Fix a FIXME and allow predication (in Thumb2) for the T1 register to
register MOV instructions. This allows some better codegen with
if-conversion (as seen in the test updates), plus it lays the groundwork
for pseudo-izing the tMOVCC instructions.
llvm-svn: 134197
It's just a t2LDMIA_UPD instruction with extra codegen properties, so it
doesn't need the encoding information. As a side-benefit, we now correctly
recognize for instruction printing as a 'pop' instruction.
llvm-svn: 134173
be the first encoded as the first feature. It then uses the CPU name to look up
features / scheduling itineray even though clients know full well the CPU name
being used to query these properties.
The fix is to just have the clients explictly pass the CPU name!
llvm-svn: 134127
This patch will sometimes choose live range split points next to
interference instead of always splitting next to a register point. That
means spill code can now appear almost anywhere, and it was necessary
to fix code that didn't expect that.
The difficult places were:
- Between a CALL returning a value on the x87 stack and the
corresponding FpPOP_RETVAL (was FpGET_ST0). Probably also near x87
inline assembly, but that didn't actually show up in testing.
- Between a CALL popping arguments off the stack and the corresponding
ADJCALLSTACKUP.
Both are fixed now. The only place spill code can't appear is after
terminators, see SplitAnalysis::getLastSplitPoint.
Original commit message:
Rewrite RAGreedy::splitAroundRegion, now with cool ASCII art.
This function has to deal with a lot of special cases, and the old
version got it wrong sometimes. In particular, it would sometimes leave
multiple uses in the stack interval in a single block. That causes bad
code with multiple reloads in the same basic block.
The new version handles block entry and exit in a single pass. It first
eliminates all the easy cases, and then goes on to create a local
interval for the blocks with difficult interference. Previously, we
would only create the local interval for completely isolated blocks.
It can happen that the stack interval becomes completely empty because
we could allocate a register in all edge bundles, and the new local
intervals deal with the interference. The empty stack interval is
harmless, but we need to remove a SplitKit assertion that checks for
empty intervals.
llvm-svn: 134125
Unlike Thumb1, Thumb2 does not have dedicated encodings for adjusting the
stack pointer. It can just use the normal add-register-immediate encoding
since it can use all registers as a source, not just R0-R7. The extra
instruction definitions are just duplicates of the normal instructions with
the (not well enforced) constraint that the source register was SP.
llvm-svn: 134114
Some x86-32 calls pop values off the stack, and we need to readjust the
stack pointer after the call. This happens when ADJCALLSTACKUP is
eliminated.
It could happen that spill code was inserted between the CALL and
ADJCALLSTACKUP instructions, and we would compute wrong stack pointer
offsets for those frame index references.
Fix this by inserting the stack pointer adjustment immediately after the
call instead of where the ADJCALLSTACKUP instruction was erased.
I don't have a test case since we don't currently insert code in that
position. We will soon, though. I am testing a regalloc patch that
didn't work on Linux because of this.
llvm-svn: 134113
already makes the assumption, which is correct on ARM, that a type's alignment is
less than its alloc size. This improves codegen with Clang (which inserts a lot of
extraneous alignment specifiers) and fixes <rdar://problem/9695089>.
llvm-svn: 134106
The tSpill and tRestore instructions are just copies of the tSTRspi and
tLDRspi instructions, respectively. Just use those directly instead.
llvm-svn: 134092
