Commit Graph

2327 Commits

Author SHA1 Message Date
Wan Xiaofei
887f9c5ec1 Quick look-up for block in loop.
This patch implements quick look-up for block in loop by maintaining a hash set for blocks.
It improves the efficiency of loop analysis a lot, the biggest improvement could be 5-6%(458.sjeng).
Below are the compilation time for our benchmark in llc before & after the patch.

Benchmark	llc - trunk		llc - patched	
401.bzip2	0.339081	100.00%	0.329657	102.86%
403.gcc		19.853966	100.00%	19.605466	101.27%
429.mcf		0.049823	100.00%	0.048451	102.83%
433.milc	0.514898	100.00%	0.510217	100.92%
444.namd	1.109328	100.00%	1.103481	100.53%
445.gobmk	4.988028	100.00%	4.929114	101.20%
456.hmmer	0.843871	100.00%	0.825865	102.18%
458.sjeng	0.754238	100.00%	0.714095	105.62%
464.h264ref	2.9668		100.00%	2.90612		102.09%
471.omnetpp	4.556533	100.00%	4.511886	100.99%
bitmnp01	0.038168	100.00%	0.0357		106.91%
idctrn01	0.037745	100.00%	0.037332	101.11%
libquake2	3.78689		100.00%	3.76209		100.66%
libquake_	2.251525	100.00%	2.234104	100.78%
linpack		0.033159	100.00%	0.032788	101.13%
matrix01	0.045319	100.00%	0.043497	104.19%
nbench		0.333161	100.00%	0.329799	101.02%
tblook01	0.017863	100.00%	0.017666	101.12%
ttsprk01	0.054337	100.00%	0.053057	102.41%

Reviewer	: Andrew Trick <atrick@apple.com>, Hal Finkel <hfinkel@anl.gov>
Approver	: Andrew Trick <atrick@apple.com>
Test		: Pass make check-all & llvm test-suite


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193460 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-26 03:08:02 +00:00
Rafael Espindola
0f978ea459 Handle calls and invokes in GlobalStatus.
This patch teaches GlobalStatus to analyze a call that uses the global value as
a callee, not as an argument.

With this change internalize call handle the common use of linkonce_odr
functions. This reduces the number of linkonce_odr functions in a LTO build of
clang (checked with the emit-llvm gold plugin option) from 1730 to 60.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193436 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-25 21:29:52 +00:00
Tom Stellard
4a6b6eea2d Inliner: Handle readonly attribute per argument when adding memcpy
Patch by: Vincent Lejeune

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193356 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-24 16:38:33 +00:00
Tom Stellard
f2089e1dd8 SimplifyCFG: Don't duplicate calls to functions marked noduplicate v2
v2:
  - Use CI->cannotDuplicate()

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193115 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-21 20:07:30 +00:00
Matt Arsenault
79de3d7b3a Teach SimplifyCFG about address spaces
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193104 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-21 18:55:08 +00:00
Rafael Espindola
713cab059e Optimize more linkonce_odr values during LTO.
When a linkonce_odr value that is on the dso list is not unnamed_addr
we can still look to see if anything is actually using its address. If
not, it is safe to hide it.

This patch implements that by moving GlobalStatus to Transforms/Utils
and using it in Internalize.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193090 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-21 17:14:55 +00:00
Michael Gottesman
6701bb7283 Fix the predecessor removal logic in r193045.
Additionally some small comment/stylistic fixes are included as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193068 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-21 05:20:11 +00:00
Bill Wendling
3e033f2923 Don't eliminate a partially redundant load if it's in a landing pad.
A landing pad can be jumped to only by the unwind edge of an invoke
instruction. If we eliminate a partially redundant load in a landing pad, it
will create a basic block that violates this constraint. It then leads to other
problems down the line if it tries to merge that basic block with the landing
pad. Avoid this by not eliminating the load in a landing pad.

PR17621


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193064 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-21 04:09:17 +00:00
Michael Gottesman
0b5fad68b2 Teach simplify-cfg how to correctly create covered lookup tables for switches on iN with N >= 3.
One optimization simplify-cfg performs is the converting of switches to
lookup tables if the switch has > 4 cases. This is done by:

1. Finding the max/min case value and calculating the switch case range.
2. Create a lookup table basic block.
3. Perform a check in the switch's BB to see if the input value is in
the switch's case range. If the input value satisfies said predicate
branch to the lookup table BB, otherwise branch to the switch's default
destination BB using the default value as the result.

The conditional check consists of subtracting the min case value of the
table from any input iN value and then ensuring that said value is
unsigned less than the size of the lookup table represented as an iN
value.

If the lookup table is a covered lookup table, the size of the table will be N
which is 0 as an iN value. Thus the comparison will be an `icmp ult` of an iN
value against 0 which is always false yielding the incorrect result.

This patch fixes this problem by recognizing if we have a covered lookup table
and if we do, unconditionally jumps to the lookup table BB since the covering
property of the lookup table implies no input values could not be handled by
said BB.

rdar://15268442

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193045 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-20 07:04:37 +00:00
Bill Wendling
d5b7f2b62c Perform an intelligent splice of the predecessor with the single successor.
If the predecessor's being spliced into a landing pad, then we need the PHIs to
come first and the rest of the predecessor's code to come *after* the landing
pad instruction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193035 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-19 11:27:12 +00:00
Chris Lattner
2a6cbba2db Basic blocks typically have few predecessors. Use a SmallDenseMap to
avoid a heap allocation when this is the case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192602 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-14 16:05:55 +00:00
Hal Finkel
fc3b7bbf49 UpdatePHINodes in BasicBlockUtils should not crash on duplicate predecessors
UpdatePHINodes has an optimization to reuse an existing PHI node, where it
first deletes all of its entries and then replaces them. Unfortunately, in the
case where we had duplicate predecessors (which are allowed so long as the
associated PHI entries have the same value), the loop removing the existing PHI
entries from the to-be-reused PHI would assert (if that PHI was not the one
which had the duplicates).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192001 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-04 23:41:05 +00:00
Chandler Carruth
dd5d86d992 Remove the very substantial, largely unmaintained legacy PGO
infrastructure.

This was essentially work toward PGO based on a design that had several
flaws, partially dating from a time when LLVM had a different
architecture, and with an effort to modernize it abandoned without being
completed. Since then, it has bitrotted for several years further. The
result is nearly unusable, and isn't helping any of the modern PGO
efforts. Instead, it is getting in the way, adding confusion about PGO
in LLVM and distracting everyone with maintenance on essentially dead
code. Removing it paves the way for modern efforts around PGO.

Among other effects, this removes the last of the runtime libraries from
LLVM. Those are being developed in the separate 'compiler-rt' project
now, with somewhat different licensing specifically more approriate for
runtimes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191835 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-02 15:42:23 +00:00
Rafael Espindola
8819c84aed Remove several unused variables.
Patch by Alp Toker.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191757 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 13:32:03 +00:00
Benjamin Kramer
d427882166 Convert manual insert point restores to the new RAII object.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191675 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-30 15:40:17 +00:00
Robert Wilhelm
f80a63fa23 Fix spelling intruction -> instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191610 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-28 11:46:15 +00:00
Benjamin Kramer
d721520e4c Push analysis passes to InstSimplify when they're around anyways.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191309 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-24 16:37:40 +00:00
Benjamin Kramer
0d293e45b6 Provide basic type safety for array_pod_sort comparators.
This makes using array_pod_sort significantly safer. The implementation relies
on function pointer casting but that should be safe as we're dealing with void*
here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191175 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-22 14:09:50 +00:00
Benjamin Kramer
94ee55d4b3 Replace some unnecessary vector copies with references.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190770 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-15 22:04:42 +00:00
Robert Wilhelm
4873c157f3 Fix spelling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190750 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-14 09:34:59 +00:00
Matt Arsenault
ffdee89a3c Use StringRef::npos for StringRef instead of std::string one
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190375 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-10 00:41:53 +00:00
Bob Wilson
db3a9e64f8 Revert patches to add case-range support for PR1255.
The work on this project was left in an unfinished and inconsistent state.
Hopefully someone will eventually get a chance to implement this feature, but
in the meantime, it is better to put things back the way the were.  I have
left support in the bitcode reader to handle the case-range bitcode format,
so that we do not lose bitcode compatibility with the llvm 3.3 release.

This reverts the following commits: 155464, 156374, 156377, 156613, 156704,
156757, 156804 156808, 156985, 157046, 157112, 157183, 157315, 157384, 157575,
157576, 157586, 157612, 157810, 157814, 157815, 157880, 157881, 157882, 157884,
157887, 157901, 158979, 157987, 157989, 158986, 158997, 159076, 159101, 159100,
159200, 159201, 159207, 159527, 159532, 159540, 159583, 159618, 159658, 159659,
159660, 159661, 159703, 159704, 160076, 167356, 172025, 186736

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190328 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-09 19:14:35 +00:00
Matt Arsenault
4598bd53ab Use type helper functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190113 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-06 00:37:24 +00:00
Benjamin Kramer
bc870037f6 SimplifyLibCalls: When emitting an overloaded fp function check that it's available.
The existing code missed some edge cases when e.g. we're going to emit sqrtf but
only the availability of sqrt was checked. This happens on odd platforms like
windows.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189724 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-31 18:19:35 +00:00
Benjamin Kramer
0b6962f4be Add a function object to compare the first or second component of a std::pair.
Replace instances of this scattered around the code base.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189169 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-24 12:54:27 +00:00
Yunzhong Gao
dfdf7f44a9 No functionality change.
Replace "(255 & value)" with "(0xFF & value)" to improve clarity.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188941 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-21 22:11:15 +00:00
Peter Collingbourne
2b762cc75d Introduce SpecialCaseList::isIn overload for GlobalAliases.
Differential Revision: http://llvm-reviews.chandlerc.com/D1437

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188688 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-19 19:00:35 +00:00
Michael Kuperstein
2063637fa7 Adds missing TLI check for library simplification of
* pow(x, 0.5) -> fabs(sqrt(x)) 
* pow(2.0, x) -> exp2(x)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188656 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-19 06:55:47 +00:00
Peter Collingbourne
353149ea2f Remove SpecialCaseList::findCategory.
It turned out that I didn't need this for DFSan.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188646 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-19 00:24:20 +00:00
Yunzhong Gao
b187b69170 Fixing a corner-case bug in strchr and strrchr lib call optimizations where
the input character is not converted to char before comparing with zero.

The patch was discussed in this thread:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130812/184069.html



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188489 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-15 20:58:59 +00:00
Mark Lacey
1b6e10f53b Fix small typo: s/succ/Succ/
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188415 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-14 22:11:42 +00:00
Chandler Carruth
79663c1910 Fix a really terrifying but improbable bug in mem2reg. If you have seen
extremely subtle miscompilations (such as a load getting replaced with
the value stored *below* the load within a basic block) related to
promoting an alloca to an SSA value, there is the dim possibility that
you hit this. Please let me know if you won this unfortunate lottery.

The first half of mem2reg's core logic (as it is used both in the
standalone mem2reg pass and in SROA) builds up a mapping from
'Instruction *' to the index of that instruction within its basic block.
This allows quickly establishing which store dominate a particular load
even for large basic blocks. We cache this information throughout the
run of mem2reg over a function in order to amortize the cost of
computing it.

This is not in and of itself a strange pattern in LLVM. However, it
introduces a very important constraint: absolutely no instruction can be
deleted from the program without updating the mapping. Otherwise a newly
allocated instruction might get the same pointer address, and then end
up with a wrong index. Yes, LLVM routinely suffers from a *single
threaded* variant of the ABA problem. Most places in LLVM don't find
avoiding this an imposition because they don't both delete and create
new instructions iteratively, but mem2reg *loves* to do this... All the
time. Fortunately, the mem2reg code was really careful about updating
this cache to handle this eventuallity... except when it comes to the
debug declare intrinsic. Oops. The fix is to invalidate that pointer in
the cache when we delete it, the same as we do when deleting alloca
instructions and other instructions.

I've also caused the same bug in new code while working on a fix to
PR16867, so this seems to be a really unfortunate pattern. Hopefully in
subsequent patches the deletion of dead instructions can be consolidated
sufficiently to make it less likely that we'll see future occurences of
this bug.

Sorry for not having a test case, but I have literally no idea how to
reliably trigger this kind of thing. It may be single-threaded, but it
remains an ABA problem. It would require a really amazing number of
stars to align.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188367 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-14 08:56:41 +00:00
Nick Lewycky
6c1fa7caae Revert r187191, which broke opt -mem2reg on the testcases included in PR16867.
However, opt -O2 doesn't run mem2reg directly so nobody noticed until r188146
when SROA started sending more things directly down the PromoteMemToReg path.

In order to revert r187191, I also revert dependent revisions r187296, r187322
and r188146. Fixes PR16867. Does not add the testcases from that PR, but both
of them should get added for both mem2reg and sroa when this revert gets
unreverted.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188327 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-13 22:51:58 +00:00
Peter Collingbourne
4f96b7e147 Reapply r188119 now that the bug it exposed is fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188217 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-12 22:38:43 +00:00
Alexey Samsonov
655abf57ed Remove unused SpecialCaseList constructors
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188171 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-12 11:50:44 +00:00
Alexey Samsonov
e39e1316f0 Add SpecialCaseList::createOrDie() factory and use it in sanitizer passes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188169 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-12 11:46:09 +00:00
Alexey Samsonov
d976d43f23 Introduce factory methods for SpecialCaseList
Summary:
Doing work in constructors is bad: this change suggests to
call SpecialCaseList::create(Path, Error) instead of
"new SpecialCaseList(Path)". Currently the latter may crash with
report_fatal_error, which is undesirable - sometimes we want to report
the error to user gracefully - for example, if he provides an incorrect
file as an argument of Clang's -fsanitize-blacklist flag.

Reviewers: pcc

Reviewed By: pcc

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1327

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188156 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-12 07:49:36 +00:00
Arnold Schwaighofer
5cf14916c3 Revert r188119 "Kill some duplicated code for removing unreachable BBs."
It is breaking builbots with libgmalloc enabled on Mac OS X.

$ cd llvm ; mkdir release ; cd release
$ ../configure --enable-optimized —prefix=$PWD/install
$ make
$ make check
$ Release+Asserts/bin/llvm-lit -v --param use_gmalloc=1 --param \
  gmalloc_path=/usr/lib/libgmalloc.dylib \
  ../test/Instrumentation/DataFlowSanitizer/args-unreachable-bb.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188142 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-10 20:16:06 +00:00
Peter Collingbourne
835738ce54 Kill some duplicated code for removing unreachable BBs.
This moves removeUnreachableBlocksFromFn from SimplifyCFGPass.cpp
to Utils/Local.cpp and uses it to replace the implementation of
llvm::removeUnreachableBlocks, which appears to do a strict subset
of what removeUnreachableBlocksFromFn does.

Differential Revision: http://llvm-reviews.chandlerc.com/D1334

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188119 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-09 22:47:24 +00:00
Serge Pavlov
900cbf5545 Unbreak Debug build on Windows
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187786 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-06 08:44:18 +00:00
Tom Stellard
01d7203ef8 Factor FlattenCFG out from SimplifyCFG
Patch by: Mei Ye

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187764 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-06 02:43:45 +00:00
Peter Collingbourne
acf4cf7757 Introduce an optimisation for special case lists with large numbers of literal entries.
Our internal regex implementation does not cope with large numbers
of anchors very efficiently.  Given a ~3600-entry special case list,
regex compilation can take on the order of seconds.  This patch solves
the problem for the special case of patterns matching literal global
names (i.e. patterns with no regex metacharacters).  Rather than
forming regexes from literal global name patterns, add them to
a StringSet which is checked before matching against the regex.
This reduces regex compilation time by an order of roughly thousands
when reading the aforementioned special case list, according to a
completely unscientific study.

No test cases.  I figure that any new tests for this code should
check that regex metacharacters are properly recognised.  However,
I could not find any documentation which documents the fact that the
syntax of global names in special case lists is based on regexes.
The extent to which regex syntax is supported in special case lists
should probably be decided on/documented before writing tests.

Differential Revision: http://llvm-reviews.chandlerc.com/D1150

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187732 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-05 17:48:04 +00:00
Alexey Samsonov
e393b73808 Fix dereferencing end iterator in SimplifyCFG. Patch by Ye Mei.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187646 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-02 08:06:43 +00:00
Matt Arsenault
186f8f9d41 Teach getOrEnforceKnownAlignment about address spaces
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187629 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-01 22:42:18 +00:00
Rafael Espindola
15658b2908 Fix -Wdocumentation warnings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187336 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-28 23:43:28 +00:00
Chandler Carruth
064a68682d Update comments for SSAUpdater to use the modern doxygen comment
standards for LLVM. Remove duplicated comments on the interface from the
implementation file (implementation comments are left there of course).
Also clean up, re-word, and fix a few typos and errors in the commenst
spotted along the way.

This is in preparation for changes to these files and to keep the
uninteresting tidying in a separate commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187335 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-28 22:00:33 +00:00
Chandler Carruth
6c3a95dab5 Thread DataLayout through the callers and into mem2reg. This will be
useful in a subsequent patch, but causes an unfortunate amount of noise,
so I pulled it out into a separate patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187322 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-28 06:43:11 +00:00
Chandler Carruth
33ae899113 Merge the removal of dead instructions and lifetime markers with the
analysis of the alloca. We don't need to visit all the users twice for
this. We build up a kill list during the analysis and then just process
it afterward. This recovers the tiny bit of performance lost by moving
to the visitor based analysis system as it removes one entire use-list
walk from mem2reg. In some cases, this is now faster than mem2reg was
previously.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187296 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-27 09:43:30 +00:00
Nick Lewycky
81e480463d Reimplement isPotentiallyReachable to make nocapture deduction much stronger.
Adds unit tests for it too.

Split BasicBlockUtils into an analysis-half and a transforms-half, and put the
analysis bits into a new Analysis/CFG.{h,cpp}. Promote isPotentiallyReachable
into llvm::isPotentiallyReachable and move it into Analysis/CFG.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187283 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-27 01:24:00 +00:00
Tom Stellard
57e6b2d1f3 SimplifyCFG: Use parallel-and and parallel-or mode to consolidate branch conditions
Merge consecutive if-regions if they contain identical statements.
Both transformations reduce number of branches.  The transformation
is guarded by a target-hook, and is currently enabled only for +R600,
but the correctness has been tested on X86 target using a variety of
CPU benchmarks.

Patch by: Mei Ye

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187278 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-27 00:01:07 +00:00