Do not store R31 into the caller's link area on PPC.
This violates the ABI (that area is "reserved"), and
while it is safe if all code is generated with current
compilers, there is some very old code around that uses
that slot for something else, and breaks if it is stored
into. Adjust testcases looking for current behavior.
I've verified that the stack frame size is right in all
testcases, whether it changed or not. 7311323.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89811 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCFrameInfo.h b/lib/Target/PowerPC/PPCFrameInfo.h
index 65f113e..4bf543a 100644
--- a/lib/Target/PowerPC/PPCFrameInfo.h
+++ b/lib/Target/PowerPC/PPCFrameInfo.h
@@ -42,11 +42,12 @@
/// frame pointer.
static unsigned getFramePointerSaveOffset(bool isPPC64, bool isDarwinABI) {
// For the Darwin ABI:
- // Use the TOC save slot in the PowerPC linkage area for saving the frame
- // pointer (if needed.) LLVM does not generate code that uses the TOC (R2
- // is treated as a caller saved register.)
+ // We cannot use the TOC save slot (offset +20) in the PowerPC linkage area
+ // for saving the frame pointer (if needed.) While the published ABI has
+ // not used this slot since at least MacOSX 10.2, there is older code
+ // around that does use it, and that needs to continue to work.
if (isDarwinABI)
- return isPPC64 ? 40 : 20;
+ return isPPC64 ? -8U : -4U;
// SVR4 ABI: First slot in the general register save area.
return -4U;
@@ -90,6 +91,17 @@
// With the SVR4 ABI, callee-saved registers have fixed offsets on the stack.
const SpillSlot *
getCalleeSavedSpillSlots(unsigned &NumEntries) const {
+ if (TM.getSubtarget<PPCSubtarget>().isDarwinABI()) {
+ NumEntries = 1;
+ if (TM.getSubtarget<PPCSubtarget>().isPPC64()) {
+ static const SpillSlot darwin64Offsets[] = {PPC::X31, -8};
+ return darwin64Offsets;
+ } else {
+ static const SpillSlot darwinOffsets[] = {PPC::R31, -4};
+ return darwinOffsets;
+ }
+ }
+
// Early exit if not using the SVR4 ABI.
if (!TM.getSubtarget<PPCSubtarget>().isSVR4ABI()) {
NumEntries = 0;