LTO: Disable extra verify runs in release builds

The verifier currently runs three times in LTO: (1) after parsing, (2)
at the beginning of the optimization pipeline, and (3) at the end of it.

The first run is important, since we're not sure where the bitcode comes
from and it's nice to validate it, but in release builds the extra runs
aren't appropriate.

This commit:
  - Allows these runs to be disabled in LTOCodeGenerator.
  - Adds command-line options to llvm-lto.
  - Adds command-line options to libLTO.dylib, and disables the verifier
    by default in release builds (based on NDEBUG).

This shaves about 3.5% off the runtime of ld64 when linking
verify-uselistorder with -flto -g.

rdar://22509081

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247729 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/LTO/LTOCodeGenerator.h b/include/llvm/LTO/LTOCodeGenerator.h
index cf31bda6dc1b8cc5ffe174f8bd02c6841e1a6609..f69dfb1e7f6c1ce255df6142e24704f12e4c682b 100644 (file)
--- a/include/llvm/LTO/LTOCodeGenerator.h
+++ b/include/llvm/LTO/LTOCodeGenerator.h
@@ -110,9 +110,9 @@ struct LTOCodeGenerator {
   /// \note It is up to the linker to remove the intermediate object file.  Do
   /// not try to remove the object file in LTOCodeGenerator's destructor as we
   /// don't who (LTOCodeGenerator or the obj file) will last longer.
-  bool compile_to_file(const char **Name, bool DisableInline,
-                       bool DisableGVNLoadPRE, bool DisableVectorization,
-                       std::string &ErrMsg);
+  bool compile_to_file(const char **Name, bool DisableVerify,
+                       bool DisableInline, bool DisableGVNLoadPRE,
+                       bool DisableVectorization, std::string &ErrMsg);
 
   /// As with compile_to_file(), this function compiles the merged module into
   /// single object file. Instead of returning the object-file-path to the
@@ -120,13 +120,13 @@ struct LTOCodeGenerator {
   /// to the caller. This function should delete intermediate object file once
   /// its content is brought to memory. Return NULL if the compilation was not
   /// successful.
-  std::unique_ptr<MemoryBuffer> compile(bool DisableInline,
+  std::unique_ptr<MemoryBuffer> compile(bool DisableVerify, bool DisableInline,
                                         bool DisableGVNLoadPRE,
                                         bool DisableVectorization,
                                         std::string &errMsg);
 
   /// Optimizes the merged module.  Returns true on success.
-  bool optimize(bool DisableInline, bool DisableGVNLoadPRE,
+  bool optimize(bool DisableVerify, bool DisableInline, bool DisableGVNLoadPRE,
                 bool DisableVectorization, std::string &ErrMsg);
 
   /// Compiles the merged optimized module into a single object file. It brings

diff --git a/lib/LTO/LTOCodeGenerator.cpp b/lib/LTO/LTOCodeGenerator.cpp
index 98266c32d90f88f3f97fd8bcbc740a9f9425af4c..8dcc53c8033ac870e1e57e33f9136cba93f0d097 100644 (file)
--- a/lib/LTO/LTOCodeGenerator.cpp
+++ b/lib/LTO/LTOCodeGenerator.cpp
@@ -265,20 +265,24 @@ LTOCodeGenerator::compileOptimized(std::string &ErrMsg) {
   return std::move(*BufferOrErr);
 }
 
-bool LTOCodeGenerator::compile_to_file(const char **Name, bool DisableInline,
+bool LTOCodeGenerator::compile_to_file(const char **Name, bool DisableVerify,
+                                       bool DisableInline,
                                        bool DisableGVNLoadPRE,
                                        bool DisableVectorization,
                                        std::string &ErrMsg) {
-  if (!optimize(DisableInline, DisableGVNLoadPRE, DisableVectorization, ErrMsg))
+  if (!optimize(DisableVerify, DisableInline, DisableGVNLoadPRE,
+                DisableVectorization, ErrMsg))
     return false;
 
   return compileOptimizedToFile(Name, ErrMsg);
 }
 
 std::unique_ptr<MemoryBuffer>
-LTOCodeGenerator::compile(bool DisableInline, bool DisableGVNLoadPRE,
-                          bool DisableVectorization, std::string &ErrMsg) {
-  if (!optimize(DisableInline, DisableGVNLoadPRE, DisableVectorization, ErrMsg))
+LTOCodeGenerator::compile(bool DisableVerify, bool DisableInline,
+                          bool DisableGVNLoadPRE, bool DisableVectorization,
+                          std::string &ErrMsg) {
+  if (!optimize(DisableVerify, DisableInline, DisableGVNLoadPRE,
+                DisableVectorization, ErrMsg))
     return nullptr;
 
   return compileOptimized(ErrMsg);
@@ -459,7 +463,8 @@ void LTOCodeGenerator::applyScopeRestrictions() {
 }
 
 /// Optimize merged modules using various IPO passes
-bool LTOCodeGenerator::optimize(bool DisableInline, bool DisableGVNLoadPRE,
+bool LTOCodeGenerator::optimize(bool DisableVerify, bool DisableInline,
+                                bool DisableGVNLoadPRE,
                                 bool DisableVectorization,
                                 std::string &ErrMsg) {
   if (!this->determineTarget(ErrMsg))
@@ -486,8 +491,8 @@ bool LTOCodeGenerator::optimize(bool DisableInline, bool DisableGVNLoadPRE,
     PMB.Inliner = createFunctionInliningPass();
   PMB.LibraryInfo = new TargetLibraryInfoImpl(TargetTriple);
   PMB.OptLevel = OptLevel;
-  PMB.VerifyInput = true;
-  PMB.VerifyOutput = true;
+  PMB.VerifyInput = !DisableVerify;
+  PMB.VerifyOutput = !DisableVerify;
 
   PMB.populateLTOPassManager(passes);
 

diff --git a/test/LTO/X86/disable-verify.ll b/test/LTO/X86/disable-verify.ll
new file mode 100644 (file)
index 0000000..5d2508a
--- /dev/null
+++ b/test/LTO/X86/disable-verify.ll
@@ -0,0 +1,18 @@
+; RUN: llvm-as < %s >%t.bc
+; RUN: llvm-lto -debug-pass=Arguments -exported-symbol=_f -o /dev/null %t.bc 2>&1 -disable-verify | FileCheck %s
+; RUN: llvm-lto -debug-pass=Arguments -exported-symbol=_f -o /dev/null %t.bc 2>&1 | FileCheck %s -check-prefix=VERIFY
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.10.0"
+
+; -disable-verify should disable verification from the optimization pipeline.
+; CHECK: Pass Arguments: -verify -internalize
+; CHECK-NOT: -verify
+
+; VERIFY: Pass Arguments: -verify -internalize
+; VERIFY: Pass Arguments: {{.*}} -verify {{.*}} -verify
+
+define void @f() {
+entry:
+  ret void
+}

diff --git a/tools/llvm-lto/llvm-lto.cpp b/tools/llvm-lto/llvm-lto.cpp
index cdb1bcaa6bca388d737f24dcc533bb57222258cf..50680ccb8ab3a21a15665ad12dac4020a08c19f3 100644 (file)
--- a/tools/llvm-lto/llvm-lto.cpp
+++ b/tools/llvm-lto/llvm-lto.cpp
@@ -36,6 +36,10 @@ OptLevel("O",
          cl::ZeroOrMore,
          cl::init('2'));
 
+static cl::opt<bool> DisableVerify(
+    "disable-verify", cl::init(false),
+    cl::desc("Do not run the verifier during the optimization pipeline"));
+
 static cl::opt<bool>
 DisableInline("disable-inlining", cl::init(false),
   cl::desc("Do not run the inliner pass"));
@@ -248,7 +252,7 @@ int main(int argc, char **argv) {
 
   if (!OutputFilename.empty()) {
     std::string ErrorInfo;
-    if (!CodeGen.optimize(DisableInline, DisableGVNLoadPRE,
+    if (!CodeGen.optimize(DisableVerify, DisableInline, DisableGVNLoadPRE,
                           DisableLTOVectorization, ErrorInfo)) {
       errs() << argv[0] << ": error optimizing the code: " << ErrorInfo << "\n";
       return 1;
@@ -285,7 +289,7 @@ int main(int argc, char **argv) {
 
     std::string ErrorInfo;
     const char *OutputName = nullptr;
-    if (!CodeGen.compile_to_file(&OutputName, DisableInline,
+    if (!CodeGen.compile_to_file(&OutputName, DisableVerify, DisableInline,
                                  DisableGVNLoadPRE, DisableLTOVectorization,
                                  ErrorInfo)) {
       errs() << argv[0]

diff --git a/tools/lto/lto.cpp b/tools/lto/lto.cpp
index 8f62929b326bb66dae91008b3d2ce8edd9fb2532..62675081464c0289b90b9bf4c0bc78b584cfa4c4 100644 (file)
--- a/tools/lto/lto.cpp
+++ b/tools/lto/lto.cpp
@@ -43,6 +43,16 @@ static cl::opt<bool>
 DisableLTOVectorization("disable-lto-vectorization", cl::init(false),
   cl::desc("Do not run loop or slp vectorization during LTO"));
 
+#ifdef NDEBUG
+static bool VerifyByDefault = false;
+#else
+static bool VerifyByDefault = true;
+#endif
+
+static cl::opt<bool> DisableVerify(
+    "disable-llvm-verifier", cl::init(!VerifyByDefault),
+    cl::desc("Don't run the LLVM verifier during the optimization pipeline"));
+
 // Holds most recent error string.
 // *** Not thread safe ***
 static std::string sLastErrorString;
@@ -321,8 +331,9 @@ bool lto_codegen_write_merged_modules(lto_code_gen_t cg, const char *path) {
 const void *lto_codegen_compile(lto_code_gen_t cg, size_t *length) {
   maybeParseOptions(cg);
   LibLTOCodeGenerator *CG = unwrap(cg);
-  CG->NativeObjectFile = CG->compile(DisableInline, DisableGVNLoadPRE,
-                                     DisableLTOVectorization, sLastErrorString);
+  CG->NativeObjectFile =
+      CG->compile(DisableVerify, DisableInline, DisableGVNLoadPRE,
+                  DisableLTOVectorization, sLastErrorString);
   if (!CG->NativeObjectFile)
     return nullptr;
   *length = CG->NativeObjectFile->getBufferSize();
@@ -331,9 +342,8 @@ const void *lto_codegen_compile(lto_code_gen_t cg, size_t *length) {
 
 bool lto_codegen_optimize(lto_code_gen_t cg) {
   maybeParseOptions(cg);
-  return !unwrap(cg)->optimize(DisableInline,
-                               DisableGVNLoadPRE, DisableLTOVectorization,
-                               sLastErrorString);
+  return !unwrap(cg)->optimize(DisableVerify, DisableInline, DisableGVNLoadPRE,
+                               DisableLTOVectorization, sLastErrorString);
 }
 
 const void *lto_codegen_compile_optimized(lto_code_gen_t cg, size_t *length) {
@@ -349,7 +359,7 @@ const void *lto_codegen_compile_optimized(lto_code_gen_t cg, size_t *length) {
 bool lto_codegen_compile_to_file(lto_code_gen_t cg, const char **name) {
   maybeParseOptions(cg);
   return !unwrap(cg)->compile_to_file(
-      name, DisableInline, DisableGVNLoadPRE,
+      name, DisableVerify, DisableInline, DisableGVNLoadPRE,
       DisableLTOVectorization, sLastErrorString);
 }