Merge pull request #1392 from swiftix/wip-prespecializations-module

Move pre-specializations of popular types away from the stdlib to reduce the stdlib code size.

Author: swiftix

include/swift/Strings.h

@@ -27,6 +27,8 @@ namespace swift {
   static const char LLVM_IR_EXTENSION[] = "ll";
   /// The name of the standard library, which is a reserved module name.
   static const char STDLIB_NAME[] = "Swift";
+  /// The name of the Onone support library, which is a reserved module name.
+  static const char SWIFT_ONONE_SUPPORT[] = "SwiftOnoneSupport";
   /// The name of the SwiftShims module, which contains private stdlib decls.
   static const char SWIFT_SHIMS_NAME[] = "SwiftShims";
   /// The prefix of module names used by LLDB to capture Swift expressions

lib/Frontend/Frontend.cpp

@@ -273,6 +273,19 @@ void CompilerInstance::performSema() {
       return;
     }
 
+    const auto &silOptions = Invocation.getSILOptions();
+    if ((silOptions.Optimization <= SILOptions::SILOptMode::None &&
+         (options.RequestedAction == FrontendOptions::EmitObject ||
+          options.RequestedAction == FrontendOptions::Immediate)) ||
+        (silOptions.Optimization == SILOptions::SILOptMode::None &&
+         options.RequestedAction >= FrontendOptions::EmitSILGen)) {
+      // Implicitly import the SwiftOnoneSupport module in non-optimized
+      // builds. This allows for use of popular specialized functions
+      // from the standard library, which makes the non-optimized builds
+      // execute much faster.
+      Invocation.getFrontendOptions()
+                .ImplicitImportModuleNames.push_back(SWIFT_ONONE_SUPPORT);
+    }
     break;
   }
   }

lib/SILOptimizer/Utils/Generics.cpp

@@ -304,7 +304,7 @@ static bool cacheSpecialization(SILModule &M, SILFunction *F) {
 
   if (M.getOptions().Optimization >= SILOptions::SILOptMode::Optimize &&
       F->getLinkage() != SILLinkage::Public &&
-      F->getModule().getSwiftModule()->getName().str() == STDLIB_NAME) {
+      F->getModule().getSwiftModule()->getName().str() == SWIFT_ONONE_SUPPORT) {
     if (F->getLinkage() != SILLinkage::Public &&
         isWhitelistedSpecialization(F->getName())) {
 
@@ -368,7 +368,8 @@ SILFunction *swift::getExistingSpecialization(SILModule &M,
     assert((Specialization->isExternalDeclaration() ||
             convertExternalDefinitionIntoDeclaration(Specialization)) &&
            "Could not remove body of the found specialization");
-    if (!convertExternalDefinitionIntoDeclaration(Specialization)) {
+    if (!Specialization->isExternalDeclaration() &&
+        !convertExternalDefinitionIntoDeclaration(Specialization)) {
       DEBUG(
           llvm::dbgs() << "Could not remove body of specialization: "
                        << FunctionName << '\n');

lib/Serialization/SerializeSIL.cpp

@@ -13,6 +13,7 @@
 #define DEBUG_TYPE "sil-serialize"
 #include "SILFormat.h"
 #include "Serialization.h"
+#include "swift/Strings.h"
 #include "swift/AST/Module.h"
 #include "swift/SIL/SILArgument.h"
 #include "swift/SIL/SILModule.h"
@@ -1682,8 +1683,16 @@ void SILSerializer::writeSILBlock(const SILModule *SILMod) {
   // Go through all the SILFunctions in SILMod and write out any
   // mandatory function bodies.
   for (const SILFunction &F : *SILMod) {
-    if (shouldEmitFunctionBody(F) || ShouldSerializeAll)
+    if (shouldEmitFunctionBody(F) || ShouldSerializeAll) {
+      if (F.getModule().getSwiftModule()->getNameStr() == SWIFT_ONONE_SUPPORT) {
+        // Serialize only the declarations so that it is possible to check the
+        // existance of this function later.
+        // FIXME: SILLinker::lookupFunction does not work with functions having
+        // empty bodies, otherwise we could have serialized only declarations.
+        //writeSILFunction(F, true);
+      }
       writeSILFunction(F);
+    }
   }
 
   if (ShouldSerializeAll)

stdlib/public/CMakeLists.txt

@@ -26,6 +26,7 @@ if(SWIFT_BUILD_STDLIB)
   add_subdirectory(runtime)
   add_subdirectory(stubs)
   add_subdirectory(core)
+  add_subdirectory(SwiftOnoneSupport)
 endif()
 
 if(CMAKE_SYSTEM_NAME STREQUAL "Darwin")

stdlib/public/SwiftOnoneSupport/CMakeLists.txt

@@ -0,0 +1,6 @@
+add_swift_library(swiftSwiftOnoneSupport SHARED IS_STDLIB
+  # This file should be listed the first.  Module name is inferred from the
+  # filename.
+  SwiftOnoneSupport.swift
+  SWIFT_COMPILE_FLAGS ${STDLIB_SIL_SERIALIZE_ALL}
+  INSTALL_IN_COMPONENT stdlib)

stdlib/public/core/Prespecialized.swift renamed to stdlib/public/SwiftOnoneSupport/SwiftOnoneSupport.swift

@@ -126,7 +126,6 @@ set(SWIFTLIB_SOURCES
   Tuple.swift.gyb
   VarArgs.swift
   Zip.swift
-  Prespecialized.swift
   )
 
 set(swift_core_link_flags)

stdlib/public/core/CMakeLists.txt

@@ -1,16 +1,16 @@
-// RUN: %target-build-swift -emit-sib %s -o %t.sib
+// RUN: %target-build-swift -Onone -emit-sib %s -o %t.sib
 // RUN: %target-build-swift %t.sib -o %t
 // RUN: %target-run %t | FileCheck %s
 
-// RUN: %target-build-swift -c %t.sib -o %t.o
+// RUN: %target-build-swift -Onone -c %t.sib -o %t.o
 // RUN: %target-build-swift %t.o -o %t
 // RUN: %target-run %t | FileCheck %s
 
-// RUN: %target-build-swift -emit-sibgen %s -o %t.sib
+// RUN: %target-build-swift -Onone -emit-sibgen %s -o %t.sib
 // RUN: %target-build-swift %t.sib -o %t
 // RUN: %target-run %t | FileCheck %s
 
-// RUN: %target-build-swift -c %t.sib -o %t.o
+// RUN: %target-build-swift -Onone -c %t.sib -o %t.o
 // RUN: %target-build-swift %t.o -o %t
 // RUN: %target-run %t | FileCheck %s
 // REQUIRES: executable_test