Commit Graph

5 Commits

Author SHA1 Message Date
Matthias Braun ce0bcb78e6 ARM: Improve/fix comment in recently added test.
llvm-svn: 271340
2016-05-31 21:59:59 +00:00
Matthias Braun fe725c9241 ARM: Do not attempt to modify register class of physregs.
Physregs have no associated register class, do not attempt to modify it
in Thumb2InstrInfo::storeRegToStackSlot()/loadFromStackSlot().

llvm-svn: 271339
2016-05-31 21:39:12 +00:00
Ahmed Bougacha b4af107239 [ARM] Set correct successors in CMPXCHG pseudo expansion.
transferSuccessors() would LoadCmpBB a successor of DoneBB, whereas
it should be a successor of the original MBB.

The testcase changes are caused by Thumb2SizeReduction, which
was previously confused by the broken CFG.

Follow-up to r266679.

Unfortunately, it's tricky to catch this in the verifier.

llvm-svn: 267778
2016-04-27 20:32:54 +00:00
Tim Northover 1ee27c74cb ARM: fix assertion failure on -O0 cmpxchg.
Because lowering of CMP_SWAP_64 occurs during type legalization, there can be
i64 types produced by more than just a BUILD_PAIR or similar. My initial tests
used just incoming function args.

llvm-svn: 266828
2016-04-19 22:25:02 +00:00
Tim Northover b629c77692 ARM: use a pseudo-instruction for cmpxchg at -O0.
The fast register-allocator cannot cope with inter-block dependencies without
spilling. This is fine for ldrex/strex loops coming from atomicrmw instructions
where any value produced within a block is dead by the end, but not for
cmpxchg. So we lower a cmpxchg at -O0 via a pseudo-inst that gets expanded
after regalloc.

Fortunately this is at -O0 so we don't have to care about performance. This
simplifies the various axes of expansion considerably: we assume a strong
seq_cst operation and ensure ordering via the always-present DMB instructions
rather than v8 acquire/release instructions.

Should fix the 32-bit part of PR25526.

llvm-svn: 266679
2016-04-18 21:48:55 +00:00