6539 Commits

Author SHA1 Message Date
Tim Northover
2883da3b51 Add LICENSE.TXT covering contributions made by ARM.
Absent a Contributor's License Agreement (CLA) with an LLVM legal entity and as
reviewed and agreed with Chris Lattner, add a patent license covering future
contributions from ARM until there is a CLA. This is to make explicit ARM's
grant of patent rights to recipients of LLVM containing ARM-contributed
material.

llvm-svn: 171721
2013-01-07 10:04:49 +00:00
Chandler Carruth
d3e73556d6 Move TargetTransformInfo to live under the Analysis library. This no
longer would violate any dependency layering and it is in fact an
analysis. =]

llvm-svn: 171686
2013-01-07 03:08:10 +00:00
Chandler Carruth
664e354de7 Switch TargetTransformInfo from an immutable analysis pass that requires
a TargetMachine to construct (and thus isn't always available), to an
analysis group that supports layered implementations much like
AliasAnalysis does. This is a pretty massive change, with a few parts
that I was unable to easily separate (sorry), so I'll walk through it.

The first step of this conversion was to make TargetTransformInfo an
analysis group, and to sink the nonce implementations in
ScalarTargetTransformInfo and VectorTargetTranformInfo into
a NoTargetTransformInfo pass. This allows other passes to add a hard
requirement on TTI, and assume they will always get at least on
implementation.

The TargetTransformInfo analysis group leverages the delegation chaining
trick that AliasAnalysis uses, where the base class for the analysis
group delegates to the previous analysis *pass*, allowing all but tho
NoFoo analysis passes to only implement the parts of the interfaces they
support. It also introduces a new trick where each pass in the group
retains a pointer to the top-most pass that has been initialized. This
allows passes to implement one API in terms of another API and benefit
when some other pass above them in the stack has more precise results
for the second API.

The second step of this conversion is to create a pass that implements
the TargetTransformInfo analysis using the target-independent
abstractions in the code generator. This replaces the
ScalarTargetTransformImpl and VectorTargetTransformImpl classes in
lib/Target with a single pass in lib/CodeGen called
BasicTargetTransformInfo. This class actually provides most of the TTI
functionality, basing it upon the TargetLowering abstraction and other
information in the target independent code generator.

The third step of the conversion adds support to all TargetMachines to
register custom analysis passes. This allows building those passes with
access to TargetLowering or other target-specific classes, and it also
allows each target to customize the set of analysis passes desired in
the pass manager. The baseline LLVMTargetMachine implements this
interface to add the BasicTTI pass to the pass manager, and all of the
tools that want to support target-aware TTI passes call this routine on
whatever target machine they end up with to add the appropriate passes.

The fourth step of the conversion created target-specific TTI analysis
passes for the X86 and ARM backends. These passes contain the custom
logic that was previously in their extensions of the
ScalarTargetTransformInfo and VectorTargetTransformInfo interfaces.
I separated them into their own file, as now all of the interface bits
are private and they just expose a function to create the pass itself.
Then I extended these target machines to set up a custom set of analysis
passes, first adding BasicTTI as a fallback, and then adding their
customized TTI implementations.

The fourth step required logic that was shared between the target
independent layer and the specific targets to move to a different
interface, as they no longer derive from each other. As a consequence,
a helper functions were added to TargetLowering representing the common
logic needed both in the target implementation and the codegen
implementation of the TTI pass. While technically this is the only
change that could have been committed separately, it would have been
a nightmare to extract.

The final step of the conversion was just to delete all the old
boilerplate. This got rid of the ScalarTargetTransformInfo and
VectorTargetTransformInfo classes, all of the support in all of the
targets for producing instances of them, and all of the support in the
tools for manually constructing a pass based around them.

Now that TTI is a relatively normal analysis group, two things become
straightforward. First, we can sink it into lib/Analysis which is a more
natural layer for it to live. Second, clients of this interface can
depend on it *always* being available which will simplify their code and
behavior. These (and other) simplifications will follow in subsequent
commits, this one is clearly big enough.

Finally, I'm very aware that much of the comments and documentation
needs to be updated. As soon as I had this working, and plausibly well
commented, I wanted to get it committed and in front of the build bots.
I'll be doing a few passes over documentation later if it sticks.

Commits to update DragonEgg and Clang will be made presently.

llvm-svn: 171681
2013-01-07 01:37:14 +00:00
Chandler Carruth
9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Chandler Carruth
be81023d74 Resort the #include lines in include/... and lib/... with the
utils/sort_includes.py script.

Most of these are updating the new R600 target and fixing up a few
regressions that have creeped in since the last time I sorted the
includes.

llvm-svn: 171362
2013-01-02 10:22:59 +00:00
Bill Wendling
74dba875e2 Remove the Function::getRetAttributes method in favor of using the AttributeSet accessor method.
llvm-svn: 171256
2012-12-30 13:01:51 +00:00
Bill Wendling
698e84fc4f Remove the Function::getFnAttributes method in favor of using the AttributeSet
directly.

This is in preparation for removing the use of the 'Attribute' class as a
collection of attributes. That will shift to the AttributeSet class instead.

llvm-svn: 171253
2012-12-30 10:32:01 +00:00
Benjamin Kramer
9d46110ff1 Use a std::string rather than a dynamically allocated char* buffer.
This affords us to use std::string's allocation routines and use the destructor
for the memory management. Switching to that also means that we can use
operator==(const std::string&, const char *) to perform the string comparison
rather than resorting to libc functionality (i.e. strcmp).

Patch by Saleem Abdulrasool!

Differential Revision: http://llvm-reviews.chandlerc.com/D230

llvm-svn: 171042
2012-12-24 19:23:30 +00:00
Benjamin Kramer
5521b94b07 Cleanup compiler warnings on discarding type qualifiers in casts. Switch to C++ style casts.
Patch by Saleem Abdulrasool!

Differential Revision: http://llvm-reviews.chandlerc.com/D204

llvm-svn: 170917
2012-12-21 19:09:53 +00:00
Roman Divacky
a229186a82 Remove duplicate includes.
llvm-svn: 170902
2012-12-21 17:06:44 +00:00
Quentin Colombet
b1b66e7a25 Add ARM cortex-r5 subtarget.
llvm-svn: 170840
2012-12-21 04:35:05 +00:00
Jakob Stoklund Olesen
33f5d1492d Add an MF argument to MI::copyImplicitOps().
This function is often used to decorate dangling instructions, so a
context reference is required to allocate memory for the operands.

Also add a corresponding MachineInstrBuilder method.

llvm-svn: 170797
2012-12-20 22:54:02 +00:00
Jakob Stoklund Olesen
2ea203694d MachineInstrBuilderize ARM.
llvm-svn: 170795
2012-12-20 22:53:55 +00:00
Bob Wilson
7bba4f8957 Revert "Adding support for llvm.arm.neon.vaddl[su].* and"
This reverts r170694.  The operations can be represented in IR without
adding any new intrinsics.

llvm-svn: 170765
2012-12-20 21:09:38 +00:00
Evan Cheng
ddc0cb6dc5 On some ARM cpus, flags setting movs with shifter operand, i.e. lsl, lsr, asr,
are more expensive than the non-flag setting variant. Teach thumb2 size
reduction pass to avoid generating them unless we are optimizing for size.

rdar://12892707

llvm-svn: 170728
2012-12-20 19:59:30 +00:00
Roman Divacky
ff95a1dc12 Remove MCTargetAsmLexer and its derived classes now that edis,
its only user, is gone.

llvm-svn: 170699
2012-12-20 14:43:30 +00:00
Renato Golin
6b2ea4a48f Adding support for llvm.arm.neon.vaddl[su].* and
llvm.arm.neon.vsub[su].* intrinsics.

Patch by Pete Couperus <pjcoup@gmail.com>

llvm-svn: 170694
2012-12-20 13:52:11 +00:00
Jim Grosbach
6df94846ec MC: Add MCInstrDesc::mayAffectControlFlow() method.
MC disassembler clients (LLDB) are interested in querying if an
instruction may affect control flow other than by virtue of being
an explicit branch instruction. For example, instructions which
write directly to the PC on some architectures.

llvm-svn: 170610
2012-12-19 23:38:53 +00:00
Jakob Stoklund Olesen
b159b5ff0d Remove the explicit MachineInstrBuilder(MI) constructor.
Use the version that also takes an MF reference instead.

It would technically be possible to extract an MF reference from the MI
as MI->getParent()->getParent(), but that would not work for MIs that
are not inserted into any basic block.

Given the reasonably small number of places this constructor was used at
all, I preferred the compile time check to a run time assertion.

llvm-svn: 170588
2012-12-19 21:31:56 +00:00
Evan Cheng
eae6d2ccea LLVM sdisel normalize bit extraction of the form:
((x & 0xff00) >> 8) << 2
to
 (x >> 6) & 0x3fc

This is general goodness since it folds a left shift into the mask. However,
the trailing zeros in the mask prevents the ARM backend from using the bit
extraction instructions. And worse since the mask materialization may require
an addition instruction. This comes up fairly frequently when the result of 
the bit twiddling is used as memory address. e.g.

 = ptr[(x & 0xFF0000) >> 16]

We want to generate:
  ubfx   r3, r1, #16, #8
  ldr.w  r3, [r0, r3, lsl #2]

vs.
  mov.w  r9, #1020
  and.w  r2, r9, r1, lsr #14
  ldr    r2, [r0, r2]

Add a late ARM specific isel optimization to
ARMDAGToDAGISel::PreprocessISelDAG(). It folds the left shift to the
'base + offset' address computation; change the mask to one which doesn't have
trailing zeros and enable the use of ubfx.

Note the optimization has to be done late since it's target specific and we
don't want to change the DAG normalization. It's also fairly restrictive
as shifter operands are not always free. It's only done for lsh 1 / 2. It's
known to be free on some cpus and they are most common for address
computation.

This is a slight win for blowfish, rijndael, etc.

rdar://12870177

llvm-svn: 170581
2012-12-19 20:16:09 +00:00
Roman Divacky
e3d323052f Remove edis - the enhanced disassembler. Fixes PR14654.
llvm-svn: 170578
2012-12-19 19:55:47 +00:00
Patrik Hagglund
f9eb168ef4 Change TargetLowering::findRepresentativeClass to take an MVT, instead
of EVT.

llvm-svn: 170532
2012-12-19 11:30:36 +00:00
Bill Wendling
3d7b0b8ac7 Rename the 'Attributes' class to 'Attribute'. It's going to represent a single attribute in the future.
llvm-svn: 170502
2012-12-19 07:18:57 +00:00
Quentin Colombet
23b404d5ad Disable ARM partial flag dependency optimization at -Oz
To not over constrain the scheduler for ARM in thumb mode, some optimizations  for code size reduction, specific to ARM thumb, are blocked when they add a dependency (like write after read dependency).

Disables this check when code size is the priority, i.e., code is compiled with -Oz.

llvm-svn: 170462
2012-12-18 22:47:16 +00:00
Jakob Stoklund Olesen
41bbf9c256 Repair bundles that were broken by removing and reinserting the first
instruction.

This isn't strictly necessary at the moment because Thumb2SizeReduction
also copies all MI flags from the old instruction to the new. However, a
future patch will make that kind of direct flag tampering illegal.

llvm-svn: 170395
2012-12-18 00:46:39 +00:00
Jakob Stoklund Olesen
43b1e13386 Extract a method, no functional change intended.
Sadly, this costs us a perfectly good opportunity to use 'goto'.

llvm-svn: 170385
2012-12-18 00:13:11 +00:00
Chad Rosier
150d35bc1d [arm fast-isel] Minor cleanup. No functional change intended.
llvm-svn: 170379
2012-12-17 22:35:29 +00:00
Chad Rosier
62a144f099 [arm fast-isel] Fast-isel only handles simple VTs, so make sure the necessary
checks are in place.  Some minor cleanup as well.

llvm-svn: 170360
2012-12-17 19:59:43 +00:00
Patrik Hagglund
c494d24a68 Revert/correct some FastISel changes in r170104 (EVT->MVT for
TargetLowering::getRegClassFor).

Some isSimple() guards were missing, or getSimpleVT() were hoisted too
far, resulting in asserts on valid LLVM assembly input.

llvm-svn: 170336
2012-12-17 14:30:06 +00:00
Kevin Enderby
06aa3eb8ce Make sure the alternate PC+imm syntax of LDR instruction with a small
immediate generates the narrow version.  Needed when doing round-trip
assemble/disassemble testing using the alternate syntax that specifies
'pc' directly.

llvm-svn: 170255
2012-12-14 23:04:25 +00:00
Patrik Hagglund
5e6c361bc0 Change TargetLowering::getRegClassFor to take an MVT, instead of EVT.
Accordingly, add helper funtions getSimpleValueType (in parallel to
getValueType) in SDValue, SDNode, and TargetLowering.

This is the first, in a series of patches.

This is the second attempt. In the first attempt (r169837), a few
getSimpleVT() were hoisted too far, detected by bootstrap failures.

llvm-svn: 170104
2012-12-13 06:34:11 +00:00
Logan Chien
4dd14fb5eb Add ARM NONE and PREL31 relocation types.
Add R_ARM_NONE and R_ARM_PREL31 relocation types
to MCExpr.  Both of them will be used while
generating .ARM.extab and .ARM.exidx sections.

llvm-svn: 169965
2012-12-12 07:14:46 +00:00
Evan Cheng
962711ee71 Sorry about the churn. One more change to getOptimalMemOpType() hook. Did I
mention the inline memcpy / memset expansion code is a mess?

This patch split the ZeroOrLdSrc argument into two: IsMemset and ZeroMemset.
The first indicates whether it is expanding a memset or a memcpy / memmove.
The later is whether the memset is a memset of zero. It's totally possible
(likely even) that targets may want to do different things for memcpy and
memset of zero.

llvm-svn: 169959
2012-12-12 02:34:41 +00:00
Evan Cheng
c3d1aca657 - Rename isLegalMemOpType to isSafeMemOpType. "Legal" is a very overloade term.
Also added more comments to explain why it is generally ok to return true.
- Rename getOptimalMemOpType argument IsZeroVal to ZeroOrLdSrc. It's meant to
be true for loaded source (memcpy) or zero constants (memset). The poor name
choice is probably some kind of legacy issue.

llvm-svn: 169954
2012-12-12 01:32:07 +00:00
Evan Cheng
04e5518783 Avoid using lossy load / stores for memcpy / memset expansion. e.g.
f64 load / store on non-SSE2 x86 targets.

llvm-svn: 169944
2012-12-12 00:42:09 +00:00
Jim Grosbach
647c702780 Trim unneeded header #include.
llvm-svn: 169933
2012-12-11 23:39:51 +00:00
Jim Grosbach
0ddedcc560 ARM: Remove old testing option.
Pre-regalloc frame allocation and referencing has been on by default
for ages. No need for the testing option that disables it.

llvm-svn: 169931
2012-12-11 23:31:12 +00:00
Jim Grosbach
1197889c44 ARM: Remove old testing options.
Base pointer referencing has been enabled for ages.

llvm-svn: 169930
2012-12-11 23:31:10 +00:00
Evan Cheng
eb54240dc2 Replace TargetLowering::isIntImmLegal() with
ScalarTargetTransformInfo::getIntImmCost() instead. "Legal" is a poorly defined
term for something like integer immediate materialization. It is always possible
to materialize an integer immediate. Whether to use it for memcpy expansion is
more a "cost" conceern.

llvm-svn: 169929
2012-12-11 23:26:14 +00:00
Patrik Hagglund
e98b7a0389 Revert EVT->MVT changes, r169836-169851, due to buildbot failures.
llvm-svn: 169854
2012-12-11 11:14:33 +00:00
Patrik Hagglund
8d2e7cf561 Change TargetLowering::findRepresentativeClass to take an MVT, instead
of EVT.

llvm-svn: 169845
2012-12-11 09:57:18 +00:00
Patrik Hagglund
3708e548f8 Change TargetLowering::getRegClassFor to take an MVT, instead of EVT.
Accordingly, add helper funtions getSimpleValueType (in parallel to
getValueType) in SDValue, SDNode, and TargetLowering.

This is the first, in a series of patches.

llvm-svn: 169837
2012-12-11 09:10:33 +00:00
Evan Cheng
c2bd620fac Stylistic tweak.
llvm-svn: 169811
2012-12-11 02:31:57 +00:00
Chad Rosier
df42cf39ab Fall back to the selection dag isel to select tail calls.
This shouldn't affect codegen for -O0 compiles as tail call markers are not
emitted in unoptimized compiles.  Testing with the external/internal nightly
test suite reveals no change in compile time performance.  Testing with -O1,
-O2 and -O3 with fast-isel enabled did not cause any compile-time or
execution-time failures.  All tests were performed on my x86 machine.
I'll monitor our arm testers to ensure no regressions occur there.

In an upcoming clang patch I will be marking the objc_autoreleaseReturnValue
and objc_retainAutoreleaseReturnValue as tail calls unconditionally.  While
it's theoretically true that this is just an optimization, it's an
optimization that we very much want to happen even at -O0, or else ARC
applications become substantially harder to debug.

Part of rdar://12553082

llvm-svn: 169796
2012-12-11 00:18:02 +00:00
Evan Cheng
79e2ca90bc Some enhancements for memcpy / memset inline expansion.
1. Teach it to use overlapping unaligned load / store to copy / set the trailing
   bytes. e.g. On 86, use two pairs of movups / movaps for 17 - 31 byte copies.
2. Use f64 for memcpy / memset on targets where i64 is not legal but f64 is. e.g.
   x86 and ARM.
3. When memcpy from a constant string, do *not* replace the load with a constant
   if it's not possible to materialize an integer immediate with a single
   instruction (required a new target hook: TLI.isIntImmLegal()).
4. Use unaligned load / stores more aggressively if target hooks indicates they
   are "fast".
5. Update ARM target hooks to use unaligned load / stores. e.g. vld1.8 / vst1.8.
   Also increase the threshold to something reasonable (8 for memset, 4 pairs
   for memcpy).

This significantly improves Dhrystone, up to 50% on ARM iOS devices.

rdar://12760078

llvm-svn: 169791
2012-12-10 23:21:26 +00:00
Benjamin Kramer
f242d8c31b Simplify code. Sort includes. No functionality change.
llvm-svn: 169676
2012-12-08 10:45:24 +00:00
Chandler Carruth
1d94e932bc Fix a use-after-free bug found by ASan. You can't assign a temporary
std::string to a StringRef. Moreover, the method being called accepts
a Twine to simplify these patterns.

Fixes this ASan failure:
==6312== ERROR: AddressSanitizer: heap-use-after-free on address 0x7fd558b1af58 at pc 0xcb7529 bp 0x7fffff572080 sp 0x7fffff572078
READ of size 1 at 0x7fd558b1af58 thread T0
    #0 0xcb7528 .../llvm/include/llvm/ADT/StringRef.h:192 llvm::StringRef::operator[]()
    #1 0x1d53c0a .../llvm/include/llvm/ADT/StringExtras.h:128 llvm::HashString()
    #2 0x1d53878 .../llvm/lib/Support/StringMap.cpp:64 llvm::StringMapImpl::LookupBucketFor()
    #3 0x1b6872f .../llvm/include/llvm/ADT/StringMap.h:352 llvm::StringMap<>::GetOrCreateValue<>()
    #4 0x1b61836 .../llvm/lib/MC/MCContext.cpp:109 llvm::MCContext::GetOrCreateSymbol()
    #5 0xe9fd47 .../llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp:154 (anonymous namespace)::ARMELFStreamer::EmitMappingSymbol()
    #6 0xea01dd .../llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp:133 (anonymous namespace)::ARMELFStreamer::EmitDataMappingSymbol()
    #7 0xe9f78b .../llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp:91 (anonymous namespace)::ARMELFStreamer::EmitBytes()
    #8 0x1b15d82 .../llvm/lib/MC/MCStreamer.cpp:89 llvm::MCStreamer::EmitIntValue()
    #9 0xcc0f9b .../llvm/lib/Target/ARM/ARMAsmPrinter.cpp:713 llvm::ARMAsmPrinter::emitAttributes()
    #10 0xcc0d44 .../llvm/lib/Target/ARM/ARMAsmPrinter.cpp:632 llvm::ARMAsmPrinter::EmitStartOfAsmFile()
    #11 0x14692ad .../llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:162 llvm::AsmPrinter::doInitialization()
    #12 0x1bc4677 .../llvm/lib/VMCore/PassManager.cpp:1561 llvm::FPPassManager::doInitialization()
    #13 0x1bc4990 .../llvm/lib/VMCore/PassManager.cpp:1595 llvm::MPPassManager::runOnModule()
    #14 0x1bc55e5 .../llvm/lib/VMCore/PassManager.cpp:1705 llvm::PassManagerImpl::run()
    #15 0x1bc5878 .../llvm/lib/VMCore/PassManager.cpp:1740 llvm::PassManager::run()
    #16 0xc3954d .../llvm/tools/llc/llc.cpp:378 compileModule()
    #17 0xc38001 .../llvm/tools/llc/llc.cpp:194 main
    #18 0x7fd557d6a11c __libc_start_main
0x7fd558b1af58 is located 24 bytes inside of 29-byte region [0x7fd558b1af40,0x7fd558b1af5d)
freed by thread T0 here:
    #0 0xc337da .../llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:56 operator delete()
    #1 0x1ee9cef .../libstdc++-v3/include/bits/basic_string.h:535 std::string::~string()
    #2 0xea01dd .../llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp:133 (anonymous namespace)::ARMELFStreamer::EmitDataMappingSymbol()
    #3 0xe9f78b .../llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp:91 (anonymous namespace)::ARMELFStreamer::EmitBytes()
    #4 0x1b15d82 .../llvm/lib/MC/MCStreamer.cpp:89 llvm::MCStreamer::EmitIntValue()
    #5 0xcc0f9b .../llvm/lib/Target/ARM/ARMAsmPrinter.cpp:713 llvm::ARMAsmPrinter::emitAttributes()
    #6 0xcc0d44 .../llvm/lib/Target/ARM/ARMAsmPrinter.cpp:632 llvm::ARMAsmPrinter::EmitStartOfAsmFile()
    #7 0x14692ad .../llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:162 llvm::AsmPrinter::doInitialization()
    #8 0x1bc4677 .../llvm/lib/VMCore/PassManager.cpp:1561 llvm::FPPassManager::doInitialization()
    #9 0x1bc4990 .../llvm/lib/VMCore/PassManager.cpp:1595 llvm::MPPassManager::runOnModule()
    #10 0x1bc55e5 .../llvm/lib/VMCore/PassManager.cpp:1705 llvm::PassManagerImpl::run()
    #11 0x1bc5878 .../llvm/lib/VMCore/PassManager.cpp:1740 llvm::PassManager::run()
    #12 0xc3954d .../llvm/tools/llc/llc.cpp:378 compileModule()
    #13 0xc38001 .../llvm/tools/llc/llc.cpp:194 main
    #14 0x7fd557d6a11c __libc_start_main

llvm-svn: 169668
2012-12-08 03:10:14 +00:00
Tim Northover
5cc3dc86bb Added Mapping Symbols for ARM ELF
Before this patch, when you objdump an LLVM-compiled file, objdump tried to
decode data-in-code sections as if they were code.  This patch adds the missing
Mapping Symbols, as defined by "ELF for the ARM Architecture" (ARM IHI 0044D).

Patch based on work by Greg Fitzgerald.

llvm-svn: 169609
2012-12-07 16:50:23 +00:00
Matt Beaumont-Gay
4a04c92001 Add a 'using' declaration to suppress GCC's -Woverloaded-virtual while we
decide what pattern we want to follow in the future.

llvm-svn: 169561
2012-12-06 23:15:36 +00:00
Evan Cheng
9ec512d768 Replace r169459 with something safer. Rather than having computeMaskedBits to
understand target implementation of any_extend / extload, just generate
zero_extend in place of any_extend for liveouts when the target knows the
zero_extend will be implicit (e.g. ARM ldrb / ldrh) or folded (e.g. x86 movz).

rdar://12771555

llvm-svn: 169536
2012-12-06 19:13:27 +00:00