[llvm-commits] [llvm] r139939 - in /llvm/trunk/lib/Target/X86: X86MachineFunctionInfo.h X86RegisterInfo.cpp

[Bruno Cardoso Lopes]

Author: bruno
Date: Fri Sep 16 15:58:28 2011
New Revision: 139939

URL: http://llvm.org/viewvc/llvm-project?rev=139939&view=rev
Log:
Fix PR10884.

This PR basically reports a problem where a crash in generated code
happened due to %rbp being clobbered:

  pushq %rbp
  movq  %rsp, %rbp
  ....
  vmovmskps %ymm12, %ebp
  ....
  movq  %rbp, %rsp
  popq  %rbp
  ret

Since Eric's r123367 commit, the default stack alignment for x86 32-bit
has changed to be 16-bytes. Since then, the MaxStackAlignmentHeuristicPass
hasn't been really used, but with AVX it becomes useful again, since per
ABI compliance we don't always align the stack to 256-bit, but only when
there are 256-bit incoming arguments.

ReserveFP was only used by this pass, but there's no RA target hook that
uses getReserveFP() to check for the presence of FP (since nothing was
triggering the pass to run, the uses of getReserveFP() were removed
through time without being noticed). Change this pass to use
setForceFramePointer, which is properly called by MachineFunction
hasFP method.

The testcase is very big and dependent on RA, not sure if it's worth
adding to test/CodeGen/X86.

Modified:
    llvm/trunk/lib/Target/X86/X86MachineFunctionInfo.h
    llvm/trunk/lib/Target/X86/X86RegisterInfo.cpp

Modified: llvm/trunk/lib/Target/X86/X86MachineFunctionInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86MachineFunctionInfo.h?rev=139939&r1=139938&r2=139939&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86MachineFunctionInfo.h (original)
+++ llvm/trunk/lib/Target/X86/X86MachineFunctionInfo.h Fri Sep 16 15:58:28 2011
@@ -53,10 +53,6 @@
   /// relocation models.
   unsigned GlobalBaseReg;
 
-  /// ReserveFP - whether the function should reserve the frame pointer
-  /// when allocating, even if there may not actually be a frame pointer used.
-  bool ReserveFP;
-
   /// VarArgsFrameIndex - FrameIndex for start of varargs area.
   int VarArgsFrameIndex;
   /// RegSaveFrameIndex - X86-64 vararg func register save area.
@@ -91,7 +87,6 @@
       TailCallReturnAddrDelta(0),
       SRetReturnReg(0),
       GlobalBaseReg(0),
-      ReserveFP(false),
       VarArgsFrameIndex(0),
       RegSaveFrameIndex(0),
       VarArgsGPOffset(0),
@@ -119,9 +114,6 @@
   unsigned getGlobalBaseReg() const { return GlobalBaseReg; }
   void setGlobalBaseReg(unsigned Reg) { GlobalBaseReg = Reg; }
 
-  bool getReserveFP() const { return ReserveFP; }
-  void setReserveFP(bool reserveFP) { ReserveFP = reserveFP; }
-
   int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
   void setVarArgsFrameIndex(int Idx) { VarArgsFrameIndex = Idx; }
 

Modified: llvm/trunk/lib/Target/X86/X86RegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86RegisterInfo.cpp?rev=139939&r1=139938&r2=139939&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86RegisterInfo.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86RegisterInfo.cpp Fri Sep 16 15:58:28 2011
@@ -822,7 +822,7 @@
       for (unsigned i = 0, e = RI.getNumVirtRegs(); i != e; ++i) {
         unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
         if (RI.getRegClass(Reg)->getAlignment() > StackAlignment) {
-          FuncInfo->setReserveFP(true);
+          FuncInfo->setForceFramePointer(true);
           return true;
         }
       }