123892 Commits

Author SHA1 Message Date
Tom Stellard
b6cc1fddcd Revert "Remove unnecessary call to getAllocatableRegClass"
This reverts commit r252565.

This also includes the revert of the commit mentioned below in order to
avoid breaking tests in AMDGPU:

Revert "AMDGPU: Set isAllocatable = 0 on VS_32/VS_64"

This reverts commit r252674.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252956 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 21:43:25 +00:00
Akira Hatanaka
85b811eedd Revert r252949.
It broke some of the bots including clang-x64-ninja-win7.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252951 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 21:19:18 +00:00
Akira Hatanaka
d68ad56b3f Provide a way to specify inliner's attribute compatibility and merging
rules using table-gen. NFC.

This commit adds new classes CompatRule and MergeRule to Attributes.td,
which are used to generate code to check attribute compatibility and
merge attributes of the caller and callee.

rdar://problem/19836465


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252949 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 20:59:43 +00:00
Sanjoy Das
22e911c8dd Revert r243347 "Add TargetTransformInfo::isZExtFree."
r243347 was intended to support a change to LSR (r243348).  That change
to LSR has since had to be reverted (r243939) because it was buggy, and
now the code added in r243347 is untested and unexercised.  Given that,
I think it is appropriate to revert r243347 for now, with the intent of
adding it back in later if I get around to checking in a fixed version
of r243348.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252948 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 20:51:52 +00:00
Sanjoy Das
13036d4421 [ImplicitNulls] Fix wrapping by breaking up a condition, NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252947 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 20:51:49 +00:00
Sanjoy Das
a2f2875b75 [ImplicitNull] Extract out a HazardDetector class, NFC
This will make later functional changes easier to follow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252946 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 20:51:44 +00:00
Mike Aizatsky
8b07272072 disabling sancov tests: too many failures on different platforms.
Differential Revision: http://reviews.llvm.org/D14624

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252945 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 20:47:12 +00:00
Mike Aizatsky
4192660fd2 sancov tests - platform independent separators
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252943 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 20:17:49 +00:00
Vyacheslav Klochkov
c319d2c8cc My first/test commit. Removed a trailing whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252940 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 20:11:57 +00:00
Tobias Grosser
8887882603 Revert "Fix bug 25440: GVN assertion after coercing loads"
This reverts 252919 which broke LNT: MultiSource/Applications/SPASS

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252936 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 20:04:21 +00:00
Mike Aizatsky
91e7b1246c sancov test suite
Differential Revision: http://reviews.llvm.org/D14589

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252933 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 19:34:21 +00:00
Teresa Johnson
8e6493db91 [ThinLTO] Update test to be more tolerant of ordering changes
Update the ThinLTO function importing test to use DAG forms of checks so
that it is more tolerant of changes to relative ordering between
imported decls/defs. This reduces the number of changes required by the
comdat importing patch I am sending for review shortly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252932 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 19:31:46 +00:00
Benjamin Kramer
667c2c29cf [Hexagon] Allocate MCInst in the MCContext to avoid leaking it.
Found by leaksanitizer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252931 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 19:30:40 +00:00
Chad Rosier
1a1fb00653 [LIR] Minor refactoring. NFCI.
This change prevents uninteresting stores from being inserted into the list of
candidate stores for memset/memcpy conversion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252926 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 19:09:16 +00:00
David Blaikie
7c389fb7c5 Roll an expression into an assert to fix -Wunused-variable in a -Asserts build
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252925 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 19:07:43 +00:00
Nathan Slingerland
69c9ea3b39 reverting r252916 to investigate test failure
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252921 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 18:39:26 +00:00
Weiming Zhao
13d37da28f Fix bug 25440: GVN assertion after coercing loads
Summary:
when coercing loads, it inserts some instructions, which have no GV assigned.

https://llvm.org/bugs/show_bug.cgi?id=25440


Reviewers: hfinkel, dberlin

Subscribers: dberlin, llvm-commits

Differential Revision: http://reviews.llvm.org/D14479

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252919 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 18:19:59 +00:00
Quentin Colombet
15dd44677b [ShrinkWrap] Fix a typo in a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252918 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 18:16:27 +00:00
Quentin Colombet
88d45c6801 [ShrinkWrap] Make sure we do not mess up with EH funclet lowering.
ShrinkWrapping does not understand exception handling constraints for now, so
make sure we do not mess with them by aborting on functions that use EH
funclets.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252917 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 18:13:42 +00:00
Nathan Slingerland
7b81b822ba [llvm-profdata] Add check for text profile formats and improve error reporting
Summary:
This change addresses two possible instances of user error / confusion when
merging sampled profile data.

Previously any input that didn't match the raw or processed instrumented format
would automatically be interpreted as instrumented profile text format data.
No error would be reported during the merge.

Example:
If foo-sampled.profdata and bar-sampled.profdata are binary sampled profiles:

Old behavior:
$ llvm-profdata merge foo-sampled.profdata bar-sampled.profdata -output foobar-sampled.profdata
$ llvm-profdata show -sample foobar-sampled.profdata
error: foobar-sampled.profdata:1: Expected 'mangled_name:NUM:NUM', found  lprofi

This change adds basic checks for valid input data when assuming text input.
It also makes error messages related to file format validity more specific about
the assumbed profile data type.

New behavior:
$ llvm-profdata merge foo-sampled.profdata bar-sampled.profdata -o foobar-sampled.profdata
error: foo.profdata: Unrecognized instrumentation profile encoding format
Perhaps you forgot to use the -sample option?

Reviewers: bogner, davidxl, dnovillo

Subscribers: davidxl, llvm-commits

Differential Revision: http://reviews.llvm.org/D14558

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252916 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 18:06:18 +00:00
Diego Novillo
7e02753319 SamplePGO - Move FunctionSamples::print() to a better location. NFC.
The class is declared in SampleProf.h, so a better home for this is
SampleProf.cpp.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252915 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 17:58:14 +00:00
Andrew Kaylor
2aca944a0e [WinEH] Fix problem with removing an element from a SetVector while iterating.
Patch provided by Yaron Keren. (Thanks!)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252913 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 17:36:03 +00:00
Rafael Espindola
d0663f3a4e Comment update. NFC.
Fix the library name.
Don't duplicate the comment in the .cpp file.
Don't repeat the name in the comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252911 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 17:13:45 +00:00
Dan Gohman
d39c38d2bc [WebAssembly] Reapply r252858, with svn add for the new file.
Switch to MC for instruction printing.

This encompasses several changes which are all interconnected:
 - Use the MC framework for printing almost all instructions.
 - AsmStrings are now live.
 - This introduces an indirection between LLVM vregs and WebAssembly registers,
   and a new pass, WebAssemblyRegNumbering, for computing a basic the mapping.
   This addresses some basic issues with argument registers and unused registers.
 - The way ARGUMENT instructions are handled no longer generates redundant
   get_local+set_local for every argument.

This also changes the assembly syntax somewhat; most notably, MC's printing
does not use sigils on label names, so those are no longer present, and
push/pop now have a sigil to keep them unambiguous.

The usage of set_local/get_local/$push/$pop will continue to evolve
significantly. This patch is just one step of a larger change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252910 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 17:04:33 +00:00
Michael Zuckerman
8e8b0ba38b [x86] translating "fp" (floating point) instructions from {fadd,fdiv,fmul,fsub,fsubr,fdivr} to {faddp,fdivp,fmulp,fsubp,fsubrp,fdivrp}
LLVM Missing the following instructions: fadd\fdiv\fmul\fsub\fsubr\fdivr.
GAS and MS supporting this instruction and lowering them in to a faddp\fdivp\fmulp\fsubp\fsubrp\fdivrp instructions.

Differential Revision: http://reviews.llvm.org/D14217


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252908 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 16:58:51 +00:00
Artyom Skrobov
957ee69c41 Cull non-standard variants of ARM architectures (NFC)
Summary:
This patch changes ARMV5, ARMV5E, ARMV6SM, ARMV6HL, ARMV7, ARMV7L,
ARMV7HL, ARMV7EM to be treated as aliases for the corresponding
standard architectures, instead of as actual architectures.

Reviewers: rengolin

Subscribers: aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D14577

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252903 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 15:51:41 +00:00
Hans Wennborg
e8073938cf Revert r252858: "[WebAssembly] Switch to MC for instruction printing."
It broke the CMake build:

"Cannot find source file: WebAssemblyRegNumbering.cpp"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252897 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 14:37:56 +00:00
Vasileios Kalintiris
f771b118df Re-apply "[mips] Use correct frame register for DWARF info when dynamically realigning the stack.""
r252219 reversed the direction of subprogram -> function edge. Fixed the
IR to account for this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252895 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 14:11:43 +00:00
James Molloy
b5caa9fd56 [ARM] CMOV->BFI combining: handle both senses of CMPZ
I completely misunderstood what ARMISD::CMPZ means. It's not "compare equal to zero", it's "compare, only setting the zero/Z flag". It can either be equal-to-zero or not-equal-to-zero, and we weren't checking what sense it was.

If it's equal-to-zero, we can swap the operands around and pretend like it is not-equal-to-zero, which is both a bug fix and lets us handle more cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252891 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 13:49:17 +00:00
Renato Golin
0e66a5f53c Revert "[ARM] Enable shrink-wrapping by default."
This reverts commit r252825, as it broke ASAN on ARM. Investigating...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252889 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 13:34:50 +00:00
Daniel Sanders
7056b68970 Implement .reloc (constant offset only) with support for R_MIPS_NONE and R_MIPS_32.
Summary:
Support for R_MIPS_NONE allows us to parse MIPS16's usage of .reloc.
R_MIPS_32 was included to be able to better test the directive.

Targets can add their relocations by overriding MCAsmBackend::getFixupKind().

Subscribers: grosbach, rafael, majnemer, dsanders, llvm-commits

Differential Revision: http://reviews.llvm.org/D13659

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252888 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 13:33:00 +00:00
Zlatko Buljan
567a66317d [mips][microMIPS] Implement LWM16, SB16, SH16, SW16, SWSP and SWM16 instructions
Differential Revision: http://reviews.llvm.org/D11406


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252885 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 13:21:33 +00:00
Vasileios Kalintiris
fff75cb0f8 Revert "[mips] Use correct frame register for DWARF info when dynamically realigning the stack."
This reverts commit r252882. LLParser complains for invalid field 'function'
in DISubprogram.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252884 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 13:19:11 +00:00
Hans Wennborg
73fcc448d3 Remove mention of {ADD,SUB}_PARTS. They were removed in r26255.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252883 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 13:18:20 +00:00
Vasileios Kalintiris
c988258daa [mips] Use correct frame register for DWARF info when dynamically realigning the stack.
Summary:
This patch overrides TargetFrameLowering::getFrameIndexReference() in order to
specify the correct register when the function needs dynamic stack realignment.
The values returned from this function are used in order to create DW_AT_locations
for DWARF info. These locations would use the wrong registers as it's been
reported in PR25028.

Reviewers: dsanders

Subscribers: dean, llvm-commits

Differential Revision: http://reviews.llvm.org/D13511

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252882 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 13:04:16 +00:00
James Molloy
7086a4139d [InstCombine] Add trivial folding (bitreverse (bitreverse x)) -> x
There are plenty more instcombines we could probably do with bitreverse, but this seems like a very obvious and trivial starting point and was brought up by Hal in his review.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252879 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 12:39:41 +00:00
James Molloy
fdd6e1b2e5 [SDAG] Introduce a new BITREVERSE node along with a corresponding LLVM intrinsic
Several backends have instructions to reverse the order of bits in an integer. Conceptually matching such patterns is similar to @llvm.bswap, and it was mentioned in http://reviews.llvm.org/D14234 that it would be best if these patterns were matched in InstCombine instead of reimplemented in every different target.

This patch introduces an intrinsic @llvm.bitreverse.i* that operates similarly to @llvm.bswap. For plumbing purposes there is also a new ISD node ISD::BITREVERSE, with simple expansion and promotion support.

The intention is that InstCombine's BSWAP detection logic will be extended to support BITREVERSE too, and @llvm.bitreverse intrinsics emitted (if the backend supports lowering it efficiently).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252878 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 12:29:09 +00:00
James Molloy
29020c0a61 Revert "Revert "[FunctionAttrs] Identify norecurse functions""
This reapplies this patch, with test fixes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252871 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 10:55:20 +00:00
Kuba Brecka
4e0567ae26 [Object, MachO] Mark symbols from DATA and BSS sections as ST_Data
In `MachOObjectFile::getSymbolType` we currently always return `SymbolRef::ST_Function` for symbols from any section. In order for llvm-symbolizer to correctly symbolize Mach-O globals, symbols from data and BSS sections should return `SymbolRef::ST_Data`.

Differential Revision: http://reviews.llvm.org/D14576



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252867 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 09:40:29 +00:00
Amjad Aboud
65d7d51529 dwarfdump: Added macro support to llvm-dwarfdump tool.
Added "macro" option to "-debug-dump" flag, which trigger parsing and dumping of the ".debug_macinfo" section.

Differential Revision: http://reviews.llvm.org/D14294

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252866 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 09:38:54 +00:00
Dylan McKay
0b9fa0c2e3 Add AVR backend skeleton
This adds part of the target info code, and adds modifications to
the build scripts so that AVR is recognized a supported, experimental
backend.

It does not include any AVR-specific code, just the bare sources required
for a backend to exist.

From D14039.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252865 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 09:26:44 +00:00
James Molloy
6cd07b45e1 Revert "[FunctionAttrs] Identify norecurse functions"
This reverts commit r252862. This introduced test failures and I'm reverting while I investigate how this happened.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252863 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 09:05:43 +00:00
James Molloy
31d4df2fc6 [FunctionAttrs] Identify norecurse functions
A function can be marked as norecurse if:
  * The SCC to which it belongs has cardinality 1; and either
    a) It does not call any non-norecurse function. This includes self-recursion; or
    b) It only has one callsite and the function that callsite is within is marked norecurse.

a) is best propagated bottom-up and b) is best propagated top-down.

We build up the norecurse attributes bottom-up using the existing SCC pass, and mark functions with no obvious recursion (but not provably norecurse) to sweep later, top-down.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252862 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 08:53:04 +00:00
David Blaikie
c65ca6797f Mostly revert 252842 due to failures on some buildbots.
I imagine there's some UB in here somewhere, though Valgrind doesn't
seem to have picked it up (not sure if I have a working asan build right
now to test there).

GDB bot seems to be crashing:
http://lab.llvm.org:8011/builders/clang-x86_64-ubuntu-gdb-75/builds/26267/steps/check-all/logs/FAIL%3A%20LLVM%3A%3Adwarfdump-dwp.test

Hexagon ELF bot is, presumably, just getting different output:
http://lab.llvm.org:8011/builders/clang-hexagon-elf/builds/32927/steps/check-all/logs/FAIL%3A%20LLVM%3A%3Adwarfdump-dwp.test

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252859 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 06:33:14 +00:00
Dan Gohman
41e2c98842 [WebAssembly] Switch to MC for instruction printing.
This encompasses several changes which are all interconnected:
 - Use the MC framework for printing almost all instructions.
 - AsmStrings are now live.
 - This introduces an indirection between LLVM vregs and WebAssembly registers,
   and a new pass, WebAssemblyRegNumbering, for computing a basic the mapping.
   This addresses some basic issues with argument registers and unused registers.
 - The way ARGUMENT instructions are handled no longer generates redundant
   get_local+set_local for every argument.

This also changes the assembly syntax somewhat; most notably, MC's printing
use sigils on label names, so those are no longer present, and push/pop now
have a sigil to keep them unambiguous.

The usage of set_local/get_local/$push/$pop will continue to evolve
significantly. This patch is just one step of a larger change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252858 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 06:10:03 +00:00
Mike Aizatsky
c1a030fd64 output_csv libfuzzer option
Summary:
The option outputs statistics in CSV format preceded by 1 header line.
This is intended for machine processing of the output.
-verbosity=0 should likely be set.

Differential Revision: http://reviews.llvm.org/D14600

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252856 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 04:38:40 +00:00
David Blaikie
704f2137a4 dwarfdump: Add error checking to fix the buildbots/correctness
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252845 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 01:57:33 +00:00
David Blaikie
c2e7b3e495 dwarfdump: Add some error handling for DWP index sections of the wrong size
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252843 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 01:41:59 +00:00
David Blaikie
ab8c64ccda dwarfdump: Dump the contents of DWP indexes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252842 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 01:41:52 +00:00
Matthias Braun
ea5575235a LegalizeDAG: Fix and improve FCOPYSIGN/FABS legalization
- Factor out code to query and modify the sign bit of a floatingpoint
  value as an integer. This also works if none of the targets integer
  types is big enough to hold all bits of the floatingpoint value.

- Legalize FABS(x) as FCOPYSIGN(x, 0.0) if FCOPYSIGN is available,
  otherwise perform bit manipulation on the sign bit. The previous code
  used "x >u 0 ? x : -x" which is incorrect for x being -0.0! It also
  takes 34 instructions on ARM Cortex-M4. With this patch we only
  require 5:
    vldr d0, LCPI0_0
    vmov r2, r3, d0
    lsrs r2, r3, #31
    bfi r1, r2, #31, #1
    bx lr
  (This could be further improved if the compiler would recognize that
   r2, r3 is zero).

- Only lower FCOPYSIGN(x, y) = sign(x) ? -FABS(x) : FABS(x) if FABS is
  available otherwise perform bit manipulation on the sign bit.

- Perform the sign(x) test by masking out the sign bit and comparing
  with 0 rather than shifting the sign bit to the highest position and
  testing for "<s 0". For x86 copysignl (on 80bit values) this gets us:
    testl $32768, %eax
  rather than:
    shlq $48, %rax
    sets %al
    testb %al, %al

Differential Revision: http://reviews.llvm.org/D11172

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252839 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 01:02:47 +00:00