[sil-llvm-gen] Add support for emitting IR before LLVM optimizations run.

Specifically, I renamed the old llvm-as which printed with optimization as
llvm-as-opt and made llvm-as just test IRGen. That is really the true reason
that I created this utility many years ago: to test how IRGen lowers specific
SIL instruction sequences. How LLVM optimizes such sequences once lowered is a
different problem. I updated the one test that used sil-llvm-gen and required
optimizations to use llvm-as-opt so that the tests output did not change.

(cherry picked from commit 5c8a95f)

Author: gottesmm

lib/DriverTool/sil_llvm_gen_main.cpp

@@ -96,17 +96,19 @@ struct SILLLVMGenOptions {
   llvm::cl::opt<bool>
     PerformWMO = llvm::cl::opt<bool>("wmo", llvm::cl::desc("Enable whole-module optimizations"));
 
-  llvm::cl::opt<IRGenOutputKind>
-    OutputKind = llvm::cl::opt<IRGenOutputKind>(
+  llvm::cl::opt<IRGenOutputKind> OutputKind = llvm::cl::opt<IRGenOutputKind>(
       "output-kind", llvm::cl::desc("Type of output to produce"),
-      llvm::cl::values(clEnumValN(IRGenOutputKind::LLVMAssemblyAfterOptimization,
-                                  "llvm-as", "Emit llvm assembly"),
-                       clEnumValN(IRGenOutputKind::LLVMBitcode, "llvm-bc",
-                                  "Emit llvm bitcode"),
-                       clEnumValN(IRGenOutputKind::NativeAssembly, "as",
-                                  "Emit native assembly"),
-                       clEnumValN(IRGenOutputKind::ObjectFile, "object",
-                                  "Emit an object file")),
+      llvm::cl::values(
+          clEnumValN(IRGenOutputKind::LLVMAssemblyBeforeOptimization, "llvm-as",
+                     "Emit llvm assembly before optimization"),
+          clEnumValN(IRGenOutputKind::LLVMAssemblyAfterOptimization,
+                     "llvm-as-opt", "Emit llvm assembly after optimization"),
+          clEnumValN(IRGenOutputKind::LLVMBitcode, "llvm-bc",
+                     "Emit llvm bitcode"),
+          clEnumValN(IRGenOutputKind::NativeAssembly, "as",
+                     "Emit native assembly"),
+          clEnumValN(IRGenOutputKind::ObjectFile, "object",
+                     "Emit an object file")),
       llvm::cl::init(IRGenOutputKind::ObjectFile));
 
   llvm::cl::opt<bool>
@@ -217,16 +219,26 @@ int sil_llvm_gen_main(ArrayRef<const char *> argv, void *MainAddr) {
       return IRGenDescriptor::forWholeModule(
           mod, Opts, TBDOpts, SILOpts, SILTypes,
           /*SILMod*/ nullptr, moduleName, PSPs);
-    } else {
-      return IRGenDescriptor::forFile(
-          mod->getFiles()[0], Opts, TBDOpts, SILOpts, SILTypes,
-          /*SILMod*/ nullptr, moduleName, PSPs, /*discriminator*/ "");
     }
+
+    return IRGenDescriptor::forFile(
+        mod->getFiles()[0], Opts, TBDOpts, SILOpts, SILTypes,
+        /*SILMod*/ nullptr, moduleName, PSPs, /*discriminator*/ "");
   };
 
   auto &eval = CI.getASTContext().evaluator;
   auto desc = getDescriptor();
   desc.out = &outFile->getOS();
+
+  if (options.OutputKind == IRGenOutputKind::LLVMAssemblyBeforeOptimization) {
+    auto generatedMod = evaluateOrFatal(eval, IRGenRequest{desc});
+    if (!generatedMod)
+      return 1;
+
+    generatedMod.getModule()->print(*outFile, nullptr);
+    return 0;
+  }
+
   auto generatedMod = evaluateOrFatal(eval, OptimizedIRRequest{desc});
   if (!generatedMod)
     return 1;

test/sil-llvm-gen/alloc.sil

@@ -1,12 +1,12 @@
-// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as -target x86_64-apple-macosx10.9 -module-name main %s -o - | %FileCheck %s
-// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as -target i386-apple-ios7.0 %s -module-name main -o - | %FileCheck %s
-// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as -target x86_64-apple-ios7.0 %s -module-name main -o - | %FileCheck %s
-// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as -target armv7-apple-ios7.0 %s -module-name main -o - | %FileCheck %s
-// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as -target arm64-apple-ios7.0 %s -module-name main -o - | %FileCheck %s
-// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as -target x86_64-unknown-linux-gnu %s -module-name main -o - | %FileCheck %s
+// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as-opt -target x86_64-apple-macosx10.9 -module-name main %s -o - | %FileCheck %s
+// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as-opt -target i386-apple-ios7.0 %s -module-name main -o - | %FileCheck %s
+// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as-opt -target x86_64-apple-ios7.0 %s -module-name main -o - | %FileCheck %s
+// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as-opt -target armv7-apple-ios7.0 %s -module-name main -o - | %FileCheck %s
+// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as-opt -target arm64-apple-ios7.0 %s -module-name main -o - | %FileCheck %s
+// RUN: %sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as-opt -target x86_64-unknown-linux-gnu %s -module-name main -o - | %FileCheck %s
 
 // Use this testfile to check if the `swift-frontend -sil-llvm-gen` option works.
-// RUN: %swift_frontend_plain -sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as -target x86_64-apple-macosx10.9 -module-name main %s -o - | %FileCheck %s
+// RUN: %swift_frontend_plain -sil-llvm-gen -disable-legacy-type-info -output-kind=llvm-as-opt -target x86_64-apple-macosx10.9 -module-name main %s -o - | %FileCheck %s
 
 // REQUIRES: CODEGENERATOR=X86
 // REQUIRES: CODEGENERATOR=ARM