Commit Graph

308 Commits

Author SHA1 Message Date
Dan Gohman
7da91aee83 Fast-isel support for simple inline asms.
llvm-svn: 130205
2011-04-26 17:18:34 +00:00
Owen Anderson
dd450b86cf Teach FastISel to deal with instructions that have two immediate operands.
llvm-svn: 130033
2011-04-22 23:38:06 +00:00
Chris Lattner
91328b317b Implement support for x86 fastisel of small fixed-sized memcpys, which are generated
en-mass for C++ PODs.  On my c++ test file, this cuts the fast isel rejects by 10x 
and shrinks the generated .s file by 5%

llvm-svn: 129755
2011-04-19 05:52:03 +00:00
Chris Lattner
48f75ad678 while we're at it, handle 'sdiv exact' of a power of 2 also,
this fixes a few rejects on c++ iterator loops.

llvm-svn: 129694
2011-04-18 07:00:40 +00:00
Chris Lattner
562d6e82bd fix rdar://9297011 - udiv by power of two causing fast-isel rejects
llvm-svn: 129693
2011-04-18 06:55:51 +00:00
Chris Lattner
b53ccb8e36 1. merge fast-isel-shift-imm.ll into fast-isel-x86-64.ll
2. implement rdar://9289501 - fast isel should fold trivial multiplies to shifts
3. teach tblgen to handle shift immediates that are different sizes than the 
   shifted operands, eliminating some code from the X86 fast isel backend.
4. Have FastISel::SelectBinaryOp use (the poorly named) FastEmit_ri_ function
   instead of FastEmit_ri to simplify code.

llvm-svn: 129666
2011-04-17 20:23:29 +00:00
Chris Lattner
fba7ca63cc fix rdar://9289583 - fast isel should handle non-canonical commutative binops
allowing us to fold the immediate into the 'and' in this case:

int test1(int i) {
  return 8&i;
}

llvm-svn: 129653
2011-04-17 01:16:47 +00:00
Chris Lattner
0ab5e2cded Fix a ton of comment typos found by codespell. Patch by
Luis Felipe Strano Moraes!

llvm-svn: 129558
2011-04-15 05:18:47 +00:00
Jay Foad
7c14a558fe Don't include Operator.h from InstrTypes.h.
llvm-svn: 129271
2011-04-11 09:35:34 +00:00
Owen Anderson
66443c034d Teach FastISel to support register-immediate-immediate instructions.
llvm-svn: 127496
2011-03-11 21:33:55 +00:00
Devang Patel
c24048a718 If dbg_declare() or dbg_value() is not lowered by isel then emit DEBUG message instead of creating DBG_VALUE for undefined value in reg0.
llvm-svn: 121059
2010-12-06 22:39:26 +00:00
Wesley Peck
527da1b6e2 Renaming ISD::BIT_CONVERT to ISD::BITCAST to better reflect the LLVM IR concept.
llvm-svn: 119990
2010-11-23 03:31:01 +00:00
Devang Patel
e4682fa8e2 Use frame index, if available for byval argument while lowering dbg_declare. Otherwise let getRegForValue() find register for this argument.
llvm-svn: 113843
2010-09-14 20:29:31 +00:00
Devang Patel
6095d818e5 Add DEBUG message.
llvm-svn: 113614
2010-09-10 20:32:09 +00:00
Eric Christopher
541f8012d9 Fix typo.
llvm-svn: 111223
2010-08-17 01:30:33 +00:00
Gabor Greif
dde79d8f1a mass elimination of reliance on automatic iterator dereferencing
llvm-svn: 109103
2010-07-22 13:36:47 +00:00
Dan Gohman
b5e918dc05 After a custom inserter, in a block which has constant instructions,
update the current basic block in addition to the current insert
position, so that they remain consistent. This fixes rdar://8204072.

llvm-svn: 108765
2010-07-19 22:48:56 +00:00
Dan Gohman
1e936277c3 Revert r108369, sorting llvm.dbg.declare information by source position,
since it doesn't work for front-ends which don't emit column information
(which includes llvm-gcc in its present configuration), and doesn't
work for clang for K&R style variables where the variables are declared
in a different order from the parameter list.

Instead, make a separate pass through the instructions to collect the
llvm.dbg.declare instructions in order. This ensures that the debug
information for variables is emitted in this order.

llvm-svn: 108538
2010-07-16 17:54:27 +00:00
Dan Gohman
c12a6731c5 Properly restore DebugLoc after leaving the local constant area.
llvm-svn: 108364
2010-07-14 22:01:31 +00:00
Dan Gohman
042523340b Delete fast-isel's trivial load optimization; it breaks debugging because
it can look past points where a debugger might modify user variables.

llvm-svn: 108336
2010-07-14 17:25:37 +00:00
Dan Gohman
1f471435f8 Don't propagate debug locations to instructions for materializing
constants, since they may not be emited near the other instructions
which get the same line, and this confuses debug info.

llvm-svn: 108302
2010-07-14 01:07:44 +00:00
Jakob Stoklund Olesen
51642aea77 Use COPY for fast-isel bitconvert, but don't create cross-class copies.
This doesn't change the behavior of SelectBitcast for X86.

llvm-svn: 108073
2010-07-11 05:16:54 +00:00
Jakob Stoklund Olesen
7147ab9e78 Use COPY for extracting ImplicitDef'ed values from fast-isel instructions.
This assumes that the registers can be copied which is probably a safe
assumption.

llvm-svn: 108070
2010-07-11 03:31:05 +00:00
Jakob Stoklund Olesen
3bb1267431 Use COPY in FastISel everywhere it is safe and trivial.
The remaining copyRegToReg calls actually check the return value (shock!), so we
cannot trivially replace them with COPY instructions.

llvm-svn: 108069
2010-07-11 03:31:00 +00:00
Dan Gohman
d7b5ce3312 Reapply bottom-up fast-isel, with several fixes for x86-32:
- Check getBytesToPopOnReturn().
 - Eschew ST0 and ST1 for return values.
 - Fix the PIC base register initialization so that it doesn't ever
   fail to end up the top of the entry block.

llvm-svn: 108039
2010-07-10 09:00:22 +00:00
Bob Wilson
6586e9b203 --- Reverse-merging r107947 into '.':
U    utils/TableGen/FastISelEmitter.cpp
--- Reverse-merging r107943 into '.':
U    test/CodeGen/X86/fast-isel.ll
U    test/CodeGen/X86/fast-isel-loads.ll
U    include/llvm/Target/TargetLowering.h
U    include/llvm/Support/PassNameParser.h
U    include/llvm/CodeGen/FunctionLoweringInfo.h
U    include/llvm/CodeGen/CallingConvLower.h
U    include/llvm/CodeGen/FastISel.h
U    include/llvm/CodeGen/SelectionDAGISel.h
U    lib/CodeGen/LLVMTargetMachine.cpp
U    lib/CodeGen/CallingConvLower.cpp
U    lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
U    lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
U    lib/CodeGen/SelectionDAG/FastISel.cpp
U    lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
U    lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
U    lib/CodeGen/SelectionDAG/InstrEmitter.cpp
U    lib/CodeGen/SelectionDAG/TargetLowering.cpp
U    lib/Target/XCore/XCoreISelLowering.cpp
U    lib/Target/XCore/XCoreISelLowering.h
U    lib/Target/X86/X86ISelLowering.cpp
U    lib/Target/X86/X86FastISel.cpp
U    lib/Target/X86/X86ISelLowering.h

llvm-svn: 107987
2010-07-09 16:37:18 +00:00
Dan Gohman
0b5aa1cdd3 Re-apply bottom-up fast-isel, with fixes. Be very careful to avoid emitting
a DBG_VALUE after a terminator, or emitting any instructions before an EH_LABEL.

llvm-svn: 107943
2010-07-09 00:39:23 +00:00
Jakob Stoklund Olesen
00264624a9 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
Dan Gohman
e75704369d Revert 107840 107839 107813 107804 107800 107797 107791.
Debug info intrinsics win for now.

llvm-svn: 107850
2010-07-08 01:00:56 +00:00
Dan Gohman
eb9164dc50 Don't forward-declare registers for static allocas, which we'll
prefer to materialize as local constants. This fixes the clang
bootstrap abort.

llvm-svn: 107840
2010-07-07 23:52:58 +00:00
Dan Gohman
e7ccc51cc1 Implement bottom-up fast-isel. This has the advantage of not requiring
a separate DCE pass over MachineInstrs.

llvm-svn: 107804
2010-07-07 19:20:32 +00:00
Dan Gohman
ffe64b1ee5 Give FunctionLoweringInfo an MBB member, avoiding the need to pass it
around everywhere, and also give it an InsertPt member, to enable isel
to operate at an arbitrary position within a block, rather than just
appending to a block.

llvm-svn: 107791
2010-07-07 16:47:08 +00:00
Dan Gohman
87fb4e8fcd Simplify FastISel's constructor by giving it a FunctionLoweringInfo
instance, rather than pointers to all of FunctionLoweringInfo's
members.

This eliminates an NDEBUG ABI sensitivity.

llvm-svn: 107789
2010-07-07 16:29:44 +00:00
Dan Gohman
e784616fbb Move FunctionLoweringInfo.h out into include/llvm/CodeGen. This will
allow target-specific fast-isel code to make use of it directly.

llvm-svn: 107787
2010-07-07 16:01:37 +00:00
Dan Gohman
93f5920914 Rename CreateReg to CreateRegs, and MakeReg to CreateReg.
llvm-svn: 107451
2010-07-02 00:10:16 +00:00
Dan Gohman
85e02e9340 Rename CreateRegForValue to CreateReg, and change its argument
from a Value to a Type, because it doesn't actually care about
the Value.

llvm-svn: 107383
2010-07-01 03:55:39 +00:00
Dan Gohman
aef3d140b7 Teach fast-isel to avoid loading a value from memory when it's already
available in a register. This is pretty primitive, but it reduces the
number of instructions in common testcases by 4%.

llvm-svn: 107380
2010-07-01 03:49:38 +00:00
Dan Gohman
722f5fc567 Enable on-demand fast-isel.
llvm-svn: 107377
2010-07-01 02:58:57 +00:00
Dan Gohman
f91aff5f13 Do one lookup instead of two.
llvm-svn: 106415
2010-06-21 14:21:47 +00:00
Dan Gohman
7c58cf75fa Generalize this to look in the regular ValueMap in addition to
the LocalValueMap, to make it more flexible when fast-isel isn't
proceding straight top-down.

llvm-svn: 106414
2010-06-21 14:17:46 +00:00
Dan Gohman
8693650422 Teach regular and fast isel to set dead flags on unused implicit defs
on calls and similar instructions.

llvm-svn: 106353
2010-06-18 23:28:01 +00:00
Dan Gohman
f1d8304fe3 Eliminate unnecessary uses of getZExtValue().
llvm-svn: 106279
2010-06-18 14:22:04 +00:00
Stuart Hastings
0125b6410a Add a DebugLoc parameter to TargetInstrInfo::InsertBranch(). This
addresses a longstanding deficiency noted in many FIXMEs scattered
across all the targets.

This effectively moves the problem up one level, replacing eleven
FIXMEs in the targets with eight FIXMEs in CodeGen, plus one path
through FastISel where we actually supply a DebugLoc, fixing Radar
7421831.

llvm-svn: 106243
2010-06-17 22:43:56 +00:00
Dan Gohman
ce3269b815 Do one map lookup instead of two.
llvm-svn: 104645
2010-05-25 21:59:42 +00:00
Dan Gohman
88fb253562 Fast ISel trivially coalesces away no-op casts, so check for this when
setting kill flags.

llvm-svn: 103832
2010-05-14 22:53:18 +00:00
Dan Gohman
5b510c1474 An Instruction has a trivial kill only if its use is in the same
basic block.

llvm-svn: 103725
2010-05-13 19:19:32 +00:00
Dan Gohman
1a1b51ff59 Add initial kill flag support to FastISel.
llvm-svn: 103529
2010-05-11 23:54:07 +00:00
Devang Patel
2ae3397536 Verify variable directly.
llvm-svn: 103305
2010-05-07 22:04:20 +00:00
Dan Gohman
e6d40166a8 Transfer debug location information from PHI nodes to resulting
lowered copies.

llvm-svn: 103228
2010-05-07 01:10:20 +00:00
Dan Gohman
779c69bbc5 Add a DebugLoc argument to TargetInstrInfo::copyRegToReg, so that it
doesn't have to guess.

llvm-svn: 103194
2010-05-06 20:33:48 +00:00
Dan Gohman
a7c717d8d4 In bottom-up mode, defer the materialization of local constant values.
llvm-svn: 103139
2010-05-06 00:02:14 +00:00
Dan Gohman
ffcb590b0f Add an "IsBottomUp" member function to FastISel, which will be used to
support a new bottom-up mode.

llvm-svn: 103138
2010-05-05 23:58:35 +00:00
Dan Gohman
626b5d8e0c Factor out FastISel's code for materializing constants and other values
in registers into a separate function to de-couple it from the
top-down-specific logic in getRegForValue.

llvm-svn: 102975
2010-05-03 23:36:34 +00:00
Devang Patel
888c17073a While lowering dbg_declare, emit DBG_VALUE machine instruction if alloca matching llvm.dbg.declare intrinsic is missing.
llvm-svn: 102513
2010-04-28 19:27:33 +00:00
Dale Johannesen
1fc01985a3 Add comment re byval args. Doesn't actually work this way yet.
xs

llvm-svn: 102316
2010-04-25 21:03:54 +00:00
Dan Gohman
6e9a8fcc28 Move FastISel's HandlePHINodesInSuccessorBlocks call down into FastISel
itself too.

llvm-svn: 102176
2010-04-23 15:29:50 +00:00
Dan Gohman
c594eab10f Move HandlePHINodesInSuccessorBlocks functions out of SelectionDAGISel
and into SelectionDAGBuilder and FastISel.

llvm-svn: 102123
2010-04-22 20:46:50 +00:00
Dan Gohman
e149e9896c Fix a comment.
llvm-svn: 102110
2010-04-22 20:06:42 +00:00
Dan Gohman
f41ad478ca Don't send PHI nodes down to SelectionDAGBuilder of FastISel, since
they end up doing nothing.

llvm-svn: 101904
2010-04-20 15:00:41 +00:00
Dan Gohman
e450d7444d Sink DebugLoc handling out of SelectionDAGISel into FastISel and
SelectionDAGBuilder, where it doesn't have to be as complicated.

llvm-svn: 101848
2010-04-20 00:48:35 +00:00
Dan Gohman
bcaf681cde Add const qualifiers to CodeGen's use of LLVM IR constructs.
llvm-svn: 101334
2010-04-15 01:51:59 +00:00
Dan Gohman
7deb447781 Factor out EH landing pad code into a separate function, and constify
a bunch of stuff to support it.

llvm-svn: 101273
2010-04-14 19:53:31 +00:00
Dan Gohman
5f40d34958 Generalize this code to handle Instructions in addition to ConstantExprs.
llvm-svn: 101210
2010-04-14 02:33:23 +00:00
Dan Gohman
8a2dae57e2 Add a few comments.
llvm-svn: 101148
2010-04-13 17:07:06 +00:00
Dale Johannesen
5d7f0a0fdd Move printing of target-indepedent DEBUG_VALUE comments
into AsmPrinter.  Target-dependent form is still generated
by FastISel and still handled in X86 code.

llvm-svn: 100596
2010-04-07 01:15:14 +00:00
Chris Lattner
305f2efb63 unthread MMI from FastISel
llvm-svn: 100416
2010-04-05 06:05:26 +00:00
Chris Lattner
7cfa70e9b3 fastisel doesn't need DwarfWriter, remove some tendricles.
llvm-svn: 100381
2010-04-05 02:19:28 +00:00
Chris Lattner
915c5f9862 Switch the code generator (except the JIT) onto the new DebugLoc
representation.  This eliminates the 'DILocation' MDNodes for 
file/line/col tuples from -O0 -g codegen.

This remove the old DebugLoc class, making it a typedef for DebugLoc,
I'll rename NewDebugLoc next.

I didn't update the JIT to use the new apis, so it will continue to
work, but be as slow as before.  Someone should eventually do this
or, better yet, rip out the JIT debug info stuff and build the JIT
on top of MC.

llvm-svn: 100209
2010-04-02 19:42:39 +00:00
Chris Lattner
009de335ac add new apis for getting/setting !dbg metadata on
instructions.  In addition to being a convenience,
they are faster than the old apis, particularly when
not going from an MDKindID like people should be
doing.

llvm-svn: 99982
2010-03-31 03:34:40 +00:00
Daniel Dunbar
84b5ddc872 Remove dead include.
llvm-svn: 98225
2010-03-11 02:28:48 +00:00
Dale Johannesen
dd33104203 Move dbg_value generation to target-independent FastISel,
as X86 is currently the only FastISel target.  Per review.

llvm-svn: 97255
2010-02-26 20:01:55 +00:00
Dale Johannesen
3d1f1cccbb Fix comments to reflect renaming elsewhere.
llvm-svn: 95730
2010-02-10 00:11:11 +00:00
Chris Lattner
b06015aa69 move target-independent opcodes out of TargetInstrInfo
into TargetOpcodes.h.  #include the new TargetOpcodes.h
into MachineInstr.  Add new inline accessors (like isPHI())
to MachineInstr, and start using them throughout the 
codebase.

llvm-svn: 95687
2010-02-09 19:54:29 +00:00
Dale Johannesen
db2eb47835 After Victor's latest commits I am seeing null
addresses in dbg.declare; ignore this for the
moment to prevent things from breaking.

llvm-svn: 95471
2010-02-06 02:26:02 +00:00
Dale Johannesen
d5575f29f1 Generate DEBUG_VALUE comments on x86. The (limited)
dbg.declare's we currently generate go through both
register allocators without perturbing the results.

llvm-svn: 94480
2010-01-26 00:09:58 +00:00
Dale Johannesen
a3db6ef9a2 Revert 93811 per request.
llvm-svn: 93818
2010-01-19 00:10:52 +00:00
Dale Johannesen
0c90d43b70 Enable code to emit dbg.declare as DEBUG_VALUE
comments (fast isel, X86).  This doesn't seem
to break any functionality, but will introduce
cases where -g affects the generated code.  I'll
be fixing that.

llvm-svn: 93811
2010-01-18 23:34:55 +00:00
Victor Hernandez
b324e66f4c Improve llvm.dbg.declare intrinsic by referring directly to the storage in its first argument, via function-local metadata (instead of via a bitcast).
This patch also cleans up code that expects there to be a bitcast in the first argument and testcases that call llvm.dbg.declare.
It also strips old llvm.dbg.declare intrinsics that did not pass metadata as the first argument.

llvm-svn: 93531
2010-01-15 19:04:09 +00:00
Victor Hernandez
8d4904b639 Revert r93504 because older uses of llvm.dbg.declare intrinsics need to be auto-upgraded
llvm-svn: 93515
2010-01-15 17:36:47 +00:00
Victor Hernandez
5d6551816b Improve llvm.dbg.declare intrinsic by referring directly to the storage in its first argument, via function-local metadata (instead of via a bitcast).
This patch also cleans up code that expects there to be a bitcast in the first argument and testcases that call llvm.dbg.declare.

llvm-svn: 93504
2010-01-15 03:37:48 +00:00
Dan Gohman
f9d6d53823 Fix a typo in a comment.
llvm-svn: 93227
2010-01-12 04:30:26 +00:00
Dan Gohman
404a984780 Don't use the ISD::NodeType enum for SDNode opcodes, as CodeGen
uses several kinds of opcode values which are not declared within
that enum. This fixes PR5946.

llvm-svn: 92794
2010-01-05 22:26:32 +00:00
Devang Patel
33f80d2303 Delete renaming use of dead dbg intrinsics.
Intrinsic::dbg_stoppoint
 Intrinsic::dbg_region_start
 Intrinsic::dbg_region_end
 Intrinsic::dbg_func_start

llvm-svn: 92672
2010-01-05 01:47:06 +00:00
Chris Lattner
8e805be369 remove a bunch of unneeded functions.
llvm-svn: 92263
2009-12-29 09:32:19 +00:00
Chris Lattner
2f2aa2b067 This is a major cleanup of the instruction metadata interfaces that
I asked Devang to do back on Sep 27.  Instead of going through the
MetadataContext class with methods like getMD() and getMDs(), just
ask the instruction directly for its metadata with getMetadata()
and getAllMetadata().

This includes a variety of other fixes and improvements: previously
all Value*'s were bloated because the HasMetadata bit was thrown into
value, adding a 9th bit to a byte.  Now this is properly sunk down to
the Instruction class (the only place where it makes sense) and it
will be folded away somewhere soon.

This also fixes some confusion in getMDs and its clients about 
whether the returned list is indexed by the MDID or densely packed.
This is now returned sorted and densely packed and the comments make
this clear.

This introduces a number of fixme's which I'll follow up on.

llvm-svn: 92235
2009-12-28 23:41:32 +00:00
Chris Lattner
7093946ab1 rename getMDKind -> getMDKindID, make it autoinsert if an MD Kind
doesn't exist already, eliminate registerMDKind.  Tidy up a bunch
of random stuff.

llvm-svn: 92225
2009-12-28 20:45:51 +00:00
Bill Wendling
846ca9b38b Remove dead variable.
llvm-svn: 92180
2009-12-28 01:02:21 +00:00
Dan Gohman
18f94469dc Make TargetSelectInstruction protected and called from FastISel.cpp
instead of SelectionDAGISel.cpp.

llvm-svn: 90636
2009-12-05 01:27:58 +00:00
Chris Lattner
a48f44d9ee improve portability to avoid conflicting with std::next in c++'0x.
Patch by Howard Hinnant!

llvm-svn: 90365
2009-12-03 00:50:42 +00:00
Dan Gohman
1a6c47f1cb Rename SelectionDAGLowering to SelectionDAGBuilder, and rename
SelectionDAGBuild.cpp to SelectionDAGBuilder.cpp.

llvm-svn: 89681
2009-11-23 18:04:58 +00:00
Dan Gohman
ad97b3dbd0 Move some more code out of SelectionDAGBuild.cpp and into
FunctionLoweringInfo.cpp.

llvm-svn: 89674
2009-11-23 17:42:46 +00:00
Devang Patel
2904aa9f6e "Attach debug info with llvm instructions" mode was enabled a month ago. Now make it permanent and remove old way of inserting intrinsics to encode debug info for line number and scopes.
llvm-svn: 87014
2009-11-12 19:02:56 +00:00
Devang Patel
f6eeaebd76 Implement support to debug inlined functions.
llvm-svn: 86748
2009-11-10 23:06:00 +00:00
Duncan Sands
8e6ccb65df I don't see any point in having both eh.selector.i32 and eh.selector.i64,
so get rid of eh.selector.i64 and rename eh.selector.i32 to eh.selector.
Likewise for eh.typeid.for.  This aligns us with gcc, which always uses a
32 bit value for the selector on all platforms.  My understanding is that
the register allocator used to assert if the selector intrinsic size didn't
match the pointer size, and this was the reason for introducing the two
variants.  However my testing shows that this is no longer the case (I
fixed some bugs in selector lowering yesterday, and some more today in the
fastisel path; these might have caused the original problems).

llvm-svn: 84106
2009-10-14 16:11:37 +00:00
Devang Patel
d7ebfe3963 s/DebugLoc.CompileUnit/DebugLoc.Scope/g
s/DebugLoc.InlinedLoc/DebugLoc.InlinedAtLoc/g

llvm-svn: 84054
2009-10-13 23:28:53 +00:00
Devang Patel
df45c7f642 Extract scope information from the variable itself, instead of relying on alloca or llvm.dbg.declare location.
While recording beginning of a function, use scope info from the first location entry instead of just relying on first location entry itself.

llvm-svn: 83684
2009-10-09 22:42:28 +00:00
Devang Patel
4598eb6214 Add support to handle debug info attached to an instruction.
This is not yet enabled.

llvm-svn: 83400
2009-10-06 18:37:31 +00:00
Devang Patel
4dbca6dfd4 If location info is attached with an instruction then keep track of alloca slots used by a variable. This info will be used by AsmPrinter to emit debug info for variables.
llvm-svn: 83189
2009-10-01 01:03:26 +00:00
Dan Gohman
9cbef32726 Make fast-isel try ISD::FNEG before resorting to bitcasts and xors.
llvm-svn: 81493
2009-09-11 00:36:43 +00:00
Dan Gohman
89b090e51e Reapply r81171 with a fix: don't try to use i64 when it
isn't legal.

llvm-svn: 81492
2009-09-11 00:34:46 +00:00