[llvm-commits] [llvm] r142028 - /llvm/trunk/lib/Target/ARM/Thumb1FrameLowering.cpp

[Chad Rosier]

Author: mcrosier
Date: Fri Oct 14 19:28:24 2011
New Revision: 142028

URL: http://llvm.org/viewvc/llvm-project?rev=142028&view=rev
Log:
Thumb1 does not support dynamic stack realignment.
rdar://10288916 is tracking this fix.

In the past, instcombine and other passes were promoting alloca alignment past
the natural alignment, resulting in dynamic stack realignment.  Lang's work now
prevents this from happening (LLVM commit r141599).  Now that this really 
shouldn't happen report a fatal error rather than silently generate bad code.

Modified:
    llvm/trunk/lib/Target/ARM/Thumb1FrameLowering.cpp

Modified: llvm/trunk/lib/Target/ARM/Thumb1FrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/Thumb1FrameLowering.cpp?rev=142028&r1=142027&r2=142028&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/Thumb1FrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/ARM/Thumb1FrameLowering.cpp Fri Oct 14 19:28:24 2011
@@ -155,6 +155,11 @@
   AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
   AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
 
+  // Thumb1 does not currently support dynamic stack realignment.  Report a
+  // fatal error rather then silently generate bad code.
+  if (RegInfo->needsStackRealignment(MF))
+      report_fatal_error("Dynamic stack realignment not supported for thumb1.");
+
   // If we need a base pointer, set it up here. It's whatever the value
   // of the stack pointer is at this point. Any variable size objects
   // will be allocated after this, so we can still use the base pointer