Without this hook, functions w/ a completely empty body (including no
epilogue) will cause an MCEmitter assertion failure.
For example,
define internal fastcc void @empty_function() {
unreachable
}
rdar://10947471
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151673 91177308-0d34-0410-b5e6-96231b3b80d8
Merge the tMOVr, tMOVgpr2tgpr, tMOVtgpr2gpr, and tMOVgpr2gpr instructions
into tMOVr. There's no need to keep them separate. Giving the tMOVr
instruction the proper GPR register class for its operands is sufficient
to give the register allocator enough information to do the right thing
directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134204 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134197 91177308-0d34-0410-b5e6-96231b3b80d8
The tSpill and tRestore instructions are just copies of the tSTRspi and
tLDRspi instructions, respectively. Just use those directly instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134092 91177308-0d34-0410-b5e6-96231b3b80d8
The only folding these load/store architectures can do is converting COPY into a
load or store, and the target independent part of foldMemoryOperand already
knows how to do that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108099 91177308-0d34-0410-b5e6-96231b3b80d8
call must not be callee-saved; following x86, add a new
regclass to represent this. Also fixes a couple of bugs.
Still disabled by default; Thumb doesn't work yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106053 91177308-0d34-0410-b5e6-96231b3b80d8
writebacks to the address register. This gets rid of the hack that the
first register on the list was the magic writeback register operand. There
was an implicit constraint that if that operand was not reg0 it had to match
the base register operand. The post-RA scheduler's antidependency breaker
did not understand that constraint and sometimes changed one without the
other. This also fixes Radar 7495976 and should help the verifier work
better for ARM code.
There are now new ld/st instructions explicit writeback operands and explicit
constraints that tie those registers together.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98409 91177308-0d34-0410-b5e6-96231b3b80d8
load of a GV from constantpool and then add pc. It allows the code sequence to
be rematerializable so it would be hoisted by machine licm.
- Add a late pass to break these pseudo instructions into a number of real
instructions. Also move the code in Thumb2 IT pass that breaks up t2MOVi32imm
to this pass. This is done before post regalloc scheduling to allow the
scheduler to proper schedule these instructions. It also allow them to be
if-converted and shrunk by later passes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86304 91177308-0d34-0410-b5e6-96231b3b80d8
the only real caller (GetFunctionSizeInBytes) uses it.
The custom ARM implementation of this is basically reimplementing
an assembler poorly for negligible gain. It should be removed
IMNSHO, but I'll leave that to ARMish folks to decide.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77877 91177308-0d34-0410-b5e6-96231b3b80d8
- This change also makes it possible to switch between ARM / Thumb on a
per-function basis.
- Fixed thumb2 routine which expand reg + arbitrary immediate. It was using
using ARM so_imm logic.
- Use movw and movt to do reg + imm when profitable.
- Other code clean ups and minor optimizations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77300 91177308-0d34-0410-b5e6-96231b3b80d8
This also fixes potential problems in ARMBaseInstrInfo routines not recognizing thumb1 instructions when 32-bit and 16-bit instructions mix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77218 91177308-0d34-0410-b5e6-96231b3b80d8
Before:
adr r12, #LJTI3_0_0
ldr pc, [r12, +r0, lsl #2]
LJTI3_0_0:
.long LBB3_24
.long LBB3_30
.long LBB3_31
.long LBB3_32
After:
adr r12, #LJTI3_0_0
add pc, r12, +r0, lsl #2
LJTI3_0_0:
b.w LBB3_24
b.w LBB3_30
b.w LBB3_31
b.w LBB3_32
This has several advantages.
1. This will make it easier to optimize this to a TBB / TBH instruction +
(smaller) table.
2. This eliminate the need for ugly asm printer hack to force the address
into thumb addresses (bit 0 is one).
3. Same codegen for pic and non-pic.
4. This eliminate the need to align the table so constantpool island pass
won't have to over-estimate the size.
Based on my calculation, the later is probably slightly faster as well since
ldr pc with shifter address is very slow. That is, it should be a win as long
as the HW implementation can do a reasonable job of branch predict the second
branch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77024 91177308-0d34-0410-b5e6-96231b3b80d8
