The old AddFixedStringToRegEx() it was based on got away with this for the
longest time, but the problem became easy to spot after the cleanup in r197096.
Also add a quick unit test to cover regex escaping.
llvm-svn: 197121
Aside from a few minor latency corrections, the major change here is a new
hazard recognizer which focuses on better dispatch-group formation on the
POWER7. As with the PPC970's hazard recognizer, the most important thing it
does is avoid load-after-store hazards within the same dispatch group. It uses
the POWER7's special dispatch-group-terminating nop instruction (instead of
inserting multiple regular nop instructions). This new hazard recognizer makes
use of the scheduling dependency graph itself, built using AA information, to
robustly detect the possibility of load-after-store hazards.
significant test-suite performance changes (the error bars are 99.5% confidence
intervals based on 5 test-suite runs both with and without the change --
speedups are negative):
speedups:
MultiSource/Benchmarks/FreeBench/pcompress2/pcompress2
-0.55171% +/- 0.333168%
MultiSource/Benchmarks/TSVC/CrossingThresholds-dbl/CrossingThresholds-dbl
-17.5576% +/- 14.598%
MultiSource/Benchmarks/TSVC/Reductions-dbl/Reductions-dbl
-29.5708% +/- 7.09058%
MultiSource/Benchmarks/TSVC/Reductions-flt/Reductions-flt
-34.9471% +/- 11.4391%
SingleSource/Benchmarks/BenchmarkGame/puzzle
-25.1347% +/- 11.0104%
SingleSource/Benchmarks/Misc/flops-8
-17.7297% +/- 9.79061%
SingleSource/Benchmarks/Shootout-C++/ary3
-35.5018% +/- 23.9458%
SingleSource/Regression/C/uint64_to_float
-56.3165% +/- 25.4234%
SingleSource/UnitTests/Vectorizer/gcc-loops
-18.5309% +/- 6.8496%
regressions:
MultiSource/Benchmarks/ASCI_Purple/SMG2000/smg2000
18.351% +/- 12.156%
SingleSource/Benchmarks/Shootout-C++/methcall
27.3086% +/- 14.4733%
llvm-svn: 197099
The assertion was checking that the virtual register VReg used to represent the
physical register PReg uses the same register class as the one passed to
MachineFunction::addLiveIn.
This is over-constraining because it is sufficient to check that the register
class of VReg (VRegRC) is a subclass of the register class of PReg (PRegRC) and
that VRegRC contains PReg.
Indeed, if VReg gets constrained because of some operation constraints
between two calls of MachineFunction::addLiveIn, the original assertion
cannot match.
This fixes <rdar://problem/15633429>.
llvm-svn: 197097
For one predicate to subsume another, they must both check the same condition
register. Failure to check this prerequisite was causing miscompiles.
Fixes PR18003.
llvm-svn: 197089
This adds two additional functions to the hazard recognizer interface. These
are optional (in the sense that the default implementations preserve the
current behavior), and used by the post-RA scheduler. Upcoming commits will use
this functionality in order to improve dispatch-group formation on the POWER7
and related cores. Dispatch groups are an odd construct: sometimes we need to
insert nops to force a new one to start (for performance reasons), and some
instructions need to appear in certain positions within a group, but the groups
are not fundamentally cycle based (they can contain instructions with data
dependencies with non-trivial latencies).
Motivation:
unsigned PreEmitNoops(SUnit *) - Used to force the post-RA scheduler to insert
nops to force a new dispatch group to begin. We already have a NoopHazard, and
this is also still needed. However, NoopHazard only causes a nop to be inserted
if there are no other available instructions, and so is not always sufficient.
The number of nops to insert depends on state that only the hazard recognizer
has, so a general callback is necessary.
bool ShouldPreferAnother(SUnit *) - Used to avoid scheduling instructions that
would start a new dispatch group when others are available that could be part
of the current dispatch group. In this case, we don't want to issue nops,
because the non-preferred instruction will implicitly start a new dispatch
group regardless.
Although the motivation for these functions is driven by the PowerPC backend,
they are completely general.
llvm-svn: 197084
The linkers on these systems don't have anything special to do with these
symbols. Since the intent is for them to be absent from the final object,
just treat them as private.
llvm-svn: 197080
This reverts commit r197073.
The test seems to be failing on some buildbots for unknown reasons.
Reverting until I can figure that out. If anyone's got a reproduction
(.s and .o together would be great) - I'd really appreciate it.
llvm-svn: 197079
This commit does not complete the type units feature - there are issues
around fission support (skeletal type units, pubtypes/pubnames) and
hashing of some types including those containing references to types in
other type units.
llvm-svn: 197073
point reciprocal exponent, and floating-point reciprocal square root estimate
LLVM AArch64 intrinsics to use f32/f64 types, rather than their vector
equivalents.
llvm-svn: 197066
The tests were no longer using fast-isel at all (MachO needs an "ios" rather
than "darwin" triple at the moment and Linux needs ARM mode). Once that was
corrected, the verifier complained about a t2ADDri created for the alloca.
llvm-svn: 197046
I moved a test from avx512-vbroadcast-crash.ll to avx512-vbroadcast.ll
I defined HasAVX512 predicate as AssemblerPredicate. It means that you should invoke llvm-mc with "-mcpu=knl" to get encoding for AVX-512 instructions. I need this to let AsmMatcher to set different encoding for AVX and AVX-512 instructions that have the same mnemonic and operands (all scalar instructions).
llvm-svn: 197041
DAGCombiner could fold (truncate (load)) -> smaller load if the original
load was the width of the truncation result or wider. This patch extends
it to handle cases where the original load was narrower (and so the
extension type stays the same).
llvm-svn: 197030
This hook reverses the order of assignment for local live ranges. This
will generally allocate shorter local live ranges first. For targets with
many registers, this could reduce regalloc compile time by a large
factor. It should still achieve optimal coloring; however, it can change
register eviction decisions. It is disabled by default for two reasons:
(1) Top-down allocation is simpler and easier to debug for targets that
don't benefit from reversing the order.
(2) Bottom-up allocation could result in poor evicition decisions on some
targets affecting the performance of compiled code.
llvm-svn: 197001
The combination of inline asm, stack realignment, and dynamic allocas
turns out to be too common to reject out of hand.
ASan inserts empy inline asm fragments and uses aligned allocas.
Compiling any trivial function containing a dynamic alloca with ASan is
enough to trigger the check.
XFAIL the test cases that would be miscompiled and add one that uses the
relevant functionality.
llvm-svn: 196986
It was failing because ASan was adding all of the following to one
function:
- dynamic alloca
- stack realignment
- inline asm
This patch avoids making the static alloca dynamic when coverage is
used.
ASan should probably not be inserting empty inline asm blobs to inhibit
duplicate tail elimination.
llvm-svn: 196973
This re-lands commit r196876, which was reverted in r196879.
The tests have been fixed to pass on platforms with a stack alignment
larger than 4.
Update to clang side tests will land shortly.
llvm-svn: 196939
Most users would be surprised if "isCOFF" and "isMachO" were simultaneously
true, unless they'd put the compiler in a box with a gun attached to a photon
detector.
This makes sure precisely one of the three formats is true for any triple and
simplifies some target logic based on that.
llvm-svn: 196934
immediately after SSE scalar fp instructions like addss or mulss.
Added patterns to select SSE scalar fp arithmetic instructions from a scalar
fp operation followed by a blend.
For example, given the following code:
__m128 foo(__m128 A, __m128 B) {
A[0] += B[0];
return A;
}
previously we generated:
addss %xmm0, %xmm1
movss %xmm1, %xmm0
now we generate:
addss %xmm1, %xmm0
llvm-svn: 196925
Save S2(reg 18) only when we are calling floating point stubs that
have a return value of float or complex. Some more work to make this
better but this is the first step.
llvm-svn: 196921
Defaulting to iOS 3.0 when LLVM has to guess the version is no longer a useful
option and can give surprising results (like tail calls being disabled).
5.0 seems like a reasonable compromise as a platform that's still interesting
to some people.
rdar://problem/15567348
llvm-svn: 196912
One unusual feature of the z architecture is that the result of a
previous load can be reused indefinitely for subsequent loads, even if
a cache-coherent store to that location is performed by another CPU.
A special serializing instruction must be used if you want to force
a load to be reattempted.
Since volatile loads are not supposed to be omitted in this way,
we should insert a serializing instruction before each such load.
The same goes for atomic loads.
The patch implements this at the IR->DAG boundary, in a similar way
to atomic fences. It is a no-op for targets other than SystemZ.
llvm-svn: 196906
One unusual feature of the z architecture is that the result of a
previous load can be reused indefinitely for subsequent loads, even if
a cache-coherent store to that location is performed by another CPU.
A special serializing instruction must be used if you want to force
a load to be reattempted.
Since volatile loads are not supposed to be omitted in this way,
we should insert a serializing instruction before each such load.
The same goes for atomic loads.
The patch implements this at the IR->DAG boundary, in a similar way
to atomic fences. It is a no-op for targets other than SystemZ.
llvm-svn: 196905
For stack frames requiring realignment, three pointers may be needed:
- ebp to address incoming arguments
- esi (could be any callee-saved register) to address locals
- esp to address outgoing arguments
We would use esi unconditionally without verifying that it did not
conflict with inline assembly.
This change doesn't do the verification, it simply emits a fatal error
on functions that use stack realignment, dynamic SP adjustments, and
inline assembly.
Because stack realignment is common on Windows, we also no longer assume
that MS inline assembly clobbers esp. Instead, we analyze the inline
instructions for implicit definitions and check if esp is there. If so,
we require the use of a base pointer and consider it in the condition
above.
Mostly fixes PR16830, but we could try harder to find a non-conflicting
base pointer.
Reviewers: sunfish
Differential Revision: http://llvm-reviews.chandlerc.com/D1317
llvm-svn: 196876
MCJIT needs to be able to run in hostile environments, even when PWD
is invalid. There's no need to crash MCJIT in this case.
The obvious fix is to simply leave MCContext's CompilationDir empty
when PWD can't be determined. This way, MCJIT clients,
and other clients that link with LLVM don’t need a valid working directory.
If we do want to guarantee valid CompilationDir, that should be done
only for clients of getCompilationDir(). This is as simple as checking
for an empty string.
The only current use of getCompilationDir is EmitGenDwarfInfo, which
won’t conceivably run with an invalid working dir. However, in the
purely hypothetically and untestable case that this happens, the
AT_comp_dir will be omitted from the compilation_unit DIE.
llvm-svn: 196874
Similar to gcov, llvm-cov will now print out the block count at the end
of each block. Multiple blocks can end on the same line.
One computational difference is by using -a, llvm-cov will no longer
simply add the block counts together to form a line count. Instead, it
will take the maximum of the block counts on that line. This has a
similar effect to what gcov does, but generates more correct counts in
certain scenarios.
Also updated tests.
llvm-svn: 196856
This avoids creating branch weight metadata of length one when we fold
cases into the default of a switch instruction, which was triggering
an assert.
llvm-svn: 196845
Patch by Jiangning Liu.
With some test case changes:
- intrinsic test added to the existing /test/CodeGen/AArch64/neon-aba-abd.ll.
- New test cases to cover movi 1D scenario without using the intrinsic in
test/CodeGen/AArch64/neon-mov.ll.
llvm-svn: 196806
Summary:
When clang is used under GNU/Linux in a chroot without /proc mount, it falls
back on the BSD method. However, since the buf variable is used twice
and fails with snprintf to produce the correct path.
When called as relatived (ie ./clang), it was failing with:
"" -cc1 [...] -x c++ x.cc
error: unable to execute command: Executable "" doesn't exist!
I also took the opportunity to simply the code (the first arg of test_dir
was useless).
Reviewers: rafael
Reviewed By: rafael
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2361
llvm-svn: 196791
Summary:
The MSA ld.[bhwd] and st.[bhwd] instructions scale the immediate by the
element size before use as an offset. The offset must therefore be a
multiple of the element size to be valid in these instructions. However,
an unaligned base address is valid in MSA.
This commit causes the compiler to emit valid code when the calculated
offset is not a multiple of the element size by accounting for the offset
using addiu and using a zero offset in the load/store.
Depends on D2338
Reviewers: matheusalmeida
Reviewed By: matheusalmeida
Differential Revision: http://llvm-reviews.chandlerc.com/D2339
llvm-svn: 196777
Summary:
The immediate in these instructions is scaled before use as an offset.
They therefore have a wider reach than ld.b/st.b.
Reviewers: matheusalmeida
Reviewed By: matheusalmeida
Differential Revision: http://llvm-reviews.chandlerc.com/D2338
llvm-svn: 196775
As we can't make a complete solution now it has been decided to enable .set directive to handle long jump expressions. This will cause parser to report errors when parsing integer based register assignments, for example:
.set r3, will be reported as error. Still, the need for expressions is higher priority as the integer based register assignments are Mips specific and can be avoided using register names.
llvm-svn: 196773
When trying to eliminate an "sub sp, sp, #N" instruction by folding
it into an existing push/pop using dummy registers, we need to account
for the fact that this might affect precisely how "fp" gets set in the
prologue.
We were attempting this, but assuming that *whenever* we performed a
fold it would make a difference. This is false, for example, in:
push {r4, r7, lr}
add fp, sp, #4
vpush {d8}
sub sp, sp, #8
we can fold the "sub" into the "vpush", forming "vpush {d7, d8}".
However, in that case the "add fp" instruction mustn't change, which
we were getting wrong before.
Should fix PR18160.
llvm-svn: 196725
Before this change, inlining one "invoke" into an outer "invoke" call
site can lead to the outer landingpad's catch/filter clauses being
copied multiple times into the resulting landingpad. This happens:
* when the inlined function contains multiple "resume" instructions,
because forwardResume() copies the clauses but is called multiple
times;
* when the inlined function contains a "resume" and a "call", because
HandleCallsInBlockInlinedThroughInvoke() copies the clauses but is
redundant with forwardResume().
Fix this by deduplicating the code.
This problem doesn't lead to any incorrect execution; it's only
untidy.
This change will make fixing PR17872 a little easier.
llvm-svn: 196710
They were out of place since the introduction of arbitrary precision integer
types.
This also synchronizes the documentation to Types.h, so it refers to first class
types and single value types.
llvm-svn: 196661
These helper classes take care of the book-keeping the drives the
GenericScheduler heuristics. It is likely that developers writing
target-specific schedulers that work similarly to GenericScheduler
will want to use these helpers too. The immediate goal is to develop a
GenericPostScheduler that can run in place of the old PostRAScheduler,
but will use the new machine model.
No functionality change intended.
llvm-svn: 196643
The sefault occurs due to an infinite loop when the verifier tries to
determine the size of a type of the form "%rt = type { %rt }" while
checking an alloca of the type.
llvm-svn: 196626
This commit caches the value of the AllowAtInIdentifier variable as
a class variable in AsmLexer. We do this to avoid repeated MAI
queries and string comparisons each time we lex an identifier.
llvm-svn: 196622
Command line arguments that begin with @ but aren't a path to an
existing file currently cause later @file arguments to be ignored.
Correctly skip over these arguments instead of trying to read a
non-existent file 20 times and giving up.
Since the problem manifests in the clang driver, the test is in that
repository.
Fixes rdar://problem/15590906
llvm-svn: 196620
- krait processor currently modeled with the same features as A9.
- Krait processor additionally has VFP4 (fused multiply add/sub)
and hardware division features enabled.
- krait has currently the same Schedule model as A9
- krait cpu flag is not recognized by the GNU assembler yet,
it is replaced with march=armv7-a to avoid a lower march
from being used.
llvm-svn: 196619
This removes another case of spooky action at a distance (building the
same label names in multiple places creating an implicit dependency
between those places) and helps pave the way for type units.
llvm-svn: 196617
The integrated assembler fails to properly lex arm comments when
they are adjacent to an identifier in the input stream. The reason
is that the arm comment symbol '@' is also used as symbol variant in
other assembly languages so when lexing an identifier it allows the
'@' symbol as part of the identifier.
Example:
$ cat comment.s
foo:
add r0, r0@got to parse this as a comment
$ llvm-mc -triple armv7 comment.s
comment.s:4:18: error: unexpected token in argument list
add r0, r0@got to parse this as a comment
^
This should be parsed as correctly as `add r0, r0`.
This commit modifes the assembly lexer to not include the '@' symbol
in identifiers when lexing for targets that use '@' for comments.
llvm-svn: 196607
This more accurately represents the actual walk - pubnames/pubtypes are
emitted into the .o, not the .dwo, and reference the skeletons not the
full units.
Use the newly established ID->index invariant to lookup the underlying
full unit to retrieve its public names and types.
llvm-svn: 196601
This simplifies reasoning about the code and enables simple navigation
from a skeleton to its full unit. (currently there are no type unit
skeletons, so the skeleton list doesn't have the same ID == index
property)
Eventually we should get rid of this ID and just store the labels we
need as the IDs are allowing this code to create difficult to
manage/understand associations (loops over non-skeletal units are
implicitly referencing their skeletal units during pub* emission, for
example). It may be necessary to have some kind of skeleton->full unit
association and a more direct pointer or similar device would be
preferable than an index.
llvm-svn: 196600
The current peephole optimizing for compare inst assumes an instr that
uses CPSR has an MO for ARM Cond code.However, for VSEL instructions
(vseqeq, vselgt, vselgt, vselvs), there is no such operand nor do
they support the modification of Cond Code.
llvm-svn: 196588
Since z has no setcc instruction as such, the choice of setBooleanContents
is a bit arbitrary. Currently it's set to ZeroOrOneBooleanContent,
so we produced a branch-free form when selecting between 0 and 1,
but not when selecting between 0 and -1. This patch handles the latter
case too.
At some point I'd like to measure whether it's better to use conditional
moves for constant selects on z196, but that's future work.
llvm-svn: 196578
Summary:
Rewrite asan's stack frame layout.
First, most of the stack layout logic is moved into a separte file
to make it more testable and (potentially) useful for other projects.
Second, make the frames more compact by using adaptive redzones
(smaller for small objects, larger for large objects).
Third, try to minimized gaps due to large alignments (this is hypothetical since
today we don't see many stack vars aligned by more than 32).
The frames indeed become more compact, but I'll still need to run more benchmarks
before committing, but I am sking for review now to get early feedback.
This change will be accompanied by a trivial change in compiler-rt tests
to match the new frame sizes.
Reviewers: samsonov, dvyukov
Reviewed By: samsonov
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2324
llvm-svn: 196568
Not only does it trigger -Wparentheses, I think the assert actually
relies on incorrect operator precedence.
Also, the grammar as questionable, but I might not know enough about the
problem at hand.
llvm-svn: 196567
The intended behaviour is to force vectorization on the presence
of the flag (either turn on or off), and to continue the behaviour
as expected in its absence. Tests were added to make sure the all
cases are covered in opt. No tests were added in other tools with
the assumption that they should use the PassManagerBuilder in the
same way.
This patch also removes the outdated -late-vectorize flag, which was
on by default and not helping much.
The pragma metadata is being attached to the same place as other loop
metadata, but nothing forbids one from attaching it to a function
(to enable #pragma optimize) or basic blocks (to hint the basic-block
vectorizers), etc. The logic should be the same all around.
Patches to Clang to produce the metadata will be produced after the
initial implementation is agreed upon and committed. Patches to other
vectorizers (such as SLP and BB) will be added once we're happy with
the pass manager changes.
llvm-svn: 196537
There is no reason to use std::deque here over std::vector. Thus given the
performance differences inbetween the two it makes sense to change deque to
vector.
llvm-svn: 196524
We use CSEBlocks to initialize a worklist:
SmallVector<BasicBlock *, 8> CSEWorkList(CSEBlocks.begin(), CSEBlocks.end());
so it must have a deterministic order.
llvm-svn: 196520
This allows a target to use MI-Sched as an in-order scheduler that
will model strict resource conflicts without defining a processor
itinerary. Instead, the target can now use the new per-operand machine
model and define in-order resources with BufferSize=0. For example,
this would allow restricting the type of operations that can be formed
into a dispatch group. (Normally NumMicroOps is sufficient to enforce
dispatch groups).
If the intent is to model latency in in-order pipeline, as opposed to
resource conflicts, then a resource with BufferSize=1 should be
defined instead.
This feature is only casually tested as there are no in-tree targets
using it yet. However, Hal will be experimenting with POWER7.
llvm-svn: 196517
We were creating external uses for scalar values in MustGather entries that also
had a ScalarToTreeEntry (they also are present in a vectorized tuple). This
meant we would keep a value 'alive' as a scalar and vectorized causing havoc.
This is not necessary because when we create a MustGather vector we explicitly
create external uses entries for the insertelement instructions of the
MustGather vector elements.
Fixes PR18129.
radar://15582184
llvm-svn: 196508
in case the operands are constants and its difference is |1|.
It should be possible in those cases to rematerialize the result using
MIPS's slt and similar instructions.
The small update to some of the tests in cmov.ll, sel1c.ll and sel2c.ll was needed
otherwise the optimization implemented in this patch would have been triggered
(difference between the operands was 1) and that would have changed the semantic
of the tests.
llvm-svn: 196498
not being correctly encoded/decoded.
In more detail, immediate fields of LD/ST instructions should be
divided/multiplied by the size of the data format before encoding and
after decoding, respectively.
llvm-svn: 196494
We were trying to fold the stack adjustment into the wrong instruction in the
situation where the entire basic-block was epilogue code. Really, it can only
ever be valid to do the folding precisely where the "add sp, ..." would be
placed so there's no need for a separate iterator to track that.
Should fix PR18136.
llvm-svn: 196493
getSymbolWithGlobalValueBase use is to create a name of a new symbol based
on the name of an existing GV. Assert that and then remove the last call
to pass true to isImplicitlyPrivate.
This gives the mangler API a 1:1 mapping from GV to names, which is what we
need to drop the mangler dependency on the target (and use an extended
datalayout instead).
llvm-svn: 196472
given
declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1)
declare void @foo()
define void @bar() {
call void @foo()
call void @llvm.memset.p0i8.i32(i8* null, i8 0, i32 188, i32 1, i1 false)
ret void
}
We used to produce
L_foo$stub:
.indirect_symbol _foo
.ascii "\364\364\364\364\364"
_memset$stub:
.indirect_symbol _memset
.ascii "\364\364\364\364\364"
We not produce a private stub for memset too.
Stubs are not needed with recent linkers, but we still produce them for darwin8.
Thanks to David Fang for confirming that gcc used to do this too.
llvm-svn: 196468
This just extends the existing hack. It should be enough to get a reproducible bootstrap
on 32 bits.
I will open a bug to track getting a real fix for this.
llvm-svn: 196462
ELF_Other_Weakref and ELF_Other_ThumbFunc seems to be LLVM
internal ELF symbol flags. These should not be emitted to
object file.
This commit defines ELF_STO_Shift for the target-defined
flags for st_other, and increase the value of
ELF_Other_Shift to 16.
llvm-svn: 196440
Where it would use a scattered relocation entry but falls back to a
normal relocation entry because the FixupOffset is more than 24-bits.
The bug is in the X86MachObjectWriter::RecordScatteredRelocation() where
it changes reference parameter FixedValue but then returns false to indicate
it did not create a scattered relocation entry. The fix is simply to save the
original value of the parameter FixedValue at the start of the method and
restore it if we are returning false in that case.
rdar://15526046
llvm-svn: 196432
ARM symbol variants are written with parens instead of @ like this:
.word __GLOBAL_I_a(target1)
This commit adds support for parsing these symbol variants in
expressions. We introduce a new flag to MCAsmInfo that indicates the
parser should use parens to parse the symbol variant. The expression
parser is modified to look for symbol variants using parens instead
of @ when the corresponding MCAsmInfo flag is true.
The MCAsmInfo parens flag is enabled only for ARM on ELF.
By adding this flag to MCAsmInfo, we are able to get rid of
redundant ARM-specific symbol variants and use the generic variants
instead (e.g. VK_GOT instead of VK_ARM_GOT). We use the new
UseParensForSymbolVariant attribute in MCAsmInfo to correctly print
the symbol variants for arm.
To achive this we need to keep a handle to the MCAsmInfo in the
MCSymbolRefExpr class that we can check when printing the symbol
variant.
Updated Tests:
Changed case of symbol variant to match the generic kind.
test/CodeGen/ARM/tls-models.ll
test/CodeGen/ARM/tls1.ll
test/CodeGen/ARM/tls2.ll
test/CodeGen/Thumb2/tls1.ll
test/CodeGen/Thumb2/tls2.ll
PR18080
llvm-svn: 196424
While we still have a few (~4) non-trivial comments with string
concatenation, etc that should remain conditionalized, these trivial
literal comments can be simplified.
llvm-svn: 196416
Since we always emit only one abbrevation section (shared by all the
compilation units in this module) there's no need for a separate label
at the start of each one (and we weren't using the CU ID anyway, so
there really was only one label). Use the section label instead and drop
the wholely unused debug_abbrev_end label.
llvm-svn: 196394
Instead, reuse the same MCSymbol - this should make the code easier to
follow by avoiding hard to trace dependencies between different bits of
code.
llvm-svn: 196392
