Commit Graph

196 Commits

Author SHA1 Message Date
Evan Cheng
5a42a6a20f After 3-addressifying a two-address instruction, update the register maps; add a missing check when considering whether it's profitable to commute. rdar://8977508.
llvm-svn: 125259
2011-02-10 02:20:55 +00:00
Jakob Stoklund Olesen
32f1783ca1 Simplify a bunch of isVirtualRegister() and isPhysicalRegister() logic.
These functions not longer assert when passed 0, but simply return false instead.

No functional change intended.

llvm-svn: 123155
2011-01-10 02:58:51 +00:00
Jakob Stoklund Olesen
c20baa8f1d Shrink a BitVector that didn't mean to store bits for all physical registers.
llvm-svn: 123108
2011-01-09 03:45:44 +00:00
Evan Cheng
aa16fd02ad Do not model all INLINEASM instructions as having unmodelled side effects.
Instead encode llvm IR level property "HasSideEffects" in an operand (shared
with IsAlignStack). Added MachineInstrs::hasUnmodeledSideEffects() to check
the operand when the instruction is an INLINEASM.

This allows memory instructions to be moved around INLINEASM instructions.

llvm-svn: 123044
2011-01-07 23:50:32 +00:00
Cameron Zwarich
64fbc5e267 StrongPHIElimination will never run before TwoAddressInstructionPass.
llvm-svn: 122197
2010-12-19 21:32:29 +00:00
Cameron Zwarich
163792fb1f Remove some checks for StrongPHIElim. These checks make it impossible to use an
alternative register allocator that does not require LiveIntervals by specifying
it on the command-line for a target that has StrongPHIElimination enabled by
default.

These checks are pretty meaningless anyways, since StrongPHIElimination and
PHIElimination are never used at the same time.

llvm-svn: 122176
2010-12-19 18:03:27 +00:00
Bob Wilson
e06f6eabe7 Fix crash compiling a QQQQ REG_SEQUENCE for a Neon vld3_lane operation.
Radar 8776599

llvm-svn: 122018
2010-12-17 01:21:12 +00:00
Evan Cheng
7e96e67d98 Fix a minor bug in two-address pass. It was missing a commute opportunity.
regB = move RCX
regA = op regB, regC
RAX  = move regA
where both regB and regC are killed. If regB is constrainted to non-compatible
physical registers but regC is not constrainted at all, then it's better to
commute the instruction.
       movl    %edi, %eax
       shlq    $32, %rcx
       leaq    (%rcx,%rax), %rax
=>
       movl    %edi, %eax
       shlq    $32, %rcx
       orq     %rcx, %rax
rdar://8762995

llvm-svn: 121793
2010-12-14 21:34:53 +00:00
Duncan Sands
0c166168a0 Remove some variables that are never really used
(gcc-4.6 warns about these).

llvm-svn: 117021
2010-10-21 16:03:28 +00:00
Owen Anderson
46990c17f7 Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.

llvm-svn: 116820
2010-10-19 17:21:58 +00:00
Owen Anderson
63f757463c Begin adding static dependence information to passes, which will allow us to
perform initialization without static constructors AND without explicit initialization
by the client.  For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve.  I hope to be able to relax
the latter requirement in the future.

llvm-svn: 116334
2010-10-12 19:48:12 +00:00
Owen Anderson
69cbf2e8b7 Now with fewer extraneous semicolons!
llvm-svn: 115996
2010-10-07 22:25:06 +00:00
Owen Anderson
fe3d206e65 Now that PassInfo and Pass::ID have been separated, move the rest of the passes over to the new registration API.
llvm-svn: 111815
2010-08-23 17:52:01 +00:00
Jakob Stoklund Olesen
f73f368ddb A REG_SEQUENCE instruction may use the same register twice.
If we are emitting COPY instructions for the REG_SEQUENCE, make sure the kill
flag goes on the last COPY. Otherwise we may be using a killed register.

<rdar://problem/8287792>

llvm-svn: 110589
2010-08-09 20:19:16 +00:00
Owen Anderson
f2fea95f2f Reapply r110396, with fixes to appease the Linux buildbot gods.
llvm-svn: 110460
2010-08-06 18:33:48 +00:00
Owen Anderson
aadd8a89ca Revert r110396 to fix buildbots.
llvm-svn: 110410
2010-08-06 00:23:35 +00:00
Owen Anderson
b9762c07cb Don't use PassInfo* as a type identifier for passes. Instead, use the address of the static
ID member as the sole unique type identifier.  Clean up APIs related to this change.

llvm-svn: 110396
2010-08-05 23:42:04 +00:00
Jakob Stoklund Olesen
bcee53a2b8 Remove many calls to TII::isMoveInstr. Targets should be producing COPY anyway.
TII::isMoveInstr is going tobe completely removed.

llvm-svn: 108507
2010-07-16 04:45:42 +00:00
Jakob Stoklund Olesen
f0d1bf23eb Replace copyRegToReg with COPY everywhere in lib/CodeGen except for FastISel.
llvm-svn: 108062
2010-07-10 22:42:59 +00:00
Jakob Stoklund Olesen
9b0f71f68f Only collect subreg extracting copies for later coalescing.
This also avoids fatal copies from physregs.

llvm-svn: 108061
2010-07-10 22:42:53 +00:00
Jakob Stoklund Olesen
609d345349 Emit COPY instructions instead of using copyRegToReg in InstrEmitter,
ScheduleDAGEmit, TwoAddressLowering, and PHIElimination.

This switches the bulk of register copies to using COPY, but many less used
copyRegToReg calls remain.

llvm-svn: 108050
2010-07-10 19:08:25 +00:00
Jakob Stoklund Olesen
30aacf68b9 Convert EXTRACT_SUBREG to COPY when emitting machine instrs.
EXTRACT_SUBREG no longer appears as a machine instruction. Use COPY instead.

Add isCopy() checks in many places using isMoveInstr() and isExtractSubreg().
The isMoveInstr hook will be removed later.

llvm-svn: 107879
2010-07-08 16:40:22 +00:00
Jakob Stoklund Olesen
8983ea915c Remove references to INSERT_SUBREG after de-SSA.
Fix X86InstrInfo::convertToThreeAddressWithLEA to generate COPY instead of
INSERT_SUBREG.

llvm-svn: 107878
2010-07-08 16:40:15 +00:00
Jakob Stoklund Olesen
3f4e5779d7 Revert "Remove references to INSERT_SUBREG after de-SSA" r107725.
Buildbot breakage.

llvm-svn: 107744
2010-07-07 00:32:25 +00:00
Jakob Stoklund Olesen
04124836b5 Remove references to INSERT_SUBREG after de-SSA
llvm-svn: 107732
2010-07-06 23:40:35 +00:00
Jakob Stoklund Olesen
83ab844c9b Convert INSERT_SUBREG to COPY in TwoAddressInstructionPass.
INSERT_SUBREG will now only appear in SSA machine instructions.

Fix the handling of partial redefs in ProcessImplicitDefs. This is now relevant
since partial redef COPY instructions appear.

llvm-svn: 107726
2010-07-06 23:26:25 +00:00
Jakob Stoklund Olesen
dba28ee3d8 Detect and handle COPY in many places.
This code is transitional, it will soon be possible to eliminate
isExtractSubreg, isInsertSubreg, and isMoveInstr in most places.

llvm-svn: 107547
2010-07-03 00:04:37 +00:00
Evan Cheng
2954bb814e - Two-address pass should not assume unfolding is always successful.
- X86 unfolding should check if the instructions being unfolded has memoperands.
  If there is no memoperands, then it must assume conservative alignment. If this
  would introduce an expensive sse unaligned load / store, then unfoldMemoryOperand
  etc. should not unfold the instruction.

llvm-svn: 107509
2010-07-02 20:36:18 +00:00
Dan Gohman
2075612492 When unfolding a load, avoid assuming which instruction that
kill and dead flags will end up on.

llvm-svn: 106520
2010-06-22 02:07:21 +00:00
Dan Gohman
ac0b4b5352 Fix the new load-unfolding code to update LiveVariable's dead flags,
in addition to the kill flags.

llvm-svn: 106512
2010-06-22 00:32:04 +00:00
Dan Gohman
bcc040be1b Teach two-address lowering how to unfold a load to open up commuting
opportunities. For example, this lets it emit this:

   movq (%rax), %rcx
   addq %rdx, %rcx

instead of this:

   movq %rdx, %rcx
   addq (%rax), %rcx

in the case where %rdx has subsequent uses. It's the same number
of instructions, and usually the same encoding size on x86, but
it appears faster, and in general, it may allow better scheduling
for the load.

llvm-svn: 106493
2010-06-21 22:17:20 +00:00
Jakob Stoklund Olesen
7150b84292 Only run CoalesceExtSubRegs when we can expect LiveIntervalAnalysis to clean up
the inserted INSERT_SUBREGs after us.

llvm-svn: 106345
2010-06-18 23:10:20 +00:00
Bob Wilson
99baadaee9 Add some missing checks for the case where the extract_subregs are
combined to an insert_subreg, i.e., where the destination register is larger
than the source.  We need to check that the subregs can be composed for that
case in a symmetrical way to the case when the destination is smaller.

llvm-svn: 106004
2010-06-15 17:27:54 +00:00
Bob Wilson
56555deb30 Generalize the pre-coalescing of extract_subregs feeding reg_sequences,
replacing the overly conservative checks that I had introduced recently to
deal with correctness issues.  This makes a pretty noticable difference
in our testcases where reg_sequences are used.  I've updated one test to
check that we no longer emit the unnecessary subreg moves.

llvm-svn: 105991
2010-06-15 05:56:31 +00:00
Evan Cheng
501c37c9ca Allow target to place 2-address pass inserted copies in better spots. Thumb2 will use this to try to avoid breaking up IT blocks.
llvm-svn: 105745
2010-06-09 19:26:01 +00:00
Bob Wilson
ff11696889 Fix a mistake in my previous change r105437: don't access operand 2 and assume
that it is an immediate before checking that the instruction is an
EXTRACT_SUBREG.

llvm-svn: 105585
2010-06-07 23:48:46 +00:00
Bob Wilson
f28f6f03a2 Add some missing checks in TwoAddressInstructionPass::CoalesceExtSubRegs.
Check that all the instructions are in the same basic block, that the
EXTRACT_SUBREGs write to the same subregs that are being extracted, and that
the source and destination registers are in the same regclass.  Some of
these constraints can be relaxed with a bit more work.  Jakob suggested
that the loop that checks for subregs when NewSubIdx != 0 should use the
"nodbg" iterator, so I made that change here, too.

llvm-svn: 105437
2010-06-03 23:53:58 +00:00
Jakob Stoklund Olesen
f0226fee37 Slightly change the meaning of the reMaterialize target hook when the original
instruction defines subregisters.

Any existing subreg indices on the original instruction are preserved or
composed with the new subreg index.

Also substitute multiple operands mentioning the original register by using the
new MachineInstr::substituteRegister() function. This is necessary because there
will soon be <imp-def> operands added to non read-modify-write partial
definitions. This instruction:

  %reg1234:foo = FLAP %reg1234<imp-def>

will reMaterialize(%reg3333, bar) like this:

  %reg3333:bar-foo = FLAP %reg333:bar<imp-def>

Finally, replace the TargetRegisterInfo pointer argument with a reference to
indicate that it cannot be NULL.

llvm-svn: 105358
2010-06-02 22:47:25 +00:00
Bob Wilson
fd208cef5d Rename canCombinedSubRegIndex method to something more grammatically correct
and tidy up the comment describing it.

llvm-svn: 105339
2010-06-02 18:54:47 +00:00
Bob Wilson
70ee614ad2 Fix an obvious mistake: don't change the operands until all of them have been
checked and it is safe to proceed with the changes.

llvm-svn: 105304
2010-06-02 00:16:08 +00:00
Jakob Stoklund Olesen
6631c8b9b7 Handle composed subreg indices when processing REQ_SEQUENCE instructions.
llvm-svn: 105066
2010-05-29 00:14:14 +00:00
Evan Cheng
3c850aecf6 - Change MachineInstr::findRegisterDefOperandIdx so it can also look for defs
that are aliases of the specified register.
- Rename modifiesRegister to definesRegister since it's looking a def of the
specific register or one of its super-registers. It's not looking for def of a
sub-register or alias that could change the specified register.
- Added modifiesRegister to look for defs of aliases.

llvm-svn: 104377
2010-05-21 20:53:24 +00:00
Jakob Stoklund Olesen
6a2bfde3c8 TwoAddressInstructionPass doesn't really know how to merge live intervals when
lowering REG_SEQUENCE instructions.

Insert copies for REG_SEQUENCE sources not killed to avoid breaking later passes.

llvm-svn: 104146
2010-05-19 20:08:00 +00:00
Evan Cheng
8aa900cf16 Fix PR7175. Insert copies of a REG_SEQUENCE source if it is used by other REG_SEQUENCE instructions.
llvm-svn: 103994
2010-05-17 23:24:12 +00:00
Evan Cheng
378d6c5d76 Fix PR7156. If the sources of a REG_SEQUENCE are all IMPLICIT_DEF's. Replace it with an IMPLICIT_DEF rather than deleting it or else it would be left without a def.
llvm-svn: 103984
2010-05-17 22:09:49 +00:00
Evan Cheng
bb0a4fbe13 Careful with reg_sequence coalescing to not to overwrite sub-register indices.
llvm-svn: 103971
2010-05-17 20:57:12 +00:00
Evan Cheng
0a651c3314 Teach two-address pass to do some coalescing while eliminating REG_SEQUENCE
instructions.

e.g.
%reg1026<def> = VLDMQ %reg1025<kill>, 260, pred:14, pred:%reg0
%reg1027<def> = EXTRACT_SUBREG %reg1026, 6
%reg1028<def> = EXTRACT_SUBREG %reg1026<kill>, 5
...
%reg1029<def> = REG_SEQUENCE %reg1028<kill>, 5, %reg1027<kill>, 6, %reg1028, 7, %reg1027, 8, %reg1028, 9, %reg1027, 10, %reg1030<kill>, 11, %reg1032<kill>, 12

After REG_SEQUENCE is eliminated, we are left with:

%reg1026<def> = VLDMQ %reg1025<kill>, 260, pred:14, pred:%reg0
%reg1029:6<def> = EXTRACT_SUBREG %reg1026, 6
%reg1029:5<def> = EXTRACT_SUBREG %reg1026<kill>, 5

The regular coalescer will not be able to coalesce reg1026 and reg1029 because it doesn't
know how to combine sub-register indices 5 and 6. Now 2-address pass will consult the
target whether sub-registers 5 and 6 of reg1026 can be combined to into a larger
sub-register (or combined to be reg1026 itself as is the case here). If it is possible, 
it will be able to replace references of reg1026 with reg1029 + the larger sub-register
index.

llvm-svn: 103835
2010-05-14 23:21:14 +00:00
Evan Cheng
791573787a If REG_SEQUENCE source is livein, copy it first. Also, update livevariables information when a copy is introduced.
llvm-svn: 103680
2010-05-13 00:00:35 +00:00
Evan Cheng
29c800f0f0 Code clean up.
llvm-svn: 103538
2010-05-12 01:27:49 +00:00
Evan Cheng
b4ac902aee Ensure REG_SEQUENCE source operands are unique.
llvm-svn: 103449
2010-05-11 00:04:31 +00:00