383 Commits

Author SHA1 Message Date
David L. Jones
32028c8f08 [Analysis] Add LibFunc_ prefix to enums in TargetLibraryInfo. (NFC)
Summary:
The LibFunc::Func enum holds enumerators named for libc functions.
Unfortunately, there are real situations, including libc implementations, where
function names are actually macros (musl uses "#define fopen64 fopen", for
example; any other transitively visible macro would have similar effects).

Strictly speaking, a conforming C++ Standard Library should provide any such
macros as functions instead (via <cstdio>). However, there are some "library"
functions which are not part of the standard, and thus not subject to this
rule (fopen64, for example). So, in order to be both portable and consistent,
the enum should not use the bare function names.

The old enum naming used a namespace LibFunc and an enum Func, with bare
enumerators. This patch changes LibFunc to be an enum with enumerators prefixed
with "LibFFunc_". (Unfortunately, a scoped enum is not sufficient to override
macros.)

There are additional changes required in clang.

Reviewers: rsmith

Subscribers: mehdi_amini, mzolotukhin, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D28476

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292848 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-23 23:16:46 +00:00
Adrian Prantl
f53a7ab5bb Refactor the DIExpression fragment query interface (NFC)
... so it becomes available to DIExpressionCursor.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290322 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-22 05:27:12 +00:00
Daniel Jasper
8de3a54f07 Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290086 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-19 08:22:17 +00:00
Hal Finkel
bffeba468d Remove the AssumptionCache
After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289756 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-15 03:02:15 +00:00
Adrian Prantl
460dd60c1a [DIExpression] Introduce a dedicated DW_OP_LLVM_fragment operation
so we can stop using DW_OP_bit_piece with the wrong semantics.

The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html

The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.

Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.

Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288683 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-05 18:04:47 +00:00
Michael Zolotukhin
3a7f010bf7 [LoopSimplify] Preserve LCSSA when removing edges from unreachable blocks.
This fixes PR30454.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287379 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-18 21:01:12 +00:00
Florian Hahn
8a56643640 [simplifycfg][loop-simplify] Preserve loop metadata in 2 transformations.
insertUniqueBackedgeBlock in lib/Transforms/Utils/LoopSimplify.cpp now
propagates existing llvm.loop metadata to newly the added backedge.

llvm::TryToSimplifyUncondBranchFromEmptyBlock in lib/Transforms/Utils/Local.cpp
now propagates existing llvm.loop metadata to the branch instructions in the
predecessor blocks of the empty block that is removed.

Differential Revision: https://reviews.llvm.org/D26495


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@287341 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-18 13:12:07 +00:00
Kuba Brecka
d84b0f9851 [tsan] Add support for C++ exceptions into TSan (call __tsan_func_exit during unwinding), LLVM part
This adds support for TSan C++ exception handling, where we need to add extra calls to __tsan_func_exit when a function is exitted via exception mechanisms. Otherwise the shadow stack gets corrupted (leaked). This patch moves and enhances the existing implementation of EscapeEnumerator that finds all possible function exit points, and adds extra EH cleanup blocks where needed.

Differential Revision: https://reviews.llvm.org/D26177



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@286893 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-14 21:41:13 +00:00
Eli Friedman
a7bfb15b26 DCE math library calls with a constant operand.
On platforms which use -fmath-errno, math libcalls without any uses
require some extra checks to figure out if they are actually dead.

Fixes https://llvm.org/bugs/show_bug.cgi?id=30464 .

Differential Revision: https://reviews.llvm.org/D25970



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285857 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-02 20:48:11 +00:00
Reid Kleckner
a02ae2b916 [DebugInfo] Add comments to phi dbg.value tracking code, NFC
LLVM developers might be surprised to learn that there are blocks
without valid insertion points (catchswitch), so it seems worth calling
that out explicitly.  Also add a FIXME about what we should really be
doing if we ever need to make optimized Windows EH code debuggable.

While I'm here, make auto usage more consistent with LLVM standards and
avoid an unecessary call to insertBefore.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282521 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-27 18:45:31 +00:00
Keith Walker
523c933b4c Reapplying r281895 (and follow-up r281964) after fixing pr30468.
The additional fix is:

When adding debug information to a lowered phi node in mem2reg
check that we have a valid insertion point after the phi for adding
the debug information.

This change addresses the issue in pr30468 where a lowered phi was
added before a catchswitch and no debug information should be added
after the phi in this case.

Differential Revision: https://reviews.llvm.org/D24797



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282155 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-22 14:13:25 +00:00
Hans Wennborg
a613eb13a3 Revert r281895 "Add @llvm.dbg.value entries for the phi node created by -mem2reg"
(And follow-up r281964.)

It caused PR30468.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282077 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-21 15:55:53 +00:00
Keith Walker
4aaf90e08e Make llvm::ConvertDebugDeclareToDebugValue() be a void function (NFC)
The routines llvm::ConvertDebugDeclareToDebugValue() always returned
a true value which was never checked at the call site; change the
function return type to void.

This NFC cleanup was approved in the review https://reviews.llvm.org/D23715


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281964 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-20 10:36:17 +00:00
Keith Walker
383922dd5b Add @llvm.dbg.value entries for the phi node created by -mem2reg
When phi nodes are created in the -mem2reg phase, the @llvm.dbg.declare
entries are converted to @llvm.dbg.value entries at the place where the
store instructions existed. However no entry is created to describe
the resulting value of the phi node.

The effect of this is especially noticeable in for loops which have a
constant for the intial value; the loop control variable's location
would be described as the intial constant value in the loop body once
the -mem2reg optimization phase was run.

This change adds the creation of the @llvm.dbg.value entries to describe
variables whose location is the result of a phi node created in -mem2reg.

Also when the phi node is finally lowered to a machine instruction it
is important that the lowered "load" instruction is placed before the
associated DEBUG_VALUE entry describing the value loaded.

Differential Revision: https://reviews.llvm.org/D23715


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281895 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-19 09:49:30 +00:00
Matt Arsenault
21409dbcdc Fix misleading comment for getOrEnforceKnownAlignment
It does not return 0 to indicate failure, and returns the known
alignment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281350 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-13 16:39:43 +00:00
Dehao Chen
035ff49cd1 revert r280427
Refactor replaceDominatedUsesWith to have a flag to control whether to replace uses in BB itself.

Summary: This is in preparation for LoopSink pass which calls replaceDominatedUsesWith to update after sinking.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280949 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-08 15:25:12 +00:00
Dehao Chen
d21744e2b8 Refactor replaceDominatedUsesWith to have a flag to control whether to replace uses in BB itself.
Summary: This is in preparation for LoopSink pass which calls replaceDominatedUsesWith to update after sinking.

Reviewers: chandlerc, davidxl, danielcdh

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24170

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280427 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-01 23:26:48 +00:00
Eli Friedman
97b394f6af [JumpThreading] Fix handling of aliasing metadata.
Summary:
The correctness fix here is that when we CSE a load with another load,
we need to combine the metadata on the two loads. This matches the
behavior of other passes, like instcombine and GVN.

There's also a minor optimization improvement here: for load PRE, the
aliasing metadata on the inserted load should be the same as the
metadata on the original load. Not sure why the old code was throwing
it away.

Issue found by inspection.

Differential Revision: http://reviews.llvm.org/D21460

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277977 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-08 04:10:22 +00:00
Benjamin Kramer
284030ab2c Move helpers into anonymous namespaces. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277916 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-06 11:13:10 +00:00
Evgeniy Stepanov
b57cbbd54d [sanitizer] Simplify and future-proof maybeMarkSanitizerLibraryCallNoBuiltin().
Sanitizers set nobuiltin attribute on certain library functions to
avoid a situation where such function is neither instrumented nor
intercepted.

At the moment the list of interesting functions is hardcoded. This
change replaces it with logic based on
TargetLibraryInfo::hasOptimizedCodegen and the presense of readnone
function attribute (sanitizers are generally interested in memory
behavior of library functions).

This is expected to be a no-op change: the new logic matches exactly
the same set of functions.

r276771 (currently reverted) added mempcpy() to the list, breaking
MSan tests. With this change, r276771 can be safely re-landed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277086 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-28 23:45:15 +00:00
David Majnemer
2d83d8a394 [Utils] Simplify combineMetadata
Use a range-based for loop, no functional change is intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276600 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-25 02:21:19 +00:00
David Majnemer
23ee217fe1 Just a small cleanup
No functional change is intended

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273780 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-25 08:34:38 +00:00
David Majnemer
db5173a31d Revert "[SimplifyCFG] Stop inserting calls to llvm.trap for UB"
This reverts commit r273778, it seems to break UBSan :/

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273779 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-25 08:19:55 +00:00
David Majnemer
46e1183e69 [SimplifyCFG] Stop inserting calls to llvm.trap for UB
SimplifyCFG had logic to insert calls to llvm.trap for two very
particular IR patterns: stores and invokes of undef/null.

While InstCombine canonicalizes certain undefined behavior IR patterns
to stores of undef, phase ordering means that this cannot be relied upon
in general.

There are much better tools than llvm.trap: UBSan and ASan.

N.B. I could be argued into reverting this change if a clear argument as
to why it is important that we synthesize llvm.trap for stores, I'd be
hard pressed to see why it'd be useful for invokes...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273778 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-25 08:04:19 +00:00
David Majnemer
ae15013971 [SimplifyCFG] Replace calls to null/undef with unreachable
Calling null is undefined behavior, a call to undef can be trivially
treated as a call to null.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273776 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-25 07:37:27 +00:00
David Majnemer
c1fd19fd0b Reinstate r273711
r273711 was reverted by r273743.  The inliner needs to know about any
call sites in the inlined function.  These were obscured if we replaced
a call to undef with an undef but kept the call around.

This fixes PR28298.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273753 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-25 00:04:10 +00:00
Nico Weber
336eefdaa0 Revert r273711, it caused PR28298.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273743 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-24 22:52:39 +00:00
David Majnemer
7748b9996e SimplifyInstruction does not imply DCE
We cannot remove an instruction with no uses just because
SimplifyInstruction succeeds.  It may have side effects.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273711 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-24 19:34:46 +00:00
Marcin Koscielnicki
ccb3bb979e [sanitizers] Disable target-specific lowering of string functions.
CodeGen has hooks that allow targets to emit specialized code instead
of calls to memcmp, memchr, strcpy, stpcpy, strcmp, strlen, strnlen.
When ASan/MSan/TSan/ESan is in use, this sidesteps its interceptors, resulting
in uninstrumented memory accesses.  To avoid that, make these sanitizers
mark the calls as nobuiltin.

Differential Revision: http://reviews.llvm.org/D19781

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273083 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-18 10:10:37 +00:00
Evgeniy Stepanov
fd0154041b [safestack] Fixup llvm.dbg.value when rewriting unsafe allocas.
When moving unsafe allocas to the unsafe stack, dbg.declare intrinsics are
updated to refer to the new location.

This change does the same to dbg.value intrinsics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272968 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-16 22:34:00 +00:00
Igor Laevsky
bf43bfa0c0 Revert r272891 "[JumpThreading] Prevent dangling pointer problems in BranchProbabilityInfo"
It was causing failures in Profile-i386 and Profile-x86_64 tests.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272912 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-16 16:25:53 +00:00
Igor Laevsky
5695246406 [JumpThreading] Prevent dangling pointer problems in BranchProbabilityInfo
We should update results of the BranchProbabilityInfo after removing block in JumpThreading. Otherwise 
we will get dangling pointer inside BranchProbabilityInfo cache.

Differential Revision: http://reviews.llvm.org/D20957



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272891 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-16 13:28:25 +00:00
Chad Rosier
c0a787d682 [InstCombine] Catch more bswap cases missed due to zext and truncs.
Fixes PR27824.
Differential Revision: http://reviews.llvm.org/D20591.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270853 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-26 14:58:51 +00:00
Chad Rosier
b744845677 Clarify that we match BSwap in InstCombine and BitReverse in CGP. NFC.
Also, rename recognizeBitReverseOrBSwapIdiom to recognizeBSwapOrBitReverseIdiom,
so the ordering of the MatchBSwaps and MatchBitReversals arguments are
consistent with the function name.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270715 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-25 16:22:14 +00:00
Chad Rosier
7143168577 Fix 80-column violation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270329 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-21 21:12:06 +00:00
Reid Kleckner
0e77da267e Revert "[SimplifyCFG] Extend TryToSimplifyUncondBranchFromEmptyBlock for empty block including lifetime intrinsics"
This reverts commit r268254.

This change causes assertion failures while building Chromium. Reduced
test case coming soon.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268288 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-02 19:43:22 +00:00
Hans Wennborg
0c15a0b738 [SimplifyCFG] Extend TryToSimplifyUncondBranchFromEmptyBlock for empty block including lifetime intrinsics
Make it possible that TryToSimplifyUncondBranchFromEmptyBlock merges empty
basic block including lifetime intrinsics as well as phi nodes and
unconditional branch into its successor or predecessor(s).

If successor of empty block has single predecessor, all contents including
lifetime intrinsics are sinked into the successor. Otherwise, they are
hoisted into its predecessor(s) and then merged into the predecessor(s).

Patch by Josh Yoon <josh.yoon@samsung.com>!

Differential Revision: http://reviews.llvm.org/D19257

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268254 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-02 17:22:54 +00:00
Sanjoy Das
3aa5468391 Mark guards on true as "trivially dead"
This moves some logic added to EarlyCSE in rL268120 into
`llvm::isInstructionTriviallyDead`.  Adds a test case for DCE to
demonstrate that passes other than EarlyCSE can now pick up on the new
information.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268126 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-29 22:23:16 +00:00
Hal Finkel
1ccb72c441 [SimplifyCFG] Preserve !llvm.mem.parallel_loop_access when merging
When SimplifyCFG merges identical instructions from both sides of a diamond, it
can preserve !llvm.mem.parallel_loop_access (as it does with most of the other
metadata). There's no real data or control dependency change in this case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267515 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-26 02:06:06 +00:00
Sanjoy Das
84a84a1723 [SimplifyCFG] Fold llvm.guard(false) to unreachable
Summary:
`llvm.guard(false)` always bails out of the current compilation unit, so
we can prune any control flow following it.

Reviewers: hfinkel, pcc, reames

Subscribers: majnemer, reames, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19245

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266955 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-21 05:09:12 +00:00
Sanjoy Das
4f285499ea [RS4GC] Lower calls to @llvm.experimental.deoptimize
This changes RS4GC to lower calls to ``@llvm.experimental.deoptimize``
to gc.statepoints wrapping ``__llvm_deoptimize``, and changes
``callsGCLeafFunction`` to recognize ``@llvm.experimental.deoptimize``
as a non GC leaf function.

I've had to hard code the ``"__llvm_deoptimize"`` name in
RewriteStatepointsForGC; since ``TargetLibraryInfo`` is available only
during codegen.  This isn't without precedent in the codebase, so I'm
not overtly concerned.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264456 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-25 20:12:13 +00:00
Duncan P. N. Exon Smith
8de6150816 ADT: Remove == and != comparisons between ilist iterators and pointers
I missed == and != when I removed implicit conversions between iterators
and pointers in r252380 since they were defined outside ilist_iterator.

Since they depend on getNodePtrUnchecked(), they indirectly rely on UB.
This commit removes all uses of these operators.  (I'll delete the
operators themselves in a separate commit so that it can be easily
reverted if necessary.)

There should be NFC here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261498 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-21 20:39:50 +00:00
Adrian Prantl
465522b1fa Debug Info: Teach LdStHasDebugValue() (Local.cpp) about DIExpressions.
This function is used to check whether a dbg.value intrinsic has already
been inserted, but without comparing the DIExpression, it would erroneously
fire on split aggregates and only the first scalar would survive.

Found via http://reviews.llvm.org/D16867.
<rdar://problem/24456528>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261145 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-17 20:02:25 +00:00
Matthias Braun
5e08bd340a Avoid overly large SmallPtrSet/SmallSet
These sets perform linear searching in small mode so it is never a good
idea to use SmallSize/N bigger than 32.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259283 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-30 01:24:31 +00:00
David Majnemer
2f0346603d [SCCP] Remove duplicate code
SCCP has code identical to changeToUnreachable's behavior, switch it
over to just call changeToUnreachable.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258654 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-24 06:26:47 +00:00
David Majnemer
6b7f46e721 [InstCombine, SCCP] Consolidate code used to remove instructions
InstCombine and SCCP both want to remove dead code in a very particular
way but using identical means to do so.  Share the code between the two.

No functionality change is intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258653 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-24 05:26:18 +00:00
David L Kreitzer
fad7d1588f Fix for two constant propagation problems in GVN with the assume intrinsic
instruction.

Patch by Yuanrui Zhang.

Differential Revision: http://reviews.llvm.org/D16100


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258435 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-21 21:32:35 +00:00
James Y Knight
b707e2a85c Stop increasing alignment of externally-visible globals on ELF
platforms.

With ELF, the alignment of a global variable in a shared library will
get copied into an executables linked against it, if the executable even
accesss the variable. So, it's not possible to implicitly increase
alignment based on access patterns, or you'll break existing binaries.

This happened to affect libc++'s std::cout symbol, for example. See
thread: http://thread.gmane.org/gmane.comp.compilers.clang.devel/45311

(This is a re-commit of r257719, without the bug reported in
PR26144. I've tweaked the code to not assert-fail in
enforceKnownAlignment when computeKnownBits doesn't recurse far enough
to find the underlying Alloca/GlobalObject value.)

Differential Revision: http://reviews.llvm.org/D16145

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257902 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-15 16:33:06 +00:00
James Molloy
cd54bb4874 [InstCombine] Rewrite bswap/bitreverse handling completely.
There are several requirements that ended up with this design;
  1. Matching bitreversals is too heavyweight for InstCombine and doesn't really need to be done so early.
  2. Bitreversals and byteswaps are very related in their matching logic.
  3. We want to implement support for matching more advanced bswap/bitreverse patterns like partial bswaps/bitreverses.
  4. Bswaps are best matched early in InstCombine.

The result of these is that a new utility function is created in Transforms/Utils/Local.h that can be configured to search for bswaps, bitreverses or both. InstCombine uses it to find only bswaps, CGP uses it to find only bitreversals.

We can then extend the matching logic in one place only.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257875 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-15 09:20:19 +00:00
Keno Fischer
4d6ccf4c99 [Utils] Fix incorrect dbg.declare store conversion
Summary: The dbg.declare -> dbg.value conversion did not check which operand of
the store instruction the alloca was passed to. As a result code that stored the
address of an alloca, rather than storing to the alloca, would still trigger
the conversion routine, leading to the insertion of an incorrect dbg.value
intrinsic.

Reviewers: aprantl

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16169

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257787 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-14 19:12:27 +00:00