Commit Graph

16208 Commits

Author SHA1 Message Date
Eric Christopher
0cefb0ecbc Add a DIELoc class to cover the DW_FORM_exprloc set of expressions
alongside DIEBlock and replace uses accordingly. Use DW_FORM_exprloc
in DWARF4 and later code. Update testcases.

Adding a DIELoc instead of using extra forms inside DIEBlock so
that we can keep location expressions separate from other uses. No
direct use at the moment, however, it's not a lot of code and
using a separately named class keeps it somewhat more obvious
what's going on in various locations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201481 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-16 08:46:55 +00:00
David Blaikie
132a287941 DebugInfo: Deduplicate entries in the fission address table
This broke in r185459 while TLS support was being generalized to handle
non-symbol TLS representations.

I thought about/tried having an enum rather than a bool to track the
TLS-ness of the address table entry, but namespaces and naming seemed
more hassle than it was worth for only one caller that needed to specify
this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201469 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-15 19:34:03 +00:00
David Blaikie
16413fa2f9 DwarfDebug: Remove dead code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201467 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-15 18:33:11 +00:00
David Blaikie
4b45137a4f DebugInfo: Implement DW_AT_stmt_list for type units
Type units will share the statement list of their defining compile unit.
This is a tradeoff that reduces .o debug info size at the cost of some
linked debug info size (since the contents of those string tables won't
be deduplicated along with the type unit) which seems right for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201445 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 23:58:13 +00:00
David Blaikie
ff1677e9c5 DwarfUnit: Remove unnecessarily explicit/out of line virtual dtors.
These types have an out of line virtual function each (emitHeader at
least) so they won't have weak vtables - no need for more than that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201444 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 22:50:59 +00:00
David Blaikie
906c8deb9e DwarfUnit: Remove unnecessary (void)t; that was previously used to suppress -Wunused-member-variable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201442 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 22:47:55 +00:00
David Blaikie
705991f2fc DwarfUnit: Refactor out DW_AT_stmt_list creation into common function for fission and non-fission cases
This probably also addresses the FIXME in the fission case regarding
multiple compile units, though I haven't tested that.

This code still confuses me (the literal zero offset makes little sense,
the limitations surrounding asm output I'm not sure about either - but
perhaps we should just always emit one line table? Or should we not rely
on .loc/.file even in assembly so we can produce the same output between
asm and object output?) but this maintains the existing functionality.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201441 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 22:41:51 +00:00
Tom Stellard
5f80594797 TargetLowering: n * r where n > 2 should be an illegal addressing mode
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201433 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 21:10:34 +00:00
David Blaikie
c4e1b13b08 DebugInfo: Don't include the name of the CU file in the line table file list when it's unneeded
Recommitting r201380 (reverted in r201389)
Recommitting r201351 and r201355 (reverted in r201351 and r201355)

We weren't emitting the an empty (header only) line table when the line
table was empty - this made the DWARF invalid (the compile unit would
point to the zero-size debug_lines section where there should've been an
empty line table but there was nothing at all). Fix that, and as a
consequence this works around/addresses PR18809.

Also, we emit a non-empty line table to workaround a darwin linker bug,
so XFAILing on darwin too.

Also, mark the test as 'REQUIRES: object-emission' because it does.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201429 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 19:51:35 +00:00
Artyom Skrobov
e228078ca6 Generate the DWARF stack frame decode operations in the function prologue for ARM/Thumb functions.
Patch by Keith Walker!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201423 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 17:19:07 +00:00
Eric Christopher
89eb5dc65d Revert "DebugInfo: Don't include the name of the CU file in the line table file list when it's unneeded"
This reverts commit r201380 for now while we investigate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201389 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 05:33:16 +00:00
David Blaikie
35d2f61510 DebugInfo: Don't include the name of the CU file in the line table file list when it's unneeded
Recommitting r201351 and r201355 (reverted in r201351 and r201355)

We weren't emitting the an empty (header only) line table when the line
table was empty - this made the DWARF invalid (the compile unit would
point to the zero-size debug_lines section where there should've been an
empty line table but there was nothing at all). Fix that, and as a
consequence this works around/addresses PR18809.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201380 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 01:57:59 +00:00
Eric Christopher
5483012b4d Disable emission of aranges by default and add a command line
option to enable again that will be matched with a commit to enable
in clang.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201378 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 01:26:55 +00:00
Rafael Espindola
cac25de43d Use __literal16. It has been supported by the linker since 2005.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201365 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-13 23:16:11 +00:00
NAKAMURA Takumi
d8be721249 [PR18809] Revert r201187, "DebugInfo: Don't include the name of the CU file in the line table file list when it's unneeded"
It really crashes cygwin's stage2 configure with "clang -g".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201351 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-13 18:18:56 +00:00
Daniel Sanders
38c6b58eec Re-commit: Demote EmitRawText call in AsmPrinter::EmitInlineAsm() and remove hasRawTextSupport() call
Summary:
AsmPrinter::EmitInlineAsm() will no longer use the EmitRawText() call for
targets with mature MC support. Such targets will always parse the inline
assembly (even when emitting assembly). Targets without mature MC support
continue to use EmitRawText() for assembly output.

The hasRawTextSupport() check in AsmPrinter::EmitInlineAsm() has been replaced
with MCAsmInfo::UseIntegratedAs which when true, causes the integrated assembler
to parse inline assembly (even when emitting assembly output). UseIntegratedAs
is set to true for targets that consider any failure to parse valid assembly
to be a bug. Target specific subclasses generally enable the integrated
assembler in their constructor. The default value can be overridden with
-no-integrated-as.

All tests that rely on inline assembly supporting invalid assembly (for example,
those that use mnemonics such as 'foo' or 'hello world') have been updated to
disable the integrated assembler.

Changes since review (and last commit attempt):
- Fixed test failures that were missed due to configuration of local build.
  (fixes crash.ll and a couple others).
- Fixed tests that happened to pass because the local build was on X86
  (should fix 2007-12-17-InvokeAsm.ll)
- mature-mc-support.ll's should no longer require all targets to be compiled.
  (should fix ARM and PPC buildbots)
- Object output (-filetype=obj and similar) now forces the integrated assembler
  to be enabled regardless of default setting or -no-integrated-as.
  (should fix SystemZ buildbots)

Reviewers: rafael

Reviewed By: rafael

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2686



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201333 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-13 14:44:26 +00:00
Quentin Colombet
126099ea23 [RegAlloc] Fix the assertion in the last chance recoloring to match the
condition at the call site.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201296 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-13 05:17:37 +00:00
Juergen Ributzka
525637575c [DAG] Fix the recognition of opaque constants in the SelectionDAGBuilder.
This fix checks the original LLVM IR node to identify opaque constants by
looking for the bitcast-constant pattern. Originally we looked at the generated
SDNode, but this might lead to incorrect results. The SDNode could have been
generated by an constant expression that was folded to a constant.

This fixes <rdar://problem/16050719>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201291 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-13 04:19:26 +00:00
Eric Christopher
58f4aa4d52 Reformat a few lines with clang-format.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201265 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 22:47:09 +00:00
Eric Christopher
35726276df 80-col.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201264 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 22:38:04 +00:00
Juergen Ributzka
53c9085800 [Stackmaps] Improve the stackmap lowering code in the SelectionDAGBuilder.
We are now no longer relying on the target-specific call lowering implementation
to lower a stackmap intrinsic call. Instead we perform the call lowering in a
target-independent way directly in the stackmap lowering code. This simplifies
the code and removes the need to fixup the code after the target-specific call
lowering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201263 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 22:17:13 +00:00
Juergen Ributzka
586004f918 [Stackmaps] Fix the ID type to be i64 also for stackmaps (as we claim in the documenation)
The ID type for the stackmap and patchpoint intrinsics are in both cases i64.
This fixes an zero extend in the SelectionDAGBuilder that still used i32. This
also updates the target independent instructions STACKMAP and PATCHPOINT to use
the correct type.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201262 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 22:17:10 +00:00
Adrian Prantl
4c1ea6b115 Debug info: Bugfix for r201190: DW_OP_piece takes bytes, not bits.
rdar://problem/16015314

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201253 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 19:34:44 +00:00
Akira Hatanaka
386fedd32e Pass edges weights to MachineBasicBlock::addSuccessor in TailDuplicatePass to
preserve branch probability information.

<rdar://problem/15893208>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201245 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 18:09:18 +00:00
Daniel Sanders
7580df334e Revert r201237+r201238: Demote EmitRawText call in AsmPrinter::EmitInlineAsm() and remove hasRawTextSupport() call
It introduced multiple test failures in the buildbots.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201241 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 15:39:20 +00:00
Daniel Sanders
57edb9588b Demote EmitRawText call in AsmPrinter::EmitInlineAsm() and remove hasRawTextSupport() call
Summary:
AsmPrinter::EmitInlineAsm() will no longer use the EmitRawText() call for targets with mature MC support. Such targets will always parse the inline assembly (even when emitting assembly). Targets without mature MC support continue to use EmitRawText() for assembly output.

The hasRawTextSupport() check in AsmPrinter::EmitInlineAsm() has been replaced with MCAsmInfo::UseIntegratedAs which when true, causes the integrated assembler to parse inline assembly (even when emitting assembly output). UseIntegratedAs is set to true for targets that consider any failure to parse valid assembly to be a bug. Target specific subclasses generally enable the integrated assembler in their constructor. The default value can be overridden with -no-integrated-as.

All tests that rely on inline assembly supporting invalid assembly (for example, those that use mnemonics such as 'foo' or 'hello world') have been updated to disable the integrated assembler.

Reviewers: rafael

Reviewed By: rafael

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2686

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201237 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 14:44:54 +00:00
David Blaikie
9a0eced3af DwarfUnit: Include type unit's file strings in the defining compile unit's file_names table
There's still one piece missing here, which is adding the
DW_AT_stmt_list to the type unit that refer's to the compile unit's line
table. Working on that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201198 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 00:40:47 +00:00
David Blaikie
f7943e5f0e Fix some formatting in my last commit (r201196)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201197 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 00:32:05 +00:00
David Blaikie
c6c93e96e9 DwarfUnit: Provide a reference to a defining DwarfCompileUnit from DwarfTypeUnit.
Type units need to insert their file strings into the compile unit's
line/file table. This is preliminary work to that end.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201196 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 00:31:30 +00:00
David Blaikie
a22a1bb8c1 DwarfUnit: Refactor DW_AT_file creation into a common function.
This is preliminary work to fix type unit file strings so they appear in
their originating CU's line table - but it's also just good/simple
cleanup, so I'm committing it ahead of time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201195 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-12 00:11:25 +00:00
David Blaikie
19cfb96184 DwarfUnit: Replace unnecessary conditionals with asserts.
We used to be pretty vague about what debug entities were what, with
many conditionals to silently drop/skip/accept things. These don't seem
to be relevant anymore.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201194 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-11 23:57:03 +00:00
Adrian Prantl
e48e9419ea Reapply r201180 with an additional error path.
Debug info: Emit values in subregisters that do not have a separate
DWARF register number by emitting a super-register + DW_OP_bit_piece.
This is necessary because on x86_64, there are no DWARF register numbers
for i386-style subregisters.
Fixes a bunch of FIXMEs.

rdar://problem/16015314

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201190 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-11 22:22:15 +00:00
Adrian Prantl
20d5e1b247 Revert "Debug info: Emit values in subregisters that do not have a separate"
This reverts commit r201179 for buildbot breakage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201188 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-11 22:03:30 +00:00
David Blaikie
feb006fac4 DebugInfo: Don't include the name of the CU file in the line table file list when it's unneeded
This comes up in empty files or files containing #file directives that
never reference the actual source file name. Came up in a small test of
line tables I was playing with.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201187 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-11 21:49:46 +00:00
Adrian Prantl
b015567256 whitespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201181 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-11 21:23:02 +00:00
Adrian Prantl
f4f80ebbc7 Debug info: Emit values in subregisters that do not have a separate
DWARF register number by emitting a super-register + DW_OP_bit_piece.
This is necessary because on x86_64, there are no DWARF register numbers
for i386-style subregisters.
Fixes a bunch of FIXMEs.

rdar://problem/16015314

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201180 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-11 21:22:59 +00:00
Robert Lougher
a63585a8f5 Teach the DAGCombiner how to fold concat_vector nodes when the input is two
BUILD_VECTOR nodes, e.g.:

(concat_vectors (BUILD_VECTOR a1, a2, a3, a4), (BUILD_VECTOR b1, b2, b3, b4))
->
(BUILD_VECTOR a1, a2, a3, a4, b1, b2, b3, b4)

This fixes an issue with AVX, where a sequence was not recognized as a 256-bit
vbroadcast due to the concat_vectors.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201158 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-11 15:42:46 +00:00
David Blaikie
efbd8e5fc0 DebugInfo: Use existing symbol rather than creating it again.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201119 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-11 01:23:52 +00:00
Juergen Ributzka
1a66b63578 [Stackmaps] Cleanup code. No functional change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201115 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-10 23:30:26 +00:00
David Blaikie
853f658ed1 Remove some prototype code accidentally committed in r201043
Thanks to Chandler for the catch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201095 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-10 16:49:07 +00:00
Rafael Espindola
965e3bc5ff Use a consistent argument order in TargetLoweringObjectFile.
These methods normally call each other and it is really annoying if the
arguments are in different order. The more common rule was that the arguments
specific to call are first (GV, Encoding, Suffix) and the auxiliary objects
(Mang, TM) come after. This patch changes the exceptions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201044 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-09 14:50:44 +00:00
David Blaikie
cc719cf87f Fix formatting introduced in r200941
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201043 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-09 09:49:29 +00:00
Rafael Espindola
e09411dd68 Pass the Mangler by reference.
It is never null and it is not used in casts, so there is no reason to use a
pointer. This matches how we pass TM.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201025 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-08 14:53:28 +00:00
Rafael Espindola
0732e94378 Fix a bug with .weak_def_can_be_hidden: Mutable variables cannot use it.
Thanks to John McCall for noticing it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200977 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-07 16:21:30 +00:00
Rafael Espindola
12eb44ddab Refactor logic into a function predicate.
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200976 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-07 16:07:11 +00:00
Manman Ren
ee5625b3c1 PGO branch weight: fix PR18752.
Fix a bug triggered in IfConverterTriangle when CvtBB has multiple predecessors
by getting the weights before removing a successor.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200958 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-07 00:38:56 +00:00
Andrew Trick
2be0fae98c Track register pressure a bit more carefully (weird corner case).
This solves a problem where a def machine operand has no uses but has
not been marked dead. In this case, the initial RP analysis was being
extra precise and determining from LiveIntervals the the register was
actually dead. This caused us to omit the register from the RP
tracker's block live out. That's all good, but the per-instruction
summary still accounted for it as a valid def. This could cause an
assertion in the tracker later when we underflow pressure.

This is from a bug report on an out-of-tree target. It is not
reproducible on well-behaved targets. I'm just making an obvious fix
without unit test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200941 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-06 19:20:41 +00:00
David Peixotto
4ed2667c13 Remove const_cast for STI when parsing inline asm
In a previous commit (r199818) we added a const_cast to an existing
subtarget info instead of creating a new one so that we could reuse
it when creating the TargetAsmParser for parsing inline assembly.
This cast was necessary because we needed to reuse the existing STI
to avoid generating incorrect code when the inline asm contained
mode-switching directives (e.g. .code 16).

The root cause of the failure was that there was an implicit sharing
of the STI between the parser and the MCCodeEmitter. To fix a
different but related issue, we now explicitly pass the STI to the
MCCodeEmitter (see commits r200345-r200351).

The const_cast is no longer necessary and we can now create a fresh
STI for the inline asm parser to use.

Differential Revision: http://llvm-reviews.chandlerc.com/D2709


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200929 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-06 18:19:40 +00:00
Puyan Lotfi
efcc736270 Yet another patch to reduce compile time for small programs:
The aim in this patch is to reduce work that VirtRegRewriter needs to do when
telling MachineRegisterInfo which physregs are in use. Up until now
VirtRegRewriter::rewrite has been doing rewriting and populating def info and
then proceeding to set whether a physreg is used based this info for every
physreg that the target provides. This can be expensive when a target has an
unusually high number of supported physregs, and is a noticeable chunk of
compile time for small programs on such targets.

So to reduce compile time, this patch simply adds the use of a SparseSet to the
rewrite function that is used to flag each physreg that is encountered in a
MachineFunction. Afterward, rather than iterating over the set of all physregs
for a given target to set the physregs used in MachineRegisterInfo, the new way
is to iterate over the set of physregs that were actually encountered and set
in the SparseSet. This improves compile time because the existing rewrite
function was iterating over all MachineOperands already, and because the
iterations afterward to setPhysRegUsed is reduced by use of the SparseSet data.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200919 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-06 09:57:39 +00:00
Puyan Lotfi
9f2252fe47 The following patch' purpose is to reduce compile time for compilation of small
programs on targets with large register files. The root of the compile time
overhead was in the use of llvm::SmallVector to hold PhysRegEntries, which
resulted in slow-down from calling llvm::SmallVector::assign(N, 0). In contrast
std::vector uses the faster __platform_bzero to zero out primitive buffers when
assign is called, while SmallVector uses an iterator.

The fix for this was simply to replace the SmallVector with a dynamically
allocated buffer and to initialize or reinitialize the buffer based on the
total registers that the target architecture requires. The changes support
cases where a pass manager may be reused for different targets, and note that
the PhysRegEntries is allocated using calloc mainly for good for, and also to
quite tools like Valgrind (see comments for more info on this).

There is an rdar to track the fact that SmallVector doesn't have platform
specific speedup optimizations inside of it for things like this, and I'll
create a bugzilla entry at some point soon as well.

TL;DR: This fix replaces the expensive llvm::SmallVector<unsigned
char>::assign(N, 0) with a call to calloc for N bytes which is much faster
because SmallVector's assign uses iterators.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200917 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-06 09:23:24 +00:00