[llvm] 6d4d017 - [llvm-extract] Delete dead `CG Profile` edges (#134940)
via llvm-commits
llvm-commits at lists.llvm.org
Wed Apr 9 10:36:16 PDT 2025
Author: Mircea Trofin
Date: 2025-04-09T10:36:12-07:00
New Revision: 6d4d017fd250b77e832bec37644f3446d0be6d6c
URL: https://github.com/llvm/llvm-project/commit/6d4d017fd250b77e832bec37644f3446d0be6d6c
DIFF: https://github.com/llvm/llvm-project/commit/6d4d017fd250b77e832bec37644f3446d0be6d6c.diff
LOG: [llvm-extract] Delete dead `CG Profile` edges (#134940)
When `llvm-extract`-ing a function, and the `CG Profile` flag is present in the original module, we end up with lots of `!{null, null, i64 1234}` entries for call edges that have disappeared as result of the removed functions.
This patch fixes that by adding a pass to `llvm-extract` that finds `CG Profile` edges with one or both operands `null` and removes them. This results in a cleaner output.
Added:
llvm/test/Transforms/StripSymbols/strip-cg-profile.ll
Modified:
llvm/include/llvm/Transforms/IPO/StripSymbols.h
llvm/lib/Passes/PassRegistry.def
llvm/lib/Transforms/IPO/StripSymbols.cpp
llvm/tools/llvm-extract/llvm-extract.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/Transforms/IPO/StripSymbols.h b/llvm/include/llvm/Transforms/IPO/StripSymbols.h
index dd76d481d668c..bd5cdde290dde 100644
--- a/llvm/include/llvm/Transforms/IPO/StripSymbols.h
+++ b/llvm/include/llvm/Transforms/IPO/StripSymbols.h
@@ -42,6 +42,10 @@ struct StripDeadDebugInfoPass : PassInfoMixin<StripDeadDebugInfoPass> {
PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
};
+struct StripDeadCGProfilePass : PassInfoMixin<StripDeadCGProfilePass> {
+ PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
+};
+
} // end namespace llvm
#endif // LLVM_TRANSFORMS_IPO_STRIPSYMBOLS_H
diff --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
index 94f5bf2c7c6c5..d5d1b2173da69 100644
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -155,6 +155,7 @@ MODULE_PASS("strip-dead-prototypes", StripDeadPrototypesPass())
MODULE_PASS("strip-debug-declare", StripDebugDeclarePass())
MODULE_PASS("strip-nondebug", StripNonDebugSymbolsPass())
MODULE_PASS("strip-nonlinetable-debuginfo", StripNonLineTableDebugInfoPass())
+MODULE_PASS("strip-dead-cg-profile", StripDeadCGProfilePass())
MODULE_PASS("trigger-crash-module", TriggerCrashModulePass())
MODULE_PASS("trigger-verifier-error", TriggerVerifierErrorPass())
MODULE_PASS("tsan-module", ModuleThreadSanitizerPass())
diff --git a/llvm/lib/Transforms/IPO/StripSymbols.cpp b/llvm/lib/Transforms/IPO/StripSymbols.cpp
index e7b70308ba7aa..647caaa123cf8 100644
--- a/llvm/lib/Transforms/IPO/StripSymbols.cpp
+++ b/llvm/lib/Transforms/IPO/StripSymbols.cpp
@@ -26,10 +26,12 @@
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/TypeFinder.h"
#include "llvm/IR/ValueSymbolTable.h"
+#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Transforms/IPO/StripSymbols.h"
#include "llvm/Transforms/Utils/Local.h"
@@ -297,3 +299,21 @@ PreservedAnalyses StripDeadDebugInfoPass::run(Module &M,
PA.preserveSet<CFGAnalyses>();
return PA;
}
+
+PreservedAnalyses StripDeadCGProfilePass::run(Module &M,
+ ModuleAnalysisManager &AM) {
+ auto *CGProf = dyn_cast_or_null<MDTuple>(M.getModuleFlag("CG Profile"));
+ if (!CGProf)
+ return PreservedAnalyses::all();
+
+ SmallVector<Metadata *, 16> ValidCGEdges;
+ for (Metadata *Edge : CGProf->operands()) {
+ if (auto *EdgeAsNode = dyn_cast_or_null<MDNode>(Edge))
+ if (llvm::all_of(EdgeAsNode->operands(),
+ [](const Metadata *V) { return V != nullptr; }))
+ ValidCGEdges.push_back(Edge);
+ }
+ M.setModuleFlag(Module::Append, "CG Profile",
+ MDTuple::getDistinct(M.getContext(), ValidCGEdges));
+ return PreservedAnalyses::none();
+}
\ No newline at end of file
diff --git a/llvm/test/Transforms/StripSymbols/strip-cg-profile.ll b/llvm/test/Transforms/StripSymbols/strip-cg-profile.ll
new file mode 100644
index 0000000000000..89176348eef9d
--- /dev/null
+++ b/llvm/test/Transforms/StripSymbols/strip-cg-profile.ll
@@ -0,0 +1,53 @@
+; RUN: opt -passes=strip-dead-cg-profile %s -S -o - | FileCheck %s --check-prefix=NOOP
+; RUN: llvm-extract %s -func=a -S -o - | FileCheck %s --check-prefix=EXTRACT-A
+; RUN: llvm-extract %s -func=a --func=b -S -o - | FileCheck %s --check-prefix=EXTRACT-AB
+; RUN: llvm-extract %s -func=solo -S -o - | FileCheck %s --check-prefix=NOTHING-LEFT
+
+define void @a() {
+ call void @b()
+ ret void
+}
+
+define void @b() {
+ call void @c()
+ ret void
+}
+
+define void @c() {
+ call void @d()
+ ret void
+}
+
+define void @d() {
+ ret void
+}
+
+define void @solo() {
+ ret void
+}
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 5, !"CG Profile", !1}
+!1 = !{!2, !3, !4}
+!2 = !{ptr @a, ptr @b, i64 42}
+!3 = !{ptr @b, ptr @c, i64 20}
+!4 = !{ptr @c, ptr @d, i64 101}
+
+; NOOP: !0 = !{i32 5, !"CG Profile", !1}
+; NOOP-NEXT: !1 = distinct !{!2, !3, !4}
+; NOOP-NEXT: !2 = !{ptr @a, ptr @b, i64 42}
+; NOOP-NEXT: !3 = !{ptr @b, ptr @c, i64 20}
+; NOOP-NEXT: !4 = !{ptr @c, ptr @d, i64 101}
+
+; EXTRACT-A: !0 = !{i32 5, !"CG Profile", !1}
+; EXTRACT-A-NEXT: !1 = distinct !{!2}
+; EXTRACT-A-NEXT: !2 = !{ptr @a, ptr @b, i64 42}
+
+; EXTRACT-AB: !0 = !{i32 5, !"CG Profile", !1}
+; EXTRACT-AB-NEXT: !1 = distinct !{!2, !3}
+; EXTRACT-AB-NEXT: !2 = !{ptr @a, ptr @b, i64 42}
+; EXTRACT-AB-NEXT: !3 = !{ptr @b, ptr @c, i64 20}
+
+; NOTHING-LEFT: !0 = !{i32 5, !"CG Profile", !1}
+; NOTHING-LEFT-NEXT: !1 = distinct !{}
\ No newline at end of file
diff --git a/llvm/tools/llvm-extract/llvm-extract.cpp b/llvm/tools/llvm-extract/llvm-extract.cpp
index 169cd0c2e4cbf..648060acb392c 100644
--- a/llvm/tools/llvm-extract/llvm-extract.cpp
+++ b/llvm/tools/llvm-extract/llvm-extract.cpp
@@ -408,6 +408,7 @@ int main(int argc, char **argv) {
PM.addPass(GlobalDCEPass());
PM.addPass(StripDeadDebugInfoPass());
PM.addPass(StripDeadPrototypesPass());
+ PM.addPass(StripDeadCGProfilePass());
std::error_code EC;
ToolOutputFile Out(OutputFilename, EC, sys::fs::OF_None);
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