ARM/Dwarf: correctly align stack before callee-saved VPRs
We were making an attempt to do this by adding an extra callee-saved GPR (so
that there was an even number in the list), but when that failed we went ahead
and pushed anyway.
This had a couple of potential issues:
+ The .cfi directives we emit misplaced dN because they were based on
PrologEpilogInserter's calculation.
+ Unaligned stores can be less efficient.
+ Unaligned stores can actually fault (likely only an issue in niche cases,
but possible).
This adds a final explicit stack adjustment if all other options fail, so that
the actual locations of the registers match up with where they should be.
llvm-svn: 221320
diff --git a/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h b/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h
index 4f9ea7a..4e67fa1 100644
--- a/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h
+++ b/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h
@@ -86,6 +86,7 @@
/// areas.
unsigned GPRCS1Size;
unsigned GPRCS2Size;
+ unsigned DPRCSAlignGapSize;
unsigned DPRCSSize;
/// NumAlignedDPRCS2Regs - The number of callee-saved DPRs that are saved in
@@ -134,7 +135,7 @@
RestoreSPFromFP(false),
LRSpilledForFarJump(false),
FramePtrSpillOffset(0), GPRCS1Offset(0), GPRCS2Offset(0), DPRCSOffset(0),
- GPRCS1Size(0), GPRCS2Size(0), DPRCSSize(0),
+ GPRCS1Size(0), GPRCS2Size(0), DPRCSAlignGapSize(0), DPRCSSize(0),
NumAlignedDPRCS2Regs(0),
JumpTableUId(0), PICLabelUId(0),
VarArgsFrameIndex(0), HasITBlocks(false), GlobalBaseReg(0) {}
@@ -183,10 +184,12 @@
unsigned getGPRCalleeSavedArea1Size() const { return GPRCS1Size; }
unsigned getGPRCalleeSavedArea2Size() const { return GPRCS2Size; }
+ unsigned getDPRCalleeSavedGapSize() const { return DPRCSAlignGapSize; }
unsigned getDPRCalleeSavedAreaSize() const { return DPRCSSize; }
void setGPRCalleeSavedArea1Size(unsigned s) { GPRCS1Size = s; }
void setGPRCalleeSavedArea2Size(unsigned s) { GPRCS2Size = s; }
+ void setDPRCalleeSavedGapSize(unsigned s) { DPRCSAlignGapSize = s; }
void setDPRCalleeSavedAreaSize(unsigned s) { DPRCSSize = s; }
unsigned getArgumentStackSize() const { return ArgumentStackSize; }