Commit Graph

4148 Commits

Author SHA1 Message Date
Dan Gohman
dd842e34c8 Use RecursivelyDeleteTriviallyDeadInstructions in EliminateIVComparisons,
instead of deleting just the user. This makes it more consistent with
other code in IndVarSimplify, and theoretically can eliminate more users
earlier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101027 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-12 07:29:15 +00:00
Dan Gohman
931e345e76 Re-apply r101000, with a fix: Don't eliminate an icmp which is part of
the loop exit test. This usually doesn't come up for a variety of
reasons, but it isn't impossible, so make IndVarSimplify handle it
conservatively.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101008 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-12 02:21:50 +00:00
Dan Gohman
ac3b9cdf15 Revert 101000, which is breaking self-host builds.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101002 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-12 00:17:10 +00:00
Dan Gohman
3fddbb337d Teach IndVarSimplify how to eliminate comparisons involving induction
variables. For example, with code like this:

  for (i=0;i<n;++i)
    if (i<n)
      x[i] = 0;

IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the if.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101000 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-11 23:10:12 +00:00
Dan Gohman
3948d0b8b0 Rename isLoopGuardedByCond to isLoopEntryGuardedByCond, to emphasise
that it's only testing for the entry condition, not full loop-invariant
conditions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100979 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-11 19:27:13 +00:00
Chris Lattner
6f285d2105 fix PR6743, a case where we'd delete an instruction before using it
in some cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100937 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-10 18:26:57 +00:00
Dan Gohman
e5f76877ae When determining a canonical insert position, don't climb deeper
into adjacent loops. Also, ensure that the insert position is
dominated by the loop latch of any loop in the post-inc set which
has a latch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100906 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-09 22:07:05 +00:00
Dan Gohman
4a2a683366 When looking for loop-invariant users, look through no-op instructions,
so that an unfortunately placed bitcast doesn't pin a value in a
register.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100883 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-09 19:12:34 +00:00
Gabor Greif
ea3eec9f85 const-ize a predicate
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100856 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-09 10:57:00 +00:00
Dan Gohman
d96eae8010 Refactor the code for computing the insertion point for an expression into
a separate function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100845 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-09 02:00:38 +00:00
Chris Lattner
8829cec25f fix a SCCP miscompilation that could happen when a
forced constant is changed to a constant, we would end
up adding the instruction to the wrong worklist, 
preventing it from being properly revisited.  This fixes
rdar://7832370


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100837 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-09 01:14:31 +00:00
Dan Gohman
e60bb15982 Avoid allocating a value of zero in a register if the initial formula
inputs happen to negate each other.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100828 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-08 23:36:27 +00:00
Dan Gohman
e056781323 Add variants of ult, ule, etc. which take a uint64_t RHS, for convenience.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100824 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-08 23:03:40 +00:00
Dan Gohman
701a4aef7f When expanding expressions which are using post-inc mode for multiple loops,
ensure that the expansion is dominated by the increments of those loops.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100748 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-08 05:57:57 +00:00
Dan Gohman
448db1cdef Generalize IVUsers to track arbitrary expressions rather than expressions
explicitly split into stride-and-offset pairs. Also, add the
ability to track multiple post-increment loops on the same expression.

This refines the concept of "normalizing" SCEV expressions used for
to post-increment uses, and introduces a dedicated utility routine for
normalizing and denormalizing expressions.

This fixes the expansion of expressions which are post-increment users
of more than one loop at a time. More broadly, this takes LSR another
step closer to being able to reason about more than one loop at a time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100699 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-07 22:27:08 +00:00
Gabor Greif
8a8a4350db performance: get rid of repeated dereferencing of use_iterator by caching its result
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100550 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-06 19:32:30 +00:00
Chris Lattner
e597f00e1a fix a really nasty bug that Evan was tracking in SCCP. When resolving
undefs in branches/switches, we have two cases: a branch on a literal
undef or a branch on a symbolic value which is undef.  If we have a
literal undef, the code was correct: forcing it to a constant is the
right thing to do.

If we have a branch on a symbolic value that is undef, we should force
the symbolic value to a constant, which then makes the successor block
live.  Forcing the condition of the branch to being a constant isn't 
safe if later paths become live and the value becomes overdefined.  This
is the case that 'forcedconstant' is designed to handle, so just use it.

This fixes rdar://7765019 but there is no good testcase for this, the
one I have is too insane to be useful in the future.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100478 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-05 22:14:48 +00:00
Chris Lattner
9e185800c0 some code cleanups, use SwitchInst::findCaseValue, reduce indentation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100468 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-05 21:18:32 +00:00
Evan Cheng
0f1666b480 Code clean up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100467 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-05 21:16:25 +00:00
Mon P Wang
20adc9dc46 Reapply address space patch after fixing an issue in MemCopyOptimizer.
Added support for address spaces and added a isVolatile field to memcpy, memmove, and memset,
e.g., llvm.memcpy.i32(i8*, i8*, i32, i32) -> llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i32, i1)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100304 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-04 03:10:48 +00:00
Chris Lattner
d52c072777 require that the branch being controlled by the IV
exits the loop.  With this information we can guarantee 
the iteration count of the loop is bounded by the 
compare.  I think this xforms is finally safe now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100285 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 07:21:39 +00:00
Chris Lattner
96fd76638b add integer overflow check for the fp induction variable
checker.  Amusingly, we already had tests that we should
have rejects because they would be miscompiled in the
testsuite.

The remaining issue with this is that we don't check that
the branch causes us to exit the loop if it fails, so we
don't actually know if we remain in bounds.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100284 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 07:18:48 +00:00
Chris Lattner
bbb91498da add a comment and fix some consistency issues, converting
to a signed vs unsigned value depending on the sign of the
constant fp means that we can't distinguish between a 
truly negative number and a positive number so large the
32nd bit is set.  So, do don't this!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100283 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 06:41:49 +00:00
Chris Lattner
43b85273ee fix PR6761, a miscompilation due to the fp->int IV conversion
stuff.  More bugs remain though.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100282 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 06:30:03 +00:00
Chris Lattner
a40e4a0c8a just eliminate the uitofp checks. This code isn't doing
the required validity checks in the first place, and supporting
a condition large enough to require the 32'nd bit isn't worth it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100280 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 06:25:21 +00:00
Chris Lattner
c91961e31b rename PH -> PN to be consistent with WeakPN and the rest
of llvm.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100276 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 06:17:08 +00:00
Chris Lattner
70c0d4f7eb improve comment and drop a dead check. If PH had
no uses, it would have been deleted by 
RecursivelyDeleteTriviallyDeadInstructions


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100275 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 06:16:22 +00:00
Chris Lattner
9698c1985f strength reduce a ridiculous use of APInt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100274 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 06:13:12 +00:00
Chris Lattner
ca703bd56b rename stuff improve comment grammar.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100273 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 06:11:07 +00:00
Chris Lattner
fa405af58a simplify some code and resolve a fixme.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100272 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 06:06:59 +00:00
Chris Lattner
c4f7e8061d There is no guarantee that the increment and the branch
are in the same block.  Insert the new increment in the
correct location.

Also, more cleanups.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100271 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 06:05:10 +00:00
Chris Lattner
07aa76ad93 first half of a pass through IndVarSimplify::HandleFloatingPointIV,
this cleans up a bunch of code and also fixes several crashes and
miscompiles.  More to come unfortunately, this optimization
is quite broken.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100270 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 05:54:59 +00:00
Evan Cheng
0272024210 Code refactoring.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100262 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-03 02:23:43 +00:00
Mon P Wang
e754d3fb85 Revert r100191 since it breaks objc in clang
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100199 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-02 18:43:02 +00:00
Mon P Wang
e33c848fa4 Reapply address space patch after fixing an issue in MemCopyOptimizer.
Added support for address spaces and added a isVolatile field to memcpy, memmove, and memset,
e.g., llvm.memcpy.i32(i8*, i8*, i32, i32) -> llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i32, i1)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100191 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-02 18:04:15 +00:00
Dan Gohman
d7bfd0028b Manually notify ScalarEvolution before making an operand replacement, since
it can't currently observe such changes automatically.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100186 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-02 14:48:31 +00:00
Gabor Greif
c8b82ccbcf Introduce ImmutableCallSite, useful for contexts where no mutation
is necessary. Inherits from new templated baseclass CallSiteBase<>
which is highly customizable. Base CallSite on it too, in a configuration
that allows full mutation.
Adapt some call sites in analyses to employ ImmutableCallSite.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100100 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-01 08:21:08 +00:00
Dale Johannesen
536d31b5b3 Fix a nasty dangling-pointer heisenbug that could
generate wrong code pretty much anywhere AFAICT.
A case that hits the bug reproducibly is impossible,
but the situation was like this:
Addr = ...
Store -> Addr
Addr2 = GEP , 0, 0
Store -> Addr2
Handling the first store, the code changed replaced Addr
with a sunkaddr and deleted Addr, but not its table
entry.  Code in OptimizedBlock replaced Addr2 with a
bitcast; if that happened to reuse the memory of Addr,
the old table entry was erroneously found when handling
the second store.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100044 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-31 20:37:15 +00:00
Bob Wilson
100f090add Revert Mon Ping's change 99928, since it broke all the llvm-gcc buildbots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99948 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-30 22:27:04 +00:00
Mon P Wang
808bab0169 Added support for address spaces and added a isVolatile field to memcpy, memmove, and memset,
e.g., llvm.memcpy.i32(i8*, i8*, i32, i32) -> llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i32, i1)
A update of langref will occur in a subsequent checkin.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99928 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-30 20:55:56 +00:00
Jeffrey Yasskin
0826e1c519 Remove another memory leak from ABCD by using Edges by value instead of
pointer.  There was also a SmallPtrSet whose settiness wasn't being used, so I
changed it to a SmallVector.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99713 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-27 09:09:17 +00:00
Jeffrey Yasskin
e9580bf254 In ABCD, change the non-null Bound*s to Bound&s.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99711 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-27 08:15:46 +00:00
Jeffrey Yasskin
2f97b46f7b Fix a memory leak in ABCD by giving ownership of Bound objects to the
MemoizedResultChart.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99710 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-27 08:09:24 +00:00
Dan Gohman
449f31cb9d Ignore debug intrinsics in yet more places.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99580 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-26 00:33:27 +00:00
Gabor Greif
60ad781c61 rename use_const_iterator to const_use_iterator for consistency's sake
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99564 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-25 23:06:16 +00:00
Chris Lattner
219d77430b fix PR6642, GVN forwarding from memset to load of the base of the memset.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99488 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-25 05:58:19 +00:00
Evan Cheng
eb8c6459fc Move OptChkCall off LibCallOptimization into StrCpyOpt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99418 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-24 20:19:04 +00:00
Gabor Greif
c9f7500d17 Finally land the InvokeInst operand reordering.
I have audited all getOperandNo calls now, fixing
hidden assumptions. CallSite related uglyness will
be eliminated successively.

Note this patch has a long and griveous history,
for all the back-and-forths have a look at
CallSite.h's log.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99399 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-24 13:21:49 +00:00
Gabor Greif
bd1f99341e increase const goodness and remove pointless getUser() calls
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99395 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-24 10:29:52 +00:00
Bill Wendling
87a10f5b2f Skip debugging intrinsics when sinking unused invariants.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99324 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-23 21:15:59 +00:00
Evan Cheng
0289b419a4 Teach simplify libcall to transform __strcpy_chk to __memcpy_chk to enable optimizations down stream.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99282 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-23 15:48:04 +00:00
Gabor Greif
1cde4af157 backing out r99170 because it still fails on clang-x86_64-darwin10-fnt
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99171 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-22 09:11:00 +00:00
Gabor Greif
9b1061e2e3 Now that hopefully all direct accesses to InvokeInst operands are fixed
we can reapply the InvokeInst operand reordering patch. (see r98957).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99170 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-22 08:28:00 +00:00
Dan Gohman
472fdf7090 Clear the SCEVExpander's insertion point after making deletions,
so that the SCEVExpander doesn't retain a dangling pointer as its
insert position. The dangling pointer in this case wasn't ever used
to insert new instructions, but it was causing trouble with
SCEVExpander's code for automatically advancing its insert position
past debug intrinsics.

This fixes use-after-free errors that valgrind noticed in
test/Transforms/IndVarSimplify/2007-06-06-DeleteDanglesPtr.ll and
test/Transforms/IndVarSimplify/exit_value_tests.ll.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99036 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-20 03:53:53 +00:00
Gabor Greif
cc52ed0c4f back out r98957, it broke http://smooshlab.apple.com:8010/builders/clang-x86_64-darwin10-fnt/builds/703 in the nightly test suite
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98958 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-19 13:50:02 +00:00
Gabor Greif
f4f10e3779 Recommit r80858 again (which has been backed out in r80871).
This time I did a self-hosted bootstrap on Linux x86-64,
with no problems. Let's see how darwin 64-bit self-hosting
goes. At the first sign of failure I'll back this out.

Maybe the valgrind bots give me a hint of what may be wrong
(it at all).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98957 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-19 11:55:53 +00:00
Benjamin Kramer
2d7186ae6d str[r]chr returns its pointer argument so we cannot mark it as nocapture. Thanks to Duncan for spotting my mistake.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98671 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-16 20:33:15 +00:00
Benjamin Kramer
4446b04052 Mark str[r]chr readonly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98663 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-16 19:36:43 +00:00
Devang Patel
7b9f6b1b21 Skip debug info intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98584 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-15 22:23:03 +00:00
Devang Patel
ca70495797 In "empty" bb, the return instruction may not be first instruction, if dbg value intrinsics are present in this bb. Use terminator to find return instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98565 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-15 19:05:46 +00:00
Bill Wendling
ead138bc62 Skip over debug info when trying to merge two return BBs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98491 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-14 10:40:55 +00:00
Benjamin Kramer
0b6cb50738 Factor checked library call optimization into a common helper class and use it
to unify the almost identical code in CodeGenPrepare and InstCombineCalls.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98338 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-12 09:27:41 +00:00
Nate Begeman
75d5fe9213 Whoops this already existed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98297 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-11 23:21:19 +00:00
Nate Begeman
47a53a6e4c Add a handful of additional useful pass manager things to the C API
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98296 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-11 23:06:07 +00:00
Benjamin Kramer
7fa30b8e5d stpcpy is so similar to strcpy, it doesn't deserve a complete copy of the __strcpy_chk -> strcpy code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98284 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-11 20:45:13 +00:00
Eric Christopher
19888ca8b4 Lower stpcpy_chk when possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98274 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-11 19:24:34 +00:00
Eric Christopher
040056fd11 Do some final lowering in CodeGenPrepare of _chk calls similar to
that in InstCombineCalls.

More call lowering needed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98228 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-11 02:41:03 +00:00
Dan Gohman
bbf81d8811 Add a DominatorTree argument to isLCSSA so that it doesn't have to
compute a set of reachable blocks for itself each time it is called, which
is fairly frequently.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98179 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-10 19:38:49 +00:00
Eric Christopher
27ceaa13f8 Migrate _chk call lowering from SimplifyLibCalls to InstCombine. Stub
out the remainder of the calls that we should lower in some way and
move the tests to the new correct directory. Fix up tests that are now
optimized more than they were before by -instcombine.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97875 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-06 10:50:38 +00:00
Eric Christopher
b6174e3605 Move SimplifyLibCalls's LibCall builders to a separate file so they
can be used in more places.  Add an argument for the TargetData that
most of them need. Update for the getInt8PtrTy() change.  Should be
no functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97844 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-05 22:25:30 +00:00
Evan Cheng
a79eb387ac Safely turn memset_chk etc. to non-chk variant if the known object size is >= memset / memcpy / memmove size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97828 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-05 20:59:47 +00:00
Chris Lattner
893075f46e fix a nice subtle reassociate bug which would only occur
in a very specific use pattern embodied in the carefully
reduced testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97794 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-05 07:18:54 +00:00
Eric Christopher
25ec483cfc Move GetStringLength and helper from SimplifyLibCalls to ValueTracking.
No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97793 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-05 06:58:57 +00:00
Dan Gohman
087bd1e3a1 Make SCEVExpander and LSR more aggressive about hoisting expressions out
of loops.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97642 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-03 05:29:13 +00:00
Dan Gohman
069d6f3396 Non-affine post-inc SCEV expansions have more code which must be
emitted after the increment. Make sure the insert position
reflects this. This fixes PR6453.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97537 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-02 01:59:21 +00:00
Bob Wilson
3bd19d753b Don't attempt load PRE when there is no real redundancy (i.e., the load is in
a loop and is itself the only dependency).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97526 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-02 00:09:29 +00:00
Bob Wilson
70704978af When GVN needs to split critical edges for load PRE, check all of the
predecessors before returning.  Otherwise, if multiple predecessor edges need
splitting, we only get one of them per iteration.  This makes a small but
measurable compile time improvement with -enable-full-load-pre.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97521 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-01 23:37:32 +00:00
Evan Cheng
19d417c346 MemoryDepAnalysis is not used if redundant load processing is disabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97512 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-01 22:23:12 +00:00
Dan Gohman
3f46a3abee Spelling fixes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97453 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-01 17:49:51 +00:00
Bob Wilson
b29d7d2542 Revert r97245 which seems to be causing performance problems.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97366 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-28 05:34:05 +00:00
Chris Lattner
9fcd72b71a fix grammaro's pointed out by daniel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97313 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-27 07:50:40 +00:00
Chris Lattner
d38cdb020e fix PR6414, a nondeterminism issue in IPSCCP which was because
of a subtle interation in a loop operating in densemap order.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97288 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-27 00:07:42 +00:00
Bob Wilson
8561dcd730 Move the EnableFullLoadPRE flag from a separate command-line option to an
argument of createGVNPass and set it automatically for -O3.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97245 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-26 19:09:47 +00:00
Bob Wilson
60df9077eb Remove unused "NoPRE" parameter in GVN and createGVNPass().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97235 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-26 18:35:19 +00:00
Dan Gohman
8566963713 Make LoopSimplify change conditional branches in loop exiting blocks
which branch on undef to branch on a boolean constant for the edge
exiting the loop. This helps ScalarEvolution compute trip counts for
loops.

Teach ScalarEvolution to recognize single-value PHIs, when safe, and
ForgetSymbolicName to forget such single-value PHI nodes as apprpriate
in ForgetSymbolicName.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97126 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-25 06:57:05 +00:00
Daniel Dunbar
6d8f2ca646 Reapply r97010, the speculative revert failed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97036 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-24 08:48:04 +00:00
Daniel Dunbar
8c0c99016b Speculatively revert r97010, "Add an argument to PHITranslateValue to specify
the DominatorTree. ...", in hopes of restoring poor old PPC bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97027 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-24 06:55:22 +00:00
Bob Wilson
9d2ed8e632 Add an argument to PHITranslateValue to specify the DominatorTree. If this
argument is non-null, pass it along to PHITranslateSubExpr so that it can
prefer using existing values that dominate the PredBB, instead of just
blindly picking the first equivalent value that it finds on a uselist.
Also when the DominatorTree is specified, have PHITranslateValue filter
out any result that does not dominate the PredBB.  This is basically just
refactoring the check that used to be in GetAvailablePHITranslatedSubExpr
and also in GVN.

Despite my initial expectations, this change does not affect the results
of GVN for any testcases that I could find, but it should help compile time.
Before this change, if PHITranslateSubExpr picked a value that does not
dominate, PHITranslateWithInsertion would then insert a new value, which GVN
would later determine to be redundant and would replace.  By picking a good
value to begin with, we save GVN the extra work of inserting and then
replacing a new value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97010 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-24 01:39:00 +00:00
Bob Wilson
188f428e4e Update memdep when load PRE inserts a new load, and add some debug output.
I don't have a small testcase for this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96890 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-23 05:55:00 +00:00
Bob Wilson
74175c2ca1 Erase deleted instructions from GVN's ValueTable. This fixes assertion
failures from ValueTable::verifyRemoved() when using -debug.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96805 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-22 21:39:41 +00:00
Dan Gohman
454d26dc43 Remove unused variables and parameters.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96780 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-22 04:11:59 +00:00
Dan Gohman
278f958c61 When emitting an instruction which depends on both a post-incremented
induction variable value and a loop-variant value, don't force the
insert position to be at the post-increment position, because it may
not be dominated by the loop-variant value. This fixes a
use-before-def problem noticed on PPC.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96774 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-22 03:59:54 +00:00
Dan Gohman
2444080ca4 This cast<Instruction> is unnecessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96771 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-22 02:07:36 +00:00
Dan Gohman
f09b71233b Rename getSDiv to getExactSDiv to reflect its behavior in cases where
the division would have a remainder.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96693 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-19 19:35:48 +00:00
Dan Gohman
aae01f17a6 Check for overflow when scaling up an add or an addrec for
scaled reuse.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96692 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-19 19:32:49 +00:00
Dale Johannesen
45a2d7d44a recommit 96626, evidence that it broke things appears
to be spurious



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96662 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-19 07:14:22 +00:00
Dale Johannesen
efd9e95051 Revert 96626, which causes build failure on ppc Darwin.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96653 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-19 01:54:37 +00:00
Dan Gohman
1b7bf18def When determining the set of interesting reuse factors, consider
strides in foreign loops. This helps locate reuse opportunities
with existing induction variables in foreign loops and reduces
the need for inserting new ones. This fixes rdar://7657764.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96629 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-19 00:05:23 +00:00
Dan Gohman
aa11defd1c Indvars needs to explicitly notify ScalarEvolution when it is replacing
a loop exit value, so that if a loop gets deleted, ScalarEvolution
isn't stick holding on to dangling SCEVAddRecExprs for that loop. This
fixes PR6339.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96626 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-18 23:26:33 +00:00
Dan Gohman
814f2b2d19 Hoist this loop-invariant logic out of the loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96614 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-18 21:34:02 +00:00
Dan Gohman
378c0b35a7 Delete some unneeded casts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96429 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-17 00:42:19 +00:00
Dan Gohman
968cb939e5 Don't attempt to divide INT_MIN by -1; consider such cases to
have overflowed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96428 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-17 00:41:53 +00:00
Bob Wilson
ae23daf63a Rename SuccessorNumber to GetSuccessorNumber.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96387 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 21:06:42 +00:00
Dan Gohman
3a02cbcd03 Refactor rewriting for PHI nodes into a separate function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96382 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 20:25:07 +00:00
Bob Wilson
484d4a30c0 Split critical edges as needed for load PRE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96378 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 19:51:59 +00:00
Bob Wilson
adb6f22671 Refactor to share code to find the position of a basic block successor in the
terminator's list of successors.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96377 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 19:49:17 +00:00
Dan Gohman
7fca2294da Fix whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96372 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 19:42:34 +00:00
Duncan Sands
1df9859c40 There are two ways of checking for a given type, for example isa<PointerType>(T)
and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96344 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 11:11:14 +00:00
Dan Gohman
c2385a0741 Split the main for-each-use loop again, this time for GenerateTruncates,
as it also peeks at which registers are being used by other uses. This
makes LSR less sensitive to use-list order.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96308 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 01:42:53 +00:00
Duncan Sands
b0bc6c361d Uniformize the names of type predicates: rather than having isFloatTy and
isInteger, we now have isFloatTy and isIntegerTy.  Requested by Chris!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96223 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-15 16:12:20 +00:00
Dan Gohman
441a38993e Fix whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96179 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14 18:51:39 +00:00
Dan Gohman
6020d85c41 Fix a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96178 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14 18:51:20 +00:00
Dan Gohman
ce947366ec When complicated expressions are broken down into subexpressions
with multiplication by constants distributed through, occasionally
those subexpressions can include both x and -x. For now, if this
condition is discovered within LSR, just prune such cases away,
as they won't be profitable. This fixes a "zero allocated in a
base register" assertion failure.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96177 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14 18:50:49 +00:00
Dan Gohman
590bfe8641 Actually, this code doesn't have to be quite so conservative in
the no-TLI case. But it should still default to declining the
transformation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96152 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14 03:21:49 +00:00
Dan Gohman
2763dfdc70 Don't attempt aggressive post-inc uses if TargetLowering is not available,
because profitability can't be sufficiently approximated.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96148 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14 02:45:21 +00:00
John McCall
6d09ab8ba2 Make LSR not crash if invoked without target lowering info, e.g. if invoked
from opt.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96135 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-13 23:40:16 +00:00
Chris Lattner
c09687bb7e remove dead code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96109 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-13 19:07:06 +00:00
Chris Lattner
98d5c3141e Split some code out to a helper function (FindReusablePredBB)
and add a doxygen comment.

Cache the phi entry to avoid doing tons of 
PHINode::getBasicBlockIndex calls in the common case.

On my insane testcase from re2c, this speeds up CGP from
617.4s to 7.9s (78x).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96083 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-13 05:35:08 +00:00
Chris Lattner
3f65b5e733 speed up CGP a bit by scanning predecessors through phi operands
instead of with pred_begin/end.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96078 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-13 04:04:42 +00:00
Dan Gohman
9214b82c54 Fix a pruning heuristic which implicitly assumed that SmallPtrSet is
deterministically sorted.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96071 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-13 02:06:02 +00:00
Dan Gohman
68d6da1f33 Reapply 95979, a compile-time speedup, now that the bug it exposed is fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96005 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12 19:35:25 +00:00
Dan Gohman
cd045c08ca Fix this code to avoid dereferencing an end() iterator in
offset distributions it doesn't expect.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96002 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12 19:20:37 +00:00
Daniel Dunbar
ae08625085 Revert "Reverse the order for collecting the parts of an addrec. The order", it
is breaking llvm-gcc bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95988 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12 17:27:08 +00:00
Dan Gohman
f21a2f15aa Reverse the order for collecting the parts of an addrec. The order
doesn't matter, except that ScalarEvolution tends to need less time
to fold the results this way.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95979 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12 11:08:26 +00:00
Dan Gohman
572645cf84 Reapply the new LoopStrengthReduction code, with compile time and
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.

This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95975 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12 10:34:29 +00:00
Chris Lattner
98df4f9cf2 Make DSE only scan blocks that are reachable from the entry
block.  Other blocks may have pointer cycles that will crash
basicaa and other alias analyses.  In any case, there is no
point wasting cycles optimizing dead blocks.  This fixes 
rdar://7635088


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95852 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-11 05:11:54 +00:00
Chris Lattner
1e452650c6 Make jump threading honor x|undef -> true and x&undef -> false,
instead of considering x|undef -> x, which may not be true.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95850 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-11 04:40:44 +00:00
Devang Patel
be905e26f6 Ignore dbg info intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95828 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-11 00:20:49 +00:00
Dan Gohman
f451cb870e Fix "the the" and similar typos.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95781 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-10 16:03:48 +00:00
Eric Christopher
d2592ff69b Pull these back out, they're a little too aggressive and time
consuming for a simple optimization.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95671 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-09 17:29:18 +00:00
Eric Christopher
940ab54755 Add file in here too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95641 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-09 01:11:03 +00:00
Eric Christopher
1926b648e1 Add a new pass to do llvm.objsize lowering using SCEV.
Initial skeleton and SCEVUnknown lowering implemented,
the rest should come relatively quickly.  Move testcase
to new directory.

Move pass to right before SimplifyLibCalls - which is
moved down a bit so we can take advantage of a few opts.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95628 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-09 00:35:38 +00:00
Jakob Stoklund Olesen
d450e5b886 Don't unroll loops containing function calls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95454 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05 23:21:31 +00:00
Jakob Stoklund Olesen
58e9ee85fd Teach SimplifyCFG about magic pointer constants.
Weird code sometimes uses pointer constants other than null. This patch
teaches SimplifyCFG to build switch instructions in those cases.

Code like this:

void f(const char *x) {
  if (!x)
    puts("null");
  else if ((uintptr_t)x == 1)
    puts("one");
  else if (x == (char*)2 || x == (char*)3)
    puts("two");
  else if ((intptr_t)x == 4)
    puts("four");
  else
    puts(x);
}

Now becomes a switch:

define void @f(i8* %x) nounwind ssp {
entry:
  %magicptr23 = ptrtoint i8* %x to i64            ; <i64> [#uses=1]
  switch i64 %magicptr23, label %if.else16 [
    i64 0, label %if.then
    i64 1, label %if.then2
    i64 2, label %if.then9
    i64 3, label %if.then9
    i64 4, label %if.then14
  ]

Note that LLVM's own DenseMap uses magic pointers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95439 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05 22:03:18 +00:00
Dan Gohman
aa0e523287 Implement releaseMemory in CodeGenPrepare and free the BackEdges
container data. This prevents it from holding onto dangling
pointers and potentially behaving unpredictably.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95409 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05 19:24:11 +00:00
Bob Wilson
fc375d2200 Do not reassociate expressions with i1 type. SimplifyCFG converts some
short-circuited conditions to AND/OR expressions, and those expressions
are often converted back to a short-circuited form in code gen.  The
original source order may have been optimized to take advantage of the
expected values, and if we reassociate them, we change the order and
subvert that optimization.  Radar 7497329.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95333 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-04 23:32:37 +00:00
Bob Wilson
3992feb075 Adjust the heuristics used to decide when SROA is likely to be profitable.
The SRThreshold value makes perfect sense for checking if an entire aggregate
should be promoted to a scalar integer, but it is not so good for splitting
an aggregate into its separate elements.  A struct may contain a large embedded
array along with some scalar fields that would benefit from being split apart
by SROA.  Even if the total aggregate size is large, it may still be good to
perform SROA.  Thus, the most important piece of this patch is simply moving
the aggregate size comparison vs. SRThreshold so that it guards only the
aggregate promotion.

We have also been checking the number of elements to decide if an aggregate
should be split up.  The limit of "SRThreshold/4" seemed rather arbitrary,
and I don't think it's very useful to derive this limit from SRThreshold
anyway.  I've collected some data showing that the current default limit of
32 (since SRThreshold defaults to 128) is a reasonable cutoff for struct
types.  One thing suggested by the data is that distinguishing between structs
and arrays might be useful.  There are (obviously) a lot more large arrays
than large structs (as measured by the number of elements and not the total
size -- a large array inside a struct still counts as a single element given
the way we do SROA right now).  Out of 8377 arrays where we successfully
performed SROA while compiling a large set of benchmarks, only 16 of them had
more than 8 elements.  And, for those 16 arrays, it's not at all clear that
SROA was actually beneficial.  So, to offset the compile time cost of
investigating more large structs for SROA, the patch lowers the limit on array
elements to 8.

This fixes Apple Radar 7563690.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95224 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-03 17:23:56 +00:00
Evan Cheng
febc81680c Revert 94937 and move the noreturn check to codegen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95198 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-03 03:55:59 +00:00
Bob Wilson
e7b635f430 Fix some comment typos.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95170 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-03 00:33:21 +00:00
Eric Christopher
0c6a8f9eda Recommit this, looks like it wasn't the cause.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95165 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-03 00:21:58 +00:00
Eric Christopher
9f34dd305b Hopefully temporarily revert this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95154 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 23:01:31 +00:00
Eric Christopher
a6a089cd24 Re-add strcmp and known size object size checking optimization.
Passed bootstrap and nightly test run here.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95145 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 22:10:43 +00:00
Chris Lattner
3d606bbc92 fix a crash in loop unswitch on a loop invariant vector condition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95055 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 02:26:54 +00:00
Eric Christopher
11225dd710 Don't need to check the last argument since it'll always be bool. We also
don't use TargetData here.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95040 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 00:51:45 +00:00
Eric Christopher
3a8bb73690 More indentation/tabification fixes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95036 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 00:13:06 +00:00
Eric Christopher
eae6ed1084 Untabify previous commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95035 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 00:06:55 +00:00
Eric Christopher
6ddf0430e1 Formatting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95027 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-01 23:25:03 +00:00
Bob Wilson
6cad41778e Add an option to GVN to remove all partially redundant loads. This is currently
disabled by default.  This divides the existing load PRE code into 2 phases:
first it checks that it is safe to move the load to each of the predecessors
where it is unavailable, and then if it is safe, the code is changed to move
the load.  Radar 7571861.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95007 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-01 21:17:14 +00:00
Evan Cheng
56a5886b20 Do not mark no-return calls tail calls. It'll screw up special calls like longjmp and it doesn't make much sense for performance reason. If my logic is faulty, please let me know.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94937 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-31 00:59:31 +00:00
Bob Wilson
49db68fba0 Check alignment of loads when deciding whether it is safe to execute them
unconditionally.  Besides checking the offset, also check that the underlying
object is aligned as much as the load itself.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94875 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-30 04:42:39 +00:00