[llvm] [InstCombine][NFC] Replace buildAssumeFromKnowledge with CreateAlignmentAssumption (PR #196254)
Nikolas Klauser via llvm-commits
llvm-commits at lists.llvm.org
Fri May 8 06:35:24 PDT 2026
https://github.com/philnik777 updated https://github.com/llvm/llvm-project/pull/196254
>From 38552d7f8085527299509de1c375860001dedb3c Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser at berlin.de>
Date: Thu, 7 May 2026 09:45:01 +0200
Subject: [PATCH] [InstCombine][NFC] Replace buildAssumeFromKnowledge with
CreateAlignmentAssumption
---
llvm/include/llvm/IR/IRBuilder.h | 2 +-
.../Transforms/Utils/AssumeBundleBuilder.h | 7 ----
llvm/lib/IR/IRBuilder.cpp | 2 +-
.../InstCombine/InstCombineCalls.cpp | 24 ++---------
.../Transforms/Utils/AssumeBundleBuilder.cpp | 10 -----
llvm/test/Transforms/InstCombine/assume.ll | 40 +++++++++++++++++++
6 files changed, 45 insertions(+), 40 deletions(-)
diff --git a/llvm/include/llvm/IR/IRBuilder.h b/llvm/include/llvm/IR/IRBuilder.h
index e28a9027740a3..ca085bb4aaa11 100644
--- a/llvm/include/llvm/IR/IRBuilder.h
+++ b/llvm/include/llvm/IR/IRBuilder.h
@@ -2807,7 +2807,7 @@ class IRBuilderBase {
/// specified alignment.
LLVM_ABI CallInst *CreateAlignmentAssumption(const DataLayout &DL,
Value *PtrValue,
- unsigned Alignment,
+ uint64_t Alignment,
Value *OffsetValue = nullptr);
/// Create an assume intrinsic call that represents an alignment
diff --git a/llvm/include/llvm/Transforms/Utils/AssumeBundleBuilder.h b/llvm/include/llvm/Transforms/Utils/AssumeBundleBuilder.h
index 2f45a1c5f5b67..1c0c318c8b0f2 100644
--- a/llvm/include/llvm/Transforms/Utils/AssumeBundleBuilder.h
+++ b/llvm/include/llvm/Transforms/Utils/AssumeBundleBuilder.h
@@ -47,13 +47,6 @@ LLVM_ABI AssumeInst *buildAssumeFromInst(Instruction *I);
LLVM_ABI bool salvageKnowledge(Instruction *I, AssumptionCache *AC = nullptr,
DominatorTree *DT = nullptr);
-/// Build and return a new assume created from the provided knowledge
-/// if the knowledge in the assume is fully redundant this will return nullptr
-LLVM_ABI AssumeInst *
-buildAssumeFromKnowledge(ArrayRef<RetainedKnowledge> Knowledge,
- Instruction *CtxI, AssumptionCache *AC = nullptr,
- DominatorTree *DT = nullptr);
-
/// This pass attempts to minimize the number of assume without loosing any
/// information.
struct AssumeSimplifyPass : public OptionalPassInfoMixin<AssumeSimplifyPass> {
diff --git a/llvm/lib/IR/IRBuilder.cpp b/llvm/lib/IR/IRBuilder.cpp
index 09945044c79a1..706a977a5b6d5 100644
--- a/llvm/lib/IR/IRBuilder.cpp
+++ b/llvm/lib/IR/IRBuilder.cpp
@@ -1363,7 +1363,7 @@ CallInst *IRBuilderBase::CreateAlignmentAssumptionHelper(const DataLayout &DL,
CallInst *IRBuilderBase::CreateAlignmentAssumption(const DataLayout &DL,
Value *PtrValue,
- unsigned Alignment,
+ uint64_t Alignment,
Value *OffsetValue) {
assert(isa<PointerType>(PtrValue->getType()) &&
"trying to create an alignment assumption on a non-pointer?");
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index b4e2ebea4d196..a622e0248fce8 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -3607,17 +3607,6 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
SmallVector<OperandBundleDef, 4> OpBundles;
II->getOperandBundlesAsDefs(OpBundles);
- /// This will remove the boolean Condition from the assume given as
- /// argument and remove the assume if it becomes useless.
- /// always returns nullptr for use as a return values.
- auto RemoveConditionFromAssume = [&](Instruction *Assume) -> Instruction * {
- assert(isa<AssumeInst>(Assume));
- if (isAssumeWithEmptyBundle(*cast<AssumeInst>(II)))
- return eraseInstFromFunction(CI);
- replaceUse(II->getOperandUse(0), ConstantInt::getTrue(II->getContext()));
- return nullptr;
- };
-
// Canonicalize assume(a && b) -> assume(a); assume(b);
// Note: New assumption intrinsics created here are registered by
// the InstCombineIRInserter object.
@@ -3706,7 +3695,6 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
}
}
- Instruction *Next = II->getNextNode();
// Convert nonnull assume like:
// %A = icmp ne i32* %PTR, null
// call void @llvm.assume(i1 %A)
@@ -3740,15 +3728,9 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
/// offset and alignment.
/// TODO: we can generate a GEP instead of merging the alignment with
/// the offset.
- RetainedKnowledge RK{Attribute::Alignment,
- MinAlign(Offset, AlignMask + 1), A};
- if (auto *Replacement =
- buildAssumeFromKnowledge(RK, Next, &AC, &DT)) {
-
- Replacement->insertAfter(II->getIterator());
- AC.registerAssumption(Replacement);
- }
- return RemoveConditionFromAssume(II);
+ Builder.CreateAlignmentAssumption(getDataLayout(), A,
+ MinAlign(Offset, AlignMask + 1));
+ return eraseInstFromFunction(*II);
}
}
}
diff --git a/llvm/lib/Transforms/Utils/AssumeBundleBuilder.cpp b/llvm/lib/Transforms/Utils/AssumeBundleBuilder.cpp
index 8df3be85c9535..26bca70e1056f 100644
--- a/llvm/lib/Transforms/Utils/AssumeBundleBuilder.cpp
+++ b/llvm/lib/Transforms/Utils/AssumeBundleBuilder.cpp
@@ -311,16 +311,6 @@ bool llvm::salvageKnowledge(Instruction *I, AssumptionCache *AC,
return Changed;
}
-AssumeInst *
-llvm::buildAssumeFromKnowledge(ArrayRef<RetainedKnowledge> Knowledge,
- Instruction *CtxI, AssumptionCache *AC,
- DominatorTree *DT) {
- AssumeBuilderState Builder(CtxI->getModule(), CtxI, AC, DT);
- for (const RetainedKnowledge &RK : Knowledge)
- Builder.addKnowledge(RK);
- return Builder.build();
-}
-
RetainedKnowledge llvm::simplifyRetainedKnowledge(AssumeInst *Assume,
RetainedKnowledge RK,
AssumptionCache *AC,
diff --git a/llvm/test/Transforms/InstCombine/assume.ll b/llvm/test/Transforms/InstCombine/assume.ll
index 40fe2f5f46f1e..c39f606382650 100644
--- a/llvm/test/Transforms/InstCombine/assume.ll
+++ b/llvm/test/Transforms/InstCombine/assume.ll
@@ -8,6 +8,7 @@ target triple = "x86_64-unknown-linux-gnu"
declare void @llvm.assume(i1) #1
declare ptr @get_ptr()
+declare void @use_i64(i64)
; Check that the assume has not been removed:
@@ -81,6 +82,45 @@ entry:
ret void
}
+define void @align_with_offset_less_than_align(ptr %ptr) {
+; CHECK-LABEL: @align_with_offset_less_than_align(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[INT:%.*]] = ptrtoint ptr [[PTR:%.*]] to i64
+; CHECK-NEXT: [[ADD:%.*]] = add i64 [[INT]], 3
+; CHECK-NEXT: [[AND:%.*]] = and i64 [[ADD]], 7
+; CHECK-NEXT: call void @use_i64(i64 [[AND]])
+; CHECK-NEXT: ret void
+;
+entry:
+ %int = ptrtoint ptr %ptr to i64
+ %add = add i64 %int, 3
+ %and = and i64 %add, 7
+ %cmp = icmp eq i64 0, %and
+ call void @llvm.assume(i1 %cmp)
+ call void @use_i64(i64 %and)
+ ret void
+}
+
+define void @align_with_offset_greater_than_align(ptr %ptr) {
+; CHECK-LABEL: @align_with_offset_greater_than_align(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[INT:%.*]] = ptrtoint ptr [[PTR:%.*]] to i64
+; CHECK-NEXT: [[ADD:%.*]] = add i64 [[INT]], 6
+; CHECK-NEXT: [[AND:%.*]] = and i64 [[ADD]], 6
+; CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(ptr [[PTR]], i64 2) ]
+; CHECK-NEXT: call void @use_i64(i64 [[AND]])
+; CHECK-NEXT: ret void
+;
+entry:
+ %int = ptrtoint ptr %ptr to i64
+ %add = add i64 %int, 14
+ %and = and i64 %add, 7
+ %cmp = icmp eq i64 0, %and
+ call void @llvm.assume(i1 %cmp)
+ call void @use_i64(i64 %and)
+ ret void
+}
+
define void @redundant_align() {
; CHECK-LABEL: @redundant_align(
; CHECK-NEXT: [[PTR:%.*]] = call ptr @get_ptr()
More information about the llvm-commits
mailing list