[llvm] Fix: Distinguish CFI Metadata Checks in MergeFunctions Pass (PR #65963)
Oskar Wirga via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 22 10:05:48 PDT 2023
https://github.com/oskarwirga updated https://github.com/llvm/llvm-project/pull/65963
>From c80c820bdd5ed4ab82458c4a9aefad75bb1a59a3 Mon Sep 17 00:00:00 2001
From: Oskar Wirga <10386631+oskarwirga at users.noreply.github.com>
Date: Fri, 22 Sep 2023 10:04:49 -0700
Subject: [PATCH] Fix: Distinguish CFI Metadata Checks in MergeFunctions Pass
---
llvm/lib/Transforms/IPO/MergeFunctions.cpp | 25 ++++++++-
.../MergeFunc/cfi-function-merging.ll | 53 +++++++++++++++++++
.../MergeFunc/merge-fp-intrinsics.ll | 28 ++++++++++
3 files changed, 105 insertions(+), 1 deletion(-)
create mode 100644 llvm/test/Transforms/MergeFunc/cfi-function-merging.ll
create mode 100644 llvm/test/Transforms/MergeFunc/merge-fp-intrinsics.ll
diff --git a/llvm/lib/Transforms/IPO/MergeFunctions.cpp b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
index 312a8df440bf1e3..89ddd7b6adebbec 100644
--- a/llvm/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
@@ -375,9 +375,32 @@ bool MergeFunctions::doFunctionalCheck(std::vector<WeakTrackingVH> &Worklist) {
}
#endif
+/// Check whether \p F has an intrinsic which references
+/// distinct metadata as an operand. The most common
+/// instance of this would be CFI checks for function-local types.
+static bool hasDistinctMetadataIntrinsic(const Function &F) {
+ for (const BasicBlock &BB : F) {
+ for (const Instruction &I : BB.instructionsWithoutDebug()) {
+ if (!isa<IntrinsicInst>(&I))
+ continue;
+
+ for (Value *Op : I.operands()) {
+ auto *MDL = dyn_cast<MetadataAsValue>(Op);
+ if (!MDL)
+ continue;
+ if (MDNode *N = dyn_cast<MDNode>(MDL->getMetadata()))
+ if (N->isDistinct())
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
/// Check whether \p F is eligible for function merging.
static bool isEligibleForMerging(Function &F) {
- return !F.isDeclaration() && !F.hasAvailableExternallyLinkage();
+ return !F.isDeclaration() && !F.hasAvailableExternallyLinkage() &&
+ !hasDistinctMetadataIntrinsic(F);
}
bool MergeFunctions::runOnModule(Module &M) {
diff --git a/llvm/test/Transforms/MergeFunc/cfi-function-merging.ll b/llvm/test/Transforms/MergeFunc/cfi-function-merging.ll
new file mode 100644
index 000000000000000..1fe5f71f95c3bf5
--- /dev/null
+++ b/llvm/test/Transforms/MergeFunc/cfi-function-merging.ll
@@ -0,0 +1,53 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+;; Check the cases involving internal CFI instrumented functions where we do not expect functions to be merged.
+; RUN: opt -S -passes=mergefunc < %s | FileCheck %s
+
+; Function Attrs: nocallback nofree nosync nounwind readnone speculatable willreturn
+declare i1 @llvm.type.test(ptr, metadata) #6
+
+define internal void @A__on_zero_sharedEv(ptr noundef nonnull align 8 dereferenceable(32) %this) {
+; CHECK-LABEL: define internal void @A__on_zero_sharedEv
+; CHECK-SAME: (ptr noundef nonnull align 8 dereferenceable(32) [[THIS:%.*]]) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[THIS_ADDR:%.*]] = alloca ptr, align 8
+; CHECK-NEXT: store ptr [[THIS]], ptr [[THIS_ADDR]], align 8
+; CHECK-NEXT: [[THIS1:%.*]] = load ptr, ptr [[THIS_ADDR]], align 8
+; CHECK-NEXT: [[VTABLE:%.*]] = load ptr, ptr [[THIS1]], align 8
+; CHECK-NEXT: [[TMP0:%.*]] = call i1 @llvm.type.test(ptr [[VTABLE]], metadata [[META0:![0-9]+]]), !nosanitize !1
+; CHECK-NEXT: ret void
+;
+entry:
+ %this.addr = alloca ptr, align 8
+ store ptr %this, ptr %this.addr, align 8
+ %this1 = load ptr, ptr %this.addr, align 8
+ %vtable = load ptr, ptr %this1, align 8
+ %0 = call i1 @llvm.type.test(ptr %vtable, metadata !11), !nosanitize !47
+ ret void
+}
+
+; Function Attrs: mustprogress noinline nounwind optnone uwtable
+define internal void @B__on_zero_sharedEv(ptr noundef nonnull align 8 dereferenceable(32) %this) {
+; CHECK-LABEL: define internal void @B__on_zero_sharedEv
+; CHECK-SAME: (ptr noundef nonnull align 8 dereferenceable(32) [[THIS:%.*]]) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[THIS_ADDR:%.*]] = alloca ptr, align 8
+; CHECK-NEXT: store ptr [[THIS]], ptr [[THIS_ADDR]], align 8
+; CHECK-NEXT: [[THIS1:%.*]] = load ptr, ptr [[THIS_ADDR]], align 8
+; CHECK-NEXT: [[VTABLE:%.*]] = load ptr, ptr [[THIS1]], align 8
+; CHECK-NEXT: [[TMP0:%.*]] = call i1 @llvm.type.test(ptr [[VTABLE]], metadata [[META2:![0-9]+]]), !nosanitize !1
+; CHECK-NEXT: ret void
+;
+entry:
+ %this.addr = alloca ptr, align 8
+ store ptr %this, ptr %this.addr, align 8
+ %this1 = load ptr, ptr %this.addr, align 8
+ %vtable = load ptr, ptr %this1, align 8
+ %0 = call i1 @llvm.type.test(ptr %vtable, metadata !22), !nosanitize !47
+ ret void
+}
+
+!10 = !{i64 16, !11}
+!11 = distinct !{}
+!21 = !{i64 16, !22}
+!22 = distinct !{}
+!47 = !{}
diff --git a/llvm/test/Transforms/MergeFunc/merge-fp-intrinsics.ll b/llvm/test/Transforms/MergeFunc/merge-fp-intrinsics.ll
new file mode 100644
index 000000000000000..2a19ed8b8cca40a
--- /dev/null
+++ b/llvm/test/Transforms/MergeFunc/merge-fp-intrinsics.ll
@@ -0,0 +1,28 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+;; Make sure internal constrained FP intrinsics still merge properly
+; RUN: opt -passes=mergefunc -S < %s | FileCheck %s
+
+declare float @llvm.experimental.constrained.fadd.f32(float, float, metadata, metadata)
+
+define float @func1(float %a, float %b) {
+; CHECK-LABEL: define float @func1
+; CHECK-SAME: (float [[A:%.*]], float [[B:%.*]]) {
+; CHECK-NEXT: [[RESULT:%.*]] = call float @llvm.experimental.constrained.fadd.f32(float [[A]], float [[B]], metadata !"round.dynamic", metadata !"fpexcept.strict")
+; CHECK-NEXT: [[RESULT_2:%.*]] = call float @llvm.experimental.constrained.fadd.f32(float [[A]], float [[B]], metadata !"round.dynamic", metadata !"fpexcept.strict")
+; CHECK-NEXT: ret float [[RESULT]]
+;
+ %result = call float @llvm.experimental.constrained.fadd.f32(float %a, float %b, metadata !"round.dynamic", metadata !"fpexcept.strict")
+ %result_2 = call float @llvm.experimental.constrained.fadd.f32(float %a, float %b, metadata !"round.dynamic", metadata !"fpexcept.strict")
+ ret float %result
+}
+
+define float @func2(float %a, float %b) {
+; CHECK-LABEL: define float @func2
+; CHECK-SAME: (float [[TMP0:%.*]], float [[TMP1:%.*]]) {
+; CHECK-NEXT: [[TMP3:%.*]] = tail call float @func1(float [[TMP0]], float [[TMP1]])
+; CHECK-NEXT: ret float [[TMP3]]
+;
+ %result = call float @llvm.experimental.constrained.fadd.f32(float %a, float %b, metadata !"round.dynamic", metadata !"fpexcept.strict")
+ %result_2 = call float @llvm.experimental.constrained.fadd.f32(float %a, float %b, metadata !"round.dynamic", metadata !"fpexcept.strict")
+ ret float %result
+}
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