+  %C = icmp ne i32 %A, %B
+  ret i1 %C
+}
+
 define <2 x i1> @eq_mul_constants_with_tz_splat(<2 x i32> %x, <2 x i32> %y) {
 ; CHECK-LABEL: @eq_mul_constants_with_tz_splat(
 ; CHECK-NEXT:    [[TMP1:%.*]] = xor <2 x i32> [[X:%.*]], [[Y:%.*]]

From 116df20ccf15a8c33958a9ec56bbd669d2ae8710 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333@gmail.com>
Date: Thu, 9 Jan 2025 20:35:10 +0800
Subject: [PATCH 2/2] [InstCombine] Further relax one-use constraint in
 `foldICmpBinOp`

---
 llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 4 ++--
 llvm/test/Transforms/InstCombine/icmp-mul.ll            | 5 ++---
 llvm/test/Transforms/InstCombine/icmp.ll                | 2 +-
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 2e45725759949..c687a813cc98b 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -5435,7 +5435,6 @@ Instruction *InstCombinerImpl::foldICmpBinOp(ICmpInst &I,
   }
 
   if (BO0 && BO1 && BO0->getOpcode() == BO1->getOpcode() &&
-      (BO0->hasOneUse() || BO1->hasOneUse()) &&
       BO0->getOperand(1) == BO1->getOperand(1)) {
     switch (BO0->getOpcode()) {
     default:
@@ -5468,7 +5467,8 @@ Instruction *InstCombinerImpl::foldICmpBinOp(ICmpInst &I,
         break;
 
       const APInt *C;
-      if (match(BO0->getOperand(1), m_APInt(C)) && !C->isZero() &&
+      if (BO0->hasOneUse() && BO1->hasOneUse() &&
+          match(BO0->getOperand(1), m_APInt(C)) && !C->isZero() &&
           !C->isOne()) {
         // icmp eq/ne (X * C), (Y * C) --> icmp (X & Mask), (Y & Mask)
         // Mask = -1 >> count-trailing-zeros(C).
diff --git a/llvm/test/Transforms/InstCombine/icmp-mul.ll b/llvm/test/Transforms/InstCombine/icmp-mul.ll
index 313fb3bba41f1..c800d23858083 100644
--- a/llvm/test/Transforms/InstCombine/icmp-mul.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-mul.ll
@@ -785,9 +785,8 @@ define i1 @eq_mul_constants_with_tz_extra_use1(i32 %x, i32 %y) {
 ; CHECK-LABEL: @eq_mul_constants_with_tz_extra_use1(
 ; CHECK-NEXT:    [[A:%.*]] = mul i32 [[X:%.*]], 12
 ; CHECK-NEXT:    call void @use32(i32 [[A]])
-; CHECK-NEXT:    [[TMP1:%.*]] = xor i32 [[X]], [[Y:%.*]]
-; CHECK-NEXT:    [[TMP2:%.*]] = and i32 [[TMP1]], 1073741823
-; CHECK-NEXT:    [[C:%.*]] = icmp ne i32 [[TMP2]], 0
+; CHECK-NEXT:    [[B:%.*]] = mul i32 [[Y:%.*]], 12
+; CHECK-NEXT:    [[C:%.*]] = icmp ne i32 [[A]], [[B]]
 ; CHECK-NEXT:    ret i1 [[C]]
 ;
   %A = mul i32 %x, 12
diff --git a/llvm/test/Transforms/InstCombine/icmp.ll b/llvm/test/Transforms/InstCombine/icmp.ll
index 6e1486660b24d..68ca6807b4fef 100644
--- a/llvm/test/Transforms/InstCombine/icmp.ll
+++ b/llvm/test/Transforms/InstCombine/icmp.ll
@@ -849,7 +849,7 @@ define i1 @test46_multiuse3(i32 %X, i32 %Y, i32 %Z) {
 ; CHECK-NEXT:    call void @use_i32(i32 [[A]])
 ; CHECK-NEXT:    [[B:%.*]] = ashr exact i32 [[Y:%.*]], [[Z]]
 ; CHECK-NEXT:    call void @use_i32(i32 [[B]])
-; CHECK-NEXT:    [[C:%.*]] = icmp ult i32 [[A]], [[B]]
+; CHECK-NEXT:    [[C:%.*]] = icmp ult i32 [[X]], [[Y]]
 ; CHECK-NEXT:    ret i1 [[C]]
 ;
   %A = ashr exact i32 %X, %Z