Commit Graph

99722 Commits

Author SHA1 Message Date
Rafael Espindola
07f1de473f Remove -print-hack-directives from a test where we already do the right thing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200116 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-26 04:14:50 +00:00
Rafael Espindola
d41a30ed8c Move tests that just use llc from test/MC/Mips to test/MC/Codegen.
This is an expanded version of r200064.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200115 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-26 04:08:47 +00:00
Jiangning Liu
6025dbfd67 Implement pattern match from v1xx to v1xx for AArch64 Neon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200113 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-26 03:27:40 +00:00
Venkatraman Govindaraju
97f2a5e52a [Sparc] Add support for sparc relocation types in ELF object file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200112 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-26 03:21:28 +00:00
Kevin Qin
97581ccb89 [AArch64 NEON] Add patterns for concat_vector on v2i32.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200111 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-26 02:46:15 +00:00
Kevin Qin
fc78232300 [AArch64 NEON] Add test case for vector FP_ROUND.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200110 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-26 02:23:33 +00:00
Kevin Qin
40bb464283 [AArch64 NEON] Fix pattern match failed on FP_ROUND from v1f128 to v1f64.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200109 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-26 02:19:35 +00:00
Venkatraman Govindaraju
65d4adccd6 removing duplicate enum value
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200104 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 23:50:21 +00:00
Venkatraman Govindaraju
f81e5053c6 Missing ELF relocations for Sparc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200103 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 23:40:07 +00:00
Renato Golin
a97f49c147 Re-enabling MCJIT tests on ARM
After several refactorings on the MCJIT remote communication, things are
finally looking good on Clang-compiled LLVM regarding MCJIT remote tests,
so I'm re-enabling them to see how the self-hosting buildbot behaves over
a longer period.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200102 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 23:38:08 +00:00
Venkatraman Govindaraju
3177a84342 [Sparc] Add sparc to the list of XFAIL architecture. It seems that the llvm-cov test is not supported in big-endian architectures.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200101 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 22:54:47 +00:00
Craig Topper
c45addd6e4 Set displacementSize to 1 for instrucitons with mod==0x1. Fixes PR17310. Modified from patch by James Courtier-Dutton.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200100 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 22:48:43 +00:00
Hal Finkel
1299df2a0b Add a TBAA CodeGen failure test case
I disabled the use of TBAA in CodeGen in r200093. This adds a test case that
demonstrates the problems with inttoptr and TBAA in CodeGen (and, specifically,
the problem that causes LLVM to miscompile itself in Release mode). This test
will currently fail if -use-tbaa-in-sched-mi is enabled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200097 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 20:16:36 +00:00
Evan Cheng
4faaca1836 Clean up hack which is no longer needed after r198617. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200095 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 19:51:19 +00:00
Hal Finkel
ebf060c26f XFAIL test/CodeGen/SystemZ/alias-01.ll which requires CodeGen TBAA
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200094 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 19:31:44 +00:00
Hal Finkel
397cd32bc2 Disable the use of TBAA when using AA in CodeGen
There are currently two issues, of which I currently know, that prevent TBAA
from being correctly usable in CodeGen:

  1. Stack coloring does not update TBAA when merging allocas. This is easy
     enough to fix, but is not the largest problem.

  2. CGP inserts ptrtoint/inttoptr pairs when sinking address computations.
     Because BasicAA does not handle inttoptr, we'll often miss basic type punning
     idioms that we need to catch so we don't miscompile real-world code (like LLVM).

I don't yet have a small test case for this, but this fixes self hosting a
non-asserts build of LLVM on PPC64 when using -enable-aa-sched-mi and -misched=shuffle.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200093 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 19:24:54 +00:00
Craig Topper
55604d9716 Don't use EnforceSmallerThan for EnforceVectorSubVectorTypeIs. EnforceSmallerThan doesn't handle vectors quite right and should really enforce that vectors have the same number of elements. Add explicit checks for vector element count differing in EnforceVectorSubVectorTypeIs instead. This removes some unnecessary type checks in X86GenDAGISel.inc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200091 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 17:40:33 +00:00
Mark Seaborn
2effd6cdc1 Fix "llvm-objdump -d -r" to show relocations inline for ELF files
This fixes a regression introduced by r182908, which broke
llvm-objdump's ability to display relocations inline in a disassembly
dump for ELF object files.

That change removed a SectionRelocMap from Object/ELF.h, which we
recreate in llvm-objdump.cpp.

I discovered this regression via an out-of-tree test
(test/NaCl/X86/pnacl-hides-sandbox-x86-64.ll) which used llvm-objdump.

Note that the "Unknown" string in the test output on i386 isn't quite
right, but this appears to be a pre-existing bug.

Differential Revision: http://llvm-reviews.chandlerc.com/D2559

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200090 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 17:38:19 +00:00
Craig Topper
858594edb0 Fix typo in commment tyep->type.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200089 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 17:34:23 +00:00
Hal Finkel
7a1fc7ad50 Add combiner-aa-only-func (debug only)
This option (which is !NDEBUG only) allows restricting the use of alias
analysis in DAGCombiner to a specific function. This has proved extremely
valuable to isolating bugs related to this feature, and mirrors the
misched-only-func option provided by the new instruction scheduler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200088 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 17:32:39 +00:00
Hal Finkel
f62acf3c54 Improve descriptions of combiner-alias-analysis and combiner-global-alias-analysis
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200087 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 17:32:37 +00:00
Artyom Skrobov
85ae0340ba Reverting r199886 (Prevent repetitive warnings for unrecognized processors and features)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200083 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 16:56:18 +00:00
Rafael Espindola
c0c6ed683a Added .DS_Store entry in .gitignore for ignoring .DS_Store files in the source
tree generated by OS X.

Patch by Abhay Kadam!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200079 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 15:15:16 +00:00
Rafael Espindola
86b535b085 This reverts commit r200064 and r200051.
r200064 depends on r200051.

r200051 is broken: I tries to replace .mips_hack_elf_flags, which is a good
thing, but what it replaces it with is even worse.

The new emitMipsELFFlags it adds corresponds to no assembly directive, is not
marked as a hack and is not even printed to the .s file.

The patch also introduces more uses of hasRawTextSupport.

The correct way to remove .mips_hack_elf_flags is to have the mips target
streamer handle the default flags (and command line options). That way the
same code path is used for asm and obj. The streamer interface should *really*
correspond to what is printed in the .s file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200078 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 15:06:56 +00:00
Chandler Carruth
754b83a51a [LPM] Conclude my immediate work by making the LoopVectorizer
a FunctionPass. With this change the loop vectorizer no longer is a loop
pass and can readily depend on function analyses. In particular, with
this change we no longer have to form a loop pass manager to run the
loop vectorizer which simplifies the entire pass management of LLVM.

The next step here is to teach the loop vectorizer to leverage profile
information through the profile information providing analysis passes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200074 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 10:01:55 +00:00
Craig Topper
f6deb18968 Use isConcrete and getConcrete instead of using TypeVec directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200071 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 05:33:48 +00:00
Craig Topper
f5f44a149e Fix EnforceSmallerThan to check !hasVectorTypes on the other type instead of this type to force this type to be scalar.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200070 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 05:17:38 +00:00
Chandler Carruth
3d69cf57e1 [LPM] Make LCSSA a utility with a FunctionPass that applies it to all
the loops in a function, and teach LICM to work in the presance of
LCSSA.

Previously, LCSSA was a loop pass. That made passes requiring it also be
loop passes and unable to depend on function analysis passes easily. It
also caused outer loops to have a different "canonical" form from inner
loops during analysis. Instead, we go into LCSSA form and preserve it
through the loop pass manager run.

Note that this has the same problem as LoopSimplify that prevents
enabling its verification -- loop passes which run at the end of the loop
pass manager and don't preserve these are valid, but the subsequent loop
pass runs of outer loops that do preserve this pass trigger too much
verification and fail because the inner loop no longer verifies.

The other problem this exposed is that LICM was completely unable to
handle LCSSA form. It didn't preserve it and it actually would give up
on moving instructions in many cases when they were used by an LCSSA phi
node. I've taught LICM to support detecting LCSSA-form PHI nodes and to
hoist and sink around them. This may actually let LICM fire
significantly more because we put everything into LCSSA form to rotate
the loop before running LICM. =/ Now LICM should handle that fine and
preserve it correctly. The down side is that LICM has to require LCSSA
in order to preserve it. This is just a fact of life for LCSSA. It's
entirely possible we should completely remove LCSSA from the optimizer.

The test updates are essentially accomodating LCSSA phi nodes in the
output of LICM, and the fact that we now completely sink every
instruction in ashr-crash below the loop bodies prior to unrolling.

With this change, LCSSA is computed only three times in the pass
pipeline. One of them could be removed (and potentially a SCEV run and
a separate LoopPassManager entirely!) if we had a LoopPass variant of
InstCombine that ran InstCombine on the loop body but refused to combine
away LCSSA PHI nodes. Currently, this also prevents loop unrolling from
being in the same loop pass manager is rotate, LICM, and unswitch.

There is one thing that I *really* don't like -- preserving LCSSA in
LICM is quite expensive. We end up having to re-run LCSSA twice for some
loops after LICM runs because LICM can undo LCSSA both in the current
loop and the parent loop. I don't really see good solutions to this
other than to completely move away from LCSSA and using tools like
SSAUpdater instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200067 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 04:07:24 +00:00
Rafael Espindola
f961273b79 Remove an easy use of EmitRawText from PPC.
This makes lib/Target/PowerPC EmitRawText free.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200065 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 02:35:56 +00:00
Jack Carter
8fe060da52 [Mips] Move 2 test cases from MC to CodeGen.
No code changes. Just reassignment of test case files.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200064 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 02:14:14 +00:00
Juergen Ributzka
943ce55f39 Revert "Revert "Add Constant Hoisting Pass" (r200034)"
This reverts commit r200058 and adds the using directive for
ARMTargetTransformInfo to silence two g++ overload warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200062 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 02:02:55 +00:00
Reid Kleckner
1d1670227b Fix llvm-dis to print the inalloca bit on allocas.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200059 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 01:24:06 +00:00
Hans Wennborg
503793e834 Revert "Add Constant Hoisting Pass" (r200034)
This commit caused -Woverloaded-virtual warnings. The two new
TargetTransformInfo::getIntImmCost functions were only added to the superclass,
and to the X86 subclass. The other targets were not updated, and the
warning highlighted this by pointing out that e.g. ARMTTI::getIntImmCost was
hiding the two new getIntImmCost variants.

We could pacify the warning by adding "using TargetTransformInfo::getIntImmCost"
to the various subclasses, or turning it off, but I suspect that it's wrong to
leave the functions unimplemnted in those targets. The default implementations
return TCC_Free, which I don't think is right e.g. for ARM.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200058 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 01:18:18 +00:00
Mark Seaborn
2760cc2967 llvm-objdump: Some style cleanups to follow LLVM coding style
Rename "ec" to "EC", and rename some iterators.

Then fix whitespace using clang-format-diff.

(As requested in http://llvm-reviews.chandlerc.com/D2559)

Differential Revision: http://llvm-reviews.chandlerc.com/D2594

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200053 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 00:32:01 +00:00
Jack Carter
998052555a [Mips] TargetStreamer ELF flag Support for default and commandline options.
This patch uses a common MipsTargetSteamer interface for both 
MipsAsmPrinter and MipsAsmParser for recording default and commandline
driven directives that affect ELF header flags.

It has been noted that the .ll tests affected by this patch belong in
test/Codegen/Mips. I will move them in a separate patch.

Also, a number of directives do not get expressed by AsmPrinter in the 
resultant .s assembly such as setting the correct ASI. I have noted this
in the tests and they will be addressed in later patches.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200051 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 00:24:07 +00:00
Aaron Ballman
f1f5a434ad Typo fix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200050 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 23:40:08 +00:00
Ana Pazos
08f6677a7f [AArch64] Removed unused i8 type from FPR8 register class.
The i8 type is not registered with any register class.
This causes a segmentation fault in MachineLICM::getRegisterClassIDAndCost.

The code selects the first type associated with register class FPR8,
which happens to be i8.
It uses this type (i8) to get the representative class pointer, which is 0.
It then uses this pointer to access a field, resulting in segmentation fault.

Since i8 type is not being used for printing any neon instruction
we can safely remove it.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200046 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 22:36:53 +00:00
Rafael Espindola
dbba2eb82f Fix c++03 build.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200042 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 21:52:44 +00:00
Rafael Espindola
584fe2db6a Make ObjectFile ownership of the MemoryBuffer optional.
This allows llvm-ar to mmap the input files only once.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200040 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 21:32:21 +00:00
Rui Ueyama
0078935812 Support/COFF: Fix PEHeader struct, and define PE32Header as its alias.
This change does not affect anything because everybody seems to be using
Object/COFF.h instead. But the definition is not for PE32 but for PE32+,
so fix it anyway.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200038 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 20:54:10 +00:00
Craig Topper
82f50dc0c2 Remove TGValueTypes.cpp from CMakeLists.txt which I forgot to do in r200036.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200037 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 20:51:32 +00:00
Craig Topper
f3474549ba Replace tablegen uses of EVT with MVT. Add isOverloaded() to MVT to facilitate. Remove TGValueTypes.cpp since its unused now (and may have been before).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200036 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 20:50:47 +00:00
Juergen Ributzka
96172cb4a4 Add Constant Hoisting Pass
Retry commit r200022 with a fix for the build bot errors. Constant expressions
have (unlike instructions) module scope use lists and therefore may have users
in different functions. The fix is to simply ignore these out-of-function uses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200034 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 20:18:00 +00:00
Hal Finkel
86720f7c65 Fix DAGCombiner::GatherAllAliases to account for non-chain dependencies
DAGCombiner::GatherAllAliases, which is only used when AA used is enabled
during DAGCombine, had a fundamentally incorrect assumption for which this
change compensates. GatherAllAliases, which is used to find aliasing
predecessor chain nodes (so that a better chain can be selected for a load or
store to enable subsequent optimizations) assumed that walking up the chain
would always catch all possibly-aliasing loads and stores. This is not true: To
really find all aliases, we also need to search for aliases through the value
operand of a store, etc.  Consider the following situation:

  Token1 = ...
  L1 = load Token1, %52
  S1 = store Token1, L1, %51
  L2 = load Token1, %52+8
  S2 = store Token1, L2, %51+8
  Token2 = Token(S1, S2)
  L3 = load Token2, %53
  S3 = store Token2, L3, %52
  L4 = load Token2, %53+8
  S4 = store Token2, L4, %52+8

If we search for aliases of S3 (which loads address %52), and we look only
through the chain, then we'll miss the trivial dependence on L1 (which loads
from %52). We then might change all loads and stores to use Token1 as their
chain operand, which could result in copying %53 into %52 before copying
%52 into %51 (which should happen first).

The problem is, however, that searching for such data dependencies can become
expensive, and the cost is not directly related to the chain depth. Instead,
we'll rule out such configurations by insisting that we've visited all chain
users (except for users of the original chain, which is not necessary).  When
doing this, we need to look through nodes we don't care about (otherwise,
things like register copies will interfere with trivial use cases).

Unfortunately, I don't have a small test case for this problem. Creating the
underlying situation is not hard (a pair of memcpys will do it), but arranging
for the default instruction schedule to be incorrect is very fragile.

This unbreaks self hosting on PPC64 when using
-mllvm -combiner-global-alias-analysis -mllvm -combiner-alias-analysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200033 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 20:12:02 +00:00
Bill Wendling
d221469cc6 Verify that attributes are not lost during linking.
We don't want to lose attributes when a function decl without them is merged
with a function decl that has them.
PR2382

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200030 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 19:20:15 +00:00
Benjamin Kramer
d7053be532 InstCombine: Don't try to use aggregate elements of ConstantExprs.
PR18600.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200028 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 19:02:37 +00:00
Lang Hames
a9699d475f Add a testcase for the changes in r199938.
<rdar://problem/15611947>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200027 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 19:00:19 +00:00
Juergen Ributzka
dc6f9b9a4f Revert "Add Constant Hoisting Pass"
This reverts commit r200022 to unbreak the build bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200024 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 18:40:30 +00:00
Hal Finkel
08aa5bf1d5 Restrict FindBetterChain DAG combines to unindexed nodes
These transformations obviously won't work for indexed (pre/post-inc) loads and
stores. In practice, I'm not sure there is any benefit to enabling them for
indexed nodes because other transformations that these might enable likely also
won't handle indexed nodes.

I don't have an in-tree test case that hits this problem, but an upcoming bug
fix will make it much more likely.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200023 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 18:25:26 +00:00
Juergen Ributzka
fb282c68b7 Add Constant Hoisting Pass
This pass identifies expensive constants to hoist and coalesces them to
better prepare it for SelectionDAG-based code generation. This works around the
limitations of the basic-block-at-a-time approach.

First it scans all instructions for integer constants and calculates its
cost. If the constant can be folded into the instruction (the cost is
TCC_Free) or the cost is just a simple operation (TCC_BASIC), then we don't
consider it expensive and leave it alone. This is the default behavior and
the default implementation of getIntImmCost will always return TCC_Free.

If the cost is more than TCC_BASIC, then the integer constant can't be folded
into the instruction and it might be beneficial to hoist the constant.
Similar constants are coalesced to reduce register pressure and
materialization code.

When a constant is hoisted, it is also hidden behind a bitcast to force it to
be live-out of the basic block. Otherwise the constant would be just
duplicated and each basic block would have its own copy in the SelectionDAG.
The SelectionDAG recognizes such constants as opaque and doesn't perform
certain transformations on them, which would create a new expensive constant.

This optimization is only applied to integer constants in instructions and
simple (this means not nested) constant cast experessions. For example:
%0 = load i64* inttoptr (i64 big_constant to i64*)

Reviewed by Eric

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200022 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 18:23:08 +00:00