Commit Graph

3753 Commits

Author SHA1 Message Date
Nick Lewycky c1f8658368 Add C++ global operator {new,new[],delete,delete[]}(unsigned {int,long}) to the
memory builtins as equivalent to malloc/free.

This is different from any attribute we have. For example, you can delete the
allocators when their result is unused, but you can't collapse two calls to the
same function, even if no global/memory state has changed in between. The
noalias return states that the result does not alias any other pointer, but
instcombine optimizes malloc() as though the result is non-null for the purpose
of eliminating unused pointers.

llvm-svn: 127673
2011-03-15 07:31:32 +00:00
Andrew Trick a34f1b1f10 Remove getMinusSCEVForExitTest().
This function performed acrobatics to prove no-self-wrap, which we now
have for free.

llvm-svn: 127643
2011-03-15 01:16:14 +00:00
Andrew Trick f6b01ff422 Propagate SCEV no-wrap flags whenever possible.
This needs review.

llvm-svn: 127638
2011-03-15 00:37:00 +00:00
Andrew Trick e92dcceab7 Negating a recurrence preserves no-self-wrap.
llvm-svn: 127593
2011-03-14 17:38:54 +00:00
Andrew Trick f1781db622 HowFarToZero can compute a trip count as long as the recurrence has no-self-wrap.
llvm-svn: 127591
2011-03-14 17:28:02 +00:00
Andrew Trick 8b55b736b1 Added SCEV::NoWrapFlags to manage unsigned, signed, and self wrap
properties.
Added the self-wrap flag for SCEV::AddRecExpr.
A slew of temporary FIXMEs indicate the intention of the no-self-wrap flag
without changing behavior in this revision.

llvm-svn: 127590
2011-03-14 16:50:06 +00:00
Benjamin Kramer 5acc751b6f Teach ComputeMaskedBits about sub nsw.
llvm-svn: 127548
2011-03-12 17:18:11 +00:00
Benjamin Kramer 391a946fa9 ComputeMaskedBits: sub falls through to add, and sub doesn't have the same overflow semantics as add.
Should fix the selfhost failures that started with r127463.

llvm-svn: 127465
2011-03-11 14:46:49 +00:00
Nick Lewycky cc79973856 Teach ComputeMaskedBits about nsw on add. I don't think there's anything we can
do with nuw here, but sub and mul should be given similar treatment.
Fixes PR9343 #15!

llvm-svn: 127463
2011-03-11 09:00:19 +00:00
Devang Patel fa31d38aad Introduce DebugInfoProbe. This is used to monitor how llvm optimizer is treating debugging information.
It generates output that lools like

8 times line number info lost by Scalar Replacement of Aggregates (SSAUp) 
1 times line number info lost by Simplify well-known library calls 
12 times variable info lost by Jump Threading

llvm-svn: 127381
2011-03-10 00:21:25 +00:00
Andrew Trick 2afa325811 When SCEV can determine the loop test is X < X, set ExactBECount=0.
When ExactBECount is a constant, use it for MaxBECount.
When MaxBECount cannot be computed, replace it with ExactBECount.
Fixes PR9424.

llvm-svn: 127342
2011-03-09 17:29:58 +00:00
Andrew Trick 2a3b71684a whitespace
llvm-svn: 127340
2011-03-09 17:23:39 +00:00
Nick Lewycky 774647d974 Fix two cases I forgot to update when doing a mental "getSwappedPredicate".
Thanks Duncan Sands!

llvm-svn: 127323
2011-03-09 08:20:06 +00:00
Nick Lewycky 980104d1d6 Add another micro-optimization. Apologies for the lack of refactoring, but I
gave up when I realized I couldn't come up with a good name for what the
refactored function would be, to describe what it does.

This is PR9343 test12, which is test3 with arguments reordered. Whoops!

llvm-svn: 127318
2011-03-09 06:26:03 +00:00
Duncan Sands 7dc3d47c34 Fix PR9331. Simplified version of a patch by Jakub Staszak.
llvm-svn: 127243
2011-03-08 12:39:03 +00:00
Nick Lewycky e467979d0a Add more analysis of the sign bit of an srem instruction. If the LHS is negative
then the result could go either way. If it's provably positive then so is the
srem. Fixes PR9343 #7!

llvm-svn: 127146
2011-03-07 01:50:10 +00:00
Nick Lewycky 9719a719c7 Thread comparisons over udiv/sdiv/ashr/lshr exact and lshr nuw/nsw whenever
possible. This goes into instcombine and instsimplify because instsimplify
doesn't need to check hasOneUse since it returns (almost exclusively) constants.

This fixes PR9343 #4 #5 and #8!

llvm-svn: 127064
2011-03-05 05:19:11 +00:00
Dan Gohman aa036eedb8 When decling to reuse existing expressions that involve casts, ignore
bitcasts, which are really no-ops here. This fixes slowdowns on
MultiSource/Applications/aha and others.

llvm-svn: 127031
2011-03-04 20:46:46 +00:00
Nick Lewycky 41c529bd09 Revert broken srem logic from r126991.
llvm-svn: 127021
2011-03-04 19:26:08 +00:00
Nick Lewycky 8e3a79da9f Fold "icmp pred (srem X, Y), Y" like we do for urem. Handle signed comparisons
in the urem case, though not the other way around. This is enough to get #3 from
PR9343!

llvm-svn: 126991
2011-03-04 10:06:52 +00:00
Nick Lewycky 3cec6f5563 Teach instruction simplify to use constant ranges to solve problems of the form
"icmp pred %X, CI" and a number of examples where "%X = binop %Y, CI2".

Some of these cases (div and rem) used to make it through opt -O2, but the
others are probably now making code elsewhere redundant (probably instcombine).

llvm-svn: 126988
2011-03-04 07:00:57 +00:00
Duncan Sands bf577d6a86 Remove DIFactory. Patch by Devang.
llvm-svn: 126871
2011-03-02 20:30:37 +00:00
Dan Gohman 7290868a1b Don't re-use existing addrec expansions if they contain casts.
This fixes PR9259.

llvm-svn: 126812
2011-03-02 01:34:10 +00:00
Devang Patel 40eee1e970 Today, the language front ends produces llvm.dbg.* intrinsics, used to encode arguments' debug info, in order any way, most of the times. However, if a front end mix-n-matches llvm.dbg.declare and llvm.dbg.value intrinsics to encode debug info for arguments then code generator needs a way to find argument order.
Use 8 bits from line number field to keep track of argument ordering while encoding debug info for an argument. That leaves 24 bit for line no, DebugLoc also allocates 24 bit for line numbers. If a function has more than 255 arguments then rest of the arguments will be ordered by llvm.dbg.* intrinsics' ordering in IR.

llvm-svn: 126793
2011-03-01 22:58:13 +00:00
Nick Lewycky c9d20067cd Optimize "icmp pred (urem X, Y), Y" --> true/false depending on pred. There's
more work to do here, "icmp ult (urem X, 10), 11" doesn't optimize away yet.
Fixes example 3 from PR9343!

llvm-svn: 126741
2011-03-01 08:15:50 +00:00
Ted Kremenek 49d15b959e Unbreak CMake build.
llvm-svn: 126717
2011-03-01 00:02:51 +00:00
Dan Gohman 161058838c Delete the LiveValues pass. I won't get get back to the project it
was started for in the foreseeable future.

llvm-svn: 126668
2011-02-28 19:37:59 +00:00
Nick Lewycky afe4a3062d Fix comment.
llvm-svn: 126645
2011-02-28 09:18:11 +00:00
Nick Lewycky 66f4f22f7b srem doesn't actually have the same resulting sign as its numerator, you could
also have a zero when numerator = denominator. Reverts parts of r126635 and
r126637.

llvm-svn: 126644
2011-02-28 09:17:39 +00:00
Nick Lewycky c9aab8567b Teach value tracking to make use of flags in more situations.
llvm-svn: 126642
2011-02-28 08:02:21 +00:00
Nick Lewycky 29dbbd12c1 Teach ValueTracking to look at the dividend when determining the sign bit of an
srem instruction.

llvm-svn: 126637
2011-02-28 06:52:12 +00:00
Tobias Grosser 98eecaf0a9 RegionPrinter: Ignore back edges when layouting the graph
llvm-svn: 126564
2011-02-27 04:11:07 +00:00
Devang Patel 9b4127349c Follow LLVM coding style.
clang uses DBuilder, so it requries corresponding change.

llvm-svn: 126231
2011-02-22 18:56:12 +00:00
Benjamin Kramer 5b7a4e0195 Move "A | ~(A & ?) -> -1" from InstCombine to InstructionSimplify.
llvm-svn: 126082
2011-02-20 15:20:01 +00:00
Chris Lattner acf6b0776a Stores of null pointers should turn into memset, we weren't recognizing
them as splat values.

llvm-svn: 126041
2011-02-19 19:35:49 +00:00
Oscar Fuentes 5ed962656c Move library stuff out of the toplevel CMakeLists.txt file.
llvm-svn: 125968
2011-02-18 22:06:14 +00:00
Devang Patel 4ab0852080 Move DbgInfoPrinter specific utlities inside DbgInfoPrinter.cpp
llvm-svn: 125571
2011-02-15 17:36:11 +00:00
Devang Patel 27924da676 Print function info. Patch by Minjang Kim.
llvm-svn: 125567
2011-02-15 17:24:56 +00:00
Chris Lattner 69229316aa convert ConstantVector::get to use ArrayRef.
llvm-svn: 125537
2011-02-15 00:14:00 +00:00
Chris Lattner 34442e6ebf revert my ConstantVector patch, it seems to have made the llvm-gcc
builders unhappy.

llvm-svn: 125504
2011-02-14 18:15:46 +00:00
Chris Lattner d9f5b88548 Switch ConstantVector::get to use ArrayRef instead of a pointer+size
idiom.  Change various clients to simplify their code.

llvm-svn: 125487
2011-02-14 07:55:32 +00:00
Duncan Sands b86070933f Remove pointless blank line.
llvm-svn: 125463
2011-02-13 18:11:05 +00:00
Duncan Sands d114ab331c Teach instsimplify that X+Y>=X+Z is the same as Y>=Z if neither side overflows,
plus some variations of this.  According to my auto-simplifier this occurs a lot
but usually in combination with max/min idioms.  Because max/min aren't handled
yet this unfortunately doesn't have much effect in the testsuite.

llvm-svn: 125462
2011-02-13 17:15:40 +00:00
Chris Lattner 4f23f2be15 teach SCEV that the scale and addition of an inbounds gep don't NSW.
This fixes a FIXME in scev-aa.ll (allowing a new no-alias result) and
generally makes things more precise.

llvm-svn: 125449
2011-02-13 03:14:49 +00:00
Chris Lattner 7936a8a488 Per discussion with Dan G, inbounds geps *certainly* can have
unsigned overflow (e.g. "gep P, -1"), and while they can have
signed wrap in theoretical situations, modelling an AddRec as
not having signed wrap is going enough for any case we can 
think of today.  In the future if this isn't enough, we can
revisit this.  Modeling them as having NUW isn't causing any
known problems either FWIW.

llvm-svn: 125410
2011-02-11 21:43:33 +00:00
Nick Lewycky ac0b62c277 Tolerate degenerate phi nodes that can occur in the middle of optimization
passes. Fixes PR9112. Patch by Jakub Staszak!

llvm-svn: 125319
2011-02-10 23:54:10 +00:00
Duncan Sands 8b4e283bfb Formatting and comment tweaks.
llvm-svn: 125200
2011-02-09 17:45:03 +00:00
Chris Lattner 9e4aa0259f Teach instsimplify some tricks about exact/nuw/nsw shifts.
improve interfaces to instsimplify to take this info.

llvm-svn: 125196
2011-02-09 17:15:04 +00:00
Chris Lattner b940091388 Rework InstrTypes.h so to reduce the repetition around the NSW/NUW/Exact
versions of creation functions.  Eventually, the "insertion point" versions
of these should just be removed, we do have IRBuilder afterall.

Do a massive rewrite of much of pattern match.  It is now shorter and less
redundant and has several other widgets I will be using in other patches.
Among other changes, m_Div is renamed to m_IDiv (since it only matches 
integer divides) and m_Shift is gone (it used to match all binops!!) and
we now have m_LogicalShift for the one client to use.

Enhance IRBuilder to have "isExact" arguments to things like CreateUDiv
and reduce redundancy within IRbuilder by having these methods chain to
each other more instead of duplicating code.

llvm-svn: 125194
2011-02-09 17:00:45 +00:00
Duncan Sands 867cb633b4 Add an m_Div pattern for matching either a udiv or an sdiv and use it
to simplify the "(X/Y)*Y->X when the division is exact" transform.

llvm-svn: 125004
2011-02-07 09:36:32 +00:00