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Commit Graph

2445 Commits

Author SHA1 Message Date
Owen Anderson
6c2454d9d1 Fix a bug in GVN that Duncan noticed, where we potentially need to insert a
pointer bitcast when performing return slot optimization.

llvm-svn: 48343
2008-03-13 22:07:10 +00:00
Chris Lattner
7925cc72c0 Reimplement the parameter attributes support, phase #1. hilights:
1. There is now a "PAListPtr" class, which is a smart pointer around
   the underlying uniqued parameter attribute list object, and manages
   its refcount.  It is now impossible to mess up the refcount.
2. PAListPtr is now the main interface to the underlying object, and
   the underlying object is now completely opaque.
3. Implementation details like SmallVector and FoldingSet are now no
   longer part of the interface.
4. You can create a PAListPtr with an arbitrary sequence of
   ParamAttrsWithIndex's, no need to make a SmallVector of a specific 
   size (you can just use an array or scalar or vector if you wish).
5. All the client code that had to check for a null pointer before
   dereferencing the pointer is simplified to just access the 
   PAListPtr directly.
6. The interfaces for adding attrs to a list and removing them is a
   bit simpler.

Phase #2 will rename some stuff (e.g. PAListPtr) and do other less 
invasive changes.

llvm-svn: 48289
2008-03-12 17:45:29 +00:00
Owen Anderson
5887233a3f Improve the return slot optimization to be both more aggressive (not limited to sret parameters), and
safer (when the passed pointer might be invalid).  Thanks to Duncan and Chris for the idea behind this, 
and extra thanks to Duncan for helping me work out the trap-safety.

llvm-svn: 48280
2008-03-12 07:37:44 +00:00
Devang Patel
0c7fb89803 Skip functions that return multiple values.
llvm-svn: 48233
2008-03-11 18:04:06 +00:00
Devang Patel
cb8f342ea8 Become multiple return value aware.
Right now, the pass does not optimize tail recursions 
involving multiple return values.

llvm-svn: 48228
2008-03-11 17:33:32 +00:00
Devang Patel
e163bda565 Add TODO reminder.
llvm-svn: 48227
2008-03-11 17:32:05 +00:00
Devang Patel
6c189c16b5 Initial multiple return values support.
llvm-svn: 48210
2008-03-11 05:46:42 +00:00
Nick Lewycky
8626cfb86d SCCP also needs to be taught to follow unwind_to
llvm-svn: 48109
2008-03-09 09:44:38 +00:00
Nick Lewycky
1d6b50743f Don't eliminate blocks that are only reachable by unwind_to.
llvm-svn: 48106
2008-03-09 08:50:23 +00:00
Nick Lewycky
50c8d20ca2 Update the block cloner which fixes bugpoint on code using unwind_to (phew!)
and also update the cloning interface's major user, the loop optimizations.

llvm-svn: 48088
2008-03-09 05:24:34 +00:00
Nick Lewycky
e13db2c263 Not all users of a BB are Instructions any more.
llvm-svn: 48047
2008-03-08 07:48:41 +00:00
Nick Lewycky
f249c5d5ad Don't try to simplify urem and srem using arithmetic rules that don't work
under modulo (overflow). Fixes PR1933.

llvm-svn: 47987
2008-03-06 06:48:30 +00:00
Chris Lattner
75f5d14574 fix a bug Anders ran into where scalarrepl would crash when promoting
a union containing a vector and an array whose elements were smaller than
the vector elements.  this means we need to compile the load of the 
array elements into an extract element plus a truncate.

llvm-svn: 47752
2008-02-29 07:12:06 +00:00
Chris Lattner
8f87e409b2 Refactor some code out of ConvertUsesToScalar into their own methods, no
functionality change.

llvm-svn: 47751
2008-02-29 07:03:13 +00:00
Chris Lattner
5aeccb7353 Folding or(fcmp,fcmp) only works if the operands of the fcmps are the same fp type.
llvm-svn: 47750
2008-02-29 06:09:11 +00:00
Owen Anderson
eadd074b22 Fix an issue where GVN had the sizes of the two memcpy's reverse, resulting
in an invalid transformation.

llvm-svn: 47639
2008-02-26 23:06:17 +00:00
Gabor Greif
2cb16cddf1 fix http://llvm.org/bugs/show_bug.cgi?id=2097
llvm-svn: 47615
2008-02-26 19:13:21 +00:00
Eli Friedman
1f2cabfbcf Fix for pr2093: direct operands aren't necessarily addresses, so don't
try to simplify them.

llvm-svn: 47610
2008-02-26 18:37:49 +00:00
Bill Wendling
bd1f1ae160 De-tabify.
llvm-svn: 47599
2008-02-26 10:53:30 +00:00
Evan Cheng
6366bbf577 Fix PR2076. CodeGenPrepare now sinks address computation for inline asm memory
operands into inline asm block.

llvm-svn: 47589
2008-02-26 02:42:37 +00:00
Owen Anderson
6eafd532ab Fix an issue where GVN was performing the return slot optimization when it was
not safe.  This is fixed by more aggressively checking that the return slot is
not used elsewhere in the function.

llvm-svn: 47544
2008-02-25 04:08:09 +00:00
Owen Anderson
432abc0479 Fix an issue where GVN would try to use an instruction before its definition when performing return slot optimization.
llvm-svn: 47541
2008-02-25 00:40:41 +00:00
Dale Johannesen
ae08bdb4cf Split ParameterAttributes.h, putting the complicated
stuff into ParamAttrsList.h.  Per feedback from
ParamAttrs changes.

llvm-svn: 47504
2008-02-22 22:17:59 +00:00
Zhou Sheng
0742fbfedf Fixed a typo.
llvm-svn: 47478
2008-02-22 10:00:35 +00:00
Dan Gohman
48d03d5a2d Add explicit keywords.
llvm-svn: 47382
2008-02-20 16:44:09 +00:00
Anton Korobeynikov
c41f5b6af4 Fix newly-introduced 4.3 warnings
llvm-svn: 47375
2008-02-20 12:07:57 +00:00
Anton Korobeynikov
fd6b669c80 Make Transforms to be 4.3 warnings-clean
llvm-svn: 47371
2008-02-20 11:26:25 +00:00
Anton Korobeynikov
0c5e186924 Unbreak build with gcc 4.3: provide missed includes and silence most annoying warnings.
llvm-svn: 47367
2008-02-20 11:08:44 +00:00
Owen Anderson
52ed56338d When performing return slot optimization, remember to inform memdep when we're removing the memcpy.
llvm-svn: 47364
2008-02-20 08:23:02 +00:00
Dale Johannesen
ecb2b233b1 Expand ParameterAttributes to 32 bits (in preparation
for adding alignment info, not there yet).  Clean up
interfaces to reference ParameterAttributes consistently.

llvm-svn: 47342
2008-02-19 21:38:47 +00:00
Chris Lattner
010e9fb704 remove the lower packed pass. It can never work and even the parts that
could work don't work fully.  This fixes PR1705.  Oh yeah, we don't have
packed types anymore either ;-)

llvm-svn: 47322
2008-02-19 07:39:17 +00:00
Owen Anderson
6196cdcb48 Refactor this method a bit, and correct a test that was completely wrong but happened to work out anyways. :-)
llvm-svn: 47321
2008-02-19 07:07:51 +00:00
Chris Lattner
99e0b1c063 isa+cast -> dyncast.
llvm-svn: 47320
2008-02-19 06:53:20 +00:00
Chris Lattner
0ee0f38084 simplify this code again, try 2 :)
llvm-svn: 47319
2008-02-19 06:52:38 +00:00
Owen Anderson
d60bb0a64b Fix a comment.
llvm-svn: 47318
2008-02-19 06:51:23 +00:00
Owen Anderson
dbc264003e Major improvements to yesterday's return slot optimization. Remove some unneccessary constraints,
and add some others that should have been in from the first place.  Document the whole thing better.

llvm-svn: 47315
2008-02-19 06:35:43 +00:00
Chris Lattner
6bb889cf84 fdiv/frem of undef can produce undef, because the undef operand
can be a SNaN.  We could be more aggressive and turn this into 
unreachable, but that is less nice, and not really worth it.

llvm-svn: 47313
2008-02-19 06:12:18 +00:00
Owen Anderson
4e6f18d5bf Factor the profitability check for return slot optimization out into a static function.
At some point in the future, this check will become smarter.

llvm-svn: 47310
2008-02-19 03:27:34 +00:00
Owen Anderson
3782cd74d1 An sret parameter is required to be the first parameter, so there's no need to loop
over all the parameters of the callee looking for it.

llvm-svn: 47309
2008-02-19 03:15:29 +00:00
Owen Anderson
ea5cdf1a83 Cleanup some of my patches from yesterday. Refactor the check for which xform
to apply to a memcpy into processInstruction.  Also, fix a bug in the check due to
missing braces.

llvm-svn: 47307
2008-02-19 03:09:45 +00:00
Owen Anderson
5c258ed93d Fix Transforms/GVN/memcpy.ll, which Chris broke in r47275 by reordering the branches. memcpy's are a kind of CallInst.
llvm-svn: 47305
2008-02-19 02:53:23 +00:00
Nick Lewycky
1f3c58df08 Correctly fold divide-by-constant, even when faced with overflow.
llvm-svn: 47287
2008-02-18 22:48:05 +00:00
Chris Lattner
a378b03483 Transforming -A + -B --> -(A + B) isn't safe for FP, thanks
to Dale for noticing this!

llvm-svn: 47276
2008-02-18 17:50:16 +00:00
Chris Lattner
a3318d17d4 minor code simplification, no functionality change.
llvm-svn: 47275
2008-02-18 17:47:29 +00:00
Owen Anderson
7b092ea631 Add support to GVN for performing sret return slot optimization. This means that, if an sret function tail calls
another sret function, it should pass its own sret parameter to the tail callee, allowing it to fill in the correct
return value.  llvm-gcc does not emit this by default.  Instead, it allocates space in the caller for the sret of
the tail call and then uses memcpy to copy the result into the caller's sret parameter.  This optimization detects
and optimizes that case.

llvm-svn: 47265
2008-02-18 09:24:53 +00:00
Chris Lattner
9851db050b optimize away stackrestore calls that have no intervening alloca or call.
llvm-svn: 47258
2008-02-18 06:12:38 +00:00
Chris Lattner
0b6ec4a6b2 simplify some code, BreakUpSubtract always returns nonnull now.
llvm-svn: 47251
2008-02-18 02:18:25 +00:00
Chris Lattner
2fa904b3af Fold (-x + -y) -> -(x+y) which promotes better association, fixing
the second half of PR2047

llvm-svn: 47244
2008-02-17 21:03:36 +00:00
Chris Lattner
51a663a8fe fix pasto
llvm-svn: 47242
2008-02-17 20:54:40 +00:00
Chris Lattner
4a34461d64 Split up subtracts into add+negate if they have a reassociable use or operand
that is also a subtract.  This implements PR2047 and Transforms/Reassociate/subtest2.ll 

llvm-svn: 47241
2008-02-17 20:51:26 +00:00
Chris Lattner
cd6f9cea98 make the logic for breaking up subtracts more explicit, no
functionality change.

llvm-svn: 47239
2008-02-17 20:44:51 +00:00
Devang Patel
01f9252f73 Fix PR2028
llvm-svn: 47150
2008-02-15 01:24:49 +00:00
Devang Patel
8af92b942c If loop header is also loop exiting block then OrigPN is incoming value for B loop header.
Fixes PR 2030.

llvm-svn: 47141
2008-02-14 23:18:47 +00:00
Chris Lattner
5005b4d0d8 simplify code, no functionality change.
llvm-svn: 47116
2008-02-14 07:39:01 +00:00
Nick Lewycky
0dd6ce5d3a Fix PR2032. Inform the alias analysis of changes to the underlying program.
llvm-svn: 47111
2008-02-14 07:11:24 +00:00
Devang Patel
38de2d11a5 A loop latch phi node may have uses inside loop, not just in loop header.
llvm-svn: 47093
2008-02-13 22:23:07 +00:00
Dan Gohman
588498082a Rename APInt's isPositive to isNonNegative, to reflect what it
actually does.

llvm-svn: 47090
2008-02-13 22:09:18 +00:00
Devang Patel
1e71afe2df While moving exit condition, do not drop loop latch on the floor.
llvm-svn: 47089
2008-02-13 22:06:36 +00:00
Devang Patel
d48bbbf07b Keep track of exit value operand number when operands are swapped.
llvm-svn: 47082
2008-02-13 19:48:48 +00:00
Owen Anderson
274aa2846e Re-apply the patch to improve the optimizations of memcpy's, with several
bugs fixed.  This now passes PPC bootstrap.

llvm-svn: 47026
2008-02-12 21:15:18 +00:00
Eli Friedman
69268a529e Fix for bug 1996: optimize out loads of undef. This code basically just
checks for a malloc/alloca immediately followed by a load.

llvm-svn: 47006
2008-02-12 12:08:14 +00:00
Chris Lattner
068321707d Fix scalarrepl to not 'miscompile' undefined code, part #2.
This fixes the store case, my previous patch just fixed the load
case.  rdar://5707076.

llvm-svn: 46932
2008-02-10 19:05:37 +00:00
Devang Patel
9aba178666 Fix PR 1995.
llvm-svn: 46898
2008-02-08 22:49:13 +00:00
Bill Wendling
8a28ab4b1f Temporarily reverting:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20080128/057882.html

This is causing a miscompilation on PPC G5 and just now seeing it on iMac x86-64.

llvm-svn: 46822
2008-02-06 20:03:07 +00:00
Chris Lattner
96deed5d4d Fix a bug compiling PR1978 (perhaps not the only one though) which
was incorrectly simplifying "x == (gep x, 1, i)" into false, even 
though i could be negative.  As it turns out, all the code to 
handle this already existed, we just need to disable the incorrect
optimization case and let the general case handle it.

llvm-svn: 46739
2008-02-05 04:45:32 +00:00
Owen Anderson
af0449f9e0 Be more precise when eliminating pointers bue to memcpy's. This allows more
stores to be deleted in some cases.

llvm-svn: 46694
2008-02-04 04:53:00 +00:00
Owen Anderson
aaba6f96da Allow GVN to hack on memcpy's, making them open to further optimization.
llvm-svn: 46693
2008-02-04 02:59:58 +00:00
Nick Lewycky
febd3642ce There are some cases where icmp(add) can be folded into a new icmp. Handle them.
llvm-svn: 46687
2008-02-03 16:33:09 +00:00
Nick Lewycky
29cd604126 Hack on vectors too.
llvm-svn: 46684
2008-02-03 08:19:11 +00:00
Nick Lewycky
ce4c4698d7 Fold away one multiply in instcombine. This would normally be caught in
reassociate anyways, but they could be generated during instcombine's run.

llvm-svn: 46683
2008-02-03 07:42:09 +00:00
Nick Lewycky
ccd60a90c5 Remove a couple more cases of "getNumUses() == 0". No need to walk the linked
list just to see if whether the list is empty.

llvm-svn: 46555
2008-01-30 08:01:28 +00:00
Nick Lewycky
e3818dcc4e Use empty() instead of comparing size() with zero.
llvm-svn: 46554
2008-01-30 07:54:16 +00:00
Nick Lewycky
719599d263 Don't DCE FreeInst's. We were using those! Patch from Owen Anderson.
llvm-svn: 46553
2008-01-30 07:45:37 +00:00
Owen Anderson
ad9a347656 Make DSE much more aggressive by performing DCE earlier. Update a testcase to reflect this increased aggressiveness.
llvm-svn: 46542
2008-01-30 01:24:47 +00:00
Chris Lattner
83227e350d Fix a bug where scalarrepl would discard offset if type would match.
In practice this can only happen on code with already undefined behavior, 
but this is still a good thing to handle correctly.

llvm-svn: 46539
2008-01-30 00:39:15 +00:00
Dan Gohman
aad233ea10 Use empty() instead of comparing size() with zero.
llvm-svn: 46514
2008-01-29 13:02:09 +00:00
Chris Lattner
83f411c586 eliminate additions of 0.0 when they are obviously dead. This has to be careful to
avoid turning -0.0 + 0.0 -> -0.0 which is incorrect.

llvm-svn: 46499
2008-01-29 06:52:45 +00:00
Owen Anderson
96b9e5423a Add support for eliminating memcpy's at the end of functions. Also fix some errors I noticed in
the handling of eliminating stores to byval arguments.

llvm-svn: 46494
2008-01-29 06:18:36 +00:00
Devang Patel
86ff705c22 Filter loops that subtract induction variables.
These loops are not yet handled.

Fix PR 1912.

llvm-svn: 46484
2008-01-29 02:20:41 +00:00
Nick Lewycky
6b070b1b93 Handle some more combinations of extend and icmp. Fixes PR1940.
llvm-svn: 46431
2008-01-28 03:48:02 +00:00
Chris Lattner
359756ea4b Fix PR1932 by disabling an xform invalid for fdiv.
llvm-svn: 46429
2008-01-28 00:58:18 +00:00
Chris Lattner
7250586ec9 Fix PR1938 by forcing the code that uses an undefined value to branch one
way or the other.  Rewriting the code itself prevents subsequent analysis
passes from making contradictory conclusions about the code that could 
cause an infeasible path to be made feasible.

llvm-svn: 46427
2008-01-28 00:32:30 +00:00
Nick Lewycky
cd28ef8950 Be more careful modifying the use_list while also iterating through it.
llvm-svn: 46417
2008-01-27 18:35:00 +00:00
Bill Wendling
629a569ce9 The CorrelatedExpressionElimination pass is known to be buggy. Remove it.
This fixes PR1769.

llvm-svn: 46408
2008-01-27 06:11:41 +00:00
Chris Lattner
aa553aa0c1 Fold fptrunc(add (fpextend x), (fpextend y)) -> add(x,y), as GCC does.
llvm-svn: 46406
2008-01-27 05:29:54 +00:00
Bill Wendling
1c92468074 If there are no machine instructions emitted for a function, then insert
a "nop" instruction so that we don't have the function's label associated
with something that it's not supposed to be associated with.

llvm-svn: 46394
2008-01-26 06:51:24 +00:00
Bill Wendling
1e56a2ffb6 If we have a function like this:
void bork() {
  int *address = 0;
  *address = 0;
}

It's compiled into LLVM code that looks like this:

define void @bork() noreturn nounwind  {
entry:
        unreachable
}

This is bad on some platforms (like PPC) because it will generate the label for
the function but no body. The label could end up being associated with some
non-code related stuff, like a section. This places a "trap" instruction if the
SimplifyCFG pass removed all code from the function leaving only one
"unreachable" instruction.

llvm-svn: 46387
2008-01-26 01:43:44 +00:00
Owen Anderson
a4ff15c69f DeadStoreElimination can treat byval parameters as if there were alloca's for the purpose of removing end-of-function stores.
llvm-svn: 46351
2008-01-25 10:10:33 +00:00
Nick Lewycky
13b6bc91d6 Enable the fix I just checked in, silly me.
llvm-svn: 46247
2008-01-22 05:42:02 +00:00
Nick Lewycky
78780f175b Multiply can be evaluated in a different type, so long as the target type has
a smaller bitwidth.

llvm-svn: 46244
2008-01-22 05:08:48 +00:00
Duncan Sands
8a2778c20e Make sure the caller doesn't use freed memory.
Fixes PR1935.

llvm-svn: 46203
2008-01-20 16:51:46 +00:00
Duncan Sands
85db5b21a7 Initializing an unsigned with ~0UL causes the compiler
to complain on x86-64 (gcc 4.1).  Use ~0U instead.

llvm-svn: 46197
2008-01-20 10:49:23 +00:00
Duncan Sands
81e35b4d47 I noticed that the trampoline straightening transformation could
drop attributes on varargs call arguments.  Also, it could generate
invalid IR if the transformed call already had the 'nest' attribute
somewhere (this can never happen for code coming from llvm-gcc,
but it's a theoretical possibility).  Fix both problems.

llvm-svn: 45973
2008-01-14 19:52:09 +00:00
Chris Lattner
d22a5f6314 Turn a memcpy from a double* into a load/store of double instead of
a load/store of i64.  The later prevents promotion/scalarrepl of the
source and dest in many cases.

This fixes the 300% performance regression of the byval stuff on 
stepanov_v1p2.

llvm-svn: 45945
2008-01-14 00:28:35 +00:00
Chris Lattner
8560bb9d98 factor memcpy/memmove simplification out to its own SimplifyMemTransfer
method, no functionality change.

llvm-svn: 45944
2008-01-13 23:50:23 +00:00
Chris Lattner
5fbf76aaf4 simplify some code. If we can infer alignment for source and dest that are
greater than memcpy alignment, and if we lower to load/store, use the best 
alignment info we have.

llvm-svn: 45943
2008-01-13 22:30:28 +00:00
Chris Lattner
4f69f1a721 simplify some code by adding a InsertBitCastBefore method,
make memmove->memcpy conversion a bit simpler.

llvm-svn: 45942
2008-01-13 22:23:22 +00:00
Chris Lattner
32eae5daa5 Fix PR1907, a nasty miscompilation because instcombine didn't
realize that ne & sgt  was a signed comparison (it was only 
looking at whether the left compare was signed).

llvm-svn: 45937
2008-01-13 20:59:02 +00:00
Duncan Sands
7414cc131b When turning a call to a bitcast function into a direct call,
if this becomes a varargs call then deal correctly with any
parameter attributes on the newly vararg call arguments.

llvm-svn: 45931
2008-01-13 08:02:44 +00:00
Chris Lattner
67f581b344 Implement PR1795, an instcombine hack for forming GEPs with integer pointer arithmetic.
llvm-svn: 45745
2008-01-08 07:23:51 +00:00
Duncan Sands
7955cf0cd7 Small cleanup for handling of type/parameter attribute
incompatibility.

llvm-svn: 45704
2008-01-07 17:16:06 +00:00
Gordon Henriksen
f0803127c6 Deleting an empty file. Thanks, /usr/bin/patch!
llvm-svn: 45675
2008-01-07 02:29:04 +00:00
Gordon Henriksen
db4f51e1b9 With this patch, the LowerGC transformation becomes the
ShadowStackCollector, which additionally has reduced overhead with
no sacrifice in portability.

Considering a function @fun with 8 loop-local roots,
ShadowStackCollector introduces the following overhead
(x86):

; shadowstack prologue
        movl    L_llvm_gc_root_chain$non_lazy_ptr, %eax
        movl    (%eax), %ecx
        movl    $___gc_fun, 20(%esp)
        movl    $0, 24(%esp)
        movl    $0, 28(%esp)
        movl    $0, 32(%esp)
        movl    $0, 36(%esp)
        movl    $0, 40(%esp)
        movl    $0, 44(%esp)
        movl    $0, 48(%esp)
        movl    $0, 52(%esp)
        movl    %ecx, 16(%esp)
        leal    16(%esp), %ecx
        movl    %ecx, (%eax)

; shadowstack loop overhead
        (none)

; shadowstack epilogue
        movl    48(%esp), %edx
        movl    %edx, (%ecx)

; shadowstack metadata
        .align  3
___gc_fun:                              # __gc_fun
        .long   8
        .space  4

In comparison to LowerGC:

; lowergc prologue
        movl    L_llvm_gc_root_chain$non_lazy_ptr, %eax
        movl    (%eax), %ecx
        movl    %ecx, 48(%esp)
        movl    $8, 52(%esp)
        movl    $0, 60(%esp)
        movl    $0, 56(%esp)
        movl    $0, 68(%esp)
        movl    $0, 64(%esp)
        movl    $0, 76(%esp)
        movl    $0, 72(%esp)
        movl    $0, 84(%esp)
        movl    $0, 80(%esp)
        movl    $0, 92(%esp)
        movl    $0, 88(%esp)
        movl    $0, 100(%esp)
        movl    $0, 96(%esp)
        movl    $0, 108(%esp)
        movl    $0, 104(%esp)
        movl    $0, 116(%esp)
        movl    $0, 112(%esp)

; lowergc loop overhead
        leal    44(%esp), %eax
        movl    %eax, 56(%esp)
        leal    40(%esp), %eax
        movl    %eax, 64(%esp)
        leal    36(%esp), %eax
        movl    %eax, 72(%esp)
        leal    32(%esp), %eax
        movl    %eax, 80(%esp)
        leal    28(%esp), %eax
        movl    %eax, 88(%esp)
        leal    24(%esp), %eax
        movl    %eax, 96(%esp)
        leal    20(%esp), %eax
        movl    %eax, 104(%esp)
        leal    16(%esp), %eax
        movl    %eax, 112(%esp)

; lowergc epilogue
        movl    48(%esp), %edx
        movl    %edx, (%ecx)

; lowergc metadata
        (none)

llvm-svn: 45670
2008-01-07 01:30:53 +00:00
Duncan Sands
fd975e4b3d The transform that tries to turn calls to bitcast functions into
direct calls bails out unless caller and callee have essentially
equivalent parameter attributes.  This is illogical - the callee's
attributes should be of no relevance here.  Rework the logic, which
incidentally fixes a crash when removed arguments have attributes.

llvm-svn: 45658
2008-01-06 18:27:01 +00:00
Duncan Sands
b8489f09a2 When transforming a call to a bitcast function into
a direct call with cast parameters and cast return
value (if any), instcombine was prepared to cast any
non-void return value into any other, whether castable
or not.  Add a new predicate for testing whether casting
is valid, and check it both for the return value and
(as a cleanup) for the parameters.

llvm-svn: 45657
2008-01-06 10:12:28 +00:00
Chris Lattner
7e1c3aa702 remove a couple more unsafe xforms in the face of overflow.
llvm-svn: 45613
2008-01-05 01:22:42 +00:00
Chris Lattner
983697dfac remove the (x-y) < 0 comparison xform, it miscompiles
things that are not equality comparisons, for example:
   (2147479553+4096)-2147479553 < 0    !=   (2147479553+4096) < 2147479553

llvm-svn: 45612
2008-01-05 01:18:20 +00:00
Wojciech Matyjewicz
9ec15f974f fix typo
llvm-svn: 45594
2008-01-04 20:02:18 +00:00
Chris Lattner
ad9a6ccb83 Remove attribution from file headers, per discussion on llvmdev.
llvm-svn: 45418
2007-12-29 20:36:04 +00:00
Chris Lattner
8193d4af33 remove attribution from lib Makefiles.
llvm-svn: 45415
2007-12-29 20:09:26 +00:00
Christopher Lamb
dfad5f19b4 Disable null pointer folding transforms for non-generic address spaces. This should probably be a target-specific predicate based on address space. That way for targets where this isn't applicable the predicate can be optimized away.
llvm-svn: 45403
2007-12-29 07:56:53 +00:00
Owen Anderson
ebd3e9c500 Repair a transform that Chris noticed a bug in. Thanks to Nicholas for pointing out my stupid mistakes when writing this patch. :-)
llvm-svn: 45384
2007-12-28 07:42:12 +00:00
Chris Lattner
2456399ce5 disable this instcombine xform, it miscompiles:
define i32 @main() {
entry:
	%z = alloca i32		; <i32*> [#uses=2]
	store i32 0, i32* %z
	%tmp = load i32* %z		; <i32> [#uses=1]
	%sub = sub i32 %tmp, 1		; <i32> [#uses=1]
	%cmp = icmp ult i32 %sub, 0		; <i1> [#uses=1]
	%retval = select i1 %cmp, i32 1, i32 0		; <i32> [#uses=1]
	ret i32 %retval
}

into ret 1, instead of ret 0.

Christopher, please investigate.

llvm-svn: 45383
2007-12-28 06:24:31 +00:00
Chris Lattner
90df7f7424 Don't break critical edges for single-bb loops, this helps with PR1877, though
it is only a partial fix.  This change is noise for most programs, but
speeds up Shootout-C++/matrix by 20%, Ptrdist/ks by 24%, smg2000 by 8%,
hexxagon by 9%, bzip2 by 9% (not sure I trust this), ackerman by 13%, etc.

OTOH, it slows down Shootout/fib2 by 40% (I'll update PR1877 with this info).

llvm-svn: 45354
2007-12-25 19:06:45 +00:00
Chris Lattner
7e1e1f2933 add a -backedge-hack llc-beta option to codegenprepare.
When specified, don't split backedges of single-bb loops.
This helps address PR1877

llvm-svn: 45344
2007-12-24 19:32:55 +00:00
Chris Lattner
d64df490ca implement InstCombine/shift-trunc-shift.ll. This allows
us to compile:
#include <math.h>
int t1(double d) { return signbit(d); }

into:

_t1:
	movd	%xmm0, %rax
	shrq	$63, %rax
	ret

instead of:

_t1:
	movd	%xmm0, %rax
	shrq	$32, %rax
	shrl	$31, %eax
	ret

on x86-64.

llvm-svn: 45311
2007-12-22 09:07:47 +00:00
Christopher Lamb
7ca648a7b1 Implement review feedback, including additional transforms
(icmp slt (sub A B) 1) -> (icmp sle A B)
icmp sgt (sub A B) -1) -> (icmp sge A B)

and add testcase.

llvm-svn: 45256
2007-12-20 07:21:11 +00:00
Evan Cheng
eb07401701 Clean up previous patch: PHI uses should not prevent iv reuse if all other uses are addresses. This trades a constant multiply for one fewer iv.
llvm-svn: 45251
2007-12-20 02:20:53 +00:00
Chris Lattner
1a386cbdae simplify this code with the new m_Zero() pattern. Make sure the select only
has a single use, and generalize it to not require N to be a constant.

llvm-svn: 45250
2007-12-20 01:56:58 +00:00
Evan Cheng
cf7b6b419a Allow iv reuse if the user is a PHI node which is in turn used as addresses.
llvm-svn: 45230
2007-12-19 23:33:23 +00:00
Duncan Sands
56f3add5b7 When inlining through an 'nounwind' call, mark inlined
calls 'nounwind'.  It is important for correct C++
exception handling that nounwind markings do not get
lost, so this transformation is actually needed for
correctness.

llvm-svn: 45218
2007-12-19 21:13:37 +00:00
Christopher Lamb
be0cbc7e92 Fold subtracts into integer compares vs. zero. This improves generate code for this case on X86
from
_foo:
        movl    $99, %ecx
        movl    4(%esp), %eax
        subl    %eax, %ecx
        xorl    %edx, %edx
        testl   %ecx, %ecx
        cmovs   %edx, %eax
        ret

to
_foo:
        xorl    %ecx, %ecx
        movl    4(%esp), %eax
        cmpl    $99, %eax
        cmovg   %ecx, %eax
        ret

llvm-svn: 45173
2007-12-18 21:32:20 +00:00
Christopher Lamb
051a1320e8 Fix comments
llvm-svn: 45170
2007-12-18 20:33:11 +00:00
Christopher Lamb
d56318b885 Remove an orthogonal transformation of the selection condition from my most recent submission.
llvm-svn: 45169
2007-12-18 20:30:28 +00:00
Duncan Sands
242f80be86 Rename isNoReturn to doesNotReturn, and isNoUnwind to
doesNotThrow.

llvm-svn: 45160
2007-12-18 09:59:50 +00:00
Christopher Lamb
437b4d229e Fix typos.
llvm-svn: 45159
2007-12-18 09:45:40 +00:00
Christopher Lamb
aeb76743dc Fold certain additions through selects (and their compares) so as to eliminate subtractions. This code is often produced by the SMAX expansion in SCEV.
This implements test/Transforms/InstCombine/2007-12-18-AddSelCmpSub.ll

llvm-svn: 45158
2007-12-18 09:34:41 +00:00
David Greene
3f3a521a33 Get rid of annoying spaces.
llvm-svn: 45100
2007-12-17 17:40:29 +00:00
David Greene
8fda00ca05 Fix GLIBCXX_DEBUG errors. Erase invalidates std::vector iterators
passed the erased element.

llvm-svn: 45099
2007-12-17 17:39:51 +00:00
Christopher Lamb
a608afb52e Change the PointerType api for creating pointer types. The old functionality of PointerType::get() has become PointerType::getUnqual(), which returns a pointer in the generic address space. The new prototype of PointerType::get() requires both a type and an address space.
llvm-svn: 45082
2007-12-17 01:12:55 +00:00
Duncan Sands
bf62f62058 Make instcombine promote inline asm calls to 'nounwind'
calls.  Remove special casing of inline asm from the
inliner.  There is a potential problem: the verifier
rejects invokes of inline asm (not sure why).  If an
asm call is not marked "nounwind" in some .ll, and
instcombine is not run, but the inliner is run, then
an illegal module will be created.  This is bad but
I'm not sure what the best approach is.  I'm tempted
to remove the check in the verifier...

llvm-svn: 45073
2007-12-16 15:51:49 +00:00
Evan Cheng
4acb4eb95e Fix typo.
llvm-svn: 44997
2007-12-13 07:50:36 +00:00
Evan Cheng
a152909956 Be extra careful with extension use optimation. Now turned on by default.
llvm-svn: 44981
2007-12-13 03:32:53 +00:00
Wojciech Matyjewicz
8bb1d9e67c 1. "Upgrage" comments.
2. Using zero-extended value of Scale and unsigned division is safe provided
   that Scale doesn't have the sign bit set.
   Previously these 2 instructions:
        %p = bitcast [100 x {i8,i8,i8}]* %x to i8*
        %q = getelementptr i8* %p, i32 -4
   were combined into:
        %q = getelementptr [100 x { i8, i8, i8 }]* %x, i32 0,
               i32 1431655764, i32 0
   what was incorrect.

llvm-svn: 44936
2007-12-12 15:21:32 +00:00
Evan Cheng
bb418c4551 Don't muck with phi nodes; bug fixes.
llvm-svn: 44905
2007-12-12 02:53:41 +00:00
Evan Cheng
d6ecb2e58d Bug fix. Only safe to perform extension uses optimization if the source of extension is also defined in the same BB as the extension.
llvm-svn: 44896
2007-12-12 00:51:06 +00:00
Duncan Sands
b7ac459292 Make PruneEH update the nounwind/noreturn attributes
on functions as it calculates them.

llvm-svn: 44802
2007-12-10 19:09:40 +00:00
Owen Anderson
e3de18ac1d Fix several cache coherence bugs in MemDep/GVN that were found. Also add some (disabled) debugging code
to make such problems easier to diagnose in the future, written by Duncan Sands.

llvm-svn: 44695
2007-12-08 01:37:09 +00:00
Chris Lattner
861df2f4e9 simplify some code.
llvm-svn: 44655
2007-12-06 06:25:04 +00:00
Chris Lattner
1f2a96f9c1 move some ashr-specific code out of commonShiftTransforms into visitAShr.
llvm-svn: 44650
2007-12-06 01:59:46 +00:00
Evan Cheng
9e69c0ada8 If both result of the {s|z}xt and its source are live out, rewrite all uses of the source with result of extension.
llvm-svn: 44643
2007-12-05 23:58:20 +00:00
Duncan Sands
1e2e4972ff Rather than having special rules like "intrinsics cannot
throw exceptions", just mark intrinsics with the nounwind
attribute.  Likewise, mark intrinsics as readnone/readonly
and get rid of special aliasing logic (which didn't use
anything more than this anyway).

llvm-svn: 44544
2007-12-03 20:06:50 +00:00
Chris Lattner
0c41f32943 update file comment.
llvm-svn: 44543
2007-12-03 19:43:18 +00:00
Devang Patel
c47f68e747 If ExitValue operand is also defined in Loop header then
insert new ExitValue after this operand definition.

This fixes PR1828.

llvm-svn: 44539
2007-12-03 19:17:21 +00:00
Duncan Sands
14f11d6836 Integrate the readonly/readnone logic more deeply
into alias analysis.  This meant updating the API
which now has versions of the getModRefBehavior,
doesNotAccessMemory and onlyReadsMemory methods
which take a callsite parameter.  These should be
used unless the callsite is not known, since in
general they can do a better job than the versions
that take a function.  Also, users should no longer
call the version of getModRefBehavior that takes
both a function and a callsite.  To reduce the
chance of misuse it is now protected.

llvm-svn: 44487
2007-12-01 07:51:45 +00:00
Owen Anderson
3b893e1f84 Fix a miscompilation in spiff on PPC.
llvm-svn: 44437
2007-11-29 18:02:22 +00:00
Duncan Sands
1b0feb42e2 Add some convenience methods for querying attributes, and
use them.

llvm-svn: 44403
2007-11-28 17:07:01 +00:00
Duncan Sands
3602011bec Fix PR1146: parameter attributes are longer part of
the function type, instead they belong to functions
and function calls.  This is an updated and slightly
corrected version of Reid Spencer's original patch.
The only known problem is that auto-upgrading of
bitcode files doesn't seem to work properly (see
test/Bitcode/AutoUpgradeIntrinsics.ll).  Hopefully
a bitcode guru (who might that be? :) ) will fix it.

llvm-svn: 44359
2007-11-27 13:23:08 +00:00
Owen Anderson
43d4a82d4b Make LoopInfoBase more generic, in preparation for having MachineLoopInfo. This involves a small interface change.
llvm-svn: 44348
2007-11-27 03:43:35 +00:00
Owen Anderson
2aa0218a6c Fix another bug that was causing siod to fail.
llvm-svn: 44325
2007-11-26 07:17:19 +00:00