[llvm-commits] [llvm] r79039 - in /llvm/trunk: lib/Target/ARM/ARMBaseRegisterInfo.cpp lib/Target/ARM/ARMBaseRegisterInfo.h test/CodeGen/Thumb2/frameless.ll

[Evan Cheng]

Author: evancheng
Date: Fri Aug 14 15:48:13 2009
New Revision: 79039

URL: http://llvm.org/viewvc/llvm-project?rev=79039&view=rev
Log:
Leaf functions which do not save CSRs can be frameless even with -disable-fp-elim.

Added:
    llvm/trunk/test/CodeGen/Thumb2/frameless.ll
Modified:
    llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp
    llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.h

Modified: llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp?rev=79039&r1=79038&r2=79039&view=diff

==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp Fri Aug 14 15:48:13 2009
@@ -440,6 +440,13 @@
           MFI->isFrameAddressTaken());
 }
 
+bool ARMBaseRegisterInfo::hasStackFrame(const MachineFunction &MF) const {
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+  if (NoFramePointerElim && MFI->hasCalls())
+    return true;
+  return MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken();
+}
+
 /// estimateStackSize - Estimate and return the size of the frame.
 static unsigned estimateStackSize(MachineFunction &MF, MachineFrameInfo *MFI) {
   const MachineFrameInfo *FFI = MF.getFrameInfo();
@@ -589,7 +596,7 @@
   }
 
   bool ExtraCSSpill = false;
-  if (!CanEliminateFrame || hasFP(MF)) {
+  if (!CanEliminateFrame || hasStackFrame(MF)) {
     AFI->setHasStackFrame(true);
 
     // If LR is not spilled, but at least one of R4, R5, R6, and R7 is spilled.

Modified: llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.h?rev=79039&r1=79038&r2=79039&view=diff

==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.h (original)
+++ llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.h Fri Aug 14 15:48:13 2009
@@ -89,6 +89,8 @@
 
   bool hasFP(const MachineFunction &MF) const;
 
+  bool hasStackFrame(const MachineFunction &MF) const;
+
   void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
                                             RegScavenger *RS = NULL) const;
 

Added: llvm/trunk/test/CodeGen/Thumb2/frameless.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Thumb2/frameless.ll?rev=79039&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/Thumb2/frameless.ll (added)
+++ llvm/trunk/test/CodeGen/Thumb2/frameless.ll Fri Aug 14 15:48:13 2009
@@ -0,0 +1,6 @@
+; RUN: llvm-as < %s | llc -mtriple=thumbv7-apple-darwin -disable-fp-elim | not grep mov
+; RUN: llvm-as < %s | llc -mtriple=thumbv7-linux -disable-fp-elim | not grep mov
+
+define arm_apcscc void @t() nounwind readnone {
+  ret void
+}