Add a instruction flag: hasPostISelHook which tells the pre-RA scheduler to
call a target hook to adjust the instruction. For ARM, this is used to
adjust instructions which may be setting the 's' flag. ADC, SBC, RSB, and RSC
instructions have implicit def of CPSR (required since it now uses CPSR physical
register dependency rather than "glue"). If the carry flag is used, then the
target hook will *fill in* the optional operand with CPSR. Otherwise, the hook
will remove the CPSR implicit def from the MachineInstr.
llvm-svn: 138810
register dependency (rather than glue them together). This is general
goodness as it gives scheduler more freedom. However it is motivated by
a nasty bug in isel.
When a i64 sub is expanded to subc + sube.
libcall #1
\
\ subc
\ / \
\ / \
\ / libcall #2
sube
If the libcalls are not serialized (i.e. both have chains which are dag
entry), legalizer can serialize them in arbitrary orders. If it's
unlucky, it can force libcall #2 before libcall #1 in the above case.
subc
|
libcall #2
|
libcall #1
|
sube
However since subc and sube are "glued" together, this ends up being a
cycle when the scheduler combine subc and sube as a single scheduling
unit.
The right solution is to fix LegalizeType too chains the libcalls together.
However, LegalizeType is not processing nodes in order so that's harder than
it should be. For now, the move to physical register dependency will do.
rdar://10019576
llvm-svn: 138791
This handles only the handling of the IT instruction itself, not the
processing and validation of the instructions in the IT block. That's next,
and will include encoding tests for IT itself.
llvm-svn: 138665
I don't really like the patterns, but I'm having trouble coming up with a
better way to handle them.
I plan on making other targets use the same legalization
ARM-without-memory-barriers is using... it's not especially efficient, but
if anyone cares, it's not that hard to fix for a given target if there's
some better lowering.
llvm-svn: 138621
Represent the operand value as it will be encoded in the instruction. This
allows removing the specialized encoder and decoder methods entirely. Add
an assembler match class while we're at it to lay groundwork for parsing the
thumb shift instructions.
llvm-svn: 137879
This new disassembler can correctly decode all the testcases that the old one did, though
some "expected failure" testcases are XFAIL'd for now because it is not (yet) as strict in
operand checking as the old one was.
llvm-svn: 137144
Memory operand parsing is a bit haphazzard at the moment, in no small part
due to the even more haphazzard representations of memory operands in the .td
files. Start cleaning that all up, at least a bit.
The addressing modes in the .td files will be being simplified to not be
so monolithic, especially with regards to immediate vs. register offsets
and post-indexed addressing. addrmode3 is on its way with this patch, for
example.
This patch is foundational to enable going back to smaller incremental patches
for the individual memory referencing instructions themselves. It does just
enough to get the basics in place and handle the "make check" regression tests
we already have.
Follow-up work will be fleshing out the details and adding more robust test
cases for the individual instructions, starting with ARM mode and moving from
there into Thumb and Thumb2.
llvm-svn: 136845
Encode the width operand as it encodes in the instruction, which simplifies
the disassembler and the encoder, by using the imm1_32 operand def. Add a
diagnostic for the context-sensitive constraint that the width must be in
the range [1,32-lsb].
llvm-svn: 136264
Refactor the rest of the extend instructions to not artificially distinguish
between a rotate of zero and a rotate of any other value. Replace the by-zero
versions with Pat<>'s for ISel.
llvm-svn: 136226
Refactor the SXTB, SXTH, SXTB16, UXTB, UXTH, and UXTB16 instructions to not
have an 'r' and an 'r_rot' version, but just a single version with a rotate
that can be zero. Use plain Pat<>'s for the ISel of the non-rotated version.
llvm-svn: 136225
Allow the rot_imm operand to be optional. This sets the stage for refactoring
away the "rr" versions from the multiclasses and replacing them with Pat<>s.
llvm-svn: 136154
Start of cleaning this up a bit. First step is to remove the encoder hook by
storing the operand as the bits it'll actually encode to so it can just be
directly used. Map it to the assembly source values 8/16/24 when we print it.
llvm-svn: 136152
Fix the Rn register encoding for both SSAT and USAT. Update the parsing of the
shift operand to correctly handle the allowed shift types and immediate ranges
and issue meaningful diagnostics when an illegal value or shift type is
specified. Add aliases to parse an ommitted shift operand (default value of
'lsl #0').
Add tests for diagnostics and proper encoding.
llvm-svn: 135990
The immediate is in the range 1-32, but is encoded as 0-31 in a 5-bit bitfield.
Update the representation such that we store the operand as 0-31, allowing us
to remove the encoder method and the special case handling in the disassembler.
Update the assembly parser and the instruction printer accordingly.
llvm-svn: 135823
Move common definitions for ARM and Thumb2 into ARMInstrFormats.td and rename
them to be a bit more descriptive that they're for the PKH instructions.
llvm-svn: 135617
The shift type is implied by the instruction (PKHBT vs. PKHTB) and so shouldn't
be also encoded as part of the shift value immediate. Otherwise we're able to
represent invalid instructions, plus it needlessly complicates the
representation. Preparatory work for asm parsing of these instructions.
llvm-svn: 135616
Add range checking for the immediate operand and handle the "mov" mnemonic
choosing between encodings based on the value of the immediate. Add tests
for fixups, encoding choice and values, and diagnostic for out of range values.
llvm-svn: 135500
Owen Anderson