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Summary

  1. [AArch64][DebugInfo] Do not recompute CalleeSavedStackSize (Take 2) (details)
Commit 814548ec8e1bf85748bc2aa3be173f20267deca4 by sander.desmalen
[AArch64][DebugInfo] Do not recompute CalleeSavedStackSize (Take 2)
Commit message from D66935:
This patch fixes a bug exposed by D65653 where a subsequent invocation
of `determineCalleeSaves` ends up with a different size for the callee
save area, leading to different frame-offsets in debug information.
In the invocation by PEI, `determineCalleeSaves` tries to determine
whether it needs to spill an extra callee-saved register to get an
emergency spill slot. To do this, it calls 'estimateStackSize' and
manually adds the size of the callee-saves to this. PEI then allocates
the spill objects for the callee saves and the remaining frame layout is
calculated accordingly.
A second invocation in LiveDebugValues causes estimateStackSize to
return the size of the stack frame including the callee-saves. Given
that the size of the callee-saves is added to this, these callee-saves
are counted twice, which leads `determineCalleeSaves` to believe the
stack has become big enough to require spilling an extra callee-save as
emergency spillslot. It then updates CalleeSavedStackSize with a larger
value.
Since CalleeSavedStackSize is used in the calculation of the frame
offset in getFrameIndexReference, this leads to incorrect offsets for
variables/locals when this information is recalculated after PEI.
This patch fixes the lldb unit tests in
`functionalities/thread/concurrent_events/*`
Changes after D66935:
Ensures AArch64FunctionInfo::getCalleeSavedStackSize does not return the
uninitialized CalleeSavedStackSize when running `llc` on a specific pass
where the MIR code has already been expected to have gone through PEI.
Instead, getCalleeSavedStackSize (when passed the MachineFrameInfo) will
try to recalculate the CalleeSavedStackSize from the CalleeSavedInfo. In
debug mode, the compiler will assert the recalculated size equals the
cached size as calculated through a call to determineCalleeSaves.
This fixes two tests:
test/DebugInfo/AArch64/asan-stack-vars.mir
test/DebugInfo/AArch64/compiler-gen-bbs-livedebugvalues.mir that
otherwise fail when compiled using msan.
Reviewed By: omjavaid, efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68783
llvm-svn: 375425
The file was modifiedllvm/lib/Target/AArch64/AArch64FrameLowering.cpp
The file was modifiedllvm/lib/Target/ARM/ARMFrameLowering.cpp
The file was modifiedllvm/include/llvm/CodeGen/TargetFrameLowering.h
The file was modifiedllvm/lib/CodeGen/TargetFrameLoweringImpl.cpp
The file was modifiedllvm/test/DebugInfo/MIR/X86/live-debug-values-reg-copy.mir
The file was addedllvm/test/CodeGen/AArch64/wrong-callee-save-size-after-livedebugvariables.mir
The file was modifiedllvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h
The file was modifiedllvm/lib/CodeGen/LiveDebugValues.cpp
The file was modifiedllvm/lib/CodeGen/RegUsageInfoCollector.cpp
The file was modifiedllvm/lib/Target/ARM/ARMFrameLowering.h