[Msan, NewPM] Reduce size of msan binaries

[vitalybuka]

Summary

EarlyCSEPass called after msan redices code size by about 10%.
Similar optimization exists for legacy pass manager in
addGeneralOptsForMemorySanitizer.

[eugenis]

LGTM, please add a TODO for more passes

clang/lib/CodeGen/BackendUtil.cpp

1336

I did not know that MSan does not add the extra optimization passes in the new pass manager (see addGeneralOptsForMemorySanitizer). If I remember correctly, it used to give ~10% or more speedup on spec2006.

clang/lib/CodeGen/BackendUtil.cpp

 #include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
 #include "llvm/Transforms/Instrumentation/InstrProfiling.h"
 #include "llvm/Transforms/Instrumentation/MemProfiler.h"
 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
 #include "llvm/Transforms/Instrumentation/SanitizerCoverage.h"
 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
 #include "llvm/Transforms/ObjCARC.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/EarlyCSE.h"
 #include "llvm/Transforms/Scalar/GVN.h"
 #include "llvm/Transforms/Scalar/LowerMatrixIntrinsics.h"
 #include "llvm/Transforms/Utils.h"
 #include "llvm/Transforms/Utils/CanonicalizeAliases.h"
 #include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
 #include "llvm/Transforms/Utils/SymbolRewriter.h"
 #include "llvm/Transforms/Utils/UniqueInternalLinkageNames.h"
PB.registerOptimizerLastEPCallback([&](ModulePassManager &MPM,
 
     auto MSanPass = [&](SanitizerMask Mask, bool CompileKernel) {
       if (LangOpts.Sanitize.has(Mask)) {
         int TrackOrigins = CodeGenOpts.SanitizeMemoryTrackOrigins;
         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
 
         MPM.addPass(
             MemorySanitizerPass({TrackOrigins, Recover, CompileKernel}));
-        MPM.addPass(createModuleToFunctionPassAdaptor(
-            MemorySanitizerPass({TrackOrigins, Recover, CompileKernel})));
+        FunctionPassManager FPM(CodeGenOpts.DebugPassManager);
+        FPM.addPass(
+            MemorySanitizerPass({TrackOrigins, Recover, CompileKernel}));
+        if (Level != PassBuilder::OptimizationLevel::O0) {
+          // MemorySanitizer inserts complex instrumentation that mostly
+          // follows the logic of the original code, but operates on
+          // "shadow" values. It can benefit from re-running some
+          // general purpose optimization passes.
+          FPM.addPass(EarlyCSEPass());
+          // TODO: Consider add more passes like in
+          // addGeneralOptsForMemorySanitizer. EarlyCSEPass makes visible
+          // difference on size. It's not clear if the rest is still
+          // usefull. InstCombinePass breakes
+          // compiler-rt/test/msan/select_origin.cpp.
+        }
+        MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
       }
     };
     MSanPass(SanitizerKind::Memory, false);
     MSanPass(SanitizerKind::KernelMemory, true);
 
     if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
       MPM.addPass(ThreadSanitizerPass());
       MPM.addPass(createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
             FPM.addPass(BoundsCheckingPass());
           });
 
     addSanitizers(TargetTriple, CodeGenOpts, LangOpts, PB);
 
     if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts))
       PB.registerPipelineStartEPCallback(
           [Options](ModulePassManager &MPM,
                     PassBuilder::OptimizationLevel Level) {
             MPM.addPass(GCOVProfilerPass(*Options));
           });
     if (Optional<InstrProfOptions> Options =
             getInstrProfOptions(CodeGenOpts, LangOpts))
       PB.registerPipelineStartEPCallback(
           [Options](ModulePassManager &MPM,
                     PassBuilder::OptimizationLevel Level) {
             MPM.addPass(InstrProfiling(*Options, false));

clang/test/Driver/msan.c

 // REQUIRES: x86-registered-target
 
-// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O1 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O3 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK
-
-// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O1 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O3 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK
-
-// RUN: %clang -target mips64-linux-gnu -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -target mips64el-unknown-linux-gnu -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -target powerpc64-unknown-linux-gnu -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -target powerpc64le-unknown-linux-gnu -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
+// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -O1 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang -O3 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK,O1
+
+// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -O1 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang -O3 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang     -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -O2 -fno-experimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK,O1
+
+// RUN: %clang -target mips64-linux-gnu -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -target mips64el-unknown-linux-gnu -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -target powerpc64-unknown-linux-gnu -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -target powerpc64le-unknown-linux-gnu -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O0
 
 // Verify that -fsanitize=memory and -fsanitize=kernel-memory invoke MSan/KMSAN instrumentation.
 
 // Also check that this works with the new pass manager with and without
 // optimization
-// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O1 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O3 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK
-// FIX: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK
-
-// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory  %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O1 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory  %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory  %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O3 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory  %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK
-// FIX: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK
-// RUN: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK
+// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -O1 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang -O3 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK,O0
+// FIX: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK,O1
+
+// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory  %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -O1 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory  %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory  %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang -O3 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory  %s -S -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK,O0
+// FIX: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto=thin -o - | FileCheck %s --check-prefixes=CHECK,O1
+// RUN: %clang     -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK,O0
+// RUN: %clang -O2 -fexperimental-new-pass-manager -target x86_64-unknown-linux -fsanitize=kernel-memory %s -S -emit-llvm -flto -o - | FileCheck %s --check-prefixes=CHECK,O1
 
 int foo(int *a) { return *a; }
+// O0: = alloca
+// O1-NOT: = alloca
 // CHECK: @__msan_