[InstCombine] Fold `A == MIN_INT ? B != MIN_INT : A < B` to `A < B` #120177

veera-sivarajan · 2024-12-17T03:37:35Z

This PR folds:
A == MIN_INT ? B != MIN_INT : A < B to A < B
A == MAX_INT ? B != MAX_INT : A > B to A > B

Proof: https://alive2.llvm.org/ce/z/bR6E2s

This helps in optimizing comparison of optional unsigned non-zero types in rust-lang/rust#49892.

Rust compiler's current output: https://rust.godbolt.org/z/9fxfq3Gn8

llvmbot · 2024-12-17T03:38:09Z

@llvm/pr-subscribers-llvm-transforms

@llvm/pr-subscribers-llvm-analysis

Author: Veera (veera-sivarajan)

Changes

This PR simplifies:
A == MIN_INT ? B != MIN_INT : A < B to A < B
A == MAX_INT ? B != MAX_INT : A > B to A > B

Proof: https://alive2.llvm.org/ce/z/bR6E2s

This helps in optimizing comparison of optional unsigned non-zero types in rust-lang/rust#49892.

Rust compiler's current output: https://rust.godbolt.org/z/9fxfq3Gn8

Full diff: https://github.com/llvm/llvm-project/pull/120177.diff

2 Files Affected:

(modified) llvm/lib/Analysis/InstructionSimplify.cpp (+43-1)
(added) llvm/test/Transforms/InstSimplify/select-with-extreme-eq-cond.ll (+360)

diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 3325cd972cf1eb..fcbaaafe69ec48 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4608,6 +4608,45 @@ static Value *simplifySelectWithEquivalence(Value *CmpLHS, Value *CmpRHS,
   return nullptr;
 }
 
+/// `A == MIN_INT ? B != MIN_INT : A < B` --> `A < B`
+/// `A == MAX_INT ? B != MAX_INT : A > B` --> `A > B`
+static Value *foldSelectWithExtremeEqCond(Value *CmpLHS, Value *CmpRHS,
+                                          Value *TrueVal, Value *FalseVal) {
+  CmpPredicate Pred;
+  Value *A, *B;
+
+  if (!match(FalseVal, m_ICmp(Pred, m_Value(A), m_Value(B))))
+    return nullptr;
+
+  // make sure `CmpLHS` is on the LHS of `FalseVal`.
+  if (match(CmpLHS, m_Specific(B))) {
+    std::swap(A, B);
+    Pred = CmpInst::getSwappedPredicate(Pred);
+  }
+
+  APInt C;
+  unsigned NumBits = A->getType()->getScalarSizeInBits();
+
+  if (ICmpInst::isLT(Pred)) {
+    C = CmpInst::isSigned(Pred) ? APInt::getSignedMinValue(NumBits)
+                                : APInt::getMinValue(NumBits);
+  } else if (ICmpInst::isGT(Pred)) {
+    C = CmpInst::isSigned(Pred) ? APInt::getSignedMaxValue(NumBits)
+                                : APInt::getMaxValue(NumBits);
+  } else {
+    return nullptr;
+  }
+
+  if (!match(CmpLHS, m_Specific(A)) || !match(CmpRHS, m_SpecificInt(C)))
+    return nullptr;
+
+  if (!match(TrueVal, m_SpecificICmp(ICmpInst::ICMP_NE, m_Specific(B),
+                                     m_SpecificInt(C))))
+    return nullptr;
+
+  return FalseVal;
+}
+
 /// Try to simplify a select instruction when its condition operand is an
 /// integer comparison.
 static Value *simplifySelectWithICmpCond(Value *CondVal, Value *TrueVal,
@@ -4728,6 +4767,10 @@ static Value *simplifySelectWithICmpCond(Value *CondVal, Value *TrueVal,
                                                    Q, MaxRecurse))
         return V;
     }
+
+    if (Value *V =
+            foldSelectWithExtremeEqCond(CmpLHS, CmpRHS, TrueVal, FalseVal))
+      return V;
   }
 
   return nullptr;
@@ -7141,7 +7184,6 @@ static Value *simplifyInstructionWithOperands(Instruction *I,
                             NewOps[1], I->getFastMathFlags(), Q, MaxRecurse);
   case Instruction::Select:
     return simplifySelectInst(NewOps[0], NewOps[1], NewOps[2], Q, MaxRecurse);
-    break;
   case Instruction::GetElementPtr: {
     auto *GEPI = cast<GetElementPtrInst>(I);
     return simplifyGEPInst(GEPI->getSourceElementType(), NewOps[0],
diff --git a/llvm/test/Transforms/InstSimplify/select-with-extreme-eq-cond.ll b/llvm/test/Transforms/InstSimplify/select-with-extreme-eq-cond.ll
new file mode 100644
index 00000000000000..3fa9468035cb7a
--- /dev/null
+++ b/llvm/test/Transforms/InstSimplify/select-with-extreme-eq-cond.ll
@@ -0,0 +1,360 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+define i1 @compare_unsigned_min(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_unsigned_min(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp ult i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[TMP2]]
+;
+start:
+  %2 = icmp eq i8 %0, 0
+  %3 = icmp ne i8 %1, 0
+  %4 = icmp ult i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_signed_min(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_signed_min(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp slt i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[TMP4]]
+;
+start:
+  %2 = icmp eq i8 %0, -128
+  %3 = icmp ne i8 %1, -128
+  %4 = icmp slt i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_unsigned_max(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_unsigned_max(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp ugt i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[TMP4]]
+;
+start:
+  %2 = icmp eq i8 %0, 255
+  %3 = icmp ne i8 %1, 255
+  %4 = icmp ugt i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_signed_max(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_signed_max(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp sgt i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[TMP4]]
+;
+start:
+  %2 = icmp eq i8 %0, 127
+  %3 = icmp ne i8 %1, 127
+  %4 = icmp sgt i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @relational_cmp_unsigned_min(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @relational_cmp_unsigned_min(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp ult i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[TMP4]]
+;
+start:
+  %2 = icmp ule i8 %0, 0
+  %3 = icmp ugt i8 %1, 0
+  %4 = icmp ult i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @relational_cmp_signed_min(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @relational_cmp_signed_min(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp slt i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[TMP4]]
+;
+start:
+  %2 = icmp sle i8 %0, -128
+  %3 = icmp sgt i8 %1, -128
+  %4 = icmp slt i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @relational_cmp_unsigned_max(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @relational_cmp_unsigned_max(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp ugt i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[TMP4]]
+;
+start:
+  %2 = icmp uge i8 %0, 255
+  %3 = icmp ult i8 %1, 255
+  %4 = icmp ugt i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @relational_cmp_signed_max(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @relational_cmp_signed_max(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp sgt i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[TMP4]]
+;
+start:
+  %2 = icmp sge i8 %0, 127
+  %3 = icmp slt i8 %1, 127
+  %4 = icmp sgt i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+declare void @use(i1)
+
+define i1 @compare_signed_max_multiuse(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_signed_max_multiuse(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp sgt i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    call void @use(i1 [[TMP4]])
+; CHECK-NEXT:    ret i1 [[TMP4]]
+;
+start:
+  %2 = icmp eq i8 %0, 127
+  %3 = icmp ne i8 %1, 127
+  %4 = icmp sgt i8 %0, %1
+  call void @use(i1 %4)
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_signed_min_samesign(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_signed_min_samesign(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp samesign slt i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[TMP4]]
+;
+start:
+  %2 = icmp eq i8 %0, -128
+  %3 = icmp ne i8 %1, -128
+  %4 = icmp samesign slt i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_flipped(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_flipped(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp ugt i8 [[TMP1]], [[TMP0]]
+; CHECK-NEXT:    ret i1 [[TMP4]]
+;
+start:
+  %2 = icmp eq i8 %0, 0
+  %3 = icmp ne i8 %1, 0
+  %4 = icmp ugt i8 %1, %0
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_swapped(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_swapped(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[RESULT:%.*]] = icmp ult i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[RESULT]]
+;
+start:
+  %2 = icmp ne i8 %0, 0
+  %3 = icmp ne i8 %1, 0
+  %4 = icmp ult i8 %0, %1
+  %result = select i1 %2, i1 %4, i1 %3
+  ret i1 %result
+}
+
+define i1 @compare_swapped_flipped_unsigned_max(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_swapped_flipped_unsigned_max(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp ult i8 [[TMP1]], [[TMP0]]
+; CHECK-NEXT:    ret i1 [[TMP2]]
+;
+start:
+  %2 = icmp ne i8 %0, 255
+  %3 = icmp ne i8 %1, 255
+  %4 = icmp ult i8 %1, %0
+  %result = select i1 %2, i1 %4, i1 %3
+  ret i1 %result
+}
+
+define i1 @compare_unsigned_min_illegal_type(i9 %0, i9 %1) {
+; CHECK-LABEL: define i1 @compare_unsigned_min_illegal_type(
+; CHECK-SAME: i9 [[TMP0:%.*]], i9 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp ult i9 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    ret i1 [[TMP2]]
+;
+start:
+  %2 = icmp eq i9 %0, 0
+  %3 = icmp ne i9 %1, 0
+  %4 = icmp ult i9 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define <2 x i1> @compare_vector(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: define <2 x i1> @compare_vector(
+; CHECK-SAME: <2 x i8> [[X:%.*]], <2 x i8> [[Y:%.*]]) {
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult <2 x i8> [[X]], [[Y]]
+; CHECK-NEXT:    ret <2 x i1> [[TMP1]]
+;
+  %2 = icmp eq <2 x i8> %x, <i8 0, i8 0>
+  %3 = icmp ne <2 x i8> %y, <i8 0, i8 0>
+  %4 = icmp ult <2 x i8> %x, %y
+  %result = select <2 x i1> %2, <2 x i1> %3, <2 x i1> %4
+  ret <2 x i1> %result
+}
+
+define i1 @compare_float_negative(half %0, half %1) {
+; CHECK-LABEL: define i1 @compare_float_negative(
+; CHECK-SAME: half [[TMP0:%.*]], half [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP2:%.*]] = fcmp oeq half [[TMP0]], 0xH0000
+; CHECK-NEXT:    [[TMP3:%.*]] = fcmp one half [[TMP1]], 0xH0000
+; CHECK-NEXT:    [[TMP4:%.*]] = fcmp ult half [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[RESULT:%.*]] = select i1 [[TMP2]], i1 [[TMP3]], i1 [[TMP4]]
+; CHECK-NEXT:    ret i1 [[RESULT]]
+;
+start:
+  %2 = fcmp oeq half %0, 0.0
+  %3 = fcmp one half %1, 0.0
+  %4 = fcmp ult half %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_unsigned_max_swapped_lhs_rhs_negative(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_unsigned_max_swapped_lhs_rhs_negative(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP0]], -1
+; CHECK-NEXT:    [[DOTNOT:%.*]] = icmp ne i8 [[TMP1]], -1
+; CHECK-NEXT:    [[RESULT:%.*]] = select i1 [[DOTNOT]], i1 [[TMP2]], i1 false
+; CHECK-NEXT:    ret i1 [[RESULT]]
+;
+start:
+  %2 = icmp eq i8 %0, 255
+  %3 = icmp ne i8 %1, 255
+  %4 = icmp ugt i8 %0, %1
+  %result = select i1 %3, i1 %2, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_signed_min_negative(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_signed_min_negative(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP0]], -127
+; CHECK-NEXT:    [[TMP3:%.*]] = icmp ne i8 [[TMP1]], -127
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp slt i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[RESULT:%.*]] = select i1 [[TMP2]], i1 [[TMP3]], i1 [[TMP4]]
+; CHECK-NEXT:    ret i1 [[RESULT]]
+;
+start:
+  %2 = icmp eq i8 %0, -127
+  %3 = icmp ne i8 %1, -127
+  %4 = icmp slt i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_unsigned_max_negative(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_unsigned_max_negative(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP0]], -1
+; CHECK-NEXT:    [[TMP3:%.*]] = icmp ne i8 [[TMP1]], -1
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp ult i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[RESULT:%.*]] = select i1 [[TMP2]], i1 [[TMP3]], i1 [[TMP4]]
+; CHECK-NEXT:    ret i1 [[RESULT]]
+;
+start:
+  %2 = icmp eq i8 %0, 255
+  %3 = icmp ne i8 %1, 255
+  %4 = icmp ult i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @non_strict_op_negative(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @non_strict_op_negative(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT:    [[TMP3:%.*]] = icmp ne i8 [[TMP1]], 0
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp ule i8 [[TMP0]], [[TMP1]]
+; CHECK-NEXT:    [[RESULT:%.*]] = select i1 [[TMP2]], i1 [[TMP3]], i1 [[TMP4]]
+; CHECK-NEXT:    ret i1 [[RESULT]]
+;
+start:
+  %2 = icmp eq i8 %0, 0
+  %3 = icmp ne i8 %1, 0
+  %4 = icmp ule i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_poison_negative(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_poison_negative(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    ret i1 poison
+;
+start:
+  %2 = icmp eq i8 %0, 0
+  %3 = icmp ne i8 poison, 0
+  %4 = icmp ult i8 %0, poison
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_cond_poison_negative(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_cond_poison_negative(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    ret i1 poison
+;
+start:
+  %2 = icmp eq i8 %0, poison
+  %3 = icmp ne i8 %1, 0
+  %4 = icmp ult i8 %0, %1
+  %result = select i1 %2, i1 %3, i1 %4
+  ret i1 %result
+}
+
+define i1 @compare_true_poison_negative(i8 %0, i8 %1) {
+; CHECK-LABEL: define i1 @compare_true_poison_negative(
+; CHECK-SAME: i8 [[TMP0:%.*]], i8 [[TMP1:%.*]]) {
+; CHECK-NEXT:  [[START:.*:]]
+; CHECK-NEXT:    ret i1 poison
+;
+start:
+  %2 = icmp eq i8 %0, poison
+  %3 = icmp ne i8 %1, 0
+  %4 = icmp ult i8 %0, %1
+  %result = select i1 %2, i1 poison, i1 %4
+  ret i1 %result
+}

llvm/lib/Analysis/InstructionSimplify.cpp

dtcxzyw

It is incorrect to preserve samesign flag: https://alive2.llvm.org/ce/z/2NdTWW

You should either implement this fold and drop the flag in InstCombine or bail out on icmps with samesign in InstSimplify.

llvm/lib/Analysis/InstructionSimplify.cpp

nikic · 2024-12-17T10:53:22Z

You should either implement this fold and drop the flag in InstCombine or bail out on icmps with samesign in InstSimplify.

The first option is preferred.

github-actions · 2024-12-18T03:33:04Z

✅ With the latest revision this PR passed the C/C++ code formatter.

llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp

llvm/test/Transforms/InstCombine/select-with-extreme-eq-cond.ll

llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp

llvm/test/Transforms/InstCombine/select-with-extreme-eq-cond.ll

llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp

dtcxzyw

LGTM. Thank you!

veera-sivarajan · 2024-12-19T06:43:25Z

Please merge it for me. I don't have commit access yet.

veera-sivarajan requested a review from nikic as a code owner December 17, 2024 03:37

llvmbot added llvm:instcombine llvm:analysis llvm:transforms labels Dec 17, 2024

dtcxzyw reviewed Dec 17, 2024

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llvm/lib/Analysis/InstructionSimplify.cpp Outdated Show resolved Hide resolved

This was referenced Dec 17, 2024

Task submission dtcxzyw/llvm-opt-benchmark#1312

Open

Fuzz PR120177 dtcxzyw/llvm-mutation-based-fuzz-service#14

Closed

pre-commit: PR120177 dtcxzyw/llvm-opt-benchmark#1875

Closed

dtcxzyw requested changes Dec 17, 2024

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nikic reviewed Dec 17, 2024

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llvm/lib/Analysis/InstructionSimplify.cpp Outdated Show resolved Hide resolved

veera-sivarajan changed the title ~~[InstSimplify] A == MIN_INT ? B != MIN_INT : A < B to A < B~~ [InstCombine] A == MIN_INT ? B != MIN_INT : A < B to A < B Dec 18, 2024

veera-sivarajan force-pushed the fix-rust-49892 branch from 92fb27e to c34b817 Compare December 18, 2024 03:27

veera-sivarajan force-pushed the fix-rust-49892 branch from c34b817 to 8b0239b Compare December 18, 2024 04:10

dtcxzyw reviewed Dec 18, 2024

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llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp Outdated Show resolved Hide resolved

dtcxzyw mentioned this pull request Dec 18, 2024

[InstCombine] samesign should be dropped when folding logical and of icmps #120361

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veera-sivarajan force-pushed the fix-rust-49892 branch from 8b0239b to 122e3eb Compare December 18, 2024 05:43

veera-sivarajan requested review from dtcxzyw and nikic December 18, 2024 13:55

dtcxzyw reviewed Dec 18, 2024

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goldsteinn reviewed Dec 18, 2024

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antoniofrighetto changed the title ~~[InstCombine] A == MIN_INT ? B != MIN_INT : A < B to A < B~~ [InstCombine] Fold A == MIN_INT ? B != MIN_INT : A < B to A < B Dec 18, 2024

veera-sivarajan added 2 commits December 19, 2024 05:29

Add Test

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Fold A == MIN_INT ? B != MIN_INT : A < B to A < B

2280f2f

veera-sivarajan force-pushed the fix-rust-49892 branch from 122e3eb to 2280f2f Compare December 19, 2024 05:45

dtcxzyw approved these changes Dec 19, 2024

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dtcxzyw mentioned this pull request Dec 19, 2024

Fuzz PR120177 dtcxzyw/llvm-fuzz-service#42

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dtcxzyw mentioned this pull request Dec 19, 2024

[SimplifyCFG] Convert conditional branch into unconditional branch if the incoming values of phi node can be represented by the condition #120539

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dtcxzyw merged commit 6f8afaf into llvm:main Dec 19, 2024
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[InstCombine] Fold `A == MIN_INT ? B != MIN_INT : A < B` to `A < B` #120177

[InstCombine] Fold `A == MIN_INT ? B != MIN_INT : A < B` to `A < B` #120177

veera-sivarajan commented Dec 17, 2024 •

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veera-sivarajan commented Dec 19, 2024

[InstCombine] Fold A == MIN_INT ? B != MIN_INT : A < B to A < B #120177

[InstCombine] Fold A == MIN_INT ? B != MIN_INT : A < B to A < B #120177

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veera-sivarajan commented Dec 19, 2024

[InstCombine] Fold `A == MIN_INT ? B != MIN_INT : A < B` to `A < B` #120177

[InstCombine] Fold `A == MIN_INT ? B != MIN_INT : A < B` to `A < B` #120177

veera-sivarajan commented Dec 17, 2024 •

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