[llvm] c625c17 - [lld][thinlto] Include -mllvm options in the thinlto cache key

[Mircea Trofin via llvm-commits]

Author: Mircea Trofin
Date: 2022-09-19T12:04:17-07:00
New Revision: c625c17b88b4831c99269546fc0ede1667528c6b

URL: https://github.com/llvm/llvm-project/commit/c625c17b88b4831c99269546fc0ede1667528c6b
DIFF: https://github.com/llvm/llvm-project/commit/c625c17b88b4831c99269546fc0ede1667528c6b.diff

LOG: [lld][thinlto] Include -mllvm options in the thinlto cache key

They may modify thinlto optimization.

This patch only extends support for `-mllvm`. There is another way to
pass llvm flags, `-plugin-opt`, but its processing is different and will
be provided in a subsequent patch.

Differential Revision: https://reviews.llvm.org/D134013

Added: 
    

Modified: 
    lld/ELF/Config.h
    lld/ELF/Driver.cpp
    lld/ELF/LTO.cpp
    lld/test/ELF/lto/cache.ll
    llvm/include/llvm/LTO/Config.h
    llvm/lib/LTO/LTO.cpp

Removed: 
    


################################################################################
diff  --git a/lld/ELF/Config.h b/lld/ELF/Config.h
index fcba9216aa966..ccb98a6bc55ea 100644
--- a/lld/ELF/Config.h
+++ b/lld/ELF/Config.h
@@ -152,6 +152,7 @@ struct Configuration {
   llvm::SmallVector<llvm::StringRef, 0> undefined;
   llvm::SmallVector<SymbolVersion, 0> dynamicList;
   llvm::SmallVector<uint8_t, 0> buildIdVector;
+  llvm::SmallVector<llvm::StringRef, 0> mllvmOpts;
   llvm::MapVector<std::pair<const InputSectionBase *, const InputSectionBase *>,
                   uint64_t>
       callGraphProfile;

diff  --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 85d1fb4a749ce..24a301b79be46 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -1347,8 +1347,10 @@ static void readConfigs(opt::InputArgList &args) {
   config->passPlugins = args::getStrings(args, OPT_load_pass_plugins);
 
   // Parse -mllvm options.
-  for (auto *arg : args.filtered(OPT_mllvm))
+  for (auto *arg : args.filtered(OPT_mllvm)) {
     parseClangOption(arg->getValue(), arg->getSpelling());
+    config->mllvmOpts.emplace_back(arg->getValue());
+  }
 
   // --threads= takes a positive integer and provides the default value for
   // --thinlto-jobs=.

diff  --git a/lld/ELF/LTO.cpp b/lld/ELF/LTO.cpp
index a8634c4c61101..60de5bb5f108a 100644
--- a/lld/ELF/LTO.cpp
+++ b/lld/ELF/LTO.cpp
@@ -79,6 +79,8 @@ static lto::Config createConfig() {
   c.Options = initTargetOptionsFromCodeGenFlags();
   c.Options.RelaxELFRelocations = true;
   c.Options.EmitAddrsig = true;
+  for (StringRef C : config->mllvmOpts)
+    c.MllvmArgs.emplace_back(C.str());
 
   // Always emit a section per function/datum with LTO.
   c.Options.FunctionSections = true;

diff  --git a/lld/test/ELF/lto/cache.ll b/lld/test/ELF/lto/cache.ll
index c17dee028479c..9878cd292c7af 100644
--- a/lld/test/ELF/lto/cache.ll
+++ b/lld/test/ELF/lto/cache.ll
@@ -38,8 +38,7 @@
 ; RUN: ls %t.cache | count 3
 
 ; Check that we remove the least recently used file first.
-; RUN: rm -fr %t.cache
-; RUN: mkdir %t.cache
+; RUN: rm -fr %t.cache && mkdir %t.cache
 ; RUN: echo xyz > %t.cache/llvmcache-old
 ; RUN: touch -t 198002011200 %t.cache/llvmcache-old
 ; RUN: echo xyz > %t.cache/llvmcache-newer
@@ -51,6 +50,37 @@
 ; CHECK: llvmcache-newer
 ; CHECK-NOT: llvmcache-old
 
+;; Check that mllvm options participate in the cache key
+; RUN: rm -rf %t.cache && mkdir %t.cache
+; RUN: ld.lld --thinlto-cache-dir=%t.cache -o %t3 %t2.o %t.o
+; RUN: ls %t.cache | count 3
+; RUN: ld.lld --thinlto-cache-dir=%t.cache -o %t3 %t2.o %t.o -mllvm -enable-ml-inliner=default
+; RUN: ls %t.cache | count 5
+
+;; Adding another option resuls in 2 more cache entries
+; RUN: rm -rf %t.cache && mkdir %t.cache
+; RUN: ld.lld --thinlto-cache-dir=%t.cache -o %t3 %t2.o %t.o
+; RUN: ls %t.cache | count 3
+; RUN: ld.lld --thinlto-cache-dir=%t.cache -o %t3 %t2.o %t.o -mllvm -enable-ml-inliner=default
+; RUN: ls %t.cache | count 5
+; RUN: ld.lld --thinlto-cache-dir=%t.cache -o %t3 %t2.o %t.o -mllvm -enable-ml-inliner=default -mllvm -max-devirt-iterations=1
+; RUN: ls %t.cache | count 7
+
+;; Changing order may matter - e.g. if overriding -mllvm options - so we get 2 more entries
+; RUN: ld.lld --thinlto-cache-dir=%t.cache -o %t3 %t2.o %t.o -mllvm -max-devirt-iterations=1 -mllvm -enable-ml-inliner=default
+; RUN: ls %t.cache | count 9
+
+;; Going back to a pre-cached order doesn't create more entries.
+; RUN: ld.lld --thinlto-cache-dir=%t.cache -o %t3 %t2.o %t.o -mllvm -enable-ml-inliner=default -mllvm -max-devirt-iterations=1
+; RUN: ls %t.cache | count 9
+
+;; Different flag values matter
+; RUN: rm -rf %t.cache && mkdir %t.cache
+; RUN: ld.lld --thinlto-cache-dir=%t.cache -o %t3 %t2.o %t.o -mllvm -enable-ml-inliner=default -mllvm -max-devirt-iterations=2
+; RUN: ls %t.cache | count 3
+; RUN: ld.lld --thinlto-cache-dir=%t.cache -o %t3 %t2.o %t.o -mllvm -enable-ml-inliner=default -mllvm -max-devirt-iterations=1
+; RUN: ls %t.cache | count 5
+
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 

diff  --git a/llvm/include/llvm/LTO/Config.h b/llvm/include/llvm/LTO/Config.h
index b2ed8e60bd779..4b50c7cce8568 100644
--- a/llvm/include/llvm/LTO/Config.h
+++ b/llvm/include/llvm/LTO/Config.h
@@ -47,6 +47,7 @@ struct Config {
   std::string CPU;
   TargetOptions Options;
   std::vector<std::string> MAttrs;
+  std::vector<std::string> MllvmArgs;
   std::vector<std::string> PassPlugins;
   /// For adding passes that run right before codegen.
   std::function<void(legacy::PassManager &)> PreCodeGenPassesHook;

diff  --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp
index cc7be24c1dbdd..10ca98f0f87d9 100644
--- a/llvm/lib/LTO/LTO.cpp
+++ b/llvm/lib/LTO/LTO.cpp
@@ -131,6 +131,8 @@ void llvm::computeLTOCacheKey(
     AddUnsigned(*Conf.CodeModel);
   else
     AddUnsigned(-1);
+  for (const auto &S : Conf.MllvmArgs)
+    AddString(S);
   AddUnsigned(Conf.CGOptLevel);
   AddUnsigned(Conf.CGFileType);
   AddUnsigned(Conf.OptLevel);