Commit Graph

30170 Commits

Author SHA1 Message Date
Yury Gribov
08e5ec43f4 [ASan] New approach to dynamic allocas unpoisoning. Patch by Max Ostapenko!
Differential Revision: http://reviews.llvm.org/D7098


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238402 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 07:51:49 +00:00
David Majnemer
48e2671cb6 [Reassociate] Canonicalizing 'x [+-] (-Constant * y)' isn't always a win
Canonicalizing 'x [+-] (-Constant * y)' is not a win if we don't *know*
we will open up CSE opportunities.

If the multiply was 'nsw', then negating 'y' requires us to clear the
'nsw' flag.  If this is actually worth pursuing, it is probably more
appropriate to do so in GVN or EarlyCSE.

This fixes PR23675.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238397 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 06:16:39 +00:00
Jingyue Wu
4977e92629 [NaryReassociate] Run EarlyCSE after NaryReassociate
Summary:
This patch made two improvements to NaryReassociate and the NVPTX pipeline

1. Run EarlyCSE/GVN after NaryReassociate to get rid of redundant common
expressions.

2. When adding an instruction to SeenExprs, maps both the SCEV before and after
reassociation to that instruction.

Test Plan: updated @reassociate_gep_nsw in nary-gep.ll

Reviewers: meheff, broune

Reviewed By: broune

Subscribers: dberlin, jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9947

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238396 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 04:56:52 +00:00
Chandler Carruth
9dacaea1a1 [x86] Refactor the tests for popcnt.
Extracted from the D6531 patch by Bruno Cardoso Lopes, and re-generated
to reflect the current state of the world. This should let Bruno's D6531
actually show the delta between the approaches by running the x86 test
case update script after re-building.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238391 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 02:40:15 +00:00
Lang Hames
8cc212a07e [RuntimeDyld] Fix MachO i386 SECTDIFF relocation to support non-zero addends.
Previously, relocations of the form 'A - B + C' would fail on i386 when C was
non-zero.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238356 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 20:50:01 +00:00
Diego Novillo
b72f3e0d32 Final fix for PR 23499 and IR test case.
This fixes a bit I forgot in r238335. In addition to the data record and
the counter, we can also move the name of the counter to the comdat for
the associated function.

I'm also adding an IR test case to check that these three elements are
placed in the proper comdat.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238351 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 19:34:01 +00:00
Renato Golin
a052a77187 ARMTargetParser: Normalising build attributes
Now that most of the methods in Clang and LLVM that were parsing arch/cpu/fpu
strings are using ARMTargetParser, it's time to make it a bit more conforming
with what the ABI says.

This commit adds some clarification on what build attributes are accepted and
which are "non-standard". It also makes clear that the "defaultCPU" and
"defaultArch" methods were really just build attribute getters.

It also diverges from GCC's behaviour to say that armv2/armv3 are really an
ARMv4 in the build attributes, when the ABI has a clear state for that: Pre-v4.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238344 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 18:15:37 +00:00
Alex Lorenz
61aecc8c23 Resubmit r237954 (MIR Serialization: print and parse LLVM IR using MIR format).
This commit a 3rd attempt at comitting the initial MIR serialization patch.
The first commit (r237708) was reverted in 237730. Then the second commit
(r237954) was reverted in r238007, as the MIR library under CodeGen caused
a circular dependency where the CodeGen library depended on MIR and MIR
library depended on CodeGen.

This commit has fixed the dependencies between CodeGen and MIR by
reorganizing the MIR serialization code - the code that prints out
MIR has been moved to CodeGen, and the MIR library has been renamed
to MIRParser. Now the CodeGen library doesn't depend on the
MIRParser library, thus the circular dependency no longer exists.

--Original Commit Message--

MIR Serialization: print and parse LLVM IR using MIR format.

This commit is the initial commit for the MIR serialization project.
It creates a new library under CodeGen called 'MIR'. This new
library adds a new machine function pass that prints out the LLVM IR
using the MIR format. This pass is then added as a last pass when a
'stop-after' option is used in llc. The new library adds the initial
functionality for parsing of MIR files as well. This commit also
extends the llc tool so that it can recognize and parse MIR input files.

Reviewers: Duncan P. N. Exon Smith, Matthias Braun, Philip Reames

Differential Revision: http://reviews.llvm.org/D9616 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238341 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 18:02:19 +00:00
Zoran Jovanovic
dbab00a2d4 [mips][microMIPSr6] Implement SEB and SEH instructions
Differential Revision: http://reviews.llvm.org/D9739


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238333 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 15:39:47 +00:00
Jozef Kolek
b8124ac882 [mips][microMIPSr6] Implement BEQZALC, BGEZALC, BGTZALC, BLEZALC, BLTZALC and BNEZALC instructions
This patch implements microMIPS32r6 BEQZALC, BGEZALC, BGTZALC, BLEZALC, BLTZALC
and BNEZALC instructions using mapping.

Differential Revision: http://reviews.llvm.org/D10031


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238325 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 14:19:22 +00:00
Elena Demikhovsky
d56dcc4243 AVX-512: Fixed a bug in extracting subvector from v64i1
By Igor Breger (igor.breger@intel.com)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238322 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 14:09:33 +00:00
Daniel Sanders
3a9cbffdcb Revert r238190 and r238197: [mips] Make TTypeEncoding indirect to allow .eh_frame to be read-only.
This broke the llvm-mips-linux builder and several of our out-of-tree builders.
Initial investigations show that the commit probably isn't the problem but
reverting anyway while I investigate.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238302 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 08:44:01 +00:00
Elena Demikhovsky
078088b790 AVX-512: Implemented all forms of sign-extend and zero-extend instructions for KNL and SKX
Implemented DAG lowering for all these forms.
Added tests for DAG lowering and encoding.

By Igor Breger (igor.breger@intel.com)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238301 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 08:15:19 +00:00
Quentin Colombet
60c91c28e4 [X86] Implement the support for shrink-wrapping.
With this patch the x86 backend is now shrink-wrapping capable
and this functionality can be tested by using the
-enable-shrink-wrap switch.

The next step is to make more test and enable shrink-wrapping by
default for x86.

Related to <rdar://problem/20821487>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238293 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 06:28:41 +00:00
Chandler Carruth
34afa06cf2 [inliner] Fix the early-exit of the inline cost analysis to correctly
model the dense vector instruction bonuses.

Previously, this code really didn't effectively compute the density of
inlined vector instructions and apply the intended inliner bonus. It
would try to compute it repeatedly while analyzing the function and
didn't handle the case where future vector instructions would tip the
scales back towards the bonus.

Instead, speculatively apply all possible bonuses to the threshold
initially. Once we *know* that a certain bonus can not be applied,
subtract it. This should delay early bailout enough to get much more
consistent results without actually causing us to analyze huge swaths of
code. I expect some (hopefully mild) compile time hit here, and some
swings in performance, but this was definitely the intended behavior of
these bonuses.

This also dramatically simplifies the computation of the bonuses to not
interact with each other in confusing ways. The previous code didn't do
a good job of this and the values for bonuses may be surprising but are
at least now clearly written in the code.

Finally, fix code to be in line with comments and use zero as the
bailout condition.

Patch by Easwaran Raman, with some comment tweaks by me to try and
further clarify what is going on with this code.

http://reviews.llvm.org/D8267

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238276 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 02:49:05 +00:00
Filipe Cabecinhas
1c0b496636 [BitcodeReader] Change assert to report_fatal_error
It can be triggered by user input.

Bug found with AFL fuzz.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238272 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 01:05:40 +00:00
Filipe Cabecinhas
316f9e05ce [BitstreamReader] Make sure the Array operand type is an encoding
Bug found with AFL fuzz.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238269 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 00:48:43 +00:00
Filipe Cabecinhas
c756772b8d [BitcodeReader] Make sure abbrev records have at least one operand (record code)
Bug found with AFL fuzz.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238265 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 23:52:21 +00:00
Owen Anderson
13146c7e3b Add initial support for the convergent attribute.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238264 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 23:48:40 +00:00
Filipe Cabecinhas
1c74d4768a [BitcodeReader] Sanity check on Comdat ID
Shouldn't be an assert, since user input can trigger it.

Bug found with AFL fuzz.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238261 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 23:00:56 +00:00
Rafael Espindola
890a876e0e Print "lock \t foo" instead of "lock \n foo".
This gets gas and llc -filetype=obj to agree on the order of prefixes.

For llvm-mc we need to fix the asm parser to know that it makes a difference
on which line the "lock" is in.

Part of pr23594.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238232 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 18:35:10 +00:00
Jan Vesely
176d1faf6a R600: Use SIGN_EXTEND_INREG for SEXT loads
Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>
Reviewed-by: Matt Arsenault <Matthew.Arsenault@amd.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238229 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 18:07:22 +00:00
Diego Novillo
9c24c958f1 Revert "Re-commit changes in r237579 with fix for bug breaking windows builds."
This reverts commit r238201 to fix linking problems in x86 Linux
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150525/278413.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238223 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 17:45:38 +00:00
Matt Arsenault
c068b91ae1 Forgot to add lit.local.cfg for new R600 directory
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238218 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 17:01:16 +00:00
Matt Arsenault
a0dd2b4df8 CodeGenPrepare: Don't match addressing modes through addrspacecast
This was resulting in the addrspacecast being removed and incorrectly
replaced with a ptrtoint when sinking.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238217 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 16:59:43 +00:00
Tom Stellard
8352b74577 R600/SI: Add assembler support for all CI and VI VOP2 instructions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238211 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 15:55:52 +00:00
Luke Cheeseman
262e24f7af Re-commit changes in r237579 with fix for bug breaking windows builds.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238201 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 13:40:31 +00:00
Elena Demikhovsky
55fd78065f AVX-512: fixed a bug in lowering VSELECT for 512-bit vector
https://llvm.org/bugs/show_bug.cgi?id=23634



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238195 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 11:32:39 +00:00
Michael Kuperstein
d714fcf5c8 Use std::bitset for SubtargetFeatures.
Previously, subtarget features were a bitfield with the underlying type being uint64_t. 
Since several targets (X86 and ARM, in particular) have hit or were very close to hitting this bound, switching the features to use a bitset.
No functional change.

The first several times this was committed (e.g. r229831, r233055), it caused several buildbot failures.
Apparently the reason for most failures was both clang and gcc's inability to deal with large numbers (> 10K) of bitset constructor calls in tablegen-generated initializers of instruction info tables. 
This should now be fixed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238192 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 10:47:10 +00:00
Daniel Sanders
bda72d8098 [mips] Make TTypeEncoding indirect to allow .eh_frame to be read-only.
Summary:
Following on from r209907 which made personality encodings indirect, do the
same for TType encodings. This fixes the case where a try/catch block needs
to generate references to, for example, std::exception in the
.gcc_except_table.

This commit uses DW_EH_PE_sdata8 for N64 as far as is possible at the moment.
However, it is possible to end up with DW_EH_PE_sdata4 when a TargetMachine is
not available. There's no risk of issues with inconsistency here since the
tables are self describing but it does mean there is a small chance of the
PC-relative offset being out of range for particularly large programs.

Reviewers: petarj

Reviewed By: petarj

Subscribers: srhines, joerg, tberghammer, llvm-commits

Differential Revision: http://reviews.llvm.org/D9669


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238190 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-26 10:19:18 +00:00
Bjorn Steinbrink
0cb6d37dea Remove conflicting attributes before adding deduced readonly/readnone
Summary:
In case of functions that have a pointer argument and only pass it to
each other, the function attributes pass deduces that the pointer should
get the readnone attribute, but fails to remove a readonly attribute
that may already have been present.

Reviewers: nlewycky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9995

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238152 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-25 19:46:38 +00:00
Davide Italiano
41a6e6a698 [llvm-readobj/ELF] Teach how to decode DF_1_XXX flags
llvm-readobj -dynamic-table output.
Before:
0x000000006FFFFFFB unknown

After:
0x000000006FFFFFFB FLAGS_1 NOW ORIGIN

Differential Revision:	http://reviews.llvm.org/D9958


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238151 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-25 19:12:18 +00:00
Simon Pilgrim
4da23583b6 [X86][AVX2] Vectorized i16 shift operators
Part of D9474, this patch extends AVX2 v16i16 types to 2 x 8i32 vectors and uses i32 shift variable shifts before packing back to i16.

Adds AVX2 tests for v8i16 and v16i16 

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238149 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-25 17:49:13 +00:00
Tom Stellard
38aad1c16a R600/SI: Fix bug with v_interp_p1_f32 instructions on 16 bank lds chips
The src and dst register cannot be the same on chips with 16 lds banks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238147 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-25 16:15:54 +00:00
Kit Barton
948ecae20e This patch adds support for the vector quadword add/sub instructions introduced
in POWER8:

vadduqm
vaddeuqm
vaddcuq
vaddecuq
vsubuqm
vsubeuqm
vsubcuq
vsubecuq
In addition to adding the instructions themselves, it also adds support for the
v1i128 type for intrinsics (Intrinsics.td, Function.cpp, and
IntrinsicEmitter.cpp).

http://reviews.llvm.org/D9081


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238144 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-25 15:49:26 +00:00
Michael Kuperstein
8ffbb68a86 [X86] When pattern-matching scalar FMA3 intrinsics, don't re-arrange the first and second operands.
The semantics of the scalar FMA intrinsics are that the high vector elements are copied from the first source.
The existing pattern switches src1 and src2 around, to match the "213" order, which ends up tying the original src2 to the dest. Since the actual scalar fma3 instructions copy the high elements from the dest register, the wrong values are copied.

This modifies the pattern to leave src1 and src2 in their original order.

Differential Revision: http://reviews.llvm.org/D9908

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238131 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-25 12:35:25 +00:00
Elena Demikhovsky
17b7d6bf25 Added promotion to EXTRACT_SUBVECTOR operand.
I encountered with this case in one of KNL tests for i1 vectors.
v16i1 = EXTRACT_SUBVECTOR v32i1, x



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238130 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-25 11:33:13 +00:00
Duncan P. N. Exon Smith
e3ae958f94 AsmPrinter: Emit the DwarfStringPool offset directly when possible
Change `DwarfStringPool` to calculate byte offsets on-the-fly, and
update `DwarfUnit::getLocalString()` to use a `DIEInteger` instead of a
`DIEDelta` when Dwarf doesn't use relocations (i.e., Mach-O).  This
eliminates another call to `EmitLabelDifference()`, and drops memory
usage from 865 MB down to 861 MB, around 0.5%.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238114 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-24 16:14:59 +00:00
Duncan P. N. Exon Smith
237137532a DebugInfo: Clarify test/DebugInfo/X86/stmt-list-multiple-compile-units.ll
This test was relying on the numbering of preceding .set directives, but
an upcoming commit is going to remove some of them.  Make the CHECKs
more nuanced.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238113 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-24 16:10:35 +00:00
Matt Arsenault
f44ed0919c Add target hook to allow merging stores of nonzero constants
On GPU targets, materializing constants is cheap and stores are
expensive, so only doing this for zero vectors was silly.

Most of the new testcases aren't optimally merged, and are for
later improvements.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238108 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-24 00:51:27 +00:00
Benjamin Kramer
083d79a583 [AArch64] Clean up the ELF streamer a bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238102 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-23 16:39:10 +00:00
Hal Finkel
43a5aa62d4 [PowerPC] Fix fast-isel when compare is split from branch
When the compare feeding a branch was in a different BB from the branch, we'd
try to "regenerate" the compare in the block with the branch, possibly trying
to make use of values not available there. Copy a page from AArch64's play book
here to fix the problem (at least in terms of correctness).

Fixes PR23640.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238097 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-23 12:18:10 +00:00
Akira Hatanaka
01461204b3 Stop resetting NoFramePointerElim in TargetMachine::resetTargetOptions.
This is part of the work to remove TargetMachine::resetTargetOptions.

In this patch, instead of updating global variable NoFramePointerElim in
resetTargetOptions, its use in DisableFramePointerElim is replaced with a call
to TargetFrameLowering::noFramePointerElim. This function determines on a
per-function basis if frame pointer elimination should be disabled.

There is no change in functionality except that cl:opt option "disable-fp-elim"
can now override function attribute "no-frame-pointer-elim". 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238080 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-23 01:14:08 +00:00
Akira Hatanaka
9484f5764c Remove unnecessary command line option "-disable-fp-elim".
This option currently has no effect as function attribute
"no-frame-pointer-elim=false" overrides it.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238077 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-23 00:31:56 +00:00
Rafael Espindola
58bf2827d3 Revert "make reciprocal estimate code generation more flexible by adding command-line options"
This reverts commit r238051.

It broke some bots:

http://lab.llvm.org:8011/builders/llvm-ppc64-linux1/builds/18190

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238075 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-23 00:22:44 +00:00
Philip Reames
4e5aa77b3d Correct a mistaken comment from 238071 [NFC]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238074 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-23 00:05:43 +00:00
Rafael Espindola
7c4f3dcc5e Produce a single string table in a ELF .o
Normally an ELF .o has two string tables, one for symbols, one for section
names.

With the scheme of naming sections like ".text.foo" where foo is a symbol,
there is a big potential saving in using a single one.

Building llvm+clang+lld with master and with this patch the results were:

master:                          193,267,008 bytes
patch:                           186,107,952 bytes
master non unique section names: 183,260,192 bytes
patch non unique section names:  183,118,632 bytes

So using non usique saves 10,006,816 bytes, and the patch saves 7,159,056 while
still using distinct names for the sections.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238073 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 23:58:30 +00:00
Philip Reames
e00c0df2c4 Extend EarlyCSE to handle basic cases from JumpThreading and CVP
This patch extends EarlyCSE to take advantage of the information that a controlling branch gives us about the value of a Value within this and dominated basic blocks. If the current block has a single predecessor with a controlling branch, we can infer what the branch condition must have been to execute this block. The actual change to support this is downright simple because EarlyCSE's existing scoped hash table logic deals with most of the complexity around merging.

The patch actually implements two optimizations.
1) The first is analogous to JumpThreading in that it enables EarlyCSE's CSE handling to fold branches which are exactly redundant due to a previous branch to branches on constants. (It doesn't actually replace the branch or change the CFG.) This is pretty clearly a win since it enables substantial CFG simplification before we start trying to inline.
2) The second is analogous to CVP in that it exploits the knowledge gained to replace dominated *uses* of the original value. EarlyCSE does not otherwise reason about specific uses, so this is the more arguable one. It does enable further simplication and constant folding within the rest of the visit by EarlyCSE.

In both cases, the added code only handles the easy dominance based case of each optimization. The general case is deferred to the existing passes.

Differential Revision: http://reviews.llvm.org/D9763



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238071 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 23:53:24 +00:00
David Majnemer
12baade498 [InstCombine] Don't eagerly propagate nsw for A*B+A*C => A*(B+C)
InstCombine transforms A *nsw B +nsw A *nsw C to A *nsw (B + C).
This is incorrect -- e.g. if A = -1, B = 1, C = INT_SMAX. Then
nothing in the LHS overflows, but the multiplication in RHS overflows.

We need to first make sure that we won't multiple by INT_SMAX + 1.

Test case `add_of_mul` contributed by Sanjoy Das.

This fixes PR23635.

Differential Revision: http://reviews.llvm.org/D9629

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238066 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 23:02:11 +00:00
Ahmed Bougacha
d8319655f2 [AArch64][CGP] Sink zext feeding stxr/stlxr into the same block.
The usual CodeGenPrepare trickery, on a target-specific intrinsic.
Without this, the expansion of atomics will usually have the zext
be hoisted out of the loop, defeating the various patterns we have
to catch this precise case.

Differential Revision: http://reviews.llvm.org/D9930


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238054 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 21:37:17 +00:00