With this patch, the profile summary data will be available in indexed
profile data file so that profiler reader/compiler optimizer can start
to make use of.
Differential Revision: http://reviews.llvm.org/D16258
llvm-svn: 259626
The purpose of PPCVSXFMAMutate is to elide copies by changing FMA forms
on PPC.
%vreg6<def> = COPY %vreg96
%vreg6<def,tied1> = XSMADDASP %vreg6<tied0>, %vreg5<kill>, %vreg7
;v6 = v6 + v5 * v7
is replaced by
%vreg5<def,tied1> = XSMADDMSP %vreg5<tied0>, %vreg7, %vreg96
;v5 = v5 * v7 + v96
This was broken in the case where the target register was also used as a
multiplicand. Fix this case by checking for it and replacing both uses
with the copied register.
%vreg6<def> = COPY %vreg96
%vreg6<def,tied1> = XSMADDASP %vreg6<tied0>, %vreg5<kill>, %vreg6
;v6 = v6 + v5 * v6
is replaced by
%vreg5<def,tied1> = XSMADDMSP %vreg5<tied0>, %vreg96, %vreg96
;v5 = v5 * v96 + v96
llvm-svn: 259617
The register coalescer can rematerialize constants that define
more of a register than the copy it is going to replace was going
to do.
This is valid in the case the register was undef before the
copy happened.
This patch makes sure that all the subranges defined by the new
rematerialization instructions have at least a dead def.
Review: http://reviews.llvm.org/D16693
llvm-svn: 259614
Summary:
LoopVersioning is a transform utility that transform passes can use to
run-time disambiguate may-aliasing accesses. I'd like to also expose as
pass to allow it to be unit-tested.
I am planning to add support for non-aliasing annotation in
LoopVersioning and I'd like to be able to write tests directly using
this pass.
(After that feature is done, the pass could also be used to look for
optimization opportunities that are hidden behind incomplete alias
information at compile time.)
The pass drives LoopVersioning in its default way which is to fully
disambiguate may-aliasing accesses no matter how many checks are
required.
Reviewers: hfinkel, ashutosh.nema, sbaranga
Subscribers: zzheng, mssimpso, llvm-commits, sanjoy
Differential Revision: http://reviews.llvm.org/D16612
llvm-svn: 259610
Please see include/llvm/Transforms/Utils/MemorySSA.h for a description
of MemorySSA, and what it does.
Differential Revision: http://reviews.llvm.org/D7864
llvm-svn: 259595
Due to staleness in a patch I committed yesterday, the debug output was reporting overdefined cases as being undefined. Confusing to say the least. The mistake appears to have only effected the debug output thankfully.
llvm-svn: 259594
I introduced a declaration in 259583 to keep the diff readable. This change just moves the definition up to remove the declaration again.
llvm-svn: 259585
This patch uses the newly introduced 'intersect' utility (from 259461: [LVI] Introduce an intersect operation on lattice values) to simplify existing code in LVI.
While not introducing any new concepts, this change is probably not NFC. The common 'intersect' function is more powerful that the ad-hoc implementations we'd had in a couple of places. Given that, we may see optimizations triggering a bit more often.
llvm-svn: 259583
This didn't affect X86_64, which is the only client of this code at the moment,
as stubs and pointers are both 8-bytes there. It will affect other platforms
though.
llvm-svn: 259575
If we can't assume the pointer value isn't within the bounds
of the object, it seems risky to try to replace the pointer
calculations.
llvm-svn: 259573
CodeView requires us to accurately describe the extent of the inlined
code. We did this by grabbing the next debug location in source order
and using *that* to denote where we stopped inlining. However, this is
not sufficient or correct in instances where there is no next debug
location or the next debug location belongs to the start of another
function.
To get this correct, use the end symbol of the function to denote the
last possible place the inlining could have stopped at.
llvm-svn: 259548
When promoting allocas to LDS, we know we are indexing
into a specific area just created, and the calculation
will also never overflow.
Also emit some of the muls as nsw nuw, because instcombine
infers this already from the range metadata. I think
putting this on the other adds and muls might be OK too,
but I'm not 100% sure.
llvm-svn: 259545
This directive emits the binary annotations that describe line and code
deltas in inlined call sites. Single-stepping through inlined frames in
windbg now works.
llvm-svn: 259535
Summary:
Enables eip-based addressing, e.g.,
lea constant(%eip), %rax
lea constant(%eip), %eax
in MC, (used for the x32 ABI). EIP-base addressing is also valid in x86_64,
it is left enabled for that architecture as well.
Patch by João Porto
Differential Revision: http://reviews.llvm.org/D16581
llvm-svn: 259528
Re-commit of r258951 after fixing layering violation.
The BPF and WebAssembly backends had identical code for emitting errors
for unsupported features, and AMDGPU had very similar code. This merges
them all into one DiagnosticInfo subclass, that can be used by any
backend.
There should be minimal functional changes here, but some AMDGPU tests
have been updated for the new format of errors (it used a slightly
different format to BPF and WebAssembly). The AMDGPU error messages will
now benefit from having precise source locations when debug info is
available.
llvm-svn: 259498
description and changed the regression test accordingly.
The default configuration of a Cortex-R7 is to implement the
VFPv3-D16 architecture and the feature line as it was is too
restrictive.
llvm-svn: 259480
When rematerializing a computation by replacing the copy, use the copy's
location. The location of the copy is more representative of the
original program.
This partially fixes PR10003.
llvm-svn: 259469
differentiate between indirect references to functions an direct calls.
This doesn't do a whole lot yet other than change the print out produced
by the analysis, but it lays the groundwork for a very major change I'm
working on next: teaching the call graph to actually be a call graph,
modeling *both* the indirect reference graph and the call graph
simultaneously. More details on that in the next patch though.
The rest of this is essentially a bunch of over-engineering that won't
be interesting until the next patch. But this also isolates essentially
all of the churn necessary to introduce the edge abstraction from the
very important behavior change necessary in order to separately model
the two graphs. So it should make review of the subsequent patch a bit
easier at the cost of making this patch seem poorly motivated. ;]
Differential Revision: http://reviews.llvm.org/D16038
llvm-svn: 259463
LVI has several separate sources of facts - edge local conditions, recursive queries, assumes, and control independent value facts - which all apply to the same value at the same location. The existing implementation was very conservative about exploiting all of these facts at once.
This change introduces an "intersect" function specifically to abstract the action of picking a good set of facts from all of the separate facts given. At the moment, this function is relatively simple (i.e. mostly just reuses the bits which were already there), but even the minor additions reveal the inherent power. For example, JumpThreading is now capable of doing an inductive proof that a particular value is always positive and removing a half range check.
I'm currently only using the new intersect function in one place. If folks are happy with the direction of the work, I plan on making a series of small changes without review to replace mergeIn with intersect at all the appropriate places.
Differential Revision: http://reviews.llvm.org/D14476
llvm-svn: 259461
Fix a crash in `getMemOpBaseRegImmOfs` that happens if the base of
`MemOp` is a frame index memory operand. The fix is to have
`getMemOpBaseRegImmOfs` bail out in such cases. We can possibly be more
clever here, if needed.
llvm-svn: 259456
Officially, we don't acknowledge non-default configurations of MXCSR,
as getting there would require usage of the FENV_ACCESS pragma (at
least insofar as rounding mode is concerned).
We don't support the pragma, so we can assume that the default
rounding mode - round to nearest, ties to even - is always used.
However, it's inconsistent with the rest of the instruction set,
where MXCSR is always effective (unless otherwise specified).
Also, it's an unnecessary obstacle to the few brave souls that use
fenv.h with LLVM.
Avoid the hard-coded rounding mode for fp_to_f16; use MXCSR instead.
llvm-svn: 259448
This routine was returning Undefined for most queries. This was utterly wrong. Amusingly, we do not appear to have any callers of this which are actually trying to exploit unreachable code or this would have broken the world.
A better approach would be to explicit describe the intersection of facts. That's blocked behind http://reviews.llvm.org/D14476 and I wanted to fix the current bug.
llvm-svn: 259446
I'll submit a test case shortly which covers this, but it's causing clang self host problems in the builders so I wanted to get it removed.
llvm-svn: 259432
Teach LVI to handle select instructions in the exact same way it handles PHI nodes. This is useful since various parts of the optimizer convert PHI nodes into selects and we don't want these transformations to cause inferior optimization.
Note that this patch does nothing to exploit the implied constraint on the inputs represented by the select condition itself. That will be a later patch and is blocked on http://reviews.llvm.org/D14476
llvm-svn: 259429
These sets do linear searching in small mode; It is not a good idea to
use huge numbers as the small value here, save people from themselves by
adding a static_assert.
Differential Revision: http://reviews.llvm.org/D16706
llvm-svn: 259419
Summary:
If the normal destination of the invoke or the parent block of the call site is unreachable-terminated, there is little point in inlining the call site unless there is literally zero cost. Unlike my previous change (D15289), this change specifically handle the call sites followed by unreachable in the same basic block for call or in the normal destination for the invoke. This change could be a reasonable first step to conservatively inline call sites leading to an unreachable-terminated block while BFI / BPI is not yet available in inliner.
Reviewers: manmanren, majnemer, hfinkel, davidxl, mcrosier, dblaikie, eraman
Subscribers: dblaikie, davidxl, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D16616
llvm-svn: 259403
- ScalarEvolution::isKnownPredicateViaConstantRanges duplicates some
logic already present in ConstantRange, use ConstantRange for those
bits.
- In some cases ScalarEvolution::isKnownPredicateViaConstantRanges
returns `false` to mean "definitely false" (e.g. see the
`LHSRange.getSignedMin().sge(RHSRange.getSignedMax())` case for
`ICmpInst::ICMP_SLT`), but for `isKnownPredicateViaConstantRanges`,
`false` actually means "don't know". Get rid of this extra bit of
code to avoid confusion.
llvm-svn: 259401
If a target can only emit 8-bits data, we would loop in EmitValueImpl
since it will try to split a 32-bits data in 1 chunk of 32-bits.
No test since all current targets can emit 32bits at a time.
Patch by Alexandru Guduleasa!
llvm-svn: 259399
Iterate over the function list instead of a DenseMap of Function pointers
when emitting the function summary into the module.
This fixes PR26419.
llvm-svn: 259398
A masked store with a zero mask means there's no store.
A masked store with an allOnes mask means it's a normal vector store.
This is a continuation of:
http://reviews.llvm.org/rL259369
llvm-svn: 259392
Summary:
This is an extension to the existing implementation of r242436 which
restricts to only select inputs. This version fixes missed opportunities
in pr26084 by attempting to lower conditional compare sequences of
and/or trees with setcc leafs. This will additionaly handle the case
when a tree with select input is not a conjunction-disjunction tree
but some of the sub trees are conjunction-disjunction trees.
Reviewers: jmolloy, t.p.northover, mcrosier, MatzeB
Subscribers: mcrosier, llvm-commits, junbuml, haicheng, mssimpso, gberry
Differential Revision: http://reviews.llvm.org/D16291
llvm-svn: 259387
Summary:
Factor out common code for callee-save register pair calculation. This
is intended to simplify follow-on changes that reduce the number of
registers saved/restored.
Depends on D16732
Reviewers: mcrosier, jmolloy, t.p.northover
Subscribers: aemerson, rengolin, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D16734
llvm-svn: 259384
We've found another bug in the code generation logic conditions for a
certain class of always-false conditions, those of the form
if ((a & 1) < 0)
These only reach the back end when compiling without optimization.
The bug was introduced by the choice of using TEST UNDER MASK
to implement a check for
if ((a & MASK) < VAL)
as
if ((a & MASK) == 0)
where VAL is less than the the lowest bit of MASK. This is correct
in all cases except for VAL == 0, in which case the original
condition is always false, but the replacement isn't.
Fixed by excluding that particular case.
llvm-svn: 259381
This miscompile came about because we tried to use a transform which was
only appropriate for xor operators when addition was present.
This fixes PR26407.
llvm-svn: 259375
A masked load with a zero mask means there's no load.
A masked load with an allOnes mask means it's a normal vector load.
Differential Revision: http://reviews.llvm.org/D16691
llvm-svn: 259369
Summary:
Simplify callee-save register save/restore code generation by
remembering the size of the callee-save area when it is computed so we
don't have to scan the prologue/epilogue instructions again later to
reconstruct it.
This is intended to simplify follow-on changes that reduce the number of
registers saved/restored.
Reviewers: mcrosier, jmolloy, t.p.northover
Subscribers: aemerson, rengolin, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D16732
llvm-svn: 259365
In the future, we will vectorize recurrences other than reductions. This patch
renames a few variables and updates their associated comments to enable them to
be reused for non-reduction PHI nodes.
This change was requested in the review for D16197.
llvm-svn: 259364
Remove the old select.ll file and use select-int.ll, select-flt.ll,
select-dbl.ll for testing selects on integers, floats & doubles respectivelly.
llvm-svn: 259361
Summary:
The bugs were:
* teq and similar take 4-bit unsigned immediates on microMIPS.
* teqi and similar have side-effects like teq do.
* shll_s.w and shra_r.w take 5-bit unsigned immediates.
* The various DSP ext* instructions take a 5-bit immediate.
* repl.qh takes an 8-bit unsigned immediate.
* repl.ph takes a 10-bit unsigned immediate.
* rddsp/wrdsp take a 10-bit unsigned immediate.
* teqi and similar take signed 16-bit immediates (10-bit for microMIPS).
* Out-of-range immediate macros for or/xor take a simm32/simm64 depending
on architecture. I'll fix the simm64 case properly when I reach simm32.
lui is a bit more lenient than GAS and accepts signed immediates in addition
to unsigned. This is because MipsMCExpr can produce signed values when
constant folding and it currently lacks a way of knowing it should fold to
an unsigned value.
Reviewers: vkalintiris
Subscribers: dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D15446
llvm-svn: 259360
Changed emitting offset of macinfo entry into compiler unit DIE to use "addSectionLabel" method rather than explicitly calculating size/offset of macro entry.
Differential Revision: http://reviews.llvm.org/D16292
llvm-svn: 259358
Patch adds a DWARF language vendor extension for RenderScript.
We are already using this identifier in LLDB with a hard coded value, so it's preferable to use a LLVM generated enum instead.
The language is intended to be added to the next version of the standard.
See http://www.dwarfstd.org/ShowIssue.php?issue=150331.1
Reviewers: dexonsmith, echristo
Subscribers: probinson domipheus, srhines, llvm-commits
Differential Revision: http://reviews.llvm.org/D16409
llvm-svn: 259348
Minor patch to trace back through target shuffles to the source of the inserted element in a (V)INSERTPS shuffle.
Differential Revision: http://reviews.llvm.org/D16652
llvm-svn: 259343
Noticed while working on scattered relocations.
I do not think these relocs can actually happen in the debug_info section,
but if they happen the code would mishandle them. Explicitely skip them
and warn if we encounter one.
llvm-svn: 259341
Although it seems like clang will never emit scattered relocations in
the debug information (at least I couldn't find a way), we have too
support them for the benefit of other compilers.
As clang doesn't generate them, the included testcase was produced
from hacked up assembly.
llvm-svn: 259339
Those commits created an artificial edge from a cleanup to a synthesized
catchswitch in order to get the MSVC personality routine to execute
cleanups which don't cleanupret and are not wrapped by a catchswitch.
This worked well enough but is not a complete solution in situations
where there the cleanup infinite loops.
However, the real deal breaker behind this approach comes about from a
degenerate case where the cleanup is post-dominated by unreachable *and*
throws an exception. This ends poorly because the catchswitch will
inadvertently catch the exception.
Because of this we should go back to our previous behavior of not
executing certain cleanups (identical behavior with the Itanium ABI
implementation in clang, GCC and ICC).
N.B. I think this could be salvaged by making the catchpad rethrow the
exception and properly transforming throwing calls in the cleanup into
invokes.
llvm-svn: 259338
With poorly chosen custom parameters, the line table encoding logic would
sometimes end up generating a special opcode bigger than 255, which is wrong.
The set of default parameters that LLVM uses isn't subject to this bug.
When carefully chosing the line table parameters, it's impossible to fall into the
corner case that this patch fixes. The standard however doesn't require that these
parameters be carefully chosen. And even if it did, we shouldn't generate broken
encoding.
Add a unittest for this specific encoding bug, and while at it, create some unit
tests for the encoding logic using different sets of parameters.
llvm-svn: 259334
llvm-dsymutil was misinterpreting the value of common symbols as their
address when it actually contains their size. This didn't impact
llvm-dsymutil's ability to link the debug information for common symbols
because these are always found by name and not by address. Things could
however go wrong when the size of a common object matched the object
file address of another symbol. Depending on the link order of the symbols
the common object might incorrectly evict this other object from the
address to symbol mapping, and then link the evicted symbol with a wrong
binary address.
Use the new ability to have symbols without an object file address to fix
this.
llvm-svn: 259318
This change just changes the data structure that ties symbol names,
object file address and linked binary addresses to accept mappings
with no object file address. Such symbol mappings are not fed into
the debug map yet, so this patch is NFC.
A subsequent patch will make use of this functionality for common
symbols.
llvm-svn: 259317
1. Mentioned that CUDA support works best with trunk.
2. Simplified the example by removing its dependency on the CUDA samples.
3. Explain the --cuda-gpu-arch flag.
llvm-svn: 259307
Previously the code assumed all uses of FI on loads and stores were as
addresses. This checks whether the use is the address or a value and
handles the latter case as it does for non-memory instructions.
llvm-svn: 259306
The previous code was incorrect (can't getReg a frameindex). We could instead optimize it to reduce tree height, but I'm not sure that's worthwhile yet because we then try to eliminate the frameindex.
This patch also fixes frame index elimination for operations which may load or store: it used to assume the base was operand 2 and immediate offset operand 1. That's not true for stores, where they're 4 and 3.
llvm-svn: 259305
The AMDGPUPromoteAlloca pass was emitting the read.local.size
calls, which with HSA was incorrectly selected to reading from
the offset mesa uses off of the kernarg pointer.
Error on intrinsics which aren't supported by HSA, and start
emitting the correct IR to read the workgroup size
out of the dispatch pointer.
Also initialize the pass so it can be tested with opt, and
start moving towards not depending on the subtarget as an
argument.
Start emitting errors for the intrinsics not handled with HSA.
llvm-svn: 259297
Only the dispatch.ptr intrinsic is supposed to be used now to get
the workgroup size, and the read.local.size intrinsics do not
work correctly.
llvm-svn: 259296
Refine the test for whether an instruction is in an expression tree so that
it detects when one tree ends and another begins, so we can place a block
at that point, rather than continuing to find the first instruction not in
a tree at all.
llvm-svn: 259294
Add an option to llvm-profdata merge for writing out sparse indexed
profiles. These profiles omit InstrProfRecords for functions which are
never executed.
Differential Revision: http://reviews.llvm.org/D16727
llvm-svn: 259258
Loop transformations can sometimes fail because the loop, while in
valid rotated LCSSA form, is not in a canonical CFG form. This is
an extremely simple pass that just merges obviously redundant
blocks, which can be used to fix some known failure cases. In the
future, it may be enhanced with more cases (and have code shared with
SimplifyCFG).
This allows us to run LoopSimplifyCFG -> LoopRotate -> LoopUnroll,
so that SimplifyCFG cleans up the loop before Rotate tries to run.
Not currently used in the pass manager, since this pass doesn't do
anything unless you can hook it up in an LPM with other loop passes.
It'll be added once Chandler cleans up things to allow this.
Tested in a custom pipeline out of tree to confirm it works in
practice (in addition to the included trivial test).
llvm-svn: 259256
The majority of attribute queries checks for the existence of an enum
attribute in the FunctionIndex slot. We only have 48 of those and can
therefore summarize them in an uint64_t bitset which measurably improves
compile time.
Differential Revision: http://reviews.llvm.org/D16618
llvm-svn: 259252
The majority of queries just checks for the existince of an enum
attribute. We only have 48 of those and can summaryiz them in an
uint64_t bitfield so we can avoid searching the list. This improves
"opt" compile time by 1-4% in my measurements.
Differential Revision: http://reviews.llvm.org/D16617
llvm-svn: 259251
We would infinite loop because we created a shufflevector that was wider than
needed and then failed to combine that with the insertelement. When subsequently
visiting the extractelement from that shuffle, we see that it's unnecessary,
delete it, and trigger another visit to the insertelement.
llvm-svn: 259236
This support is _very_ rudimentary, just enough to get some basic data
into the CodeView debug section.
Left to do is:
- Use the combined opcodes to save space.
- Do something about code offsets.
llvm-svn: 259230
The basic optimisation was to convert (mul $LHS, $complex_constant) into
roughly "(shl (mul $LHS, $simple_constant), $simple_amt)" when it was expected
to be cheaper. The original logic checks that the mul only has one use (since
we're mangling $complex_constant), but when used in even more complex
addressing modes there may be an outer addition that can pick up the wrong
value too.
I *think* the ARM addressing-mode problem is actually unreachable at the
moment, but that depends on complex assessments of the profitability of
pre-increment addressing modes so I've put a real check in there instead of an
assertion.
llvm-svn: 259228
Add support for frame pointer use in prolog/epilog.
Supports dynamic allocas but not yet over-aligned locals.
Target-independend CG generates SP updates, but we still need to write
back the SP value to memory when necessary.
llvm-svn: 259220
Summary:
There are three parts to inlined call frames:
1. The inlinee line subsection
2. The inline site symbol record
3. The function ids referenced by both
This change starts by emitting function ids (3) for all subprograms and
emitting the base inline site symbol record (2). The actual line numbers
in (2) use an encoded format that will come next, along with the inlinee
line subsection.
Reviewers: majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16333
llvm-svn: 259217
- Locally declare struct, and call it BaseDerivedPair
- Use a lambda to compare, instead of a singleton with uninitialized
fields
- Add a constructor to BaseDerivedPair and use SmallVector::emplace_back
llvm-svn: 259208
The buildSchedGraph() was in need of reworking as the AA features had been
added on top of earlier code. It was very difficult to understand, and buggy.
There had been found cases where scheduling dependencies had actually been
missed (see r228686).
AliasChain, RejectMemNodes, adjustChainDeps() and iterateChainSucc() have
been removed. There are instead now just the four maps from Value to SUs, which
have been renamed to Stores, Loads, NonAliasStores and NonAliasLoads.
An unknown store used to become the AliasChain, but now becomes a store mapped
to 'unknownValue' (in Stores). What used to be PendingLoads is instead the
list of SUs mapped to 'unknownValue' in Loads.
RejectMemNodes and adjustChainDeps() used to be a safety-net for everything.
The SU maps were sometimes cleared and SUs were put in RejectMemNodes, where
adjustChainDeps() would look. Instead of this, a more straight forward approach
is used in maintaining the SU maps without clearing them and simply letting
them grow over time. Instead of the cutt-off in adjustChainDeps() search, a
reduction of maps will be done if needed (see below).
Each SUnit either becomes the BarrierChain, or is put into one of the maps. For
each SUnit encountered, all the information about previous ones are still
available until a new BarrierChain is set, at which point the maps are cleared.
For huge regions, the algorithm becomes slow, therefore the maps will get
reduced at a threshold (current default is 1000 nodes), by a fraction (default 1/2).
These values can be tuned by use of CL options in case some test case shows that
they need to be changed (-dag-maps-huge-region and -dag-maps-reduction-size).
There has not been any considerable change observed in output quality or compile
time. There may now be more DAG edges inserted than before (i.e. if A->B->C,
then A->C is not needed). However, in a comparison run there were fewer total
calls to AA, and a somewhat improved compile time, which means this seems to
be not a problem.
http://reviews.llvm.org/D8705
Reviewers: Hal Finkel, Andy Trick.
llvm-svn: 259201
The trap instruction is emitted as a data-in-text rather
than an instruction. This patch uses the .inst directive
for emitting trap.
Differential Revision: http://reviews.llvm.org/D16684
llvm-svn: 259182
Also removed a few redundant `else`s.
Bug was found by a test I wrote for MemorySSA (in review at
http://reviews.llvm.org/D7864; shiny update coming soon). So, assuming
that lands at some point, this should be covered by that. If anyone
feels this deserves its own explicit test case, please let me know.
I'll write one.
llvm-svn: 259179
check that the sign extended constant fits into 16-bits if we want a
zero extended value, otherwise go ahead and put it together piecemeal.
Fixes PR26356.
llvm-svn: 259177
This patch enables llvm-bcanalyzer to print the bitcode wrapper header
if the file has one, which is needed to test the changes made in
r258627 (bitcode-wrapper-header-armv7m.ll is the test case for r258627).
Differential Revision: http://reviews.llvm.org/D16642
llvm-svn: 259162
Xinliang David Li