Commit Graph

390 Commits

Author SHA1 Message Date
Evan Cheng
8d1f0dd983 Teach isSafeToClobberEFLAGS to ignore dbg_value's. We need a MachineBasicBlock::iterator that does this automatically?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99320 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-23 20:35:45 +00:00
Evan Cheng
f48ef03655 Do not force indirect tailcall through fixed registers: eax, r11. Add support to allow loads to be folded to tail call instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98465 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-14 03:48:46 +00:00
Dan Gohman
81d0c36d22 Don't try to fold V_SET0 and V_SETALLONES to loads in medium and
large code models.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98042 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-09 03:01:40 +00:00
Bill Wendling
18ce64e069 Revert r97766. It's deleting a tag.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97768 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-05 00:33:59 +00:00
Bill Wendling
37b52ee6d9 Micro-optimization:
This code:

float floatingPointComparison(float x, float y) {
    double product = (double)x * y;
    if (product == 0.0)
        return product;
    return product - 1.0;
}

produces this:

_floatingPointComparison:
0000000000000000        cvtss2sd        %xmm1,%xmm1
0000000000000004        cvtss2sd        %xmm0,%xmm0
0000000000000008        mulsd           %xmm1,%xmm0
000000000000000c        pxor            %xmm1,%xmm1
0000000000000010        ucomisd         %xmm1,%xmm0
0000000000000014        jne             0x00000004
0000000000000016        jp              0x00000002
0000000000000018        jmp             0x00000008
000000000000001a        addsd           0x00000006(%rip),%xmm0
0000000000000022        cvtsd2ss        %xmm0,%xmm0
0000000000000026        ret

The "jne/jp/jmp" sequence can be reduced to this instead:

_floatingPointComparison:
0000000000000000        cvtss2sd        %xmm1,%xmm1
0000000000000004        cvtss2sd        %xmm0,%xmm0
0000000000000008        mulsd           %xmm1,%xmm0
000000000000000c        pxor            %xmm1,%xmm1
0000000000000010        ucomisd         %xmm1,%xmm0
0000000000000014        jp              0x00000002
0000000000000016        je              0x00000008
0000000000000018        addsd           0x00000006(%rip),%xmm0
0000000000000020        cvtsd2ss        %xmm0,%xmm0
0000000000000024        ret

for a savings of 2 bytes.

This xform can happen when we recognize that jne and jp jump to the same "true"
MBB, the unconditional jump would jump to the "false" MBB, and the "true" branch
is the fall-through MBB.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97766 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-05 00:24:26 +00:00
Dan Gohman
874cadaf21 Implement XMM subregs.
Extracting the low element of a vector is now done with EXTRACT_SUBREG,
and the zero-extension performed by load movss is now modeled with
SUBREG_TO_REG, and so on.

Register-to-register movss and movsd are no longer considered copies;
they are two-address instructions which insert a scalar into a vector.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97354 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-28 00:17:42 +00:00
Dan Gohman
6fe0df2abb movl is a cheaper way to materialize 0 without clobbering EFLAGS than movabsq.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97227 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-26 16:49:27 +00:00
Dan Gohman
b4e8aabba7 Fix a typo in a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96778 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-22 04:09:26 +00:00
Chris Lattner
0d8db8e0a8 add a bunch of mod/rm encoding types for fixed mod/rm bytes.
This will work better for the disassembler for modeling things
like lfence/monitor/vmcall etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95960 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12 02:06:33 +00:00
Chris Lattner
bd13fb6254 refactor the conditional jump instructions in the .td file to
use a multipattern that generates both the 1-byte and 4-byte 
versions from the same defm


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95901 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-11 19:25:55 +00:00
Chris Lattner
518bb53485 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95687 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-09 19:54:29 +00:00
Chris Lattner
39a612e6f9 port X86InstrInfo::determineREX over to the new encoder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95440 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05 22:10:22 +00:00
Chris Lattner
74a2151392 move functions for decoding X86II values into the X86II namespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95410 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05 19:24:13 +00:00
Chris Lattner
a3a0db0121 change getSizeOfImm and getBaseOpcodeFor to just take
TSFlags directly instead of a TargetInstrDesc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95405 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05 19:16:26 +00:00
Dale Johannesen
6ec25f570f use findDebugLoc in more places.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94477 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-26 00:03:12 +00:00
Evan Cheng
afc36739cd Be more conservative with clustering f32 / f64 loads.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94254 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-22 23:49:11 +00:00
Evan Cheng
96dc115ef3 Add two target hooks to determine whether two loads are near and should be scheduled together.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94147 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-22 03:34:51 +00:00
Evan Cheng
94da721d8c Fix a minor issue in x86 load / store folding table. movups does an unaligned load so it doesn't require 16-byte alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94058 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-21 00:55:14 +00:00
Dale Johannesen
73e884bb3e make findDebugLoc a class method
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94032 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-20 21:36:02 +00:00
Dale Johannesen
918f0f0bea Move findDebugLoc somewhere more central. Fix
more cases where debug declarations affect
debug line info.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93953 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-20 00:19:24 +00:00
Jim Grosbach
e45ab8a0a9 For aligned load/store instructions, it's only required to know whether a
function can support dynamic stack realignment. That's a much easier question
to answer at instruction selection stage than whether the function actually
will have dynamic alignment prologue. This allows the removal of the
stack alignment heuristic pass, and improves code quality for cases where
the heuristic would result in dynamic alignment code being generated when
it was not strictly necessary.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93885 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-19 18:31:11 +00:00
Evan Cheng
57d1d936fc For now, avoid issuing extract_subreg to reuse lower 8-bit, it's not safe in 32-bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93307 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-13 08:01:32 +00:00
Evan Cheng
7da9ecf967 Add a quick pass to optimize sign / zero extension instructions. For targets where the pre-extension values are available in the subreg of the result of the extension, replace the uses of the pre-extension value with the result + extract_subreg.
For now, this pass is fairly conservative. It only perform the replacement when both the pre- and post- extension values are used in the block. It will miss cases where the post-extension values are live, but not used.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93278 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-13 00:30:23 +00:00
Dan Gohman
f1b4d26e67 Reapply the MOV64r0 patch, with a fix: MOV64r0 clobbers EFLAGS.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93229 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-12 04:42:54 +00:00
Evan Cheng
a5a81d7072 Add TargetInstrInfo::isCoalescableInstr. It returns true if the specified
instruction is copy like where the source and destination registers can
overlap. This is to be used by the coalescable to coalesce the source and
destination registers of instructions like X86::MOVSX64rr32. Apparently
some crazy people believe the coalescer is too simple.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93210 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-12 00:09:37 +00:00
Evan Cheng
05920b8146 Revert 93158. It's breaking quite a few x86_64 tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93185 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11 21:13:41 +00:00
Dan Gohman
71c25b7d7b Re-instate MOV64r0 and MOV16r0, with adjustments to work with the
new AsmPrinter. This is perhaps less elegant than describing them
in terms of MOV32r0 and subreg operations, but it allows the
current register to rematerialize them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93158 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11 17:37:57 +00:00
David Greene
5b90132332 Change errs() to dbgs().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92653 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 01:29:29 +00:00
Bill Wendling
c41b638d4a Remove dead variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92184 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-28 01:36:02 +00:00
Chris Lattner
9e3238303c completely eliminate the MOV16r0 'instruction'. The only
interesting part of this is the divrem changes, which are
already tested by CodeGen/X86/divrem.ll.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91975 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-23 01:45:04 +00:00
Evan Cheng
b1f4981333 Remove target attribute break-sse-dep. Instead, do not fold load into sse partial update instructions unless optimizing for size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91910 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-22 17:47:23 +00:00
Evan Cheng
400073d546 On recent Intel u-arch's, folding loads into some unary SSE instructions can
be non-optimal. To be precise, we should avoid folding loads if the instructions
only update part of the destination register, and the non-updated part is not
needed. e.g. cvtss2sd, sqrtss. Unfolding the load from these instructions breaks
the partial register dependency and it can improve performance. e.g.

movss (%rdi), %xmm0
cvtss2sd %xmm0, %xmm0

instead of
cvtss2sd (%rdi), %xmm0

An alternative method to break dependency is to clear the register first. e.g.
xorps %xmm0, %xmm0
cvtss2sd (%rdi), %xmm0


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91672 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-18 07:40:29 +00:00
Sean Callanan
108934c65d Instruction fixes, added instructions, and AsmString changes in the
X86 instruction tables.

Also (while I was at it) cleaned up the X86 tables, removing tabs and
80-line violations.

This patch was reviewed by Chris Lattner, but please let me know if
there are any problems.

* X86*.td
	Removed tabs and fixed 80-line violations

* X86Instr64bit.td
	(IRET, POPCNT, BT_, LSL, SWPGS, PUSH_S, POP_S, L_S, SMSW)
		Added
	(CALL, CMOV) Added qualifiers
	(JMP) Added PC-relative jump instruction
	(POPFQ/PUSHFQ) Added qualifiers; renamed PUSHFQ to indicate
		that it is 64-bit only (ambiguous since it has no
		REX prefix)
	(MOV) Added rr form going the other way, which is encoded
		differently
	(MOV) Changed immediates to offsets, which is more correct;
		also fixed MOV64o64a to have to a 64-bit offset
	(MOV) Fixed qualifiers
	(MOV) Added debug-register and condition-register moves
	(MOVZX) Added more forms
	(ADC, SUB, SBB, AND, OR, XOR) Added reverse forms, which
		(as with MOV) are encoded differently
	(ROL) Made REX.W required
	(BT) Uncommented mr form for disassembly only
	(CVT__2__) Added several missing non-intrinsic forms
	(LXADD, XCHG) Reordered operands to make more sense for
		MRMSrcMem
	(XCHG) Added register-to-register forms
	(XADD, CMPXCHG, XCHG) Added non-locked forms
* X86InstrSSE.td
	(CVTSS2SI, COMISS, CVTTPS2DQ, CVTPS2PD, CVTPD2PS, MOVQ)
		Added
* X86InstrFPStack.td
	(COM_FST0, COMP_FST0, COM_FI, COM_FIP, FFREE, FNCLEX, FNOP,
	 FXAM, FLDL2T, FLDL2E, FLDPI, FLDLG2, FLDLN2, F2XM1, FYL2X,
	 FPTAN, FPATAN, FXTRACT, FPREM1, FDECSTP, FINCSTP, FPREM,
	 FYL2XP1, FSINCOS, FRNDINT, FSCALE, FCOMPP, FXSAVE,
	 FXRSTOR)
		Added
	(FCOM, FCOMP) Added qualifiers
	(FSTENV, FSAVE, FSTSW) Fixed opcode names
	(FNSTSW) Added implicit register operand
* X86InstrInfo.td
	(opaque512mem) Added for FXSAVE/FXRSTOR
	(offset8, offset16, offset32, offset64) Added for MOV
	(NOOPW, IRET, POPCNT, IN, BTC, BTR, BTS, LSL, INVLPG, STR,
	 LTR, PUSHFS, PUSHGS, POPFS, POPGS, LDS, LSS, LES, LFS,
	 LGS, VERR, VERW, SGDT, SIDT, SLDT, LGDT, LIDT, LLDT,
	 LODSD, OUTSB, OUTSW, OUTSD, HLT, RSM, FNINIT, CLC, STC,
	 CLI, STI, CLD, STD, CMC, CLTS, XLAT, WRMSR, RDMSR, RDPMC,
	 SMSW, LMSW, CPUID, INVD, WBINVD, INVEPT, INVVPID, VMCALL,
	 VMCLEAR, VMLAUNCH, VMRESUME, VMPTRLD, VMPTRST, VMREAD,
	 VMWRITE, VMXOFF, VMXON) Added
	(NOOPL, POPF, POPFD, PUSHF, PUSHFD) Added qualifier
	(JO, JNO, JB, JAE, JE, JNE, JBE, JA, JS, JNS, JP, JNP, JL,
	 JGE, JLE, JG, JCXZ) Added 32-bit forms
	(MOV) Changed some immediate forms to offset forms
	(MOV) Added reversed reg-reg forms, which are encoded
		differently
	(MOV) Added debug-register and condition-register moves
	(CMOV) Added qualifiers
	(AND, OR, XOR, ADC, SUB, SBB) Added reverse forms, like MOV
	(BT) Uncommented memory-register forms for disassembler
	(MOVSX, MOVZX) Added forms
	(XCHG, LXADD) Made operand order make sense for MRMSrcMem
	(XCHG) Added register-register forms
	(XADD, CMPXCHG) Added unlocked forms
* X86InstrMMX.td
	(MMX_MOVD, MMV_MOVQ) Added forms
* X86InstrInfo.cpp: Changed PUSHFQ to PUSHFQ64 to reflect table
	change

* X86RegisterInfo.td: Added debug and condition register sets
* x86-64-pic-3.ll: Fixed testcase to reflect call qualifier
* peep-test-3.ll: Fixed testcase to reflect test qualifier
* cmov.ll: Fixed testcase to reflect cmov qualifier
* loop-blocks.ll: Fixed testcase to reflect call qualifier
* x86-64-pic-11.ll: Fixed testcase to reflect call qualifier
* 2009-11-04-SubregCoalescingBug.ll: Fixed testcase to reflect call
  qualifier
* x86-64-pic-2.ll: Fixed testcase to reflect call qualifier
* live-out-reg-info.ll: Fixed testcase to reflect test qualifier
* tail-opts.ll: Fixed testcase to reflect call qualifiers
* x86-64-pic-10.ll: Fixed testcase to reflect call qualifier
* bss-pagealigned.ll: Fixed testcase to reflect call qualifier
* x86-64-pic-1.ll: Fixed testcase to reflect call qualifier
* widen_load-1.ll: Fixed testcase to reflect call qualifier


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91638 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-18 00:01:26 +00:00
Bill Wendling
85de1e5bad Whitespace changes, comment clarification. No functional changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91274 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-14 06:51:19 +00:00
Evan Cheng
dd99f3a7dc Disable r91104 for x86. It causes partial register stall which pessimize code in 32-bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91223 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-12 20:03:14 +00:00
Evan Cheng
04ab19cb14 Add comment about potential partial register stall.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91220 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-12 18:55:26 +00:00
Evan Cheng
656e51454a Add support to 3-addressify 16-bit instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91104 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-11 06:01:48 +00:00
Dan Gohman
864e2efce2 Remove the target hook TargetInstrInfo::BlockHasNoFallThrough in favor of
MachineBasicBlock::canFallThrough(), which is target-independent and more
thorough.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90634 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-05 00:44:40 +00:00
David Greene
adbc23cae1 Remove an unneeded include.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90625 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-04 23:55:07 +00:00
David Greene
29dbf50b18 Have hasLoad/StoreFrom/ToStackSlot return the relevant MachineMemOperand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90608 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-04 22:38:46 +00:00
Chris Lattner
7896c9f436 improve portability to avoid conflicting with std::next in c++'0x.
Patch by Howard Hinnant!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90365 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-03 00:50:42 +00:00
Dan Gohman
735afe14ee Remove ISD::DEBUG_LOC and ISD::DBG_LABEL, which are no longer used.
Note that "hasDotLocAndDotFile"-style debug info was already broken;
people wanting this functionality should implement it in the
AsmPrinter/DwarfWriter code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89711 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-23 23:20:51 +00:00
Evan Cheng
d15ac2fce3 Re-apply 89011. It's not to be blamed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89081 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-17 09:51:18 +00:00
Evan Cheng
6db07eac95 Revert 89011. Buildbot thinks it might be breaking stuff.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89076 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-17 09:20:28 +00:00
Evan Cheng
574186f8ad A few more instructions that should be marked re-materializable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89011 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-17 00:23:22 +00:00
Evan Cheng
600c043697 - Check memoperand alignment instead of checking stack alignment. Most load / store folding instructions are not referencing spill stack slots.
- Mark MOVUPSrm re-materializable.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88974 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-16 21:56:03 +00:00
Evan Cheng
d57cdd5683 - Change TargetInstrInfo::reMaterialize to pass in TargetRegisterInfo.
- If destination is a physical register and it has a subreg index, use the
  sub-register instead.
This fixes PR5423.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88745 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-14 02:55:43 +00:00
David Greene
dda3978d78 Fix a bootstrap failure.
Provide special isLoadFromStackSlotPostFE and isStoreToStackSlotPostFE
interfaces to explicitly request checking for post-frame ptr elimination
operands.  This uses a heuristic so it isn't reliable for correctness.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@87047 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-13 00:29:53 +00:00
David Greene
b87bc95db0 Add hasLoadFromStackSlot and hasStoreToStackSlot to return whether a
machine instruction loads or stores from/to a stack slot.  Unlike
isLoadFromStackSlot and isStoreFromStackSlot, the instruction may be
something other than a pure load/store (e.g. it may be an arithmetic
operation with a memory operand).  This helps AsmPrinter determine when
to print a spill/reload comment.

This is only a hint since we may not be able to figure this out in all
cases.  As such, it should not be relied upon for correctness.

Implement for X86.  Return false by default for other architectures.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@87026 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 20:55:29 +00:00
Jeffrey Yasskin
81cf432569 Fix DenseMap iterator constness.
This patch forbids implicit conversion of DenseMap::const_iterator to
DenseMap::iterator which was possible because DenseMapIterator inherited
(publicly) from DenseMapConstIterator. Conversion the other way around is now
allowed as one may expect.

The template DenseMapConstIterator is removed and the template parameter
IsConst which specifies whether the iterator is constant is added to
DenseMapIterator.

Actually IsConst parameter is not necessary since the constness can be
determined from KeyT but this is not relevant to the fix and can be addressed
later.

Patch by Victor Zverovich!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86636 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 01:02:17 +00:00