[llvm] r176986 - Reset some of the target options which affect code generation.

[Bill Wendling]

Author: void
Date: Wed Mar 13 17:26:59 2013
New Revision: 176986

URL: http://llvm.org/viewvc/llvm-project?rev=176986&view=rev
Log:
Reset some of the target options which affect code generation.

This doesn't reset all of the target options within the TargetOptions
object. This is because some of those are ABI-specific and must be determined if
it's okay to change those on the fly.

Modified:
    llvm/trunk/include/llvm/Target/TargetMachine.h
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
    llvm/trunk/lib/Target/TargetMachine.cpp

Modified: llvm/trunk/include/llvm/Target/TargetMachine.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetMachine.h?rev=176986&r1=176985&r2=176986&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Target/TargetMachine.h (original)
+++ llvm/trunk/include/llvm/Target/TargetMachine.h Wed Mar 13 17:26:59 2013
@@ -95,7 +95,10 @@ public:
   /// a reference to that target's TargetSubtargetInfo-derived member variable.
   virtual const TargetSubtargetInfo *getSubtargetImpl() const { return 0; }
 
-  TargetOptions Options;
+  mutable TargetOptions Options;
+
+  /// \brief Reset the target options based on the function's attributes.
+  void resetTargetOptions(const MachineFunction *MF) const;
 
   // Interfaces to the major aspects of target machine information:
   // -- Instruction opcode and operand information

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp?rev=176986&r1=176985&r2=176986&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp Wed Mar 13 17:26:59 2013
@@ -362,6 +362,7 @@ bool SelectionDAGISel::runOnMachineFunct
   TargetSubtargetInfo &ST =
     const_cast<TargetSubtargetInfo&>(TM.getSubtarget<TargetSubtargetInfo>());
   ST.resetSubtargetFeatures(MF);
+  TM.resetTargetOptions(MF);
 
   DEBUG(dbgs() << "\n\n\n=== " << Fn.getName() << "\n");
 

Modified: llvm/trunk/lib/Target/TargetMachine.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/TargetMachine.cpp?rev=176986&r1=176985&r2=176986&view=diff
==============================================================================
--- llvm/trunk/lib/Target/TargetMachine.cpp (original)
+++ llvm/trunk/lib/Target/TargetMachine.cpp Wed Mar 13 17:26:59 2013
@@ -12,6 +12,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalAlias.h"
 #include "llvm/IR/GlobalValue.h"
 #include "llvm/IR/GlobalVariable.h"
@@ -61,6 +63,30 @@ TargetMachine::~TargetMachine() {
   delete AsmInfo;
 }
 
+/// \brief Reset the target options based on the function's attributes.
+void TargetMachine::resetTargetOptions(const MachineFunction *MF) const {
+  const Function *F = MF->getFunction();
+  TargetOptions &TO = MF->getTarget().Options;
+  
+#define RESET_OPTION(X, Y)                                              \
+  do {                                                                  \
+    if (F->hasFnAttribute(Y))                                           \
+      TO.X =                                                            \
+        (F->getAttributes().                                            \
+           getAttribute(AttributeSet::FunctionIndex,                    \
+                        Y).getValueAsString() == "true");               \
+  } while (0)
+
+  RESET_OPTION(NoFramePointerElim, "no-frame-pointer-elim");
+  RESET_OPTION(NoFramePointerElimNonLeaf, "no-frame-pointer-elim-non-leaf");
+  RESET_OPTION(LessPreciseFPMADOption, "less-precise-fpmad");
+  RESET_OPTION(UnsafeFPMath, "unsafe-fp-math");
+  RESET_OPTION(NoInfsFPMath, "no-infs-fp-math");
+  RESET_OPTION(NoNaNsFPMath, "no-nans-fp-math");
+  RESET_OPTION(UseSoftFloat, "use-soft-float");
+  RESET_OPTION(DisableTailCalls, "disable-tail-calls");
+}
+
 /// getRelocationModel - Returns the code generation relocation model. The
 /// choices are static, PIC, and dynamic-no-pic, and target default.
 Reloc::Model TargetMachine::getRelocationModel() const {