Commit Graph

918 Commits

Author SHA1 Message Date
Alexey Samsonov
f50e395308 Remove sanitizer blacklist from ASan/TSan/MSan function passes.
Instrumentation passes now use attributes
address_safety/thread_safety/memory_safety which are added by Clang frontend.
Clang parses the blacklist file and adds the attributes accordingly.

Currently blacklist is still used in ASan module pass to disable instrumentation
for certain global variables. We should fix this as well by collecting the
set of globals we're going to instrument in Clang and passing it to ASan
in metadata (as we already do for dynamically-initialized globals and init-order
checking).

This change also removes -tsan-blacklist and -msan-blacklist LLVM commandline
flags in favor of -fsanitize-blacklist= Clang flag.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210038 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-02 18:08:27 +00:00
Karthik Bhat
8ffc96a163 Allow vectorization of intrinsics such as powi,cttz and ctlz in Loop and SLP Vectorizer.
This patch adds support to vectorize intrinsics such as powi, cttz and ctlz in Vectorizer. These intrinsics are different from other
intrinsics as second argument to these function must be same in order to vectorize them and it should be represented as a scalar.
Review: http://reviews.llvm.org/D3851#inline-32769 and http://reviews.llvm.org/D3937#inline-32857


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209873 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-30 04:31:24 +00:00
Michael J. Spencer
ed0e90576d [LoadCombine] Missed a file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209792 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-29 02:05:37 +00:00
Michael J. Spencer
8bfb46e790 Add LoadCombine pass.
This pass is disabled by default. Use -combine-loads to enable in -O[1-3]

Differential revision: http://reviews.llvm.org/D3580

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209791 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-29 01:55:07 +00:00
Owen Anderson
866ed7f63f Make the LoopRotate pass's maximum header size configurable both programmatically
and via the command line, mirroring similar functionality in LoopUnroll.  In
situations where clients used custom unrolling thresholds, their intent could
previously be foiled by LoopRotate having a hardcoded threshold.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209617 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-26 08:58:51 +00:00
NAKAMURA Takumi
a1b1165f30 Reformat linefeeds.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209609 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-26 00:25:26 +00:00
NAKAMURA Takumi
a9b0742276 Trailing whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209608 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-26 00:25:09 +00:00
Peter Collingbourne
62692b442a Add an extension point for peephole optimizers.
This extension point allows adding passes that perform peephole optimizations
similar to the instruction combiner. These passes will be inserted after
each instance of the instruction combiner pass.

Differential Revision: http://reviews.llvm.org/D3905

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209595 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-25 10:27:02 +00:00
Benjamin Kramer
29e068bac0 Flip on vectorization of bswap intrinsics.
The cost model conservatively assumes that it will always get scalarized and
that's about as good as we can get with the generic TTI; reasoning whether a
shuffle with an efficient lowering is available is hard. We can override that
conservative estimate for some targets in the future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209125 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-19 13:48:08 +00:00
NAKAMURA Takumi
6f1b92a0d4 Reformat blank lines.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209106 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-19 04:43:26 +00:00
NAKAMURA Takumi
14c7036563 Whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209105 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-19 04:43:03 +00:00
Richard Smith
c51c340989 [modules] Add missing #include.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208276 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-08 02:34:32 +00:00
Richard Smith
36ecb2ee9d Re-commit r208025, reverted in r208030, with a fix for a conformance issue
which GCC detects and Clang does not!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208033 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-06 01:44:26 +00:00
Richard Smith
f3a199b2ae Revert r208025, which made buildbots unhappy for unknown reasons.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208030 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-06 01:26:00 +00:00
Richard Smith
245e8bdfba Add llvm::function_ref (and a couple of uses of it), representing a type-erased reference to a callable object.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208025 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-06 01:01:29 +00:00
Karthik Bhat
486ad6262e Vectorize intrinsic math function calls in SLPVectorizer.
This patch adds support to recognize and vectorize intrinsic math functions in SLPVectorizer.
Review: http://reviews.llvm.org/D3560 and http://reviews.llvm.org/D3559


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207901 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-03 09:59:54 +00:00
Nico Weber
3a5b1043d0 Teach GlobalDCE how to remove empty global_ctor entries.
This moves most of GlobalOpt's constructor optimization
code out of GlobalOpt into Transforms/Utils/CDtorUtils.{h,cpp}. The
public interface is a single function OptimizeGlobalCtorsList() that
takes a predicate returning which constructors to remove.

GlobalOpt calls this with a function that statically evaluates all
constructors, just like it did before. This part of the change is
behavior-preserving.

Also add a call to this from GlobalDCE with a filter that removes global
constructors that contain a "ret" instruction and nothing else – this
fixes PR19590.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207856 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-02 18:35:25 +00:00
Eli Bendersky
167a57ca45 Add an optimization that does CSE in a group of similar GEPs.
This optimization merges the common part of a group of GEPs, so we can compute
each pointer address by adding a simple offset to the common part.

The optimization is currently only enabled for the NVPTX backend, where it has
a large payoff on some benchmarks.

Review: http://reviews.llvm.org/D3462

Patch by Jingyue Wu.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207783 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-01 18:38:36 +00:00
Craig Topper
8d7221ccf5 [C++] Use 'nullptr'. Transforms edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207196 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 05:29:35 +00:00
Karthik Bhat
ac16f0e024 Allow vectorization of bit intrinsics in BB Vectorizer.
This patch adds support for vectorization of  bit intrinsics such as bswap,ctpop,ctlz,cttz.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207174 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 03:33:48 +00:00
Chandler Carruth
283b399377 [Modules] Make Support/Debug.h modular. This requires it to not change
behavior based on other files defining DEBUG_TYPE, which means it cannot
define DEBUG_TYPE at all. This is actually better IMO as it forces folks
to define relevant DEBUG_TYPEs for their files. However, it requires all
files that currently use DEBUG(...) to define a DEBUG_TYPE if they don't
already. I've updated all such files in LLVM and will do the same for
other upstream projects.

This still leaves one important change in how LLVM uses the DEBUG_TYPE
macro going forward: we need to only define the macro *after* header
files have been #include-ed. Previously, this wasn't possible because
Debug.h required the macro to be pre-defined. This commit removes that.
By defining DEBUG_TYPE after the includes two things are fixed:

- Header files that need to provide a DEBUG_TYPE for some inline code
  can do so by defining the macro before their inline code and undef-ing
  it afterward so the macro does not escape.

- We no longer have rampant ODR violations due to including headers with
  different DEBUG_TYPE definitions. This may be mostly an academic
  violation today, but with modules these types of violations are easy
  to check for and potentially very relevant.

Where necessary to suppor headers with DEBUG_TYPE, I have moved the
definitions below the includes in this commit. I plan to move the rest
of the DEBUG_TYPE macros in LLVM in subsequent commits; this one is big
enough.

The comments in Debug.h, which were hilariously out of date already,
have been updated to reflect the recommended practice going forward.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206822 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 22:55:11 +00:00
Richard Smith
f4a2635c25 Add missing #include found by modules build.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206726 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-20 23:39:19 +00:00
Duncan P. N. Exon Smith
bf1d0f417e PMBuilder: Expose an option to disable tail calls
Adds API to allow frontends to disable tail calls in PassManagerBuilder.

<rdar://problem/16050591>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206542 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-18 01:05:15 +00:00
Craig Topper
0b6cb7104b [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206252 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 06:32:26 +00:00
Craig Topper
4ba844388c [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206142 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-14 00:51:57 +00:00
Arnold Schwaighofer
b0ee2374ce SLPVectorizer: Only vectorize intrinsics whose operands are widened equally
The vectorizer only knows how to vectorize intrinics by widening all operands by
the same factor.

Patch by Tyler Nowicki!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205855 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-09 14:20:47 +00:00
Duncan P. N. Exon Smith
3845c071a7 Revert "Reapply "LTO: add API to set strategy for -internalize""
This reverts commit r199244.

Conflicts:
	include/llvm-c/lto.h
	include/llvm/LTO/LTOCodeGenerator.h
	lib/LTO/LTOCodeGenerator.cpp

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205471 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-02 22:05:57 +00:00
Hal Finkel
6bbb01bbf8 Move partial/runtime unrolling late in the pipeline
The generic (concatenation) loop unroller is currently placed early in the
standard optimization pipeline. This is a good place to perform full unrolling,
but not the right place to perform partial/runtime unrolling. However, most
targets don't enable partial/runtime unrolling, so this never mattered.

However, even some x86 cores benefit from partial/runtime unrolling of very
small loops, and follow-up commits will enable this. First, we need to move
partial/runtime unrolling late in the optimization pipeline (importantly, this
is after SLP and loop vectorization, as vectorization can drastically change
the size of a loop), while keeping the full unrolling where it is now. This
change does just that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205264 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-31 23:23:51 +00:00
Mark Seaborn
9bb9615e1f Remove LowerInvoke's obsolete "-enable-correct-eh-support" option
This option caused LowerInvoke to generate code using SJLJ-based
exception handling, but there is no code left that interprets the
jmp_buf stack that the resulting code maintained (llvm.sjljeh.jblist).
This option has been obsolete for a while, and replaced by
SjLjEHPrepare.

This leaves the default behaviour of LowerInvoke, which is to convert
invokes to calls.

Differential Revision: http://llvm-reviews.chandlerc.com/D3136

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204388 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-20 19:54:47 +00:00
Evgeniy Stepanov
610469f4c2 [msan] Origin tracking with history.
LLVM part of MSan implementation of advanced origin tracking,
when we record not only creation point, but all locations where
an uninitialized value was stored to memory, too.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204151 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-18 13:30:56 +00:00
NAKAMURA Takumi
7f0871c97f Untabify.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204020 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-16 23:58:43 +00:00
Eli Bendersky
ce306f9f99 Move duplicated code into a helper function (exposed through overload).
There's a bit of duplicated "magic" code in opt.cpp and Clang's CodeGen that
computes the inliner threshold from opt level and size opt level.

This patch moves the code to a function that lives alongside the inliner itself,
providing a convenient overload to the inliner creation.

A separate patch can be committed to Clang to use this once it's committed to
LLVM. Standalone tools that use the inlining pass can also avoid duplicating
this code and fearing it will go out of sync.

Note: this patch also restructures the conditinal logic of the computation to
be cleaner.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203669 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-12 16:12:36 +00:00
Alon Mishne
e74c0bf111 Cloning a function now also clones its debug metadata if 'ModuleLevelChanges' is true.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203662 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-12 14:42:51 +00:00
Craig Topper
7b62be28cb [C++11] Add 'override' keyword to virtual methods that override their base class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202953 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-05 09:10:37 +00:00
Chandler Carruth
03e36d752c [Modules] Move CFG.h to the IR library as it defines graph traits over
IR types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202827 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 11:45:46 +00:00
Chandler Carruth
7225e27b4c [Modules] Move ValueMap to the IR library. While this class does not
directly care about the Value class (it is templated so that the key can
be any arbitrary Value subclass), it is in fact concretely tied to the
Value class through the ValueHandle's CallbackVH interface which relies
on the key type being some Value subclass to establish the value handle
chain.

Ironically, the unittest is already in the right library.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202824 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 11:26:31 +00:00
Chandler Carruth
eb3d76da81 [Modules] Move ValueHandle into the IR library where Value itself lives.
Move the test for this class into the IR unittests as well.

This uncovers that ValueMap too is in the IR library. Ironically, the
unittest for ValueMap is useless in the Support library (honestly, so
was the ValueHandle test) and so it already lives in the IR unittests.
Mmmm, tasty layering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202821 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 11:17:44 +00:00
Chandler Carruth
bd7cba0d81 [Modules] Move GetElementPtrTypeIterator into the IR library. As its
name might indicate, it is an iterator over the types in an instruction
in the IR.... You see where this is going.

Another step of modularizing the support library.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202815 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 10:40:04 +00:00
Diego Novillo
f05b45fdb2 Pass to emit DWARF path discriminators.
DWARF discriminators are used to distinguish multiple control flow paths
on the same source location. When this happens, instructions across
basic block boundaries will share the same debug location.

This pass detects this situation and creates a new lexical scope to one
of the two instructions. This lexical scope is a child scope of the
original and contains a new discriminator value. This discriminator is
then picked up from MCObjectStreamer::EmitDwarfLocDirective to be
written on the object file.

This fixes http://llvm.org/bugs/show_bug.cgi?id=18270.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202752 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-03 20:06:11 +00:00
Quentin Colombet
8048c44580 [CodeGenPrepare] Move CodeGenPrepare into lib/CodeGen.
CodeGenPrepare uses extensively TargetLowering which is part of libLLVMCodeGen.
This is a layer violation which would introduce eventually a dependence on
CodeGen in ScalarOpts.

Move CodeGenPrepare into libLLVMCodeGen to avoid that.

Follow-up of <rdar://problem/15519855>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201912 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-22 00:07:45 +00:00
Rafael Espindola
39d8dcb53b Rename some member variables from TD to DL.
TargetData was renamed DataLayout back in r165242.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201581 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-18 15:33:12 +00:00
Stephen Hines
d60c43b4f3 Don't build DFSan functionality for Android.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201362 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-13 21:21:09 +00:00
Chandler Carruth
5ea4a54551 [LPM] Fix PR18616 where the shifts to the loop pass manager to extract
LCSSA from it caused a crasher with the LoopUnroll pass.

This crasher is really nasty. We destroy LCSSA form in a suprising way.
When unrolling a loop into an outer loop, we not only need to restore
LCSSA form for the outer loop, but for all children of the outer loop.
This is somewhat obvious in retrospect, but hey!

While this seems pretty heavy-handed, it's not that bad. Fundamentally,
we only do this when we unroll a loop, which is already a heavyweight
operation. We're unrolling all of these hypothetical inner loops as
well, so their size and complexity is already on the critical path. This
is just adding another pass over them to re-canonicalize.

I have a test case from PR18616 that is great for reproducing this, but
pretty useless to check in as it relies on many 10s of nested empty
loops that get unrolled and deleted in just the right order. =/ What's
worse is that investigating this has exposed another source of failure
that is likely to be even harder to test. I'll try to come up with test
cases for these fixes, but I want to get the fixes into the tree first
as they're causing crashes in the wild.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200273 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-28 01:25:38 +00:00
Chandler Carruth
3d69cf57e1 [LPM] Make LCSSA a utility with a FunctionPass that applies it to all
the loops in a function, and teach LICM to work in the presance of
LCSSA.

Previously, LCSSA was a loop pass. That made passes requiring it also be
loop passes and unable to depend on function analysis passes easily. It
also caused outer loops to have a different "canonical" form from inner
loops during analysis. Instead, we go into LCSSA form and preserve it
through the loop pass manager run.

Note that this has the same problem as LoopSimplify that prevents
enabling its verification -- loop passes which run at the end of the loop
pass manager and don't preserve these are valid, but the subsequent loop
pass runs of outer loops that do preserve this pass trigger too much
verification and fail because the inner loop no longer verifies.

The other problem this exposed is that LICM was completely unable to
handle LCSSA form. It didn't preserve it and it actually would give up
on moving instructions in many cases when they were used by an LCSSA phi
node. I've taught LICM to support detecting LCSSA-form PHI nodes and to
hoist and sink around them. This may actually let LICM fire
significantly more because we put everything into LCSSA form to rotate
the loop before running LICM. =/ Now LICM should handle that fine and
preserve it correctly. The down side is that LICM has to require LCSSA
in order to preserve it. This is just a fact of life for LCSSA. It's
entirely possible we should completely remove LCSSA from the optimizer.

The test updates are essentially accomodating LCSSA phi nodes in the
output of LICM, and the fact that we now completely sink every
instruction in ashr-crash below the loop bodies prior to unrolling.

With this change, LCSSA is computed only three times in the pass
pipeline. One of them could be removed (and potentially a SCEV run and
a separate LoopPassManager entirely!) if we had a LoopPass variant of
InstCombine that ran InstCombine on the loop body but refused to combine
away LCSSA PHI nodes. Currently, this also prevents loop unrolling from
being in the same loop pass manager is rotate, LICM, and unswitch.

There is one thing that I *really* don't like -- preserving LCSSA in
LICM is quite expensive. We end up having to re-run LCSSA twice for some
loops after LICM runs because LICM can undo LCSSA both in the current
loop and the parent loop. I don't really see good solutions to this
other than to completely move away from LCSSA and using tools like
SSAUpdater instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200067 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 04:07:24 +00:00
Juergen Ributzka
943ce55f39 Revert "Revert "Add Constant Hoisting Pass" (r200034)"
This reverts commit r200058 and adds the using directive for
ARMTargetTransformInfo to silence two g++ overload warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200062 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 02:02:55 +00:00
Hans Wennborg
503793e834 Revert "Add Constant Hoisting Pass" (r200034)
This commit caused -Woverloaded-virtual warnings. The two new
TargetTransformInfo::getIntImmCost functions were only added to the superclass,
and to the X86 subclass. The other targets were not updated, and the
warning highlighted this by pointing out that e.g. ARMTTI::getIntImmCost was
hiding the two new getIntImmCost variants.

We could pacify the warning by adding "using TargetTransformInfo::getIntImmCost"
to the various subclasses, or turning it off, but I suspect that it's wrong to
leave the functions unimplemnted in those targets. The default implementations
return TCC_Free, which I don't think is right e.g. for ARM.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200058 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 01:18:18 +00:00
Juergen Ributzka
96172cb4a4 Add Constant Hoisting Pass
Retry commit r200022 with a fix for the build bot errors. Constant expressions
have (unlike instructions) module scope use lists and therefore may have users
in different functions. The fix is to simply ignore these out-of-function uses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200034 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 20:18:00 +00:00
Juergen Ributzka
dc6f9b9a4f Revert "Add Constant Hoisting Pass"
This reverts commit r200022 to unbreak the build bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200024 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 18:40:30 +00:00
Juergen Ributzka
fb282c68b7 Add Constant Hoisting Pass
This pass identifies expensive constants to hoist and coalesces them to
better prepare it for SelectionDAG-based code generation. This works around the
limitations of the basic-block-at-a-time approach.

First it scans all instructions for integer constants and calculates its
cost. If the constant can be folded into the instruction (the cost is
TCC_Free) or the cost is just a simple operation (TCC_BASIC), then we don't
consider it expensive and leave it alone. This is the default behavior and
the default implementation of getIntImmCost will always return TCC_Free.

If the cost is more than TCC_BASIC, then the integer constant can't be folded
into the instruction and it might be beneficial to hoist the constant.
Similar constants are coalesced to reduce register pressure and
materialization code.

When a constant is hoisted, it is also hidden behind a bitcast to force it to
be live-out of the basic block. Otherwise the constant would be just
duplicated and each basic block would have its own copy in the SelectionDAG.
The SelectionDAG recognizes such constants as opaque and doesn't perform
certain transformations on them, which would create a new expensive constant.

This optimization is only applied to integer constants in instructions and
simple (this means not nested) constant cast experessions. For example:
%0 = load i64* inttoptr (i64 big_constant to i64*)

Reviewed by Eric

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200022 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 18:23:08 +00:00
Alp Toker
ae43cab6ba Fix known typos
Sweep the codebase for common typos. Includes some changes to visible function
names that were misspelt.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200018 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 17:20:08 +00:00