Use fast regalloc and codegen at OptLevel=0.

Author: cixtor

src/comp/back/link.rs

@@ -138,6 +138,30 @@ mod write {
             let int LLVMAssemblyFile = 0;
             let int LLVMObjectFile = 1;
             let int LLVMNullFile = 2;
+            let int LLVMOptNone = 0;        // -O0
+            let int LLVMOptLess = 1;        // -O1
+            let int LLVMOptDefault = 2;     // -O2, -Os
+            let int LLVMOptAggressive = 3;  // -O3
+
+            auto CodeGenOptLevel;
+            alt (opts.optimize) {
+                case (0u) {
+                     CodeGenOptLevel = LLVMOptNone;
+                }
+                case (1u) {
+                     CodeGenOptLevel = LLVMOptLess;
+                }
+                case (2u) {
+                     CodeGenOptLevel = LLVMOptDefault;
+                }
+                case (3u) {
+                     CodeGenOptLevel = LLVMOptAggressive;
+                }
+                case (_) {
+                     fail;
+                }
+            }
+
             auto FileType;
             if (opts.output_type == output_type_object ||
                     opts.output_type == output_type_exe) {
@@ -159,7 +183,8 @@ mod write {
                     llvm::LLVMRustWriteOutputFile(pm.llpm, llmod,
                                                   str::buf(triple),
                                                   str::buf(output),
-                                                  LLVMAssemblyFile);
+                                                  LLVMAssemblyFile,
+                                                  CodeGenOptLevel);
                 }
 
                 // Save the object file for -c or --save-temps alone
@@ -170,7 +195,8 @@ mod write {
                     llvm::LLVMRustWriteOutputFile(pm.llpm, llmod,
                                                   str::buf(triple),
                                                   str::buf(output),
-                                                  LLVMObjectFile);
+                                                  LLVMObjectFile,
+                                                  CodeGenOptLevel);
                 }
             } else {
                 // If we aren't saving temps then just output the file
@@ -179,7 +205,8 @@ mod write {
                 auto triple = x86::get_target_triple();
                 llvm::LLVMRustWriteOutputFile(pm.llpm, llmod,
                                               str::buf(triple),
-                                              str::buf(output), FileType);
+                                              str::buf(output), FileType,
+                                              CodeGenOptLevel);
             }
             // Clean up and return
 

src/comp/lib/llvm.rs

@@ -856,7 +856,7 @@ native mod llvm = "rustllvm" {
     /* FIXME: The FileType is an enum.*/
     fn LLVMRustWriteOutputFile(PassManagerRef PM, ModuleRef M,
                                sbuf Triple, sbuf Output,
-                               int FileType);
+                               int FileType, int OptLevel);
 
     /** Returns a string describing the last error caused by an LLVMRust*
         call. */

src/rustllvm/RustWrapper.cpp

@@ -53,11 +53,6 @@ extern "C" void LLVMAddStandardModulePasses(LLVMPassManagerRef PM,
 int *RustHackToFetchPassesO = (int*)LLVMAddBasicAliasAnalysisPass;
 int *RustHackToFetchPasses2O = (int*)LLVMAddStandardModulePasses;
 
-enum LLVMCodeGenFileType {
-  LLVMAssemblyFile,
-  LLVMObjectFile,
-  LLVMNullFile         // Do not emit any output.
-};
 
 extern "C" bool LLVMLinkModules(LLVMModuleRef Dest, LLVMModuleRef Src) {
   static std::string err;
@@ -77,7 +72,8 @@ extern "C" void LLVMRustWriteOutputFile(LLVMPassManagerRef PMR,
                                         LLVMModuleRef M,
                                         const char *triple,
                                         const char *path,
-                                        LLVMCodeGenFileType FileType) {
+                                        TargetMachine::CodeGenFileType FileType,
+                                        CodeGenOpt::Level OptLevel) {
 
   // Set compilation options.
   llvm::NoFramePointerElim = true;
@@ -91,16 +87,14 @@ extern "C" void LLVMRustWriteOutputFile(LLVMPassManagerRef PMR,
   std::string FeaturesStr;
   TargetMachine *Target = TheTarget->createTargetMachine(triple, FeaturesStr);
   bool NoVerify = false;
-  CodeGenOpt::Level OLvl = CodeGenOpt::Default;
   PassManager *PM = unwrap<PassManager>(PMR);
   std::string ErrorInfo;
   raw_fd_ostream OS(path, ErrorInfo,
                     raw_fd_ostream::F_Binary);
   formatted_raw_ostream FOS(OS);
-  TargetMachine::CodeGenFileType FileType2 =
-    static_cast<TargetMachine::CodeGenFileType>(FileType);
 
-  bool foo = Target->addPassesToEmitFile(*PM, FOS, FileType2, OLvl, NoVerify);
+  bool foo = Target->addPassesToEmitFile(*PM, FOS, FileType, OptLevel,
+                                         NoVerify);
   assert(!foo);
   (void)foo;
   PM->run(*unwrap(M));