Use the 'target-features' and 'target-cpu' attributes to reset the subtarget features.

If two functions require different features (e.g., `-mno-sse' vs. `-msse') then
we want to honor that, especially during LTO. We can do that by resetting the
subtarget's features depending upon the 'target-feature' attribute.

llvm-svn: 175314

1 files changed, 7 insertions, 1 deletions

diff --git a/llvm/lib/Target/X86/X86Subtarget.h b/llvm/lib/Target/X86/X86Subtarget.h
index 1466041712e..d1c706725de 100644
--- a/llvm/lib/Target/X86/X86Subtarget.h
+++ b/llvm/lib/Target/X86/X86Subtarget.h
@@ -168,11 +168,13 @@ protected:
   InstrItineraryData InstrItins;
 
 private:
+  /// StackAlignOverride - Override the stack alignment.
+  unsigned StackAlignOverride;
+
   /// In64BitMode - True if compiling for 64-bit, false for 32-bit.
   bool In64BitMode;
 
 public:
-
   /// This constructor initializes the data members to match that
   /// of the specified triple.
   ///
@@ -197,6 +199,10 @@ public:
   /// instruction.
   void AutoDetectSubtargetFeatures();
 
+  /// \brief Reset the features for the X86 target.
+  virtual void resetSubtargetFeatures(const MachineFunction *MF);
+  void resetSubtargetFeatures(StringRef CPU, StringRef FS);
+
   /// Is this x86_64? (disregarding specific ABI / programming model)
   bool is64Bit() const {
     return In64BitMode;