Stop resetting NoFramePointerElim in TargetMachine::resetTargetOptions.

This is part of the work to remove TargetMachine::resetTargetOptions.

In this patch, instead of updating global variable NoFramePointerElim in
resetTargetOptions, its use in DisableFramePointerElim is replaced with a call
to TargetFrameLowering::noFramePointerElim. This function determines on a
per-function basis if frame pointer elimination should be disabled.

There is no change in functionality except that cl:opt option "disable-fp-elim"
can now override function attribute "no-frame-pointer-elim". 

llvm-svn: 238080

1 files changed, 2 insertions, 16 deletions

diff --git a/llvm/lib/Target/ARM/ARMFastISel.cpp b/llvm/lib/Target/ARM/ARMFastISel.cpp
index 97995d3..4175b4a 100644
--- a/llvm/lib/Target/ARM/ARMFastISel.cpp
+++ b/llvm/lib/Target/ARM/ARMFastISel.cpp
@@ -3065,23 +3065,9 @@ bool ARMFastISel::fastLowerArguments() {
 namespace llvm {
   FastISel *ARM::createFastISel(FunctionLoweringInfo &funcInfo,
                                 const TargetLibraryInfo *libInfo) {
-    const TargetMachine &TM = funcInfo.MF->getTarget();
-    const ARMSubtarget &STI =
-        static_cast<const ARMSubtarget &>(funcInfo.MF->getSubtarget());
-    // Thumb2 support on iOS; ARM support on iOS, Linux and NaCl.
-    bool UseFastISel = false;
-    UseFastISel |= STI.isTargetMachO() && !STI.isThumb1Only();
-    UseFastISel |= STI.isTargetLinux() && !STI.isThumb();
-    UseFastISel |= STI.isTargetNaCl() && !STI.isThumb();
-
-    if (UseFastISel) {
-      // iOS always has a FP for backtracking, force other targets
-      // to keep their FP when doing FastISel. The emitted code is
-      // currently superior, and in cases like test-suite's lencod
-      // FastISel isn't quite correct when FP is eliminated.
-      TM.Options.NoFramePointerElim = true;
+    if (funcInfo.MF->getSubtarget<ARMSubtarget>().useFastISel())
       return new ARMFastISel(funcInfo, libInfo);
-    }
+
     return nullptr;
   }
 }