Commit Graph

1632 Commits

Author SHA1 Message Date
Evan Cheng 1bc8af207e Implement multiple with overflow by 2 with an add instruction.
llvm-svn: 63090
2009-01-27 03:30:42 +00:00
Dan Gohman 8738997c11 Add a regression test for x86-64 red zone usage.
llvm-svn: 63075
2009-01-27 00:40:27 +00:00
Duncan Sands d77e476921 Fix PR3393, which amounts to a bug in the expensive
checking logic.  Rather than make the checking more
complicated, I've tweaked some logic to make things
conform to how the checking thought things ought to
be, since this results in a simpler "mental model".

llvm-svn: 63048
2009-01-26 21:54:18 +00:00
Dan Gohman ac272eaf13 At Nick Lewycky's request, rename this test with a more informative name.
llvm-svn: 63042
2009-01-26 21:36:31 +00:00
Evan Cheng 6c7e85142b Enhance logic in X86DAGToDAGISel::PreprocessForRMW which move load inside callseq_start to allow it to be folded into a call. It was not considering the cases where a token factor is between the load and the callseq_start.
llvm-svn: 63022
2009-01-26 18:43:34 +00:00
Scott Michel 9e3e4a9219 CellSPU:
- Rename fcmp.ll test to fcmp32.ll, start adding new double tests to fcmp64.ll
- Fix select_bits.ll test
- Capitulate to the DAGCombiner and move i64 constant loads to instruction
  selection (SPUISelDAGtoDAG.cpp).

  <rant>DAGCombiner will insert all kinds of 64-bit optimizations after
  operation legalization occurs and now we have to do most of the work that
  instruction selection should be doing twice (once to determine if v2i64
  build_vector can be handled by SelectCode(), which then runs all of the
  predicates a second time to select the necessary instructions.) But,
  CellSPU is a good citizen.</rant>

llvm-svn: 62990
2009-01-26 03:31:40 +00:00
Nate Begeman 5eca265519 Map address space 256 to gs; similar mappings could be supported for the
other x86 segments.  address space 0 is stack/default, 1-255 are reserved for
client use.

llvm-svn: 62980
2009-01-26 01:24:32 +00:00
Torok Edwin 97be2f5840 revert this patch for now, because Codegen does still want to generate SSE code,
for example in the case of va-args. XFAIL associated tests.

llvm-svn: 62972
2009-01-25 20:21:24 +00:00
Torok Edwin a23c73bbdc If user explicitly asks not to use SSE, don't force it. This fixes LLVM part of PR3402.
llvm-svn: 62967
2009-01-25 17:58:56 +00:00
Evan Cheng 1c7c019229 Private linkage support for PPC / Darwin.
llvm-svn: 62955
2009-01-25 06:32:01 +00:00
Evan Cheng abda665f5f Teach 2addr pass to be do more commuting. If both uses of a two-address instruction are killed, but the first operand has a use before and after the def, commute if the second operand does not suffer from the same issue.
%reg1028<def> = EXTRACT_SUBREG %reg1027<kill>, 1                                                                                                                                     
%reg1029<def> = MOV8rr %reg1028                                                                                                                                                      
%reg1029<def> = SHR8ri %reg1029, 7, %EFLAGS<imp-def,dead>                                                                                                                            
insert => %reg1030<def> = MOV8rr %reg1028                                                                                                                                            
%reg1030<def> = ADD8rr %reg1028<kill>, %reg1029<kill>, %EFLAGS<imp-def,dead>                                                                                                         

In this case, it might not be possible to coalesce the second MOV8rr                                                                                                                 
instruction if the first one is coalesced. So it would be profitable to                                                                                                              
commute it:                                                                                                                                                                          
%reg1028<def> = EXTRACT_SUBREG %reg1027<kill>, 1                                                                                                                                     
%reg1029<def> = MOV8rr %reg1028                                                                                                                                                      
%reg1029<def> = SHR8ri %reg1029, 7, %EFLAGS<imp-def,dead>                                                                                                                            
insert => %reg1030<def> = MOV8rr %reg1029                                                                                                                                            
%reg1030<def> = ADD8rr %reg1029<kill>, %reg1028<kill>, %EFLAGS<imp-def,dead>

llvm-svn: 62954
2009-01-25 03:53:59 +00:00
Dan Gohman 73fd5a5651 Add a PR comment to this test.
llvm-svn: 62921
2009-01-24 17:32:54 +00:00
Evan Cheng f347c3615b Update test to reflect command line option name change.
llvm-svn: 62836
2009-01-23 05:45:31 +00:00
Dan Gohman 1f3411de47 Don't create ISD::FNEG nodes after legalize if they aren't legal.
Simplify x+0 to x in unsafe-fp-math mode. This avoids a bunch of
redundant work in many cases, because in unsafe-fp-math mode,
ISD::FADD with a constant is considered free to negate, so the
DAGCombiner often negates x+0 to -0-x thinking it's free, when
in reality the end result is -x, which is more expensive than x.

Also, combine x*0 to 0.

This fixes PR3374.

llvm-svn: 62789
2009-01-22 21:58:43 +00:00
Devang Patel dec7fe2e71 Do not use buggy llvm-gcc to generate testcases.
llvm-svn: 62770
2009-01-22 18:28:11 +00:00
Bill Wendling 6cf1f8fd5b Now with RUN line.
llvm-svn: 62716
2009-01-21 21:28:03 +00:00
Bill Wendling ba11cd338b Run this through -simplifycfg and -mem2reg to test only what we need to test.
llvm-svn: 62714
2009-01-21 21:02:27 +00:00
Dan Gohman 7e6b932f18 Simplify ReduceLoadWidth's logic: it doesn't need several different
special cases after producing the new reduced-width load, because the
new load already has the needed adjustments built into it. This fixes
several bugs due to the special cases, including PR3317.

llvm-svn: 62692
2009-01-21 15:17:51 +00:00
Dan Gohman b43c8996f2 Fix a recent regression. ClrOpcode is not set for i8; for i8, if
we want to clear %ah to zero before a division, just use a
zero-extending mov to %al. This fixes PR3366.

llvm-svn: 62691
2009-01-21 14:50:16 +00:00
Duncan Sands 1de451d0d0 Let's try to have our cake and eat it to: move
this test into FrontendC to ensure that llvm-gcc
is available; assemble using "llvm-gcc -xassembler"
rather than "as".

llvm-svn: 62683
2009-01-21 11:37:31 +00:00
Duncan Sands 696f4a8598 Don't rely on grep -w working.
llvm-svn: 62682
2009-01-21 09:41:42 +00:00
Scott Michel ed7d79fce4 CellSPU:
- Ensure that (operation) legalization emits proper FDIV libcall when needed.
- Fix various bugs encountered during llvm-spu-gcc build, along with various
  cleanups.
- Start supporting double precision comparisons for remaining libgcc2 build.
  Discovered interesting DAGCombiner feature, which is currently solved via
  custom lowering (64-bit constants are not legal on CellSPU, but DAGCombiner
  insists on inserting one anyway.)
- Update README.

llvm-svn: 62664
2009-01-21 04:58:48 +00:00
Evan Cheng 201501995f Favors generating "not" over "xor -1". For example.
unsigned test(unsigned a) {
  return ~a;
}
llvm used to generate:
movl    $4294967295, %eax
xorl    4(%esp), %eax

Now it generates:
movl      4(%esp), %eax
notl      %eax

It's 3 bytes shorter.

llvm-svn: 62661
2009-01-21 02:09:05 +00:00
Owen Anderson be7a29de0b Be more aggressive about renumbering vregs after splitting them.
llvm-svn: 62639
2009-01-21 00:13:28 +00:00
Chris Lattner f8a8c13c1e Don't bother running the assembler, we don't know that it will be configured
for whatever llc defaults to.  This fixes PR3363

llvm-svn: 62619
2009-01-20 21:41:53 +00:00
Evan Cheng f1e873a221 Fix PR3243: a LiveVariables bug. When HandlePhysRegKill is checking whether the last reference is also the last def (i.e. dead def), it should also check if last reference is the current machine instruction being processed. This can happen when it is processing a physical register use and setting the current machine instruction as sub-register's last ref.
llvm-svn: 62617
2009-01-20 21:25:12 +00:00
Evan Cheng 4022b7c3f4 Add test case for PR3154.
llvm-svn: 62604
2009-01-20 19:29:54 +00:00
Bill Wendling 1d9c8e5522 Testcase for limited precision stuff.
llvm-svn: 62572
2009-01-20 06:23:59 +00:00
Dan Gohman 161b7b66ac Fix a dagcombine to not generate loads of non-round integer types,
as its comment says, even in the case where it will be generating
extending loads. This fixes PR3216.

llvm-svn: 62557
2009-01-20 01:06:45 +00:00
Evan Cheng 8f79775a66 Make linear scan's trivial coalescer slightly more aggressive.
llvm-svn: 62547
2009-01-20 00:16:18 +00:00
Dale Johannesen d067ecd1c7 Move & restructure test per review.
llvm-svn: 62538
2009-01-19 22:33:12 +00:00
Dan Gohman cd0b1bf0a0 Fix SelectionDAG::ReplaceAllUsesWith to behave correctly when
uses are added to the From node while it is processing From's
use list, because of automatic local CSE. The fix is to avoid
visiting any new uses.

Fix a few places in the DAGCombiner that assumed that after
a RAUW call, the From node has no users and may be deleted.

This fixes PR3018.

llvm-svn: 62533
2009-01-19 21:44:21 +00:00
Dale Johannesen 740e98704d compile-time fmod was done incorrectly. PR 3316.
llvm-svn: 62528
2009-01-19 21:17:05 +00:00
Devang Patel 8c8aa2ac29 Verify Intrinsic::dbg_declare.
llvm-svn: 62526
2009-01-19 21:00:48 +00:00
Evan Cheng 44cc554311 DIVREM isel deficiency: If sign bit is known zero, zero out DX/EDX/RDX instead of sign extending the low part (in AX/EAX/RAX) into it.
llvm-svn: 62519
2009-01-19 19:06:11 +00:00
Evan Cheng 7e9ef4d776 Now not UINT_TO_FP is legal (it's marked custom), dag combiner won't
optimize it to a SINT_TO_FP when the sign bit is known zero. X86 isel should perform the optimization itself.

llvm-svn: 62504
2009-01-19 08:08:22 +00:00
Chris Lattner 64b7bd7f9e Fix rdar://6505632, an llc crash on 483.xalancbmk
llvm-svn: 62470
2009-01-18 20:35:00 +00:00
Bill Wendling 9880a2cb2f Testcase for last commit.
llvm-svn: 62418
2009-01-17 07:42:44 +00:00
Evan Cheng bf38a5e540 Fix MatchAddress bug that's preventing negative displacement from being folded in 64-bit mode.
llvm-svn: 62413
2009-01-17 07:09:27 +00:00
Mon P Wang ca6d6dea0b Simplify extract element of a scalar to vector.
llvm-svn: 62383
2009-01-17 00:07:25 +00:00
Evan Cheng 41e9f6a854 Fix PPC ISD::Declare isel and eliminate the need for PPCTargetLowering::LowerGlobalAddress to check if isVerifiedDebugInfoDesc() is true. Given the recent changes, it would falsely return true for a lot of GlobalAddressSDNode's.
llvm-svn: 62373
2009-01-16 22:57:32 +00:00
Dan Gohman f1002495e3 Disable the post-RA scheduler on this test, since it uses a
simple %prcontext which doesn't find what it's looking for
if the scheduler has rearranged the instructions.

llvm-svn: 62363
2009-01-16 21:40:12 +00:00
Evan Cheng 968e2e7b3d CreateVirtualRegisters does trivial copy coalescing. If a node def is used by a single CopyToReg, it reuses the virtual register assigned to the CopyToReg. This won't work for SDNode that is a clone or is itself cloned. Disable this optimization for those nodes or it can end up with non-SSA machine instructions.
llvm-svn: 62356
2009-01-16 20:57:18 +00:00
Bill Wendling e04334730e Add support for non-zero __builtin_return_address values on X86.
llvm-svn: 62338
2009-01-16 19:25:27 +00:00
Mon P Wang e248edff1b Added missing support to widen an operand from a bit convert.
llvm-svn: 62285
2009-01-15 22:43:38 +00:00
Rafael Espindola f2831d6cd1 Fix Alpha test and support for private linkage.
llvm-svn: 62282
2009-01-15 21:51:46 +00:00
Mon P Wang ebfafee903 Expand insert/extract of a <4 x i32> with a variable index.
llvm-svn: 62281
2009-01-15 21:10:20 +00:00
Rafael Espindola 6de96a1b5d Add the private linkage.
llvm-svn: 62279
2009-01-15 20:18:42 +00:00
Richard Osborne 40119780a8 Don't fold address calculations which use negative offsets into
the ADDRspii addressing mode.

llvm-svn: 62258
2009-01-15 11:32:30 +00:00
Scott Michel a292fc6d6b - Convert remaining i64 custom lowering into custom instruction emission
sequences in SPUDAGToDAGISel.cpp and SPU64InstrInfo.td, killing custom
  DAG node types as needed.
- i64 mul is now a legal instruction, but emits an instruction sequence
  that stretches tblgen and the imagination, as well as violating laws of
  several small countries and most southern US states (just kidding, but
  looking at a function with 80+ parameters is really weird and just plain
  wrong.)
- Update tests as needed.

llvm-svn: 62254
2009-01-15 04:41:47 +00:00
Richard Osborne 4359325ba8 Add pseudo instructions to the XCore for (load|store|load address) of a
frame index. eliminateFrameIndex will replace these instructions with
(LDWSP|STWSP|LDAWSP) or (LDW|STW|LDAWF) if a frame pointer is in use.

This fixes PR 3324. Previously we used LDWSP, STWSP, LDAWSP before frame
pointer elimination. However since they were marked as implicitly using
SP they could not be rematerialised.

llvm-svn: 62238
2009-01-14 18:26:46 +00:00
Dan Gohman b8f5ba6781 Disable the register+memory forms of the bt instructions for now. Thanks
to Eli for pointing out that these forms don't ignore the high bits of
their index operands, and as such are not immediately suitable for use
by isel.

llvm-svn: 62194
2009-01-13 23:23:30 +00:00
Dan Gohman 1407484178 The list-td and list-tdrr schedulers don't yet support physreg
scheduling dependencies. Add assertion checks to help catch
this.

It appears the Mips target defaults to list-td, and it has a
regression test that uses a physreg dependence. Such code was
liable to be miscompiled, and now evokes an assertion failure.

llvm-svn: 62177
2009-01-13 20:24:13 +00:00
Duncan Sands ffc6133318 When replacing uses and the same node is reached
via two paths, process it once not twice, d'oh!
Analysis, testcase and original patch thanks to
Mon Ping Wang.

llvm-svn: 62169
2009-01-13 15:17:14 +00:00
Evan Cheng f343168f1f FIX llvm-gcc bootstrap on x86_64 linux. If a virtual register is copied to a physical register, it's not necessarily defined by a copy. We have to watch out it doesn't clobber any sub-register that might be live during its live interval. If the live interval crosses a basic block, then it's not safe to check with the less conservative check (by scanning uses and defs) because it's possible a sub-register might be live out of the block.
llvm-svn: 62144
2009-01-13 03:57:45 +00:00
Devang Patel 76007e009e Use DebugInfo interface to lower dbg_* intrinsics.
llvm-svn: 62126
2009-01-13 00:32:17 +00:00
Evan Cheng b2c42c648d Fix PR3241: Currently EmitCopyFromReg emits a copy from the physical register to a virtual register unless it requires an expensive cross class copy. That means we are only treating "expensive to copy" register dependency as physical register dependency.
Also future proof the scheduler to handle "normal" physical register dependencies. The code is not exercised yet.

llvm-svn: 62074
2009-01-12 03:19:55 +00:00
Evan Cheng 8e7d88b916 This is a dup of pr2659.ll.
llvm-svn: 62029
2009-01-10 19:06:32 +00:00
Evan Cheng ed74d8ac2a Duplicated node may produce a non-physical register def.
llvm-svn: 62015
2009-01-09 22:44:02 +00:00
Evan Cheng c1f5a659de Add test case from PR2659.
llvm-svn: 62006
2009-01-09 21:01:31 +00:00
Dan Gohman ea1086b7f2 PR2659 was fixed by r61847. Add the testcase as a regression test.
llvm-svn: 61986
2009-01-09 08:16:12 +00:00
Chris Lattner 9170731cb7 this test should not run opt -std-compile-opts, it should run
just llc.

llvm-svn: 61979
2009-01-09 05:32:00 +00:00
Misha Brukman b51cdfadda Fix off-by-one error in traversing an array; this fixes a test.
The error was reported by gcc-4.3.0 during compilation.

llvm-svn: 61896
2009-01-07 23:07:29 +00:00
Evan Cheng f6768bd9cb The coalescer does not coalesce a virtual register to a physical register if any of the physical register's sub-register live intervals overlaps with the virtual register. This is overly conservative. It prevents a extract_subreg from being coalesced away:
v1024 = EDI  // not killed
      =
      = EDI

One possible solution is for the coalescer to examine the sub-register live intervals in the same manner as the physical register. Another possibility is to examine defs and uses (when needed) of sub-registers. Both solutions are too expensive. For now, look for "short virtual intervals" and scan instructions to look for conflict instead.

This is a small win on x86-64. e.g. It shaves 403.gcc by ~80 instructions.

llvm-svn: 61847
2009-01-07 02:08:57 +00:00
Chris Lattner 4687432d03 add a testcase.
llvm-svn: 61845
2009-01-07 01:48:08 +00:00
Dan Gohman 8e8d1da35a Add patterns to match conditional moves with loads folded
into their left operand, rather than their right. Do this
by commuting the operands and inverting the condition.

llvm-svn: 61842
2009-01-07 01:00:24 +00:00
Dan Gohman 33e6fcd56f X86_COND_C and X86_COND_NC are alternate mnemonics for
X86_COND_B and X86_COND_AE, respectively.

llvm-svn: 61835
2009-01-07 00:15:08 +00:00
Dan Gohman 44a3da6c4d Now that fold-pcmpeqd-0.ll is effectively testing that scheduling helps
avoid the need for spilling, add a new testcase that tests that the
pcmpeqd used for V_SETALLONES is changed to a constant-pool load as
needed.

llvm-svn: 61831
2009-01-06 23:48:10 +00:00
Dan Gohman beac19e299 Revert r42653 and forward-port the code that lets INC64_32r be
converted to LEA64_32r in x86's convertToThreeAddress. This
replaces code like this:
   movl  %esi, %edi
   inc   %edi
with this:
   lea   1(%rsi), %edi
which appears to be beneficial.

llvm-svn: 61830
2009-01-06 23:34:46 +00:00
Dan Gohman c7847cdb8d Fix a bug in ComputeLinearIndex computation handling multi-level
aggregate types. Don't increment the current index after reaching
the end of a struct, as it will already be pointing at
one-past-the end. This fixes PR3288.

llvm-svn: 61828
2009-01-06 22:53:52 +00:00
Scott Michel 6887caf11c CellSPU:
- Fix bugs 3194, 3195: i128 load/stores produce correct code (although, we
  need to ensure that i128 is 16-byte aligned in real life), and 128 zero-
  extends are supported.
- New td file: SPU128InstrInfo.td: this is where all new i128 support should
  be put in the future.
- Continue to hammer on i64 operations and test cases; ensure that the only
  remaining problem will be i64 mul.

llvm-svn: 61784
2009-01-06 03:36:14 +00:00
Dan Gohman 53c282cce8 Delete this test; it's a duplicate of 2006-07-03-schedulers.ll.
llvm-svn: 61781
2009-01-06 01:36:23 +00:00
Dan Gohman 79c3516912 Use a latency value of 0 for the artificial edges inserted by
AddPseudoTwoAddrDeps. This lets the scheduling infrastructure
avoid recalculating node heights. In very large testcases this
was a major bottleneck. Thanks to Roman Levenstein for finding
this!

As a side effect, fold-pcmpeqd-0.ll is now scheduled better
and it no longer requires spilling on x86-32.

llvm-svn: 61778
2009-01-06 01:19:04 +00:00
Evan Cheng 8804293fe9 Find loop back edges only after empty blocks are eliminated.
llvm-svn: 61752
2009-01-05 21:17:27 +00:00
Scott Michel 74f249517e CellSPU:
- Teach SPU64InstrInfo.td about the remaining signed comparisons, update tests
  accordingly.

llvm-svn: 61672
2009-01-05 04:05:53 +00:00
Scott Michel f87d41d8b9 CellSPU:
- Add an 8-bit operation test, which doesn't do much at this point.

llvm-svn: 61665
2009-01-05 01:35:22 +00:00
Scott Michel a664240476 CellSPU:
- Fix (brcond (setq ...)) bug, where BRNZ should have been used vice BRZ.
- Kill unused/unnecessary nodes in SPUNodes.td
- Beef out the i64operations.c test harness to use a lot of unaligned
  loads, test loops and LLVM loop/basic block optimizations; run the
  test harness successfully on real Cell hardware.

llvm-svn: 61664
2009-01-05 01:34:35 +00:00
Dan Gohman b9fa1d24f8 Fix a DAGCombiner abort on an invalid shift count constant. This fixes PR3250.
llvm-svn: 61613
2009-01-03 19:22:06 +00:00
Scott Michel 6a1f6279ad CellSPU:
- Remove custom lowering for BRCOND
- Add remaining functionality for branches in SPUInstrInfo, such as branch
  condition reversal and load/store folding. Updated BrCond test to reflect
  branch reversal.

llvm-svn: 61597
2009-01-03 00:27:53 +00:00
Evan Cheng 4c91aa3418 Do not isel load folding bt instructions for pentium m, core, core2, and AMD processors. These are significantly slower than a load followed by a bt of a register.
llvm-svn: 61557
2009-01-02 05:35:45 +00:00
Evan Cheng 1671a309fd Use movaps / movd to extract vector element 0 even with sse4.1. It's still cheaper than pextrw especially if the value is in memory.
llvm-svn: 61555
2009-01-02 05:29:08 +00:00
Chris Lattner 836dd95506 rename a file to follow naming conventions.
llvm-svn: 61550
2009-01-02 01:52:35 +00:00
Duncan Sands 8feb694e8f Fix PR3274: when promoting the condition of a BRCOND node,
promote from i1 all the way up to the canonical SetCC type.
In order to discover an appropriate type to use, pass
MVT::Other to getSetCCResultType.  In order to be able to
do this, change getSetCCResultType to take a type as an
argument, not a value (this is also more logical).

llvm-svn: 61542
2009-01-01 15:52:00 +00:00
Bill Wendling 15a47ddf40 This is not failing on Darwin for some reason. XFAIL for other platforms.
llvm-svn: 61533
2008-12-31 19:26:09 +00:00
Scott Michel 36a494c1d1 XFAIL this for now until I can figure out what's going on.
llvm-svn: 61512
2008-12-31 00:08:25 +00:00
Scott Michel 18d756a411 Fix test erratum (which is wierd: works locally for me?)
llvm-svn: 61511
2008-12-30 23:52:05 +00:00
Scott Michel 41236c0cf3 - Start moving target-dependent nodes that could be represented by an
instruction sequence and cannot ordinarily be simplified by DAGcombine
  into the various target description files or SPUDAGToDAGISel.cpp.

  This makes some 64-bit operations legal.

- Eliminate target-dependent ISD enums.

- Update tests.

llvm-svn: 61508
2008-12-30 23:28:25 +00:00
Scott Michel 8233527b05 - Remove Tilmann's custom truncate lowering: it completely hosed over
DAGcombine's ability to find reasons to remove truncates when they were not
  needed. Consequently, the CellSPU backend would produce correct, but _really
  slow and horrible_, code.

  Replaced with instruction sequences that do the equivalent truncation in
  SPUInstrInfo.td.

- Re-examine how unaligned loads and stores work. Generated unaligned
  load code has been tested on the CellSPU hardware; see the i32operations.c
  and i64operations.c in CodeGen/CellSPU/useful-harnesses.  (While they may be
  toy test code, it does prove that some real world code does compile
  correctly.)

- Fix truncating stores in bug 3193 (note: unpack_df.ll will still make llc
  fault because i64 ult is not yet implemented.)

- Added i64 eq and neq for setcc and select/setcc; started new instruction
  information file for them in SPU64InstrInfo.td. Additional i64 operations
  should be added to this file and not to SPUInstrInfo.td.

llvm-svn: 61447
2008-12-27 04:51:36 +00:00
Chris Lattner 3d1bce04e0 add PR #
llvm-svn: 61427
2008-12-25 05:40:38 +00:00
Chris Lattner 2a7c988627 Add a simple pattern for matching 'bt'.
llvm-svn: 61426
2008-12-25 05:34:37 +00:00
Bill Wendling f4e6356d06 Revert the changes in this testcase until Anton can fix them.
llvm-svn: 61414
2008-12-24 05:23:34 +00:00
Dan Gohman 198b8e78c3 Fix a compiler-abort on a testcase where the stack-pointer is added to
a symbolic constant. This is unlikely to be intentional, but it
shouldn't crash the compiler.

llvm-svn: 61408
2008-12-24 00:27:51 +00:00
Dale Johannesen acc84e5aa0 Add another permutation where we should get rid of a-a.
llvm-svn: 61401
2008-12-23 23:01:27 +00:00
Anton Korobeynikov cfe108a064 Update test
llvm-svn: 61399
2008-12-23 22:26:37 +00:00
Mon P Wang f566eea614 Added shuffle and splat test cases for r61365.
llvm-svn: 61366
2008-12-23 04:05:08 +00:00
Dale Johannesen d2a4685860 One more permutation of subtracting off a base value.
llvm-svn: 61361
2008-12-23 01:59:54 +00:00
Dan Gohman ab316350bf Fix fast-isel to not emit invalid assembly when presented with a
constant shift count that doesn't fit in the shift instruction's
immediate field. This fixes PR3242.

llvm-svn: 61281
2008-12-20 17:19:40 +00:00
Dan Gohman bb92a1b815 Use the correct Preds and Succs lists in setHeightDirty()
and setDepthDirty(), respectively. This fixes PR3241.

llvm-svn: 61276
2008-12-20 16:34:57 +00:00
Evan Cheng 0869f78555 Fix PR3149. If an early clobber def is a physical register and it is tied to an input operand, it effectively extends the live range of the physical register. Currently we do not have a good way to represent this.
172     %ECX<def> = MOV32rr %reg1039<kill>
180     INLINEASM <es:subl $5,$1
        sbbl $3,$0>, 10, %EAX<def>, 14, %ECX<earlyclobber,def>, 9, %EAX<kill>,
36, <fi#0>, 1, %reg0, 0, 9, %ECX<kill>, 36, <fi#1>, 1, %reg0, 0
188     %EAX<def> = MOV32rr %EAX<kill>
196     %ECX<def> = MOV32rr %ECX<kill>
204     %ECX<def> = MOV32rr %ECX<kill>
212     %EAX<def> = MOV32rr %EAX<kill>
220     %EAX<def> = MOV32rr %EAX
228     %reg1039<def> = MOV32rr %ECX<kill>

The early clobber operand ties ECX input to the ECX def.

The live interval of ECX is represented as this:
%reg20,inf = [46,47:1)[174,230:0)  0@174-(230) 1@46-(47)

The right way to represent this is something like
%reg20,inf = [46,47:2)[174,182:1)[181:230:0)  0@174-(182) 1@181-230 @2@46-(47)

Of course that won't work since that means overlapping live ranges defined by two val#.

The workaround for now is to add a bit to val# which says the val# is redefined by a early clobber def somewhere. This prevents the move at 228 from being optimized away by SimpleRegisterCoalescing::AdjustCopiesBackFrom.

llvm-svn: 61259
2008-12-19 20:58:01 +00:00
Evan Cheng 3b3de7c228 - CodeGenPrepare does not split loop back edges but it only knows about back edges of single block loops. It now does a DFS walk to find loop back edges.
- Use SplitBlockPredecessors to factor out common predecessors of the critical edge destination. This is disabled for now due to some regressions.

llvm-svn: 61248
2008-12-19 18:03:11 +00:00
Rafael Espindola 770b4b830a Fix bug 3202.
The EH_frame and .eh symbols are now private, except for darwin9 and earlier.
The patch also fixes the definition of PrivateGlobalPrefix on pcc linux.

llvm-svn: 61242
2008-12-19 10:55:56 +00:00
Mon P Wang 308a1acaaf Fix test to account for generating some vector code for mul v2i64 instead
of incorrectly generating pmuldq

llvm-svn: 61228
2008-12-18 23:42:37 +00:00
Mon P Wang 6e5f4bc1e7 Added some basic test cases for r61209
llvm-svn: 61210
2008-12-18 20:05:58 +00:00
Eli Friedman 6cf404f2d1 Fix for PR3225: disable a broken optimization in
DAGTypeLegalizer::ExpandShiftWithKnownAmountBit.

In terms of restoring the optimization, the best fix here isn't 
obvious... any ideas?

llvm-svn: 61119
2008-12-17 03:35:17 +00:00
Dale Johannesen f51dcef803 A new dag combine; several permutations of this
are there under ADD, this one was missing.

llvm-svn: 61107
2008-12-16 22:13:49 +00:00
Evan Cheng c35fc49477 We have decided not to support inline asm where an output operand with a matching input operand with incompatible type (i.e. either one is a floating point and the other is an integer or the sizes of the types differ). SelectionDAGBuild will catch these and exit with an error.
llvm-svn: 61092
2008-12-16 18:21:39 +00:00
Dan Gohman 51559185f1 Enable anti-dependence breaking by default when post-RA scheduling is enabled.
llvm-svn: 61078
2008-12-16 06:21:45 +00:00
Dan Gohman dddc1ac7ea Fix some register-alias-related bugs in the post-RA scheduler liveness
computation code. Also, avoid adding output-depenency edges when both
defs are dead, which frequently happens with EFLAGS defs.

Compute Depth and Height lazily, and always in terms of edge latency
values. For the schedulers that don't care about latency, edge latencies
are set to 1.

Eliminate Cycle and CycleBound, and LatencyPriorityQueue's Latencies array.
These are all subsumed by the Depth and Height fields.

llvm-svn: 61073
2008-12-16 03:25:46 +00:00
Mon P Wang 580f2c7b61 Added support for splitting and scalarizing vector shifts.
llvm-svn: 61050
2008-12-15 21:44:00 +00:00
Mon P Wang ac4e120912 Added support to LegalizeType for expanding the operands of scalar to vector
and insert vector element.  Modified extract vector element to extend the
result to match the expected promoted type.

llvm-svn: 61029
2008-12-15 06:57:02 +00:00
Bill Wendling c4499feb1a - Use patterns instead of creating completely new instruction matching patterns,
which are identical to the original patterns.

- Change the multiply with overflow so that we distinguish between signed and
  unsigned multiplication. Currently, unsigned multiplication with overflow
  isn't working!

llvm-svn: 60963
2008-12-12 21:15:41 +00:00
Bill Wendling 0864a75ebf If ADD, SUB, or MUL have an overflow bit that's used, don't do transformation on
them. The DAG combiner expects that nodes that are transformed have one value
result.

llvm-svn: 60857
2008-12-10 22:36:00 +00:00
Duncan Sands 09ed3bba2b For amusement, implement SADDO, SSUBO, UADDO, USUBO
for promoted integer types, eg: i16 on ppc-32, or
i24 on any platform.  Complete support for arbitrary
precision integers would require handling expanded
integer types, eg: i128, but I couldn't be bothered.

llvm-svn: 60834
2008-12-10 12:30:42 +00:00
Mon P Wang 4637c3c698 Fixed a bug when trying to optimize a extract vector element of a
bit convert that changes the number of elements of a shuffle.

llvm-svn: 60829
2008-12-10 03:59:02 +00:00
Bill Wendling 8008cb9a77 Implement fast-isel conversion of a branch instruction that's branching on an
overflow/carry from the "arithmetic with overflow" intrinsics. It searches the
machine basic block from bottom to top to find the SETO/SETC instruction that is
its conditional. If an instruction modifies EFLAGS before it reaches the
SETO/SETC instruction, then it defaults to the normal instruction emission.

llvm-svn: 60807
2008-12-09 23:19:12 +00:00
Bill Wendling db8ec2d75a Add sub/mul overflow intrinsics. This currently doesn't have a
target-independent way of determining overflow on multiplication. It's very
tricky. Patch by Zoltan Varga!

llvm-svn: 60800
2008-12-09 22:08:41 +00:00
Duncan Sands 445071c44f Fix PR3117: not all nodes being legalized. The
essential problem was that the DAG can contain
random unused nodes which were never analyzed.
When remapping a value of a node being processed,
such a node may become used and need to be analyzed;
however due to operands being transformed during
analysis the node may morph into a different one.
Users of the morphing node need to be updated, and
this wasn't happening.  While there I added a bunch
of documentation and sanity checks, so I (or some
other poor soul) won't have to scratch their head
over this stuff so long trying to remember how it
was all supposed to work next time some obscure
problem pops up!  The extra sanity checking exposed
a few places where invariants weren't being preserved,
so those are fixed too.  Since some of the sanity
checking is expensive, I added a flag to turn it
on.  It is also turned on when building with
ENABLE_EXPENSIVE_CHECKS=1.

llvm-svn: 60797
2008-12-09 21:33:20 +00:00
Scott Michel 02e2c2450e CellSPU:
- Fix call.ll and call_indirect.ll expected results, now that it's using a
  different pre-register allocation scheduler.

llvm-svn: 60741
2008-12-09 06:12:03 +00:00
Mon P Wang 4dd832d241 Fix getNode to allow a vector for the shift amount for shifts of vectors.
Fix the shift amount when unrolling a vector shift into scalar shifts.
Fix problem in getShuffleScalarElt where it assumes that the input of
a bit convert must be a vector.

llvm-svn: 60740
2008-12-09 05:46:39 +00:00
Dan Gohman 4c31524bec Factor out the code for sign-extending/truncating gep indices
and use it in x86 address mode folding. Also, make
getRegForValue return 0 for illegal types even if it has a
ValueMap for them, because Argument values are put in the
ValueMap. This fixes PR3181.

llvm-svn: 60696
2008-12-08 07:57:47 +00:00
Evan Cheng ab85feb91c Clean up some ARM GV asm printing out; minor fixes to match what gcc does.
llvm-svn: 60621
2008-12-06 02:00:55 +00:00
Dale Johannesen 0733759b5a Fix test to pass on Linux.
llvm-svn: 60614
2008-12-05 22:38:21 +00:00
Dale Johannesen 9efd2ce55b Make LoopStrengthReduce smarter about hoisting things out of
loops when they can be subsumed into addressing modes.

Change X86 addressing mode check to realize that
some PIC references need an extra register.
(I believe this is correct for Linux, if not, I'm sure
someone will tell me.)

llvm-svn: 60608
2008-12-05 21:47:27 +00:00
Evan Cheng 7a15646d69 This test also requires -mattr=+sse41.
llvm-svn: 60601
2008-12-05 19:26:37 +00:00
Evan Cheng fd8c4d5975 Effectively undo 60461 in PIC mode which simply transform V_SET0 / V_SETALLONES into a load from constpool in order to fold into restores. This is not safe to do when PIC base is being used for a number of reasons:
1. GlobalBaseReg may have been spilled.
2. It may not be live at the use.
3. Spiller doesn't know this is happening so it won't prevent GlobalBaseReg from being spilled later (That by itself is a nasty hack. It's needed because we don't insert the reload until later).

llvm-svn: 60595
2008-12-05 17:23:48 +00:00
Evan Cheng 2a03c7e977 Re-did 60519. It turns out Darwin's handling of hidden visibility symbols are a bit more complicate than I expected. Both declarations and weak definitions still need a stub indirection. However, the stubs are in data section and they contain the addresses of the actual symbols.
llvm-svn: 60571
2008-12-05 01:06:39 +00:00
Scott Michel 6ce01ab378 CellSPU: Add new directory under tests/CodeGen/CellSPU to retain tests that
aren't part of the test suite but are generally useful nonetheless, and can
be expanded later to test the backend against the actual Cell SPU system.

There's basically no other good place to put this code, so put it here for
the time being.

- vecoperations.c: Vector shuffles for all supported vector types, tests
  for v16i8 add and multiply.

llvm-svn: 60566
2008-12-05 00:01:00 +00:00
Bill Wendling 6949f6135b Temporarily revert r60519. It was causing a bootstrap failure:
/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.obj/./gcc/xgcc -B/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.obj/./gcc/ -B/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.install/i386-apple-darwin9.5.0/bin/ -B/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.install/i386-apple-darwin9.5.0/lib/ -isystem /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.install/i386-apple-darwin9.5.0/include -isystem /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.install/i386-apple-darwin9.5.0/sys-include -DHAVE_CONFIG_H -I. -I../../../llvm-gcc.src/libgomp -I. -I../../../llvm-gcc.src/libgomp/config/posix -I../../../llvm-gcc.src/libgomp -Wall -pthread -Werror -O2 -g -O2 -MT barrier.lo -MD -MP -MF .deps/barrier.Tpo -c ../../../llvm-gcc.src/libgomp/barrier.c  -fno-common -DPIC -o .libs/barrier.o
checking for sys/file.h... /var/folders/zG/zGE-ZJOGFiGjv0B5cs5oYE+++TM/-Tmp-//cc34Jg5P.s:13:non-relocatable subtraction expression, "_gomp_tls_key" minus "L1$pb"
/var/folders/zG/zGE-ZJOGFiGjv0B5cs5oYE+++TM/-Tmp-//cc34Jg5P.s:13:symbol: "_gomp_tls_key" can't be undefined in a subtraction expression
make[4]: *** [barrier.lo] Error 1
make[4]: *** Waiting for unfinished jobs....
/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.obj/./gcc/xgcc -B/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.obj/./gcc/ -B/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.install/i386-apple-darwin9.5.0/bin/ -B/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.install/i386-apple-darwin9.5.0/lib/ -isystem /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.install/i386-apple-darwin9.5.0/include -isystem /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm-gcc.install/i386-apple-darwin9.5.0/sys-include -DHAVE_CONFIG_H -I. -I../../../llvm-gcc.src/libgomp -I. -I../../../llvm-gcc.src/libgomp/config/posix -I../../../llvm-gcc.src/libgomp -Wall -pthread -Werror -O2 -g -O2 -MT alloc.lo -MD -MP -MF .deps/alloc.Tpo -c ../../../llvm-gcc.src/libgomp/alloc.c -o alloc.o >/dev/null 2>&1
yes
checking for sys/param.h... make[3]: *** [all-recursive] Error 1
make[2]: *** [all] Error 2
make[1]: *** [all-target-libgomp] Error 2
make[1]: *** Waiting for unfinished jobs....

llvm-svn: 60527
2008-12-04 04:07:00 +00:00
Evan Cheng 011c4fa8a1 Visibility hidden GVs do not require extra load of symbol address from the GOT or non-lazy-ptr.
llvm-svn: 60519
2008-12-04 01:56:50 +00:00
Evan Cheng 1339e72d97 Use mmx (punpckldq VR64, (mmx_v_set0)) to clear high 32-bits of a VR64 register.
llvm-svn: 60499
2008-12-03 19:38:05 +00:00
Rafael Espindola 74dc32d422 Fix some tests. The grep for "il" was matching "file".
llvm-svn: 60485
2008-12-03 17:14:56 +00:00
Richard Osborne feece7edab Add support for ISD::TRAP to the XCore backend
llvm-svn: 60479
2008-12-03 10:59:16 +00:00
Evan Cheng b5a97ff651 Fix test.
llvm-svn: 60476
2008-12-03 08:20:45 +00:00
Dan Gohman cc78cdf275 Mark x86's V_SET0 and V_SETALLONES with isSimpleLoad, and teach X86's
foldMemoryOperand how to "fold" them, by converting them into constant-pool
loads. When they aren't folded, they use xorps/cmpeqd, but for example when
register pressure is high, they may now be folded as memory operands, which
reduces register pressure.

Also, mark V_SET0 isAsCheapAsAMove so that two-address-elimination will
remat it instead of copying zeros around (V_SETALLONES was already marked).

llvm-svn: 60461
2008-12-03 05:21:24 +00:00
Bill Wendling e3402692d8 Change label to 'carry' for unsigned adds.
llvm-svn: 60460
2008-12-03 02:43:12 +00:00
Dan Gohman 5d3d1f69e1 Fix byval arguments in the fastcc calling convention. The fastcc convention
delegates to the regular x86-32 convention which handles byval, but only
after it handles a few cases, and it's necessary to handle byval before
handling those cases. This fixes PR3122 (and rdar://6400815), llvm-gcc
miscompiling LLVM.

llvm-svn: 60453
2008-12-03 01:28:04 +00:00
Dan Gohman 971c88f3b2 Add nounwind attributes to this test.
llvm-svn: 60451
2008-12-03 01:10:18 +00:00
Dale Johannesen b43a689520 testcases for recent dag combiner changes
llvm-svn: 60449
2008-12-03 00:52:41 +00:00
Evan Cheng e62150cae4 Remove a (what appears to be) overly strict assertion. Here is what happened:
1. ppcf128 select is expanded to f64 select's.
2. f64 select operand 0 is an i1 truncate, it's promoted to i32 zero_extend.
3. f64 select is updated. It's changed back to a "NewNode" and being re-analyzed.
4. f64 select operands are being processed. Operand 0 is a "NewNode". It's being expunged out of ReplacedValues map.
5. ExpungeNode tries to remap f64 select and notice it's a "NewNode" and assert.
Duncan, please take a look. Thanks.

llvm-svn: 60443
2008-12-02 21:57:09 +00:00
Scott Michel 7364025ff8 CellSPU:
- Incorporate Tilmann Scheller's ISD::TRUNCATE custom lowering patch
- Update SPU calling convention info, even if it's not used yet (but can be
  at some point or another)
- Ensure that any-extended f32 loads are custom lowered, especially when
  they're promoted for use in printf.

llvm-svn: 60438
2008-12-02 19:53:53 +00:00
Evan Cheng 1718fd4375 Fix PR3124: overly strict assert.
llvm-svn: 60392
2008-12-02 02:15:36 +00:00
Bill Wendling 30e9dc81c8 Second stab at target-dependent lowering of everyone's favorite nodes: [SU]ADDO
- LowerXADDO lowers [SU]ADDO into an ADD with an implicit EFLAGS define. The
  EFLAGS are fed into a SETCC node which has the conditional COND_O or COND_C,
  depending on the type of ADDO requested.

- LowerBRCOND now recognizes if it's coming from a SETCC node with COND_O or
  COND_C set.

llvm-svn: 60388
2008-12-02 01:06:39 +00:00
Chris Lattner b2f131a4ab Add rdar reference, make this actually fail when the patch isn't applied.
llvm-svn: 60376
2008-12-01 22:35:31 +00:00
Dale Johannesen 069a4eee55 Consider only references to an IV within the loop when
figuring out the base of the IV.  This produces better
code in the example.  (Addresses use (IV) instead of 
(BASE,IV) - a significant improvement on low-register
machines like x86).

llvm-svn: 60374
2008-12-01 22:00:01 +00:00
Scott Michel 08a4e2045d CellSPU:
- Fix v2[if]64 vector insertion code before IBM files a bug report.
- Ensure that zero (0) offsets relative to $sp don't trip an assert
  (add $sp, 0 gets legalized to $sp alone, tripping an assert)
- Shuffle masks passed to SPUISD::SHUFB are now v16i8 or v4i32

llvm-svn: 60358
2008-12-01 17:56:02 +00:00
Eli Friedman c8228d263b Followup to r60283: optimize arbitrary width signed divisions as well
as unsigned divisions.  Same caveats as before.

llvm-svn: 60284
2008-11-30 06:35:39 +00:00
Eli Friedman 1b7fc154a5 Fix for PR2164: allow transforming arbitrary-width unsigned divides into
multiplies.

Some more cleverness would be nice, though. It would be nice if we 
could do this transformation on illegal types.  Also, we would 
prefer a narrower constant when possible so that we can use a narrower
multiply, which can be cheaper.

llvm-svn: 60283
2008-11-30 06:02:26 +00:00
Eli Friedman bd0f57821a APIntify a test which is potentially unsafe otherwise, and fix the
nearby FIXME.

I'm not sure what the right way to fix the Cell test was; if the 
approach I used isn't okay, please let me know.

llvm-svn: 60277
2008-11-30 04:59:26 +00:00
Bill Wendling 077eb6fcc2 XFAil test due to reverting of patch.
llvm-svn: 60161
2008-11-27 07:34:10 +00:00
Evan Cheng 3761143755 Avoid inserting noop's in the middle of a loop.
llvm-svn: 60141
2008-11-27 01:16:00 +00:00
Evan Cheng 83bdb38965 On x86 favors folding short immediate into some arithmetic operations (e.g. add, and, xor, etc.) because materializing an immediate in a register is expensive in turns of code size.
e.g.
movl 4(%esp), %eax
addl $4, %eax

is 2 bytes shorter than

movl $4, %eax
addl 4(%esp), %eax

llvm-svn: 60139
2008-11-27 00:49:46 +00:00
Evan Cheng d1dda5339d Add -march=x86.
llvm-svn: 60135
2008-11-27 00:37:06 +00:00
Bill Wendling a69ced6b68 Add x86-specific test for add-with-overflow intrinsics.
llvm-svn: 60125
2008-11-26 22:42:19 +00:00
Chris Lattner 397a11ccd8 Turn on my codegen prepare heuristic by default. It doesn't affect
performance in most cases on the Grawp tester, but does speed some 
things up (like shootout/hash by 15%).  This also doesn't impact 
compile time in a noticable way on the Grawp tester.

It also, of course, gets the testcase it was designed for right :)

llvm-svn: 60120
2008-11-26 22:16:44 +00:00
Duncan Sands d1ba7908cf Check that running the DAG combiner between type
and operation legalization does something useful.

llvm-svn: 60108
2008-11-26 16:44:30 +00:00
Chris Lattner eb3e4fb6fb This adds in some code (currently disabled unless you pass
-enable-smarter-addr-folding to llc) that gives CGP a better
cost model for when to sink computations into addressing modes.
The basic observation is that sinking increases register 
pressure when part of the addr computation has to be available
for other reasons, such as having a use that is a non-memory
operation.  In cases where it works, it can substantially reduce
register pressure.

This code is currently an overall win on 403.gcc and 255.vortex
(the two things I've been looking at), but there are several 
things I want to do before enabling it by default:

1. This isn't doing any caching of results, so it is much slower 
   than it could be.  It currently slows down release-asserts llc 
   by 1.7% on 176.gcc: 27.12s -> 27.60s.
2. This doesn't think about inline asm memory operands yet.
3. The cost model botches the case when the needed value is live
   across the computation for other reasons.

I'll continue poking at this, and eventually turn it on as llcbeta.

llvm-svn: 60074
2008-11-26 02:00:14 +00:00
Chris Lattner a9ab165b08 Teach CodeGenPrepare to look through Bitcast instructions when attempting to
optimize addressing modes.  This allows us to optimize things like isel-sink2.ll
into:

	movl	4(%esp), %eax
	cmpb	$0, 4(%eax)
	jne	LBB1_2	## F
LBB1_1:	## TB
	movl	$4, %eax
	ret
LBB1_2:	## F
	movzbl	7(%eax), %eax
	ret

instead of:

_test:
	movl	4(%esp), %eax
	cmpb	$0, 4(%eax)
	leal	4(%eax), %eax
	jne	LBB1_2	## F
LBB1_1:	## TB
	movl	$4, %eax
	ret
LBB1_2:	## F
	movzbl	3(%eax), %eax
	ret

This shrinks (e.g.) 403.gcc from 1133510 to 1128345 lines of .s.

Note that the 2008-10-16-SpillerBug.ll testcase is dubious at best, I doubt
it is really testing what it thinks it is.

llvm-svn: 60068
2008-11-26 00:26:16 +00:00
Chris Lattner f0e01def8c fix an over-reduced test.
llvm-svn: 60067
2008-11-26 00:12:08 +00:00
Chris Lattner 0f98f74c74 this doesn't need EH
llvm-svn: 60066
2008-11-26 00:03:26 +00:00
Scott Michel 910046d174 CellSPU:
(a) Remove conditionally removed code in SelectXAddr. Basically, hope for the
    best that the A-form and D-form address predicates catch everything before
    the code decides to emit a X-form address.
(b) Expand vector store test cases to include the usual suspects.

llvm-svn: 60034
2008-11-25 17:29:43 +00:00
Scott Michel 5149430c6e CellSPU: test should use shlqby, not shlqbyi
llvm-svn: 60001
2008-11-25 01:30:37 +00:00
Bill Wendling aec5a56446 XFAIL this test. A recent CellSPU check-in broke it.
llvm-svn: 60000
2008-11-25 00:56:34 +00:00
Dan Gohman ad2134d45d Initial support for anti-dependence breaking. Currently this code does not
introduce any new spilling; it just uses unused registers.

Refactor the SUnit topological sort code out of the RRList scheduler and
make use of it to help with the post-pass scheduler.

llvm-svn: 59999
2008-11-25 00:52:40 +00:00
Scott Michel 2e5df906f8 CellSPU:
(a) Slight rethink on i64 zero/sign/any extend code - use a shuffle to
    directly zero-extend i32 to i64, but use rotates and shifts for
    sign extension. Also ensure unified register consistency.
(b) Add new test harness for i64 operations: i64ops.ll

llvm-svn: 59970
2008-11-24 18:20:46 +00:00
Scott Michel efc8c7a292 CellSPU:
(a) Improve the extract element code: there's no need to do gymnastics with
    rotates into the preferred slot if a shuffle will do the same thing.
(b) Rename a couple of SPUISD pseudo-instructions for readability and better
    semantic correspondence.
(c) Fix i64 sign/any/zero extension lowering.

llvm-svn: 59965
2008-11-24 17:11:17 +00:00
Bill Wendling 411eaa5c57 Test add-with-overflow with fast ISel.
llvm-svn: 59945
2008-11-24 05:23:38 +00:00
Bill Wendling 2278f8f5e1 Add support for llvm.uadd.with.overflow.
llvm-svn: 59926
2008-11-24 01:38:29 +00:00
Scott Michel 0be0339baa CellSPU: Fix bug 3056. Varadic extract_element was not implemented (nor was it
ever conceived to occur).

llvm-svn: 59891
2008-11-22 23:50:42 +00:00
Scott Michel c6918c1ffa CellSPU:
(a) Fix bgs 3052, 3057
(b) Incorporate Duncan's suggestions re: i1 promotion
(c) Indentation updates.

llvm-svn: 59790
2008-11-21 02:56:16 +00:00
Bill Wendling d10202bfb1 Add generic test for add with overflow.
llvm-svn: 59781
2008-11-21 02:15:51 +00:00
Dan Gohman 52aece7eff Test -pre-RA-sched=fast too, for completeness.
llvm-svn: 59741
2008-11-20 19:26:04 +00:00
Evan Cheng c22215a090 - Register scavenger should use MachineRegisterInfo and internal map to find the first use of a register after a given machine instruction.
- When scavenging a register, in addition to the spill, insert a restore before the first use.
- Abort if client is looking to scavenge a register even when a previously scavenged register is still live.

llvm-svn: 59697
2008-11-20 02:32:35 +00:00
Dan Gohman 7f480e04eb Revert r59640. It broke this test for builds that aren't
configured with llvm-gcc.

llvm-svn: 59641
2008-11-19 16:24:37 +00:00
Dan Gohman f09aabfe70 Use %llvmgcc -xassembler instead of invoking as directly. This avoids
problems for example when LLVM is built with --with-extra-options=-m64
and as defaults to x86-32 mode.

llvm-svn: 59640
2008-11-19 16:02:14 +00:00
Owen Anderson 1af37c2fca Add support for rematerialization in pre-alloc-splitting.
llvm-svn: 59587
2008-11-19 04:28:29 +00:00
Evan Cheng 3095c32c89 Register scavenger should process early clobber defs first. A dead early clobber def should not interfere with a normal def which happens one slot later.
llvm-svn: 59559
2008-11-18 22:28:38 +00:00
Duncan Sands 1315f80ea8 Reapply r59464, this time using the correct type
when softening FNEG.

llvm-svn: 59513
2008-11-18 09:15:03 +00:00
Bill Wendling c6c6dc5b90 A simple test for stack protectors. This should be valid on all platforms.
llvm-svn: 59505
2008-11-18 07:34:50 +00:00
Bill Wendling e0d5e67c98 Revert r59464. It was causing this failure:
Running /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/CodeGen/XCore/dg.exp ...
FAIL: /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/CodeGen/XCore/fneg.ll
Failed with signal(SIGABRT) at line 1
while running:  llvm-as < /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/CodeGen/XCore/fneg.ll |  llc -march=xcore > fneg.ll.tmp1.s
Assertion failed: (VT.isFloatingPoint() && "Cannot create integer FP constant!"), function getConstantFP, file /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/lib/CodeGen/SelectionDAG/SelectionDAG.cpp, line 913.
0   llc                                 0x0092115c _ZN4llvm3sys18RemoveFileOnSignalERKNS0_4PathEPSs + 844
1   libSystem.B.dylib                   0x9217809b _sigtramp + 43
2   ???                                 0xffffffff 0x0 + 4294967295
3   libSystem.B.dylib                   0x921f0ec2 raise + 26
4   libSystem.B.dylib                   0x9220047f abort + 73
5   libSystem.B.dylib                   0x921f2063 __assert_rtn + 101
6   llc                                 0x005a5b0a _ZN4llvm12SelectionDAG13getConmake[1]: *** [check-local] Error 1
make: *** [check] Error 2

llvm-svn: 59487
2008-11-18 01:49:24 +00:00
Duncan Sands f046b50ecd Add soft float support for a bunch more operations. Original
patch by Richard Osborne, tweaked and extended by your humble
servant.

llvm-svn: 59464
2008-11-17 20:52:38 +00:00
Dale Johannesen 39b34e6d32 Remove these, which test for optimizations that
are not currently done (cf PowerPC/README.txt).

llvm-svn: 59456
2008-11-17 18:57:45 +00:00
Richard Osborne 6751b4a604 Don't produce ADDC/ADDE when expanding SHL unless they are legal
for the target. This fixes PR3080.

llvm-svn: 59450
2008-11-17 17:34:31 +00:00
Lang Hames 41df63945d Removed 2008-10-17-SpillerBug.ll as it does not provide an accurate test of PR2898.
llvm-svn: 59431
2008-11-16 23:30:12 +00:00
Lang Hames 782ec1a746 2008-10-17-SpillerBug.ll is currently failing, but this doesn't reflect an actual regression of PR2898. This test should probably be removed. I've XFAILed it for now to keep buildbot quiet while this is considered.
llvm-svn: 59415
2008-11-16 13:11:09 +00:00
Mon P Wang 7a82474387 Improved shuffle normalization to avoid using extract/build when we
can extract using different indexes for two vectors. Added a few tests
for vector shuffles.

llvm-svn: 59399
2008-11-16 05:06:27 +00:00
Richard Osborne 5fe5933909 [XCore] Fix expansion of 64 bit add/sub. Don't custom expand
these operations if ladd/lsub are not available on the current
subtarget.

llvm-svn: 59305
2008-11-14 15:59:19 +00:00
Richard Osborne d16b37efae Add XCore intrinsics for getid (returns thread id) and bitrev (reverses
bits in a word).

llvm-svn: 59296
2008-11-14 10:12:16 +00:00
Dan Gohman 072734ebd6 Remove the FlaggedNodes member from SUnit. Instead of requiring each SUnit
to carry a SmallVector of flagged nodes, just calculate the flagged nodes
dynamically when they are needed.

The local-liveness change is due to a trivial scheduling change where
the scheduler arbitrary decision differently.

llvm-svn: 59273
2008-11-13 23:24:17 +00:00
Dale Johannesen b47f6d3237 testcase for PR 1779.
llvm-svn: 59268
2008-11-13 22:17:10 +00:00
Duncan Sands aa7060c885 Correct some thinkos in the expansion of ADD/SUB
when the target does not support ADDC/SUBC.  This
fixes PR3044.

llvm-svn: 59120
2008-11-12 08:23:26 +00:00
Dale Johannesen ffc67df2aa Fix the testb optimization so x86 also bootstraps.
Reenable test.

llvm-svn: 59101
2008-11-12 02:00:35 +00:00
Andrew Lenharth 2126a6d3c4 fix another libgcc blocker
llvm-svn: 59026
2008-11-11 06:06:07 +00:00
Bill Wendling 4942f296c9 Un-XFAIL tests now that they're fixed.
llvm-svn: 59023
2008-11-11 04:44:42 +00:00
Bill Wendling 6fcefa065e r59009 broke these tests. XFAIL for now.
llvm-svn: 59010
2008-11-11 00:36:10 +00:00
Bill Wendling b85755c829 Temporarily revert r58979 and related patch. It's causing a failure in X86 bootstrap:
Comparing stages 2 and 3
warning: ./cc1-checksum.o differs
warning: ./cc1obj-checksum.o differs
warning: ./cc1objplus-checksum.o differs
warning: ./cc1plus-checksum.o differs
Bootstrap comparison failure!
./alias.o differs
./alloc-pool.o differs
./attribs.o differs
./bb-reorder.o differs
./bitmap.o differs
./build/errors.o differs
./build/genattrtab.o differs
./build/genautomata.o differs
./build/genemit.o differs
./build/genextract.o differs
...

-bw

llvm-svn: 59003
2008-11-10 21:22:06 +00:00
Duncan Sands ddacbb39ab Fix PR2667: add soft float support for sint_to_fp/uint_to_fp
where the argument is an apint, or smaller than the minimum
size for which there is a libcall (i32). 

llvm-svn: 58994
2008-11-10 17:36:26 +00:00
Duncan Sands d5b53e1c6c When promoting the result of fp_to_uint/fp_to_sint,
inform the optimizers that the result must be zero/
sign extended from the smaller type.  For example,
if a fp to unsigned i16 is promoted to fp to i32,
then we are allowed to assume that the extra 16 bits
are zero (because the result of fp to i16 is undefined
if the result does not fit in an i16).  This is
quite aggressive, but should help the optimizers
produce better code.  This requires correcting a
test which thought that fp_to_uint is some kind
of truncation, which it is not: in the testcase
(which does fp to i1), either the fp value converts
to 0 or 1 or the result is undefined, which is
quite different to truncation.

llvm-svn: 58991
2008-11-10 17:28:30 +00:00
Dale Johannesen 23be3fd970 Reenable test.
llvm-svn: 58980
2008-11-10 07:30:32 +00:00
Duncan Sands 3b36fd87a4 XFAIL this while waiting for a fix.
llvm-svn: 58934
2008-11-09 13:07:47 +00:00
Scott Michel 5c0378db8e CellSPU: Update expected counts on expected patterns
llvm-svn: 58927
2008-11-09 01:03:41 +00:00
Dale Johannesen d70bd61758 Generated code for generic expansion of SETUGT etc.
is noticeably worse than previous PPC-specific code.
Since the latter was also wrong in some cases and
correctness is more important than efficiency, I'm
disabling this test temporarily while I fix it.

llvm-svn: 58876
2008-11-08 00:49:19 +00:00
Dale Johannesen ee04c24bd5 Xfail an incorrect test.
llvm-svn: 58875
2008-11-08 00:40:24 +00:00
Richard Osborne 86d68a492a Add basic test for XCore backend
llvm-svn: 58841
2008-11-07 11:24:12 +00:00
Dale Johannesen a129e0b826 Testcase for testb optimization.
llvm-svn: 58827
2008-11-07 01:30:18 +00:00
Dan Gohman 3777ed765f Make ISel ignore dead nodes. The DAGCombiner normally eliminates
dead nodes, but in this case its missing one. Fixing the DAGCombiner
is desirable, but it's somewhat involved.

llvm-svn: 58777
2008-11-05 22:56:47 +00:00
Evan Cheng 27889ab29f Add more vector move low and zero-extend patterns.
llvm-svn: 58752
2008-11-05 06:04:51 +00:00
Evan Cheng e3827d9061 Actually ARM / Mac OS X does have UINTTOFP_I64_F{64|32} libcalls.
llvm-svn: 58725
2008-11-04 22:19:55 +00:00
Evan Cheng 297b32a367 Custom lower bit_convert i64 -> f64 into FMDRR. This is now happening with legalizetypes.
llvm-svn: 58714
2008-11-04 19:57:48 +00:00
Duncan Sands d5f935921a Fix PR3011: LegalizeTypes support for scalarizing
SELECT_CC.

llvm-svn: 58706
2008-11-04 17:31:08 +00:00
Dan Gohman b9110e7fbb The ANDMask node folds to a constant, and isn't the node that needs to
have its node id set. The new and and shift nodes are the nodes that need
the IDs. This fixes PR2982.

llvm-svn: 58655
2008-11-03 23:43:55 +00:00
Dan Gohman d7546abb8a Change how extended types are represented in MVTs. Instead of fiddling
bits, use a union of a SimpleValueType enum and a regular Type*.

This increases the size of MVT on 64-bit hosts from 32 bits to 64 bits.
In most cases, this doesn't add significant overhead. There are places
in codegen that use arrays of MVTs, so these are now larger, but
they're small in common cases.

This eliminates restrictions on the size of integer types and vector
types that can be represented in codegen. As the included testcase
demonstrates, it's now possible to codegen very large add operations.
There are still some complications with using very large types. PR2880
is still open so they can't be used as return values on normal targets,
there are no libcalls defined for very large integers so operations
like multiply and divide aren't supported.

This also introduces a minimal tablgen Type library, capable of
handling IntegerType and VectorType. This will allow parts of
TableGen that don't depend on using SimpleValueType values to handle
arbitrary integer and vector types.

llvm-svn: 58623
2008-11-03 17:56:27 +00:00
Duncan Sands 0207a3f897 Make VAARG work with x86 long double (which is
10 bytes long, but is passed in 12/16 bytes).

llvm-svn: 58608
2008-11-03 11:51:11 +00:00
Duncan Sands 8758851908 Add a bunch of libcalls for ppcf128 that were somehow
completely forgotten about when writing LegalizeTypes.

llvm-svn: 58508
2008-10-31 14:06:52 +00:00
Dan Gohman 99cdf8893e Use MOVSSmr instead of EXTRACTPSmr in the case of extracting
vector element 0 for a store, as it's smaller and faster.

llvm-svn: 58483
2008-10-31 00:57:24 +00:00
Duncan Sands 8311657b98 Testcase for PR2986.
llvm-svn: 58456
2008-10-30 20:34:30 +00:00
Scott Michel 487c43412d Resolve bug 2947: vararg-marked functions must spill registers R3-R79 to stack
so that va_start/va_arg/et.al. will walk arguments correctly for Cell SPU.

N.B.: Because neither clang nor llvm-gcc-4.2 can be built for CellSPU, this is
still unexorcised code.

llvm-svn: 58415
2008-10-30 01:51:48 +00:00
Chris Lattner 7ee0012707 add testcase for PR2964
llvm-svn: 58393
2008-10-29 18:42:22 +00:00
Duncan Sands fbb10bbec4 Fix PR2977: LegalizeTypes support for expanding
VAARG.

llvm-svn: 58379
2008-10-29 14:25:28 +00:00
Evan Cheng ce3ccc1ea0 - More pre-split fixes: spill slot live interval computation bug; restore point bug.
- If a def is spilt, remember its spill index to allow its reuse.

llvm-svn: 58375
2008-10-29 08:39:34 +00:00
Duncan Sands 4068a7f31e Fix darwin ppc llvm-gcc build breakage: intercept
ppcf128 to i32 conversion and expand it into a code
sequence like in LegalizeDAG.  This needs custom
ppc lowering of FP_ROUND_INREG, so turn that on and
make it work with LegalizeTypes.  Probably PPC should
simply custom lower the original conversion.

llvm-svn: 58329
2008-10-28 15:00:32 +00:00
Duncan Sands b68694f17d Turn off LegalizeTypes for this test for the
moment, while waiting for a proper solution.

llvm-svn: 58324
2008-10-28 09:55:04 +00:00
Duncan Sands f3e5850f80 Fix a testcase provided by Bill in which the node
id could end up being wrong mostly because of
forgetting to remap new nodes that morphed into
processed nodes through CSE.

llvm-svn: 58323
2008-10-28 09:38:36 +00:00
Chris Lattner 38461f6b2f Fix a nasty miscompilation of 176.gcc on linux/x86 where we synthesized
a memset using 16-byte XMM stores, but where the stack realignment code
didn't work.  Until it does (PR2962) disable use of xmm regs in memcpy
and memset formation for linux and other targets with insufficiently
aligned stacks.

This is part of PR2888

llvm-svn: 58317
2008-10-28 05:49:35 +00:00
Evan Cheng fab31680e1 Avoid putting a split past the end of the live range; always shrink wrap live interval in the barrier mbb.
llvm-svn: 58309
2008-10-28 00:47:49 +00:00
Evan Cheng f46642ada6 Remove val# defined by a remat'ed def that is now dead.
llvm-svn: 58294
2008-10-27 23:21:01 +00:00
Chris Lattner b5cf101fa2 rename vec_spat -> vec_splat, pointed out by duncan
llvm-svn: 58260
2008-10-27 18:28:24 +00:00
Duncan Sands 8475d56794 Turn on LegalizeTypes, the new type legalization
codegen infrastructure, by default.  Please report
any breakage to the mailing lists.

llvm-svn: 58232
2008-10-27 08:42:46 +00:00
Evan Cheng f713722975 For now, don't split live intervals around x87 stack register barriers. FpGET_ST0_80 must be right after a call instruction (and ADJCALLSTACKUP) so we need to find a way to prevent reload of x87 registers between them.
llvm-svn: 58230
2008-10-27 07:14:50 +00:00
Chris Lattner a43f2b21e7 remove eh output from this test.
llvm-svn: 58196
2008-10-26 18:53:07 +00:00
Evan Cheng ed033ede22 Do not shrink wrap live interval in a mbb if it's livein any of its successor blocks. The mbb can be revisited again after all of the successors are processed.
llvm-svn: 58184
2008-10-26 07:49:03 +00:00
Evan Cheng f48367b8e9 Handle cases where there aren't uses in the barrier mbb.
llvm-svn: 58174
2008-10-25 23:49:39 +00:00
Gordon Henriksen bf40eee91a Related to PR2911, reject as invalid non-pointer GC roots.
llvm-svn: 58143
2008-10-25 16:28:35 +00:00
Evan Cheng 85d71d4588 If val# def is ~0U, meaning it's defined by a PHI, and it's previously split, spill before the barrier because it's impossible to determine if all the defs are spilled in the same spill slot.
llvm-svn: 58129
2008-10-25 00:52:41 +00:00
Dale Johannesen e45896fc4f Be kind to non-x86 hosts.
llvm-svn: 58113
2008-10-24 21:20:25 +00:00
Duncan Sands 014f5bbaad Fix translateX86CC: if SetCCOpcode is SETULE and
LHS is a foldable load, then LHS and RHS are swapped
and SetCCOpcode is changed to SETUGT.  But the later
code is expecting operands to be the wrong way round
for SETUGT, but they are not in this case, resulting
in an inverted compare.  The solution is to move the
load normalization before the correction for SETUGT.
This bug was tickled by LegalizeTypes which happened
to legalize the testcase slightly differently to
LegalizeDAG.

llvm-svn: 58092
2008-10-24 13:03:10 +00:00
Evan Cheng 4bac4d0a16 Avoid splitting an interval multiple times; avoid splitting re-materializable val# (for now).
llvm-svn: 58068
2008-10-24 02:05:00 +00:00
Chris Lattner 35b40f8c2f Fix PR2907 by digging through constant expressions to find FP constants that
are their operands.

llvm-svn: 57956
2008-10-22 04:53:16 +00:00
Dan Gohman 8b44b88eff Fix SelectionDAGBuild lowering of Select instructions to
handle first-class aggregate values. Also, fix a bug in
the Ret handling for empty aggregates.

llvm-svn: 57925
2008-10-21 20:00:42 +00:00
Chris Lattner 192f27cb5c really fix run line
llvm-svn: 57889
2008-10-21 03:55:19 +00:00
Chris Lattner b4ee2aebb5 fix run line
llvm-svn: 57888
2008-10-21 03:54:49 +00:00
Chris Lattner 0b641e4718 remove some unneeded eh generation
llvm-svn: 57887
2008-10-21 03:49:19 +00:00
Dan Gohman 269246b034 Don't create TargetGlobalAddress nodes with offsets that don't fit
in the 32-bit signed offset field of addresses. Even though this
may be intended, some linkers refuse to relocate code where the
relocated address computation overflows.

Also, fix the sign-extension of constant offsets to use the
actual pointer size, rather than the size of the GlobalAddress
node, which may be different, for example on x86-64 where MVT::i32
is used when the address is being fit into the 32-bit displacement
field.

llvm-svn: 57885
2008-10-21 03:38:42 +00:00
Dan Gohman 97d95d6d85 Optimized FCMP_OEQ and FCMP_UNE for x86.
Where previously LLVM might emit code like this:

        ucomisd %xmm1, %xmm0
        setne   %al
        setp    %cl
        orb     %al, %cl
        jne     .LBB4_2

it now emits this:

        ucomisd %xmm1, %xmm0
        jne     .LBB4_2
        jp      .LBB4_2

It has fewer instructions and uses fewer registers, but it does
have more branches. And in the case that this code is followed by
a non-fallthrough edge, it may be followed by a jmp instruction,
resulting in three branch instructions in sequence. Some effort
is made to avoid this situation.

To achieve this, X86ISelLowering.cpp now recognizes FCMP_OEQ and
FCMP_UNE in lowered form, and replace them with code that emits
two branches, except in the case where it would require converting
a fall-through edge to an explicit branch.

Also, X86InstrInfo.cpp's branch analysis and transform code now
knows now to handle blocks with multiple conditional branches. It
uses loops instead of having fixed checks for up to two
instructions. It can now analyze and transform code generated
from FCMP_OEQ and FCMP_UNE.

llvm-svn: 57873
2008-10-21 03:29:32 +00:00
Dan Gohman c835458da9 When the coalescer is doing rematerializing, have it remove
the copy instruction from the instruction list before asking the
target to create the new instruction. This gets the old instruction
out of the way so that it doesn't interfere with the target's
rematerialization code. In the case of x86, this helps it find
more cases where EFLAGS is not live.

Also, in the X86InstrInfo.cpp, teach isSafeToClobberEFLAGS to check
to see if it reached the end of the block after scanning each
instruction, instead of just before. This lets it notice when the
end of the block is only two instructions away, without doing any
additional scanning.

These changes allow rematerialization to clobber EFLAGS in more
cases, for example using xor instead of mov to set the return value
to zero in the included testcase.

llvm-svn: 57872
2008-10-21 03:24:31 +00:00
Chris Lattner 4396e0d2c3 Fix gcc.c-torture/compile/920520-1.c by inserting bitconverts
for strange asm conditions earlier.  In this case, we have a
double being passed in an integer reg class.  Convert to like
sized integer register so that we allocate the right number 
for the class (two i32's for the f64 in this case).

llvm-svn: 57862
2008-10-21 00:45:36 +00:00
Chris Lattner 160e8abd77 Reapply r57699 with a fix to not crash on asms with multiple results. Unlike
the previous patch this one actually passes make check.

"Fix PR2356 on PowerPC: if we have an input and output that are tied together
that have different sizes (e.g. i32 and i64) make sure to reserve registers for
the bigger operand."

llvm-svn: 57771
2008-10-18 18:49:30 +00:00
Dan Gohman 2fe6bee5b6 Teach DAGCombine to fold constant offsets into GlobalAddress nodes,
and add a TargetLowering hook for it to use to determine when this
is legal (i.e. not in PIC mode, etc.)

This allows instruction selection to emit folded constant offsets
in more cases, such as the included testcase, eliminating the need
for explicit arithmetic instructions.

This eliminates the need for the C++ code in X86ISelDAGToDAG.cpp
that attempted to achieve the same effect, but wasn't as effective.

Also, fix handling of offsets in GlobalAddressSDNodes in several
places, including changing GlobalAddressSDNode's offset from
int to int64_t.

The Mips, Alpha, Sparc, and CellSPU targets appear to be
unaware of GlobalAddress offsets currently, so set the hook to
false on those targets.

llvm-svn: 57748
2008-10-18 02:06:02 +00:00
Dan Gohman 6de2556205 Revert r57699. It's causing regressions in
test/CodeGen/X86/2008-09-17-inline-asm-1.ll
and a few others, and it breaks the llvm-gcc build.

llvm-svn: 57747
2008-10-18 01:03:45 +00:00
Evan Cheng 94169f1021 Fix PR2898. Spiller delete a store for reuse before it knows for sure the reuse happened.
Patch by Lang Hames!

llvm-svn: 57720
2008-10-17 20:56:41 +00:00
Chris Lattner c7e65f4377 Fix a bug where the x86 backend would reject 64-bit r constraints when
in 32-bit mode instead of assigning a register pair.  This has nothing to
do with PR2356, but I happened to notice it while working on it.

llvm-svn: 57704
2008-10-17 17:59:52 +00:00