From: Bill Wendling <isanbard@gmail.com>
Date: Wed, 13 Mar 2013 22:26:59 +0000 (+0000)
Subject: Reset some of the target options which affect code generation.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4cb1f5f4064f2eec1420dc30bf32ac54bd40e222;p=oota-llvm.git

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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176986 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Target/TargetMachine.h b/include/llvm/Target/TargetMachine.h
index 35cf20a7028..66f3a3c71b6 100644
--- a/include/llvm/Target/TargetMachine.h
+++ b/include/llvm/Target/TargetMachine.h
@@ -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
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 39a1f8a3d0d..c3b6276a8dc 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -362,6 +362,7 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
   TargetSubtargetInfo &ST =
     const_cast<TargetSubtargetInfo&>(TM.getSubtarget<TargetSubtargetInfo>());
   ST.resetSubtargetFeatures(MF);
+  TM.resetTargetOptions(MF);
 
   DEBUG(dbgs() << "\n\n\n=== " << Fn.getName() << "\n");
 
diff --git a/lib/Target/TargetMachine.cpp b/lib/Target/TargetMachine.cpp
index 7d8b49cdf23..e7282519d59 100644
--- a/lib/Target/TargetMachine.cpp
+++ b/lib/Target/TargetMachine.cpp
@@ -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 {