Commit Graph

3436 Commits

Author SHA1 Message Date
Cameron Zwarich
838b97edfa Do not add PHIs with no users when creating LCSSA form. Patch by Andrew Clinton.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127674 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15 07:41:25 +00:00
Eli Friedman
b1a6eab655 PR9450: Make switch optimization in SimplifyCFG not dependent on the ordering
of pointers in an std::map.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127650 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15 02:23:35 +00:00
Eric Christopher
b9b80c3268 If we don't know how long a string is we can't fold an _chk version to the
normal version.

Fixes rdar://9123638


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127636 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15 00:25:41 +00:00
Benjamin Kramer
14b2a59301 Teach ComputeMaskedBits about sub nsw.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127548 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-12 17:18:11 +00:00
Cameron Zwarich
899eaa3569 Roll r127459 back in:
Optimize trivial branches in CodeGenPrepare, which often get created from the
lowering of objectsize intrinsics. Unfortunately, a number of tests were relying
on llc not optimizing trivial branches, so I had to add an option to allow them
to continue to test what they originally tested.

This fixes <rdar://problem/8785296> and <rdar://problem/9112893>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127498 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-11 21:52:04 +00:00
Daniel Dunbar
950d3db5f4 Revert r127459, "Optimize trivial branches in CodeGenPrepare, which often get
created from the", it broke some GCC test suite tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127477 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-11 19:30:30 +00:00
Benjamin Kramer
2715a58149 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127465 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-11 14:46:49 +00:00
Benjamin Kramer
6b4972518c InstCombine: Fix a thinko where transform an icmp under the assumption that it's a zero comparison when it's not.
Fixes PR9454.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127464 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-11 11:37:40 +00:00
Nick Lewycky
b69050a94c 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!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127463 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-11 09:00:19 +00:00
Cameron Zwarich
592ca3fda9 Optimize trivial branches in CodeGenPrepare, which often get created from the
lowering of objectsize intrinsics. Unfortunately, a number of tests were relying
on llc not optimizing trivial branches, so I had to add an option to allow them
to continue to test what they originally tested.

This fixes <rdar://problem/8785296> and <rdar://problem/9112893>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127459 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-11 04:54:27 +00:00
Dan Gohman
fa0e6facc7 Fix reassociate to postpone certain instruction deletions until
after it has finished all of its reassociations, because its
habit of unlinking operands and holding them in a datastructure
while working means that it's not easy to determine when an
instruction is really dead until after all its regular work is
done. rdar://9096268.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127424 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-10 19:51:54 +00:00
Benjamin Kramer
6b96fe7e14 InstCombine: Turn umul_with_overflow into mul nuw if we can prove that it cannot overflow.
This happens a lot in clang-compiled C++ code because it adds overflow checks to operator new[]:
  unsigned *foo(unsigned n) { return new unsigned[n]; }
We can optimize away the overflow check on 64 bit targets because (uint64_t)n*4 cannot overflow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127418 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-10 18:40:14 +00:00
Benjamin Kramer
7bff3e7c1b Fix mistyped CHECK lines.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127366 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 22:07:31 +00:00
Devang Patel
a2ab3999ed Preserve line number information while simplifying libcalls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127362 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 21:27:52 +00:00
Cameron Zwarich
35e5475062 Add a test case for r127320.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127321 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 08:11:02 +00:00
Nick Lewycky
84dd4fa2e3 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!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127318 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 06:26:03 +00:00
Cameron Zwarich
b2fd770136 Add support to scalar replacement for partial vector accesses of an alloca, e.g.
a union of a float, <2 x float>, and <4 x float>. This mostly comes up with the
use of vector intrinsics, especially in NEON when programmers know the layout of
the register file. This enables codegen to eliminate a lot of the subregister
traffic it would otherwise generate.

This commit only enables this for a small number of floating-point cases, but a
lot more integer cases. I assume this is okay for all ports, but I did not do
extensive testing of the quality of code involving i512 vectors and the like. If
there is a use case where this generates worse code than before, let me know and
we can scale it back.

This fixes <rdar://problem/9036264>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127317 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 05:43:05 +00:00
Eli Friedman
c6b018b737 PR9346: Prevent SimplifyDemandedBits from incorrectly introducing
INT_MIN % -1.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127306 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 01:28:35 +00:00
Eli Friedman
2adc5b6a17 PR9420; an instruction before an unreachable is guaranteed not to have any
reachable uses, but there still might be uses in dead blocks.  Use the
standard solution of replacing all the uses with undef.  This is
a rare case because it's very sensitive to phase ordering in SimplifyCFG.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127299 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 00:48:33 +00:00
Duncan Sands
606199fb85 Fix PR9331. Simplified version of a patch by Jakub Staszak.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127243 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-08 12:39:03 +00:00
Devang Patel
290342a157 While sinking an instruction, do not lose llvm.dbg.value intrinsic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127214 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-08 03:06:19 +00:00
Devang Patel
cd77a50e63 Preserve line no. info.
Radar 9097659


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127182 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-07 22:43:45 +00:00
Rafael Espindola
e390b3245f Add test for r127138.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127172 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-07 21:28:14 +00:00
Nick Lewycky
bf433e5f46 Tweak this test. We can analyze what happens and show that we still do the
right thing, instead of merely being unable to analyze and the transform
doesn't occur.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127149 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-07 02:10:18 +00:00
Nick Lewycky
c14bc77315 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!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127146 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-07 01:50:10 +00:00
Nick Lewycky
d01f50f42c ConstantInt has some getters which return ConstantInt's or ConstantVector's of
the value splatted into every element. Extend this to getTrue and getFalse which
by providing new overloads that take Types that are either i1 or <N x i1>. Use
it in InstCombine to add vector support to some code, fixing PR8469!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127116 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-06 03:36:19 +00:00
Nick Lewycky
58bfcdbcf6 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!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127064 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-05 05:19:11 +00:00
Nick Lewycky
9feda1730c Try once again to optimize "icmp (srem X, Y), Y" by turning the comparison into
true/false or "icmp slt/sge Y, 0".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127063 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-05 04:28:48 +00:00
Nick Lewycky
e2ee753bc4 Revert broken srem logic from r126991.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127021 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-04 19:26:08 +00:00
Nick Lewycky
786792784e 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!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126991 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-04 10:06:52 +00:00
Nick Lewycky
3a73e343d0 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).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126988 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-04 07:00:57 +00:00
Richard Osborne
022708f221 Optimize fprintf -> iprintf if there are no floating point arguments
and siprintf is available on the target.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126940 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-03 14:20:22 +00:00
Richard Osborne
419454ad37 Optimize sprintf -> siprintf if there are no floating point arguments
and siprintf is available on the target.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126937 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-03 14:09:28 +00:00
Richard Osborne
3649824bec Optimize printf -> iprintf if there are no floating point arguments
and iprintf is available on the target. Currently iprintf is only
marked as being available on the XCore.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126935 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-03 13:17:51 +00:00
Anders Carlsson
d70be0b2c1 Make InstCombiner::FoldAndOfICmps create a ConstantRange that's the
intersection of the LHS and RHS ConstantRanges and return "false" when
the range is empty.

This simplifies some code and catches some extra cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126744 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-01 15:05:01 +00:00
Nick Lewycky
88cd0aadb2 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!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126741 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-01 08:15:50 +00:00
Eli Friedman
f291ab2fba Add an obvious missing safety check to DAE::RemoveDeadArgumentsFromCallers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126720 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-01 00:33:47 +00:00
Dan Gohman
a722e781cc Delete obsolete test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126680 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 19:58:14 +00:00
Frits van Bommel
f7b2a9d7df Teach SimplifyCFG that (switch (select cond, X, Y)) is better expressed as a branch.
Based on a patch by Alistair Lynn.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126647 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 09:44:07 +00:00
Nick Lewycky
3dc7e49c70 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126644 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 09:17:39 +00:00
Nick Lewycky
b042f8e969 Teach InstCombine to fold "(shr exact X, Y) == 0" --> X == 0, fixing #1 from
PR9343.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126643 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 08:31:40 +00:00
Nick Lewycky
d8d1584c13 The sign of an srem instruction is the sign of its dividend (the first
argument), regardless of the divisor. Teach instcombine about this and fix
test7 in PR9343!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126635 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 06:20:05 +00:00
Benjamin Kramer
278be783b5 Revert "SimplifyCFG: GEPs with just one non-constant index are also cheap."
Yes, there are other types than i8* and GEPs on them can produce an add+multiply.
We don't consider that cheap enough to be speculatively executed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126481 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-25 10:33:33 +00:00
Benjamin Kramer
9ae59e3444 SimplifyCFG: GEPs with just one non-constant index are also cheap.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126452 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-24 23:26:09 +00:00
Benjamin Kramer
9b61c550c2 SimplifyCFG: GEPs with constant indices are cheap enough to be executed unconditionally.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126445 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-24 22:46:11 +00:00
Chris Lattner
091b1e3c74 change instcombine to not turn a call to non-varargs bitcast of
function prototype into a call to a varargs prototype.  We do
allow the xform if we have a definition, but otherwise we don't
want to risk that we're changing the abi in a subtle way.  On
X86-64, for example, varargs require passing stuff in %al.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126363 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-24 05:10:56 +00:00
Cameron Zwarich
c4f3d51e12 Make LoopDeletion work on loops with multiple edges, as long as the incoming
values from all of the loop's exiting blocks are equal. Patch by Andrew Clinton.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126253 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-22 22:25:39 +00:00
Benjamin Kramer
91e37ef278 InstCombine: Add a bunch of combines of the form x | (y ^ z).
We usually catch this kind of optimization through InstSimplify's distributive
magic, but or doesn't distribute over xor in general.

"A | ~(A | B) -> A | ~B" hits 24 times on gcc.c.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126081 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-20 13:23:43 +00:00
Nick Lewycky
1a4021a2be Teach RecursivelyDeleteDeadPHINodes to handle multiple self-references. Patch
by Andrew Clinton!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126077 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-20 08:38:20 +00:00
Eli Friedman
1347623aaf PR9218: SimplifyDemandedVectorElts can return a non-null value that is not
the instruction passed in.  Make sure to account for this correctly, instead
of looping infinitely.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126058 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-19 22:42:40 +00:00