Commit Graph

7659 Commits

Author SHA1 Message Date
Chris Lattner
6cdf2ea98e implement the first part of PR8882: when lowering an inbounds
gep to explicit addressing, we know that none of the intermediate
computation overflows.

This could use review: it seems that the shifts certainly wouldn't
overflow, but could the intermediate adds overflow if there is a 
negative index?

Previously the testcase would instcombine to:

define i1 @test(i64 %i) {
  %p1.idx.mask = and i64 %i, 4611686018427387903
  %cmp = icmp eq i64 %p1.idx.mask, 1000
  ret i1 %cmp
}

now we get:

define i1 @test(i64 %i) {
  %cmp = icmp eq i64 %i, 1000
  ret i1 %cmp
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125271 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10 07:11:16 +00:00
Chris Lattner
7a6aa1a391 Enhance a bunch of transformations in instcombine to start generating
exact/nsw/nuw shifts and have instcombine infer them when it can prove
that the relevant properties are true for a given shift without them.

Also, a variety of refactoring to use the new patternmatch logic thrown
in for good luck.  I believe that this takes care of a bunch of related
code quality issues attached to PR8862.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125267 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10 05:36:31 +00:00
Chris Lattner
b20c0b5092 Enhance the "compare with shift" and "compare with div"
optimizations to be much more aggressive in the face of
exact/nsw/nuw div and shifts.  For example, these (which
are the same except the first is 'exact' sdiv:

define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
  %A = sdiv exact i64 %X, -5   ; X/-5 == 0 --> x == 0
  %B = icmp eq i64 %A, 0
  ret i1 %B
}

define i1 @sdiv_icmp4(i64 %X) nounwind {
  %A = sdiv i64 %X, -5   ; X/-5 == 0 --> x == 0
  %B = icmp eq i64 %A, 0
  ret i1 %B
}

compile down to:

define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
  %1 = icmp eq i64 %X, 0
  ret i1 %1
}

define i1 @sdiv_icmp4(i64 %X) nounwind {
  %X.off = add i64 %X, 4
  %1 = icmp ult i64 %X.off, 9
  ret i1 %1
}

This happens when you do something like:
  (ptr1-ptr2) == 42

where the pointers are pointers to non-unit types.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125266 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10 05:23:05 +00:00
Chris Lattner
44cc997d42 more cleanups, notably bitcast isn't used for "signed to unsigned type
conversions". :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125265 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10 05:17:27 +00:00
Chris Lattner
b9b9044600 A bunch of cleanups and simplifications using the new PatternMatch predicates
and generally tidying things up.  Only very trivial functionality changes
like now doing (-1 - A) -> (~A) for vectors too.

 InstCombineAddSub.cpp |  296 +++++++++++++++++++++-----------------------------
 1 file changed, 126 insertions(+), 170 deletions(-)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125264 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10 05:14:58 +00:00
Chris Lattner
a81556fb52 teach SimplifyDemandedBits that exact shifts demand the bits they
are shifting out since they do require them to be zeros.  Similarly
for NUW/NSW bits of shl


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125263 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10 05:09:34 +00:00
Eric Christopher
6793c49bb4 Revert this in an attempt to bring the builders back.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125257 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10 01:48:24 +00:00
Cameron Zwarich
de0c42a73a Turn this pass ordering:
Natural Loop Information
 Loop Pass Manager
   Canonicalize natural loops
 Scalar Evolution Analysis
 Loop Pass Manager
   Induction Variable Users
   Canonicalize natural loops
   Induction Variable Users
   Loop Strength Reduction

into this:

Scalar Evolution Analysis
Loop Pass Manager
  Canonicalize natural loops
  Induction Variable Users
  Loop Strength Reduction

This fixes <rdar://problem/8869639>. I also filed PR9184 on doing this sort of
thing automatically, but it seems easier to just change the ordering of the
passes if this is the only case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125254 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10 01:07:54 +00:00
Chris Lattner
81a0dc9115 Teach instsimplify some tricks about exact/nuw/nsw shifts.
improve interfaces to instsimplify to take this info.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125196 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-09 17:15:04 +00:00
Chris Lattner
aeaf3d484b 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.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125194 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-09 17:00:45 +00:00
Nick Lewycky
3ba974a1c5 When removing a function from the function set and adding it to deferred, we
could end up removing a different function than we intended because it was
functionally equivalent, then end up with a comparison of a function against
itself in the next round of comparisons (the one in the function set and the
one on the deferred list). To fix this, I introduce a choice in the form of
comparison for ComparableFunctions, either normal or "pointer only" used to
find exact Function*'s in lookups.

Also add some debugging statements.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125180 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-09 06:32:02 +00:00
Dan Gohman
3ef9838f89 Don't split any loop backedges, including backedges of loops other than
the active loop. This is generally desirable, and it avoids trouble
in situations such as the testcase in PR9123, though the failure
mode depends on use-list order, so it is infeasible to test.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125065 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-08 00:55:13 +00:00
Benjamin Kramer
33828bcb24 SimplifyCFG: Track the number of used icmps when turning a icmp chain into a switch. If we used only one icmp, don't turn it into a switch.
Also prevent the switch-to-icmp transform from creating identity adds, noticed by Marius Wachtler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125056 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-07 22:37:28 +00:00
Chris Lattner
35bda8914c enhance vmcore to know that udiv's can be exact, and add a trivial
instcombine xform to exercise this.

Nothing forms exact udivs yet though.  This is progress on PR8862



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124992 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-06 21:44:57 +00:00
Nick Lewycky
39c33e3b63 Simplify away redundant test, and document what's going on.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124977 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-06 05:04:00 +00:00
Nick Lewycky
d489332549 Remove specialized comparison of InlineAsm objects. They're uniqued on creation
now, and this wasn't comparing some of their relevant bits anyhow.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124976 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-06 04:33:50 +00:00
Benjamin Kramer
042b27f40e SimplifyCFG: Also transform switches that represent a range comparison but are not sorted into sub+icmp.
This transforms another 1000 switches in gcc.c.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124826 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-03 22:51:41 +00:00
Benjamin Kramer
56442dfdcf SimplifyCFG: Turn switches into sub+icmp+branch if possible.
This makes the job of the later optzn passes easier, allowing the vast amount of
icmp transforms to chew on it.

We transform 840 switches in gcc.c, leading to a 16k byte shrink of the resulting
binary on i386-linux.

The testcase from README.txt now compiles into
  decl  %edi
  cmpl  $3, %edi
  sbbl  %eax, %eax
  andl  $1, %eax
  ret

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124724 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02 15:56:22 +00:00
Nick Lewycky
8eb3e54592 Remove wasteful caching. This isn't needed for correctness because any function
that might have changed been affected by a merge elsewhere will have been
removed from the function set, and it isn't needed for performance because we
call grow() ahead of time to prevent reallocations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124717 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02 05:31:01 +00:00
Dan Gohman
5195b71941 Conservatively, clear optional flags, such as nsw, when performing
reassociation. No testcase, because I wasn't able to create a testcase
which actually demonstrates a problem.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124713 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02 02:05:46 +00:00
Dan Gohman
46985a1440 Fix reassociate to clear optional flags, such as nsw.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124712 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02 02:02:34 +00:00
Anders Carlsson
77bc49e5e2 Recognize and simplify
(A+B) == A  ->  B == 0
A == (A+B)  ->  B == 0



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124567 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-30 22:01:13 +00:00
Francois Pichet
337c081138 Unbreak the MSVC build.
The DEBUG() call at line 606 demands to see raw_ostream's definition. I have no idea why this seems to only break MSVC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124545 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 20:06:16 +00:00
Frits van Bommel
31726c154d Call SimplifyFDivInst() in InstCombiner::visitFDiv().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124535 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 17:50:27 +00:00
Frits van Bommel
1fca2c32cc Move InstCombine's knowledge of fdiv to SimplifyInstruction().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124534 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 15:26:31 +00:00
Evan Cheng
60f5ad46c2 Add a test for TCE return duplication.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124527 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 04:53:35 +00:00
Evan Cheng
c3f507f98a Re-apply r124518 with fix. Watch out for invalidated iterator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124526 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 04:46:23 +00:00
Evan Cheng
b0a42fdb36 Revert r124518. It broke Linux self-host.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124522 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 02:43:04 +00:00
Evan Cheng
5e6940788f Re-commit r124462 with fixes. Tail recursion elim will now dup ret into unconditional predecessor to enable TCE on demand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124518 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 01:29:26 +00:00
Andrew Trick
04317cc618 Implementation of path profiling.
Modified patch by Adam Preuss.

This builds on the existing framework for block tracing, edge profiling and optimal edge profiling.
See -help-hidden for new flags.
For documentation, see the technical report "Implementation of Path Profiling..." in llvm.org/pubs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124515 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-29 01:09:53 +00:00
Duncan Sands
593faa53fa My auto-simplifier noticed that ((X/Y)*Y)/Y occurs several times in SPEC
benchmarks, and that it can be simplified to X/Y.  (In general you can only
simplify (Z*Y)/Y to Z if the multiplication did not overflow; if Z has the
form "X/Y" then this is the case).  This patch implements that transform and
moves some Div logic out of instcombine and into InstructionSimplify.
Unfortunately instcombine gets in the way somewhat, since it likes to change
(X/Y)*Y into X-(X rem Y), so I had to teach instcombine about this too.
Finally, thanks to the NSW/NUW flags, sometimes we know directly that "Z*Y"
does not overflow, because the flag says so, so I added that logic too.  This
eliminates a bunch of divisions and subtractions in 447.dealII, and has good
effects on some other benchmarks too.  It seems to have quite an effect on
tramp3d-v4 but it's hard to say if it's good or bad because inlining decisions
changed, resulting in massive changes all over.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124487 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 16:51:11 +00:00
Nick Lewycky
468ee0a90d Rename functions to follow coding standard. Also rejiggers comments. No
functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124482 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 08:43:14 +00:00
Nick Lewycky
8b5964381e Add a doxygen comment for this class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124480 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 08:19:00 +00:00
Nick Lewycky
285cf8040d Reorder for readability. (Chris, is this what you meant?)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124479 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 07:36:21 +00:00
Evan Cheng
1b5c0cb71d Revert r124462. There are a few big regressions that I need to fix first.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124478 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 07:12:38 +00:00
Nick Lewycky
07317f7d33 Reduce the number of functions we look at in the first pass, and preallocate
the function equality set.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124475 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 05:48:15 +00:00
Nick Lewycky
df3bfae151 Fold select + select where both selects are on the same condition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124469 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 03:28:10 +00:00
Evan Cheng
40f64cb0de - Stop simplifycfg from duplicating "ret" instructions into unconditional
branches. PR8575, rdar://5134905, rdar://8911460.
- Allow codegen tail duplication to dup small return blocks after register
  allocation is done.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124462 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-28 02:19:21 +00:00
Benjamin Kramer
9c1858cf4a Unbreak the build.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124426 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-27 20:30:54 +00:00
Nick Lewycky
c9d69489eb Expound upon this comparison!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124406 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-27 19:51:31 +00:00
Nick Lewycky
dfc5972974 Use dyn_cast instead of isa+cast.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124404 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-27 19:42:43 +00:00
Nick Lewycky
25296e25fd Fix surprising missed optimization in mergefunc where we forgot to consider
that relationships like "i8* null" is equivalent to "i32* null".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124368 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-27 08:38:19 +00:00
Duncan Sands
37f87c7aa9 Fix PR9039, a use-after-free in reassociate. The issue was that the
operand being factorized (and erased) could occur several times in Ops,
resulting in freed memory being used when the next occurrence in Ops was
analyzed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124287 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 10:08:38 +00:00
Nick Lewycky
f6c63c2320 AttrListPtr has an overloaded operator== which does this for us, we should use
it. No functionality change!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124286 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 09:23:19 +00:00
Nick Lewycky
207c193e7e Teach mergefunc that intptr_t is the same width as a pointer. We still can't
merge vector<intptr_t>::push_back() and vector<void*>::push_back() because
Enumerate() doesn't realize that "i64* null" and "i8** null" are equivalent.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124285 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 09:13:58 +00:00
Nick Lewycky
388f4918fb There are no vectors of pointer or arrays, so we don't need to check vector
elements for type equivalence.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124284 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 08:50:18 +00:00
Nick Lewycky
b38824f866 Teach mergefunc how to emit aliases safely again -- but keep it turned it off
for now. It's controlled by the HasGlobalAliases variable which is not attached
to any flag yet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124182 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 08:56:50 +00:00
Dan Gohman
bd1801b555 Give GetUnderlyingObject a TargetData, to keep it in sync
with BasicAA's DecomposeGEPExpression, which recently began
using a TargetData. This fixes PR8968, though the testcase
is awkward to reduce.

Also, update several off GetUnderlyingObject's users
which happen to have a TargetData handy to pass it in.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124134 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-24 18:53:32 +00:00
Chris Lattner
867be59684 fix PR9017, a bug where we'd assert when promoting in unreachable
code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124100 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-24 03:29:07 +00:00
Chris Lattner
51e62f0f73 fix PR9015, a crash linking recursive metadata.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124099 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-24 03:18:24 +00:00