svn commit: r256178 - stable/9/contrib/llvm/lib/Target/X86

[Dimitry Andric]

Author: dim
Date: Wed Oct  9 06:19:01 2013
New Revision: 256178
URL: http://svnweb.freebsd.org/changeset/base/256178

Log:
  MFC r256090:
  
  Pull in r192064 from upstream llvm trunk:
  
    X86: Don't fold spills into SSE operations if the stack is unaligned.
  
    Regalloc can emit unaligned spills nowadays, but we can't fold the
    spills into SSE ops if we can't guarantee alignment. PR12250.
  
  This fixes unaligned SSE accesses (leading to a SIGBUS) which could
  occur in the ffmpeg ports.
  
  Reported by:	tijl

Modified:
  stable/9/contrib/llvm/lib/Target/X86/X86InstrInfo.cpp
Directory Properties:
  stable/9/contrib/llvm/   (props changed)

Modified: stable/9/contrib/llvm/lib/Target/X86/X86InstrInfo.cpp
==============================================================================
--- stable/9/contrib/llvm/lib/Target/X86/X86InstrInfo.cpp	Wed Oct  9 05:27:21 2013	(r256177)
+++ stable/9/contrib/llvm/lib/Target/X86/X86InstrInfo.cpp	Wed Oct  9 06:19:01 2013	(r256178)
@@ -3881,6 +3881,10 @@ MachineInstr* X86InstrInfo::foldMemoryOp
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   unsigned Size = MFI->getObjectSize(FrameIndex);
   unsigned Alignment = MFI->getObjectAlignment(FrameIndex);
+  // If the function stack isn't realigned we don't want to fold instructions
+  // that need increased alignment.
+  if (!RI.needsStackRealignment(MF))
+    Alignment = std::min(Alignment, TM.getFrameLowering()->getStackAlignment());
   if (Ops.size() == 2 && Ops[0] == 0 && Ops[1] == 1) {
     unsigned NewOpc = 0;
     unsigned RCSize = 0;