Pass target triple string in to TargetMachine constructor.

This is not just a matter of passing in the target triple from the module;
currently backends are making decisions based on the build and host
architecture. The goal is to migrate to making these decisions based off of the
triple (in conjunction with the feature string). Thus most clients pass in the
target triple, or the host triple if that is empty.

This has one important change in the way behavior of the JIT and llc.

For the JIT, it was previously selecting the Target based on the host
(naturally), but it was setting the target machine features based on the triple
from the module. Now it is setting the target machine features based on the
triple of the host.

For LLC, -march was previously only used to select the target, the target
machine features were initialized from the module's triple (which may have been
empty). Now the target triple is taken from the module, or the host's triple is
used if that is empty. Then the triple is adjusted to match -march.

The take away is that -march for llc is now used in conjunction with the host
triple to initialize the subtarget. If users want more deterministic behavior
from llc, they should use -mtriple, or set the triple in the input module.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77946 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 20 insertions, 4 deletions

diff --git a/include/llvm/ADT/Triple.h b/include/llvm/ADT/Triple.h
index 7ae2c3033d..5c8244c638 100644
--- a/include/llvm/ADT/Triple.h
+++ b/include/llvm/ADT/Triple.h
@@ -95,7 +95,7 @@ public:
   /// @{
   
   Triple() : Data(""), Arch(InvalidArch) {}
-  explicit Triple(const char *Str) : Data(Str), Arch(InvalidArch) {}
+  explicit Triple(const StringRef &Str) : Data(Str), Arch(InvalidArch) {}
   explicit Triple(const char *ArchStr, const char *VendorStr, const char *OSStr)
     : Data(ArchStr), Arch(InvalidArch) {
     Data += '-';
@@ -212,6 +212,10 @@ public:
   /// getOSTypeName - Get the canonical name for the \arg Kind vendor.
   static const char *getOSTypeName(OSType Kind);
 
+  /// getArchTypeForLLVMName - The canonical type for the given LLVM
+  /// architecture name (e.g., "x86").
+  static ArchType getArchTypeForLLVMName(const StringRef &Str);
+
   /// @}
 };
 
diff --git a/include/llvm/Target/TargetRegistry.h b/include/llvm/Target/TargetRegistry.h
index 9b164ba23e..93991dc687 100644
--- a/include/llvm/Target/TargetRegistry.h
+++ b/include/llvm/Target/TargetRegistry.h
@@ -51,6 +51,7 @@ namespace llvm {
 
     typedef TargetMachine *(*TargetMachineCtorTy)(const Target &,
                                                   const Module &, 
+                                                  const std::string &,
                                                   const std::string &);
     typedef FunctionPass *(*AsmPrinterCtorTy)(formatted_raw_ostream &,
                                               TargetMachine &,
@@ -110,12 +111,21 @@ namespace llvm {
     /// hasAsmParser - Check if this target supports .s parsing.
     bool hasAsmParser() const { return AsmParserCtorFn != 0; }
 
-    /// createTargetMachine - Create a target specific machine implementation.
+    /// createTargetMachine - Create a target specific machine implementation
+    /// for the module \arg M and \arg Triple.
+    ///
+    /// \arg M - This argument is used for some machines to access the target
+    /// data.
+    /// \arg Triple - This argument is used to determine the target machine
+    /// feature set; it should always be provided. Generally this should be
+    /// either the target triple from the module, or the target triple of the
+    /// host if that does not exist.
     TargetMachine *createTargetMachine(const Module &M,
+                                       const std::string &Triple,
                                        const std::string &Features) const {
       if (!TargetMachineCtorFn)
         return 0;
-      return TargetMachineCtorFn(*this, M, Features);
+      return TargetMachineCtorFn(*this, M, Triple, Features);
     }
 
     /// createAsmPrinter - Create a target specific assembly printer pass.
@@ -325,8 +335,9 @@ namespace llvm {
 
   private:
     static TargetMachine *Allocator(const Target &T, const Module &M,
+                                    const std::string &TT,
                                     const std::string &FS) {
-      return new TargetMachineImpl(T, M.getTargetTriple(), FS);
+      return new TargetMachineImpl(T, TT, FS);
     }
   };
 
@@ -338,6 +349,7 @@ namespace llvm {
 
   private:
     static TargetMachine *Allocator(const Target &T, const Module &M,
+                                    const std::string &TT,
                                     const std::string &FS) {
       return new TargetMachineImpl(T, M, FS);
     }