Author: Vitaly Buka Date: 2024-12-07T16:12:58-08:00 New Revision: 7787328dd64c750c7acf30b86b31f0d7166c8f27
URL: https://github.com/llvm/llvm-project/commit/7787328dd64c750c7acf30b86b31f0d7166c8f27 DIFF: https://github.com/llvm/llvm-project/commit/7787328dd64c750c7acf30b86b31f0d7166c8f27.diff LOG: [ubsan] Improve lowering of @llvm.allow.ubsan.check (#119013) This fix the case, when single hot inlined callsite, prevent checks for all other. This helps to reduce number of removed checks up to 50% (deppedes on `cutoff-hot` value) . `ScalarOptimizerLateEPCallback` was happening during CGSCC walk, after each inlining, but this is effectively after inlining. Example, order in comments: ``` static void overflow() { // 1. Inline get/set if possible // 2. Simplify // 3. LowerAllowCheckPass set(get() + get()); } void test() { // 4. Inline // 5. Nothing for LowerAllowCheckPass overflow(); } ``` With this patch it will look like: ``` static void overflow() { // 1. Inline get/set if possible // 2. Simplify set(get() + get()); } void test() { // 3. Inline // 4. Simplify overflow(); } // Later, after inliner CGSCC walk complete: // 5. LowerAllowCheckPass for `overflow` // 6. LowerAllowCheckPass for `test` ``` Added: Modified: clang/lib/CodeGen/BackendUtil.cpp clang/test/CodeGen/allow-ubsan-check-inline.c Removed: ################################################################################ diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp index fbb3fb6e5ea423..8cf44592a17475 100644 --- a/clang/lib/CodeGen/BackendUtil.cpp +++ b/clang/lib/CodeGen/BackendUtil.cpp @@ -789,13 +789,12 @@ static void addSanitizers(const Triple &TargetTriple, } if (LowerAllowCheckPass::IsRequested()) { - // We can optimize after inliner, and PGO profile matching. The hook below - // is called at the end `buildFunctionSimplificationPipeline`, which called - // from `buildInlinerPipeline`, which called after profile matching. - PB.registerScalarOptimizerLateEPCallback( - [](FunctionPassManager &FPM, OptimizationLevel Level) { - FPM.addPass(LowerAllowCheckPass()); - }); + // We want to call it after inline, which is about OptimizerEarlyEPCallback. + PB.registerOptimizerEarlyEPCallback([](ModulePassManager &MPM, + OptimizationLevel Level, + ThinOrFullLTOPhase Phase) { + MPM.addPass(createModuleToFunctionPassAdaptor(LowerAllowCheckPass())); + }); } } diff --git a/clang/test/CodeGen/allow-ubsan-check-inline.c b/clang/test/CodeGen/allow-ubsan-check-inline.c index cabe76d8034d77..1de24ab90dac0e 100644 --- a/clang/test/CodeGen/allow-ubsan-check-inline.c +++ b/clang/test/CodeGen/allow-ubsan-check-inline.c @@ -7,8 +7,8 @@ void set(int x); // We will only make decision in the `overflow` function. // NOINL-COUNT-1: remark: Allowed check: -// FIXME: We will make decision on every inline. -// INLINE-COUNT-1: remark: Allowed check: +// We will make decision on every inline. +// INLINE-COUNT-5: remark: Allowed check: static void overflow() { set(get() + get()); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
