Commit Graph

130 Commits

Author SHA1 Message Date
Benjamin Kramer ed84360a45 GlobalOpt: non-constexpr bitcasts or GEPs can occur even if the global value is only stored once.
Fixes PR13968.

llvm-svn: 164815
2012-09-28 10:01:27 +00:00
Nick Lewycky d2c3bdd269 Add testcases for GlobalOpt changes in r160693 and r160757.
llvm-svn: 160925
2012-07-29 01:15:37 +00:00
Nick Lewycky faa9c3b035 Teach globalopt to not nuke all stores to globals. Keep them around of they
might be deliberate "one time" leaks, so that leak checkers can find them.
This is a reapply of r160602 with the fix that this time I'm committing the
code I thought I was committing last time; the I->eraseFromParent() goes
*after* the break out of the loop.

llvm-svn: 160664
2012-07-24 07:21:08 +00:00
Nick Lewycky 9669c198ba Revert r160602.
llvm-svn: 160603
2012-07-21 09:03:15 +00:00
Nick Lewycky 72b83e5eaa Teach globalopt to play nice with leak checkers. This is a reapplication of
r160529 that was subsequently reverted. The fix was to not call
GV->eraseFromParent() right before the caller does the same. The existing
testcases already caught this bug if run under valgrind.

llvm-svn: 160602
2012-07-21 08:29:45 +00:00
Nick Lewycky 7707e23429 Revert r160529 due to crashes.
llvm-svn: 160532
2012-07-19 23:59:21 +00:00
Nick Lewycky 0fa6a28141 Don't wipe out global variables that are probably storing pointers to heap
memory. This makes clang play nice with leak checkers.

llvm-svn: 160529
2012-07-19 22:35:28 +00:00
Duncan Sands e8ce94fcd7 GlobalOpt forgot to handle bitcast when analyzing globals. Found by inspection.
llvm-svn: 159546
2012-07-02 18:55:39 +00:00
Chandler Carruth 5da53436d5 Convert the uses of '|&' to use '2>&1 |' instead, which works on old
versions of Bash. In addition, I can back out the change to the lit
built-in shell test runner to support this.

This should fix the majority of fallout on Darwin, but I suspect there
will be a few straggling issues.

llvm-svn: 159544
2012-07-02 18:37:59 +00:00
Chandler Carruth a5a29f970e Convert all tests using TCL-style quoting to use shell-style quoting.
This was done through the aid of a terrible Perl creation. I will not
paste any of the horrors here. Suffice to say, it require multiple
staged rounds of replacements, state carried between, and a few
nested-construct-parsing hacks that I'm not proud of. It happens, by
luck, to be able to deal with all the TCL-quoting patterns in evidence
in the LLVM test suite.

If anyone is maintaining large out-of-tree test trees, feel free to poke
me and I'll send you the steps I used to convert things, as well as
answer any painful questions etc. IRC works best for this type of thing
I find.

Once converted, switch the LLVM lit config to use ShTests the same as
Clang. In addition to being able to delete large amounts of Python code
from 'lit', this will also simplify the entire test suite and some of
lit's architecture.

Finally, the test suite runs 33% faster on Linux now. ;]
For my 16-hardware-thread (2x 4-core xeon e5520): 36s -> 24s

llvm-svn: 159525
2012-07-02 12:47:22 +00:00
Matt Beaumont-Gay a58862310c Revert r159136 due to PR13124.
Original commit message:

If a constant or a function has linkonce_odr linkage and unnamed_addr, mark it
hidden. Being linkonce_odr guarantees that it is available in every dso that
needs it. Being a constant/function with unnamed_addr guarantees that the
copies don't have to be merged.

llvm-svn: 159272
2012-06-27 17:10:33 +00:00
Rafael Espindola 540c3d23df If a constant or a function has linkonce_odr linkage and unnamed_addr, mark it
hidden. Being linkonce_odr guarantees that it is available in every dso that
needs it. Being a constant/function with unnamed_addr guarantees that the
copies don't have to be merged.

llvm-svn: 159136
2012-06-25 14:30:31 +00:00
Rafael Espindola 1821c6c3b0 Some optimizations done by globalopt are safe only for internal linkage, not
linkonce linkage. For example, it is not valid to add unnamed_addr.

This also fixes a crash in g++.dg/opt/static5.C.

llvm-svn: 158528
2012-06-15 18:00:24 +00:00
Rafael Espindola def1b09be2 Implement the isSafeToDiscardIfUnused predicate and use it in globalopt and
globaldce. Globaldce was already removing linkonce globals, but globalopt was
not.

llvm-svn: 158476
2012-06-14 22:48:13 +00:00
Jay Foad ca0c499609 Teach Function::hasAddressTaken that BlockAddress doesn't really take
the address of a function.

llvm-svn: 156703
2012-05-12 08:30:16 +00:00
Chandler Carruth aacb8a5809 Fix a crash on valid (if UB) bitcode that is produced for some global
constants in C++11 mode. I have no idea why it required such particular
circumstances to get here, the code seems clearly to rely upon unchecked
assumptions.

Specifically, when we decide to form an index into a struct type, we may
have gone through (at least one) zero-length array indexing round, which
would have left the offset un-adjusted, and thus not necessarily valid
for use when indexing the struct type.

This is just an canonicalization step, so the correct thing is to refuse
to canonicalize nonsensical GEPs of this form. Implemented, and test
case added.

Fixes PR12642. Pair debugged and coded with Richard Smith. =] I credit
him with most of the debugging, and preventing me from writing the wrong
code.

llvm-svn: 155466
2012-04-24 18:42:47 +00:00
Benjamin Kramer aa9e4a5e59 GlobalOpt: If we have an inbounds GEP from a ConstantAggregateZero global that we just determined to be constant, replace all loads from it with a zero value.
llvm-svn: 153576
2012-03-28 14:50:09 +00:00
Dan Gohman eab06fa3c9 Teach globalopt how to evaluate an invoke with a non-void return type.
llvm-svn: 152634
2012-03-13 18:01:37 +00:00
Nick Lewycky 9d0da18597 Use the target-aware constant folder on expressions to improve the chance
they'll be simple enough to simulate, and to reduce the chance we'll encounter
equal but different simple pointer constants.

This removes the symptoms from PR11352 but is not a full fix. A proper fix would
either require a guarantee that two constant objects we simulate are folded
when equal, or a different way of handling equal pointers (ie., trying a
constantexpr icmp on them to see whether we know they're equal or non-equal or
unsure).

llvm-svn: 151093
2012-02-21 22:08:06 +00:00
Nick Lewycky 519561f418 Check for the correct size in the invariant marker.
llvm-svn: 151003
2012-02-20 23:32:26 +00:00
Nick Lewycky aed0553360 Remove question.
llvm-svn: 150809
2012-02-17 09:55:20 +00:00
Nick Lewycky 68f9f9d9c8 Add support for invariant.start inside the static constructor evaluator. This is
useful to represent a variable that is const in the source but can't be constant
in the IR because of a non-trivial constructor. If globalopt evaluates the
constructor, and there was an invariant.start with no matching invariant.end
possible, it will mark the global constant afterwards.

llvm-svn: 150794
2012-02-17 06:59:21 +00:00
Eli Bendersky 924f9a671d Replace all instances of dg.exp file with lit.local.cfg, since all tests are run with LIT now and now Dejagnu. dg.exp is no longer needed.
Patch reviewed by Daniel Dunbar. It will be followed by additional cleanup patches.

llvm-svn: 150664
2012-02-16 06:28:33 +00:00
Benjamin Kramer 487a3962c7 GlobalOpt: Be more aggressive about elminating side-effect free static dtors.
GlobalOpt runs early in the pipeline (before inlining) and complex class
hierarchies often introduce bitcasts or GEPs which weren't optimized away.
Teach it to ignore side-effect free instructions instead of depending on
other passes to remove them.

llvm-svn: 150174
2012-02-09 14:26:06 +00:00
Nick Lewycky 52da72b12a Teach GlobalOpt to handle atomic accesses to globals.
* Most of the transforms come through intact by having each transformed load or
store copy the ordering and synchronization scope of the original.
 * The transform that turns a global only accessed in main() into an alloca
(since main is non-recursive) with a store of the initial value uses an
unordered store, since it's guaranteed to be the first thing to happen in main.
(Threads may have started before main (!) but they can't have the address of a
function local before the point in the entry block we insert our code.)
 * The heap-SRoA transforms are disabled in the face of atomic operations. This
can probably be improved; it seems odd to have atomic accesses to an alloca
that doesn't have its address taken.

AnalyzeGlobal keeps track of the strongest ordering found in any use of the
global. This is more information than we need right now, but it's cheap to
compute and likely to be useful.

llvm-svn: 149847
2012-02-05 19:56:38 +00:00
Eli Friedman 55fa49f32d PR11705, part 2: globalopt shouldn't put inttoptr/ptrtoint operations into global initializers if there's an implied extension or truncation.
llvm-svn: 147625
2012-01-05 23:03:32 +00:00
Chris Lattner ee471c484a remove autoupgrade support for old forms of llvm.prefetch and the old
trampoline forms.  Both of these were correct in LLVM 3.0, and we don't
need to support LLVM 2.9 and earlier in mainline.

llvm-svn: 145174
2011-11-27 07:42:04 +00:00
Chris Lattner 6a144a2227 Upgrade syntax of tests using volatile instructions to use 'load volatile' instead of 'volatile load', which is archaic.
llvm-svn: 145171
2011-11-27 06:54:59 +00:00
Eli Friedman 1923a330e6 Refactor code from inlining and globalopt that checks whether a function definition is unused, and enhance it so it can tell that functions which are only used by a blockaddress are in fact dead. This probably doesn't happen much on most code, but the Linux kernel's _THIS_IP_ can trigger this issue with blockaddress. (GlobalDCE can also handle the given tescase, but we only run that at -O3.) Found while looking at PR11180.
llvm-svn: 142572
2011-10-20 05:23:42 +00:00
Eli Friedman 02e737b08e Move "atomic" and "volatile" designations on instructions after the opcode
of the instruction.

Note that this change affects the existing non-atomic load and store
instructions; the parser now accepts both forms, and the change is noted
in the release notes.

llvm-svn: 137527
2011-08-12 22:50:01 +00:00
Chris Lattner b1ed91f397 Land the long talked about "type system rewrite" patch. This
patch brings numerous advantages to LLVM.  One way to look at it
is through diffstat:
 109 files changed, 3005 insertions(+), 5906 deletions(-)

Removing almost 3K lines of code is a good thing.  Other advantages
include:

1. Value::getType() is a simple load that can be CSE'd, not a mutating
   union-find operation.
2. Types a uniqued and never move once created, defining away PATypeHolder.
3. Structs can be "named" now, and their name is part of the identity that
   uniques them.  This means that the compiler doesn't merge them structurally
   which makes the IR much less confusing.
4. Now that there is no way to get a cycle in a type graph without a named
   struct type, "upreferences" go away.
5. Type refinement is completely gone, which should make LTO much MUCH faster
   in some common cases with C++ code.
6. Types are now generally immutable, so we can use "Type *" instead 
   "const Type *" everywhere.

Downsides of this patch are that it removes some functions from the C API,
so people using those will have to upgrade to (not yet added) new API.  
"LLVM 3.0" is the right time to do this.

There are still some cleanups pending after this, this patch is large enough
as-is.

llvm-svn: 134829
2011-07-09 17:41:24 +00:00
Chris Lattner 80ed9dc9e5 rip out a ton of intrinsic modernization logic from AutoUpgrade.cpp, which is
for pre-2.9 bitcode files.  We keep x86 unaligned loads, movnt, crc32, and the
target indep prefetch change.

As usual, updating the testsuite is a PITA.

llvm-svn: 133337
2011-06-18 06:05:24 +00:00
Chris Lattner b90ed2233c manually upgrade a bunch of tests to modern syntax, and remove some that
are either unreduced or only test old syntax.

llvm-svn: 133228
2011-06-17 03:14:27 +00:00
Nick Lewycky 63353933c6 Add testcase for r132290, to check for the crasher caught by the buildbots
doing llvm-gcc selfhost (or cross).

llvm-svn: 132292
2011-05-29 19:41:14 +00:00
Nick Lewycky a3bb03e400 Obey the isVolatile bit on memory intrinsics when analyzing uses of a global
variable. Noticed by inspection.

Simulate memset in EvaluateFunction where the target of the memset and the
value we're setting are both the null value. Fixes PR10047!

llvm-svn: 132288
2011-05-29 18:41:56 +00:00
Chris Lattner 1a1acc2191 fix PR9856, an incorrectly conservative assertion: a global can be
"stored once" even if its address is compared.

llvm-svn: 131849
2011-05-22 07:15:13 +00:00
Eli Friedman 9cca0715aa Add back a couple checks removed by r129128; the fact that an intitializer
is an array of structures doesn't imply it's a ConstantArray of
ConstantStruct.

llvm-svn: 129207
2011-04-09 09:11:09 +00:00
Anders Carlsson ee6bc70d2f Add an optimization to GlobalOpt that eliminates calls to __cxa_atexit, if the function passed is empty.
llvm-svn: 127970
2011-03-20 17:59:11 +00:00
Rafael Espindola fc355bc070 Add unnamed_addr when we can show that address of a global is not used.
llvm-svn: 123834
2011-01-19 16:32:21 +00:00
Owen Anderson ec3b10fc56 Reduce and merge testcases.
llvm-svn: 123579
2011-01-16 09:13:31 +00:00
Owen Anderson 4e54efd625 Improve the safety of my globalopt enhancement by ensuring that the bitcast
of the stored value to the new store type is always.  Also, add a testcase.

llvm-svn: 123563
2011-01-16 04:33:33 +00:00
Chris Lattner 1903c42b97 fix a globalopt crash on two Adobe-C++ testcases that the recent
loop idiom pass exposed.

llvm-svn: 122674
2011-01-01 22:31:46 +00:00
Chris Lattner 0d71c4f564 reapply r121100 with a tweak to constant fold ConstExprs with TargetData
(if available) as we go so that we get simple constantexprs not insane ones.
This fixes the failure of clang/test/CodeGenCXX/virtual-base-ctor.cpp
that the previous iteration of this patch had.

llvm-svn: 121111
2010-12-07 04:33:29 +00:00
Eric Christopher f10dcfb9fb Temporarily revert r121100 as it's causing clang to fail
CodeGenCXX/virtual-base-ctor.cpp.

llvm-svn: 121102
2010-12-07 02:41:11 +00:00
Chris Lattner 287f4366c1 fix PR8710 - teach global opt that some constantexprs are too complex to
put in a global variable's initializer.

llvm-svn: 121100
2010-12-07 01:59:32 +00:00
Mikhail Glushenkov 2072db24ed GlobalOpt: EvaluateFunction() must not evaluate stores to weak_odr globals.
Fixes PR8389.

llvm-svn: 116812
2010-10-19 16:47:23 +00:00
Dan Gohman f3a9c464b4 Fix this test to avoid an "inexact" fold.
llvm-svn: 114202
2010-09-17 20:25:43 +00:00
Chris Lattner 72d283c826 fix PR8063, a crash in globalopt in the malloc analysis code.
llvm-svn: 113109
2010-09-05 17:20:46 +00:00
Chris Lattner 65fb25a257 more test cleanup
llvm-svn: 112892
2010-09-02 22:38:56 +00:00
Duncan Sands 687900ed83 Use llvm.foo as the intrinsic, rather than llvm.dbg.value. Since the
values passed to llvm.dbg.value were not valid for the intrinsic, it
might have caused trouble one day if the verifier ever started checking
for valid debug info.

llvm-svn: 103038
2010-05-04 20:09:25 +00:00