When a function contains something, such as inline asm, which explicitly
clobbers the register used as the frame pointer, don't spill it twice. If we
need a frame pointer, it will be saved/restored in the prologue/epilogue code.
Explicitly spilling it again will reuse the same spill slot used by the
prologue/epilogue code, thus clobbering the saved value. The same applies
to the base-pointer or PIC-base register.
Partially fixes PR26856. Thanks to Ulrich for his analysis and the small
inline-asm reproducer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280188 91177308-0d34-0410-b5e6-96231b3b80d8
Avoid implicit conversions from MachineInstrBundleIterator to
MachineInstr* in the PowerPC backend, mainly by preferring MachineInstr&
over MachineInstr* when a pointer isn't nullable and using range-based
for loops.
There was one piece of questionable code in PPCInstrInfo::AnalyzeBranch,
where a condition checked a pointer converted from an iterator for
nullptr. Since this case is impossible (moreover, the code above
guarantees that the iterator is valid), I removed the check when I
changed the pointer to a reference.
Despite that case, there should be no functionality change here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276864 91177308-0d34-0410-b5e6-96231b3b80d8
In the ELFv2 ABI, we are not required to save all CR fields. If only one
nonvolatile CR field is clobbered, use mfocrf instead of mfcr to
selectively save the field, because mfocrf has short latency compares to
mfcr.
Thanks Nemanja's invaluable hint!
Reviewers: nemanjai tjablin hfinkel kbarton
http://reviews.llvm.org/D17749
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266038 91177308-0d34-0410-b5e6-96231b3b80d8
Make it obvious that the argument cannot be nullptr.
Remove an unnecessary nullptr check in initRegState.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265511 91177308-0d34-0410-b5e6-96231b3b80d8
This will become necessary in a subsequent change to make this method
merge adjacent stack adjustments, i.e. it might erase the previous
and/or next instruction.
It also greatly simplifies the calls to this function from Prolog-
EpilogInserter. Previously, that had a bunch of logic to resume iteration
after the call; now it just continues with the returned iterator.
Note that this changes the behaviour of PEI a little. Previously,
it attempted to re-visit the new instruction created by
eliminateCallFramePseudoInstr(). That code was added in r36625,
but I can't see any reason for it: the new instructions will obviously
not be pseudo instructions, they will not have FrameIndex operands,
and we have already accounted for the stack adjustment.
Differential Revision: http://reviews.llvm.org/D18627
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265036 91177308-0d34-0410-b5e6-96231b3b80d8
This is what was meant to be in the initial commit to fix this bug. The
parens were missing. This commit also adds a test case for the bug and
has undergone full testing on PPC and X86.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261546 91177308-0d34-0410-b5e6-96231b3b80d8
I mistook BitVector::empty() to mean BitVector::count() == 0 and it does
not. Corrected the issue with the fix for PR26500.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261525 91177308-0d34-0410-b5e6-96231b3b80d8
The patch has a necessary call to a function inside an assert. Which is fine
when you have asserts turned on. Not so much when they're off. Sorry about
the regression.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261447 91177308-0d34-0410-b5e6-96231b3b80d8
This patch corresponds to review:
http://reviews.llvm.org/D17294
It ensures that whatever block we are emitting the prologue/epilogue into, we
have the necessary scratch registers. It takes away the hard-coded register
numbers for use as scratch registers as registers that are guaranteed to be
available in the function prologue/epilogue are not guaranteed to be available
within the function body. Since we shrink-wrap, the prologue/epilogue may end
up in the function body.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261441 91177308-0d34-0410-b5e6-96231b3b80d8
This call should in fact be made by RegScavenger::enterBasicBlock()
called below. The first call does nothing except for triggering UB,
indicated by UBSan (passing nullptr to memset()).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254548 91177308-0d34-0410-b5e6-96231b3b80d8
Re-enable shrink wrapping for PPC64 Little Endian.
One minor modification to PPCFrameLowering::findScratchRegister was necessary to handle fall-thru blocks (blocks with no terminator) correctly.
Tested with all LLVM test, clang tests, and the self-hosting build, with no problems found.
PHabricator: http://reviews.llvm.org/D14778
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254314 91177308-0d34-0410-b5e6-96231b3b80d8
Matthias Braun
Simon Pilgrim
Krzysztof Parzyszek
Hal Finkel
Duncan P. N. Exon Smith
Nemanja Ivanovic
Rafael Espindola
Benjamin Kramer
Chuang-Yu Cheng
Hans Wennborg
Aaron Ballman
Craig Topper
Alexey Samsonov
Kit Barton