[llvm] beb0e7e - [VPlan] Fold (x | !x) -> true. (#177887)
via llvm-commits
llvm-commits at lists.llvm.org
Sun Feb 1 12:12:26 PST 2026
Author: Florian Hahn
Date: 2026-02-01T20:12:21Z
New Revision: beb0e7e15005f96b144fcac51a765fedd52c4b7c
URL: https://github.com/llvm/llvm-project/commit/beb0e7e15005f96b144fcac51a765fedd52c4b7c
DIFF: https://github.com/llvm/llvm-project/commit/beb0e7e15005f96b144fcac51a765fedd52c4b7c.diff
LOG: [VPlan] Fold (x | !x) -> true. (#177887)
PR: https://github.com/llvm/llvm-project/pull/177887
Added:
llvm/test/Transforms/LoopVectorize/binop-folds.ll
Modified:
llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
llvm/test/Transforms/LoopVectorize/cse-replicate-regions.ll
llvm/test/Transforms/LoopVectorize/hoist-predicated-loads-with-predicated-stores.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index 2655b539ee7ff..0c691f7355200 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -1279,6 +1279,12 @@ static void simplifyRecipe(VPSingleDefRecipe *Def, VPTypeAnalysis &TypeInfo) {
if (match(Def, m_c_BinaryOr(m_VPValue(X), m_ZeroInt())))
return Def->replaceAllUsesWith(X);
+ // x | !x -> AllOnes
+ if (match(Def, m_c_BinaryOr(m_VPValue(X), m_Not(m_Deferred(X))))) {
+ return Def->replaceAllUsesWith(Plan->getOrAddLiveIn(
+ ConstantInt::getAllOnesValue(TypeInfo.inferScalarType(Def))));
+ }
+
// x & 0 -> 0
if (match(Def, m_c_BinaryAnd(m_VPValue(X), m_ZeroInt())))
return Def->replaceAllUsesWith(Def->getOperand(Def->getOperand(0) == X));
diff --git a/llvm/test/Transforms/LoopVectorize/binop-folds.ll b/llvm/test/Transforms/LoopVectorize/binop-folds.ll
new file mode 100644
index 0000000000000..5ba6b26894269
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/binop-folds.ll
@@ -0,0 +1,39 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals none --version 5
+; RUN: opt -passes=loop-vectorize -force-vector-width=4 -force-vector-interleave=1 -S %s | FileCheck %s
+
+define void @negated_or_i8(ptr %A) {
+; CHECK-LABEL: define void @negated_or_i8(
+; CHECK-SAME: ptr [[A:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: br label %[[VECTOR_PH:.*]]
+; CHECK: [[VECTOR_PH]]:
+; CHECK-NEXT: br label %[[VECTOR_BODY:.*]]
+; CHECK: [[VECTOR_BODY]]:
+; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds i8, ptr [[A]], i64 [[INDEX]]
+; CHECK-NEXT: store <4 x i8> splat (i8 -1), ptr [[TMP0]], align 1
+; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i64 [[INDEX_NEXT]], 100
+; CHECK-NEXT: br i1 [[TMP1]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
+; CHECK: [[MIDDLE_BLOCK]]:
+; CHECK-NEXT: br label %[[EXIT:.*]]
+; CHECK: [[EXIT]]:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %loop
+
+loop:
+ %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+ %gep = getelementptr inbounds i8, ptr %A, i64 %iv
+ %l = load i8, ptr %gep, align 1
+ %not = xor i8 %l, -1
+ %or = or i8 %l, %not
+ store i8 %or, ptr %gep
+ %iv.next = add nuw nsw i64 %iv, 1
+ %ec = icmp eq i64 %iv.next, 100
+ br i1 %ec, label %exit, label %loop
+
+exit:
+ ret void
+}
diff --git a/llvm/test/Transforms/LoopVectorize/cse-replicate-regions.ll b/llvm/test/Transforms/LoopVectorize/cse-replicate-regions.ll
index c0692f3231e89..c0d603c22a5c8 100644
--- a/llvm/test/Transforms/LoopVectorize/cse-replicate-regions.ll
+++ b/llvm/test/Transforms/LoopVectorize/cse-replicate-regions.ll
@@ -95,11 +95,9 @@ define void @multiple_vppredinstphi_with_
diff erent_predicate(ptr %A, i32 %d) {
; CHECK-NEXT: br label %[[PRED_SDIV_CONTINUE2]]
; CHECK: [[PRED_SDIV_CONTINUE2]]:
; CHECK-NEXT: [[TMP9:%.*]] = phi <2 x i32> [ [[TMP5]], %[[PRED_SDIV_CONTINUE]] ], [ [[TMP8]], %[[PRED_SDIV_IF1]] ]
-; CHECK-NEXT: [[TMP10:%.*]] = xor <2 x i1> [[TMP1]], splat (i1 true)
-; CHECK-NEXT: [[TMP11:%.*]] = or <2 x i1> [[TMP1]], [[TMP10]]
; CHECK-NEXT: [[PREDPHI:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[TMP9]], <2 x i32> zeroinitializer
; CHECK-NEXT: [[TMP12:%.*]] = icmp sgt <2 x i32> [[WIDE_LOAD]], splat (i32 20)
-; CHECK-NEXT: [[TMP13:%.*]] = select <2 x i1> [[TMP11]], <2 x i1> [[TMP12]], <2 x i1> zeroinitializer
+; CHECK-NEXT: [[TMP13:%.*]] = select <2 x i1> splat (i1 true), <2 x i1> [[TMP12]], <2 x i1> zeroinitializer
; CHECK-NEXT: [[TMP14:%.*]] = extractelement <2 x i1> [[TMP13]], i32 0
; CHECK-NEXT: br i1 [[TMP14]], label %[[PRED_SDIV_IF3:.*]], label %[[PRED_SDIV_CONTINUE4:.*]]
; CHECK: [[PRED_SDIV_IF3]]:
diff --git a/llvm/test/Transforms/LoopVectorize/hoist-predicated-loads-with-predicated-stores.ll b/llvm/test/Transforms/LoopVectorize/hoist-predicated-loads-with-predicated-stores.ll
index 7450fcccbb484..dca1c3fd08382 100644
--- a/llvm/test/Transforms/LoopVectorize/hoist-predicated-loads-with-predicated-stores.ll
+++ b/llvm/test/Transforms/LoopVectorize/hoist-predicated-loads-with-predicated-stores.ll
@@ -1069,10 +1069,8 @@ define void @test_three_stores_with_
diff erent_predicates(ptr %dst, ptr %src, ptr
; CHECK-NEXT: store i32 1, ptr [[TMP7]], align 4, !alias.scope [[META95]], !noalias [[META92]]
; CHECK-NEXT: br label %[[PRED_STORE_CONTINUE3]]
; CHECK: [[PRED_STORE_CONTINUE3]]:
-; CHECK-NEXT: [[TMP8:%.*]] = xor <2 x i1> [[TMP3]], splat (i1 true)
-; CHECK-NEXT: [[TMP9:%.*]] = or <2 x i1> [[TMP3]], [[TMP8]]
; CHECK-NEXT: [[TMP10:%.*]] = icmp ule <2 x i32> [[WIDE_LOAD]], splat (i32 10)
-; CHECK-NEXT: [[TMP11:%.*]] = select <2 x i1> [[TMP9]], <2 x i1> [[TMP10]], <2 x i1> zeroinitializer
+; CHECK-NEXT: [[TMP11:%.*]] = select <2 x i1> splat (i1 true), <2 x i1> [[TMP10]], <2 x i1> zeroinitializer
; CHECK-NEXT: [[TMP12:%.*]] = extractelement <2 x i1> [[TMP11]], i32 0
; CHECK-NEXT: br i1 [[TMP12]], label %[[PRED_STORE_IF4:.*]], label %[[PRED_STORE_CONTINUE5:.*]]
; CHECK: [[PRED_STORE_IF4]]:
@@ -1088,7 +1086,7 @@ define void @test_three_stores_with_
diff erent_predicates(ptr %dst, ptr %src, ptr
; CHECK-NEXT: br label %[[PRED_STORE_CONTINUE7]]
; CHECK: [[PRED_STORE_CONTINUE7]]:
; CHECK-NEXT: [[TMP16:%.*]] = icmp ule <2 x i32> [[WIDE_LOAD]], splat (i32 9)
-; CHECK-NEXT: [[TMP17:%.*]] = select <2 x i1> [[TMP9]], <2 x i1> [[TMP16]], <2 x i1> zeroinitializer
+; CHECK-NEXT: [[TMP17:%.*]] = select <2 x i1> splat (i1 true), <2 x i1> [[TMP16]], <2 x i1> zeroinitializer
; CHECK-NEXT: [[TMP18:%.*]] = extractelement <2 x i1> [[TMP17]], i32 0
; CHECK-NEXT: br i1 [[TMP18]], label %[[PRED_STORE_IF8:.*]], label %[[PRED_STORE_CONTINUE9:.*]]
; CHECK: [[PRED_STORE_IF8]]:
More information about the llvm-commits
mailing list