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Commit Graph

1210 Commits

Author SHA1 Message Date
Dan Gohman
50061675c5 Canonicalize sext(i1) to i1?-1:0, and update various instcombine
optimizations accordingly.

llvm-svn: 58457
2008-10-30 20:40:10 +00:00
Dan Gohman
3ceee36545 (A & sext(C)) | (B & ~sext(C) -> C ? A : B
llvm-svn: 58351
2008-10-28 22:38:57 +00:00
Dan Gohman
6f40163d83 Teach instcombine's visitLoad to scan back several instructions
to find opportunities for store-to-load forwarding or load CSE,
in the same way that visitStore scans back to do DSE. Also, define
a new helper function for testing whether the addresses of two
memory accesses are known to have the same value, and use it in
both visitStore and visitLoad.

These two changes allow instcombine to eliminate loads in code
produced by front-ends that frequently emit obviously redundant
addressing for memory references.

llvm-svn: 57608
2008-10-15 23:19:35 +00:00
Evan Cheng
591baeed7c Combine (fcmp cc0 x, y) | (fcmp cc1 x, y) into a single fcmp when possible.
llvm-svn: 57515
2008-10-14 18:44:08 +00:00
Evan Cheng
778b47e6c0 - Somehow I forgot about one / une.
- Renumber fcmp predicates to match their icmp counterparts.
- Try swapping operands to expose more optimization opportunities.

llvm-svn: 57513
2008-10-14 18:13:38 +00:00
Evan Cheng
91528965e7 Optimize anding of two fcmp into a single fcmp if the operands are the same. e.g. uno && ueq -> ueq
ord && olt -> olt
     ord && ueq -> oeq

llvm-svn: 57507
2008-10-14 17:15:11 +00:00
Matthijs Kooijman
b86d48c717 Make InstructionCombining::getBitCastOperand() recognize GEP instructions and
constant expression with all zero indices as being the same as a bitcast.

llvm-svn: 57442
2008-10-13 15:17:01 +00:00
Chris Lattner
7a61ef92f5 Fix PR2697 by rewriting the '(X / pos) op neg' logic. This also changes
a couple other cases for clarity, but shouldn't affect correctness.

Patch by Eli Friedman!

llvm-svn: 57387
2008-10-11 22:55:00 +00:00
Dale Johannesen
075a62519f Add a "loses information" return value to APFloat::convert
and APFloat::convertToInteger.  Restore return value to
IEEE754.  Adjust all users accordingly.

llvm-svn: 57329
2008-10-09 23:00:39 +00:00
Chris Lattner
0aa4423c8c Add parentheses to avoid warnings in GCC 4.4.0,
patch by Samuel Tardieu!

llvm-svn: 57288
2008-10-08 06:42:28 +00:00
Chris Lattner
107e8f8b60 rewrite bswap matching to be more general, allowing arbitrary
shifting and masking inside a bswap expr.  This allows it to handle
the cases from PR2842, which involve the intermediate 'or' 
expressions being shifted, not just the input value.

llvm-svn: 57095
2008-10-05 02:13:19 +00:00
Chris Lattner
6fae76bbf3 fix a bug where the bswap matcher could match a case involving
ashr.  It should only apply to lshr.

llvm-svn: 57089
2008-10-05 00:50:57 +00:00
Duncan Sands
88d8323743 Factorize code: remove variants of "strip off
pointer bitcasts and GEP's", and centralize the
logic in Value::getUnderlyingObject.  The
difference with stripPointerCasts is that
stripPointerCasts only strips GEPs if all
indices are zero, while getUnderlyingObject
strips GEPs no matter what the indices are.

llvm-svn: 56922
2008-10-01 15:25:41 +00:00
Nick Lewycky
9e918179c8 Fix misoptimization of: xor i1 (icmp eq (X, C1), icmp s[lg]t (X, C2))
llvm-svn: 56834
2008-09-30 06:08:34 +00:00
Devang Patel
e4e6ea0728 Now Attributes are divided in three groups
- return attributes - inreg, zext and sext
- parameter attributes
- function attributes - nounwind, readonly, readnone, noreturn

Return attributes use 0 as the index.
Function attributes use ~0U as the index.

This patch requires corresponding changes in llvm-gcc and clang.

llvm-svn: 56704
2008-09-26 22:53:05 +00:00
Devang Patel
64dd7a2e89 Large mechanical patch.
s/ParamAttr/Attribute/g
s/PAList/AttrList/g
s/FnAttributeWithIndex/AttributeWithIndex/g
s/FnAttr/Attribute/g

This sets the stage 
- to implement function notes as function attributes and 
- to distinguish between function attributes and return value attributes.

This requires corresponding changes in llvm-gcc and clang.

llvm-svn: 56622
2008-09-25 21:00:45 +00:00
Devang Patel
f0bda74eca s/ParamAttrsWithIndex/FnAttributeWithIndex/g
llvm-svn: 56535
2008-09-24 00:55:02 +00:00
Devang Patel
a3e9bf1bca s/ParameterAttributes/Attributes/g
llvm-svn: 56513
2008-09-23 23:03:40 +00:00
Dan Gohman
c598e29a1c Improve instcombine's handling of integer min and max in two ways:
- Recognize expressions like "x > -1 ? x : 0" as min/max and turn them
   into expressions like "x < 0 ? 0 : x", which is easily recognizable
   as a min/max operation.
 - Refrain from folding expression like "y/2 < 1" to "y < 2" when the
   comparison is being used as part of a min or max idiom, like
   "y/2 < 1 ? 1 : y/2". In that case, the division has another use, so
   folding doesn't eliminate it, and obfuscates the min/max, making it
   harder to recognize as a min/max operation.

These benefit ScalarEvolution, CodeGen, and anything else that wants to
recognize integer min and max.

llvm-svn: 56246
2008-09-16 18:46:06 +00:00
Dan Gohman
0b6d3a9a9b On 64-bit targets, change 32-bit getelementptr indices to be 64-bit
getelementptr indices, inserting an explicit cast if necessary.
This helps expose the sign-extension operation to other optimizations.

llvm-svn: 56133
2008-09-11 23:06:38 +00:00
Dan Gohman
5e154a591d Fix a vectorshuffle instcombine bug introduced by r55995.
Patch by Nicolas Capens!

llvm-svn: 56129
2008-09-11 22:47:57 +00:00
Dan Gohman
4ae5fa57b4 Fix a copy+paste bug that Duncan spotted. For several
cases it was still getting lucky and detecting overflow
but it was clearly incorrect.

llvm-svn: 56113
2008-09-11 18:53:02 +00:00
Dan Gohman
36e01356ec In my analysis for r56076 I missed the case where the original
multiplication overflows.

llvm-svn: 56082
2008-09-11 00:25:00 +00:00
Dan Gohman
ebfb483309 Fix an icmp+sdiv optimization to check for and handle an overflow
condition. This fixes PR2740.

llvm-svn: 56076
2008-09-10 23:30:57 +00:00
Dan Gohman
3809753d3b Fix a warning about comparing signed and unsigned values.
llvm-svn: 56040
2008-09-10 01:09:32 +00:00
Dan Gohman
28c911b79b Make SimplifyDemandedVectorElts simplify vectors with multiple
users, and teach it about shufflevector instructions.

Also, fix a subtle bug in SimplifyDemandedVectorElts'
insertelement code.

This is a patch that was originally written by Eli Friedman,
with some fixes and cleanup by me.

llvm-svn: 55995
2008-09-09 18:11:14 +00:00
Dan Gohman
e1f9be27bc Tidy up several unbeseeming casts from pointer to intptr_t.
llvm-svn: 55779
2008-09-04 17:05:41 +00:00
Nick Lewycky
3b35dcc455 Don't apply this transform to vectors. Fixes PR2756.
llvm-svn: 55690
2008-09-03 06:24:21 +00:00
Nick Lewycky
7b87c4d8a4 Revert r54876 r54877 r54906 and r54907. Evan found that these caused a 20%
slowdown in bzip2.

llvm-svn: 55113
2008-08-21 05:56:10 +00:00
Evan Cheng
0a35c35153 Silence a compiler warning.
llvm-svn: 55087
2008-08-20 23:36:48 +00:00
Mon P Wang
e5aefd3967 Fixed shuffle optimizations to handle non power of 2 vectors
llvm-svn: 55035
2008-08-20 02:23:25 +00:00
Nick Lewycky
371935de4a Make this comment clearer. Instead of using an ambiguous ~ (not) on an icmp
predicate, swap the order of the operands.

llvm-svn: 54907
2008-08-17 20:02:02 +00:00
Nick Lewycky
30a0ad8900 Consider the case where xor by -1 and xor by 128 have been combined already to
produce an xor by 127.

llvm-svn: 54906
2008-08-17 19:58:24 +00:00
Nick Lewycky
d797456fb4 I found a better place for this optz'n.
llvm-svn: 54877
2008-08-17 07:54:14 +00:00
Nick Lewycky
205be593b8 Xor'ing both sides of icmp by sign-bit is equivalent to swapping signedness of
the predicate.

Also, make this optz'n apply in more cases where it's safe to do so.

llvm-svn: 54876
2008-08-17 07:34:14 +00:00
Chris Lattner
28a74aa6ca use smallvector instead of vector for a couple worklists. This speeds up instcombine
by ~10% on some testcases.

llvm-svn: 54811
2008-08-15 04:03:01 +00:00
Dan Gohman
db5b503d60 Fix a bogus srem rule - a negative value srem'd by a power-of-2
can have a non-negative result; for example, -16%16 is 0. Also,
clarify the related comments. This fixes PR2670.

llvm-svn: 54767
2008-08-13 23:12:35 +00:00
Chris Lattner
ae09ade343 Implement support for simplifying vector comparisons by 0.0 and 1.0 like we
do for scalars.  Patch contributed by Nicolas Capens

This also generalizes the previous xforms to work on long double, now that 
isExactlyValue works for long double.

llvm-svn: 54653
2008-08-11 22:06:05 +00:00
Dan Gohman
4ad77e1ca2 Fix a shufflevector instcombine that was emitting invalid masks indices
when it meant to be emitting undef indices.

llvm-svn: 54417
2008-08-06 18:17:32 +00:00
Chris Lattner
55b99a6739 optimize a common idiom generated by clang for bitfield access, PR2638.
llvm-svn: 54408
2008-08-06 07:35:52 +00:00
Chris Lattner
cae04940bd Zap sitofp/fptoui pairs. In all cases when the sign difference
matters, the result is undefined anyway.

llvm-svn: 54396
2008-08-06 05:13:06 +00:00
Nick Lewycky
0bf3c812d2 Reinstate this optimization, but without the miscompile. Thanks to Bill for
tracking down that this was breaking llvm-gcc bootstrap on Linux.

llvm-svn: 54394
2008-08-06 04:54:03 +00:00
Bill Wendling
3882f060ef Revert r53282. This was causing a miscompile on Linux. Also, the transformation
looks bogus. Please see PR2629 for details on why this is breaking things.

llvm-svn: 54372
2008-08-05 21:23:45 +00:00
Nate Begeman
9a71580e21 Add vector shifts to the IR, patch by Eli Friedman.
CodeGen & Clang work coming next.

llvm-svn: 54161
2008-07-29 15:49:41 +00:00
Dan Gohman
6564581be0 Enable first-class aggregates support.
Remove the GetResultInst instruction. It is still accepted in LLVM assembly
and bitcode, where it is now auto-upgraded to ExtractValueInst. Also, remove
support for return instructions with multiple values. These are auto-upgraded
to use InsertValueInst instructions.

The IRBuilder still accepts multiple-value returns, and auto-upgrades them
to InsertValueInst instructions.

llvm-svn: 53941
2008-07-23 00:34:11 +00:00
Chris Lattner
eccd57d118 Fix PR2553
llvm-svn: 53715
2008-07-17 06:07:20 +00:00
Matthijs Kooijman
ceee0ddd1b Redo InstCombiner::visitExtractValueInst. Instead of using the (complicate)
FindInsertedValue, it now performs a number of simple transformations that
should result in the same effect when applied iteratively.

llvm-svn: 53673
2008-07-16 12:55:45 +00:00
Evan Cheng
7218339189 Fix PR2296. Do not transform x86_sse2_storel_dq into a full-width store.
llvm-svn: 53666
2008-07-16 07:28:14 +00:00
Chris Lattner
14faada3a3 Fix PR2506 by being a bit more careful about reverse fact propagation when
disproving a condition.  This actually compiles the existing testcase
(udiv_select_to_select_shift) to:

define i64 @test(i64 %X, i1 %Cond) {
entry:
	%divisor1.t = lshr i64 %X, 3		; <i64> [#uses=1]
	%quotient2 = lshr i64 %X, 3		; <i64> [#uses=1]
	%sum = add i64 %divisor1.t, %quotient2		; <i64> [#uses=1]
	ret i64 %sum
}

instead of:

define i64 @test(i64 %X, i1 %Cond) {
entry:
	%quotient1.v = select i1 %Cond, i64 3, i64 4		; <i64> [#uses=1]
	%quotient1 = lshr i64 %X, %quotient1.v		; <i64> [#uses=1]
	%quotient2 = lshr i64 %X, 3		; <i64> [#uses=1]
	%sum = add i64 %quotient1, %quotient2		; <i64> [#uses=1]
	ret i64 %sum
}

llvm-svn: 53534
2008-07-14 00:15:52 +00:00
Nick Lewycky
3fb5816774 Enhance analysis of srem.
Remove dead code analyzing urem. 'urem' of power-of-2 is canonicalized to an
'and' instruction.

llvm-svn: 53506
2008-07-12 05:04:38 +00:00
Nick Lewycky
cafc3d583d Document 'mask' in this calculation.
llvm-svn: 53454
2008-07-11 08:16:26 +00:00
Nick Lewycky
12c88a28f5 Remove misleading constant from comment.
llvm-svn: 53452
2008-07-11 07:36:19 +00:00
Nick Lewycky
8cd0f2058e Add another optimization from PR2330. Also catch some missing cases that are
similar.

llvm-svn: 53451
2008-07-11 07:20:53 +00:00
Chris Lattner
07bfade2d4 a missed optimization that Eli spotted
llvm-svn: 53449
2008-07-11 06:40:29 +00:00
Chris Lattner
34b0895d4d another bug in the same line.
llvm-svn: 53448
2008-07-11 06:38:16 +00:00
Chris Lattner
3cdb6789b9 fix a bug spotted by Eli's eagle eyes
llvm-svn: 53447
2008-07-11 06:36:01 +00:00
Chris Lattner
3d40848bfd simplify and merge a bunch of code. Instead of comparing against
the min/max values for an integer type, compare against the min/max
values we can prove contain the input.  This might be a tighter bound,
so this is general goodness.

llvm-svn: 53446
2008-07-11 05:40:05 +00:00
Chris Lattner
d1198896ae fold away (x <= cst) earlier, allowing us to not have to
handle them in some code.

llvm-svn: 53445
2008-07-11 05:08:55 +00:00
Chris Lattner
16b8ae98c1 Fix folding of icmp's of i1 where the comparison is signed. The code
was using the algorithm for folding unsigned comparisons which is
completely wrong.  This has been broken since the signless types change.

llvm-svn: 53444
2008-07-11 04:20:58 +00:00
Chris Lattner
f3f6b6d7af Fix a bogus optimization: folding (slt (zext i1 A to i32), 1) -> (slt i1 A, true)
This cause a regression in InstCombine/JavaCompare, which was doing the right
thing on accident.  To handle the missed case, generalize the comparisons based
on masked bits a little bit to handle comparisons against the max value. For 
example, we can now xform (slt i32 (and X, 4), 4) -> (setne i32 (and X, 4), 4)

llvm-svn: 53443
2008-07-11 04:09:09 +00:00
Nick Lewycky
26ccb8e9a8 Fix overzealous optimization. Thanks to Duncan Sands for pointing out my error!
llvm-svn: 53393
2008-07-10 05:51:40 +00:00
Nick Lewycky
a7d102aca3 Simplify, suggested by Chris Lattner.
llvm-svn: 53283
2008-07-09 07:35:26 +00:00
Nick Lewycky
6341c5a7ec Fold (a < 8) && (b < 8) into (a|b) < 8 for unsigned less or greater than.
llvm-svn: 53282
2008-07-09 07:29:11 +00:00
Nick Lewycky
38fa84fa12 Fold ((1 << a) & 1) to (a == 0).
llvm-svn: 53276
2008-07-09 05:20:13 +00:00
Nick Lewycky
2a6469c9a5 Reduce x - y to -y when we know the 'x' part will get masked off anyways.
llvm-svn: 53271
2008-07-09 04:32:37 +00:00
Chris Lattner
c144216d78 Fix PR2496, a really nasty bug which involved sinking volatile loads
into phis.  This is actually the same bug as PR2262 /
2008-04-29-VolatileLoadDontMerge.ll, but I missed checking the first 
predecessor for multiple successors.  Testcase here:
InstCombine/2008-07-08-VolatileLoadMerge.ll

llvm-svn: 53240
2008-07-08 17:18:32 +00:00
Dan Gohman
c97817aac3 Make DenseMap's insert return a pair, to more closely resemble std::map.
llvm-svn: 53177
2008-07-07 17:46:23 +00:00
Nick Lewycky
94f9c5a42e Fix missed optimization opportunity when analyzing cast of mul and select.
llvm-svn: 53151
2008-07-05 21:19:34 +00:00
Evan Cheng
2005804de6 - Re-apply 52748 and friends with fix. GetConstantStringInfo() returns an empty string for ConstantAggregateZero case which surprises selectiondag.
- Correctly handle memcpy from constant string which is zero-initialized.

llvm-svn: 52891
2008-06-30 07:31:25 +00:00
Anton Korobeynikov
6f260767ec Revert (52748 and friends):
Move GetConstantStringInfo to lib/Analysis. Remove
string output routine from Constant. Update all
callers. Change debug intrinsic api slightly to
accomodate move of routine, these now return values
instead of strings.

This unbreaks llvm-gcc bootstrap.

llvm-svn: 52884
2008-06-29 17:57:03 +00:00
Eric Christopher
4f05c48718 Move GetConstantStringInfo to lib/Analysis. Remove
string output routine from Constant. Update all
callers. Change debug intrinsic api slightly to
accomodate move of routine, these now return values
instead of strings.

llvm-svn: 52748
2008-06-26 00:31:12 +00:00
Chris Lattner
73b52018e9 Fix PR2488, a case where we deleted stack restores too aggressively.
llvm-svn: 52702
2008-06-25 05:59:28 +00:00
Eli Friedman
369401ef95 Fix for PR2479: correctly optimize expressions like (a > 13) & (a ==
15).

See also PR1800, which is about the signed case.

llvm-svn: 52608
2008-06-21 23:36:13 +00:00
Chris Lattner
e588f546c5 Fix PR2471, which is a bug involving an invalid promotion from a conditional load.
llvm-svn: 52525
2008-06-20 05:12:56 +00:00
Bill Wendling
68bdf9f6d4 Remove dead code causing a warning.
llvm-svn: 52502
2008-06-19 18:00:44 +00:00
Dan Gohman
a18aa3f3a2 Use Instruction::moveBefore instead of manipulating the instruction list
directly.

llvm-svn: 52498
2008-06-19 17:47:47 +00:00
Chris Lattner
f9d9f0ec4c Fix the regressions on sext-misc.ll my patch yesterday caused.
llvm-svn: 52466
2008-06-18 18:11:55 +00:00
Chris Lattner
93da79f7a1 implement some simple bswap optimizations, rdar://5992453
llvm-svn: 52442
2008-06-18 04:33:20 +00:00
Chris Lattner
7e403da191 make truncate/sext elimination capable of changing phi's. This
implements rdar://6013816 and the testcase in Transforms/InstCombine/sext-misc.ll.

llvm-svn: 52440
2008-06-18 04:00:49 +00:00
Duncan Sands
ec220a7c48 Fix typo that changed the logic to something wrong.
Spotted by Nick Lewycky.

llvm-svn: 52411
2008-06-17 15:55:30 +00:00
Matthijs Kooijman
238b1e8d69 Pass around Instruction* instead of Instruction& in FindInsertedValue and friends.
llvm-svn: 52318
2008-06-16 13:13:08 +00:00
Matthijs Kooijman
dedcf00fcc 80 column fixes.
llvm-svn: 52316
2008-06-16 12:57:37 +00:00
Matthijs Kooijman
1dd7d9cdc1 Move FindScalarValue from InstructionCombining.cpp to ValueTracking.cpp. While
I'm at it, rename it to FindInsertedValue.

The only functional change is that newly created instructions are no longer
added to instcombine's worklist, but that is not really necessary anyway (and
I'll commit some improvements next that will completely remove the need).

llvm-svn: 52315
2008-06-16 12:48:21 +00:00
Eli Friedman
11d4c94933 Don't skip over instructions other than loads that might read memory
when trying to sink stores.

llvm-svn: 52259
2008-06-13 22:02:12 +00:00
Eli Friedman
d38a639deb Make sure SimplifyStoreAtEndOfBlock doesn't mess with loops; the
structure checks are incorrect if the blocks aren't distinct.
Fixes PR2435.

llvm-svn: 52257
2008-06-13 21:17:49 +00:00
Gabor Greif
10de8c6c59 fix a minor deviation from the original in my previous commit
llvm-svn: 52247
2008-06-12 21:51:29 +00:00
Gabor Greif
509b3a75f4 op_iterator-ify some loops, low hanging fruit only, there is more
llvm-svn: 52246
2008-06-12 21:37:33 +00:00
Matthijs Kooijman
0f9df32e12 Teach instruction combining about the extractvalue. It can succesfully fold
useless insert-extract chains, similar to how it folds them for vectors.

Add a testcase for this.

llvm-svn: 52217
2008-06-11 14:05:05 +00:00
Matthijs Kooijman
511d6a5cd3 Clarify a comment.
llvm-svn: 52212
2008-06-11 09:00:12 +00:00
Chris Lattner
4a896996cb Limit the icmp+phi merging optimization to the cases where it is profitable:
don't make i1 phis when it won't be possible to eliminate them.

llvm-svn: 52097
2008-06-08 20:52:11 +00:00
Zhou Sheng
06fc769e52 As Chris suggested, handle the situation if ShAmt larger than BitWidth,
otherwise, opt might crash.

llvm-svn: 52041
2008-06-06 08:32:05 +00:00
Zhou Sheng
eaa93efd52 If BitWidth equals to ShtAmt, the RHSKnownZero[BitWidth-ShiftAmt-1] will
crash the opt. Just fix this.

Test case in llvm/test/Transforms/InstCombine/2008-06-05-ashr-crash.ll

llvm-svn: 52003
2008-06-05 14:23:44 +00:00
Chris Lattner
ea60f0ccc3 move CannotBeNegativeZero to ValueTracking. Simplify some signbit comparisons.
llvm-svn: 51864
2008-06-02 01:29:46 +00:00
Chris Lattner
4960857273 move ComputeMaskedBits, MaskedValueIsZero, and ComputeNumSignBits
out of instcombine into a new file in libanalysis.  This also teaches
ComputeNumSignBits about the number of sign bits in a constantint.

llvm-svn: 51863
2008-06-02 01:18:21 +00:00
Duncan Sands
d14212a3e1 When simplifying a call to a bitcast function, tighten up
the conditions for performing the transform when only the
function declaration is available: no longer allow turning
i32 into i64 for example.  Only allow changing between
pointer types, and between pointer types and integers of
the same size.  For return values ptr -> intptr was already
allowed; I added ptr -> ptr and intptr -> ptr while there.
As shown by a recent objc testcase, changing the way
parameters/return values are passed can be fatal when calling
code written in assembler that directly manipulates call
arguments and return values unless the transform has no
impact on the way they are passed at the codegen level.
While it is possible to imagine an ABI that treats integers
of pointer size differently to pointers, I don't think LLVM
supports any so the transform should now be safe while still
being useful.

llvm-svn: 51834
2008-06-01 07:38:42 +00:00
Nick Lewycky
1bcd80adf7 Peer through sext/zext when looking for not(cmp).
llvm-svn: 51819
2008-05-31 19:01:33 +00:00
Nick Lewycky
b30afdb62b Add more i1 optimizations. add, sub, mul, s/udiv on i1 are now simplified away.
llvm-svn: 51817
2008-05-31 17:59:52 +00:00
Nick Lewycky
cdcdcddc85 Adding i1 is always Xor.
llvm-svn: 51816
2008-05-31 17:10:28 +00:00
Dan Gohman
d8b84813d5 const-ify getOpcode.
llvm-svn: 51698
2008-05-29 19:53:46 +00:00
Chris Lattner
7a7da4f9c3 Implement PR2370: memmove(x,x,size) -> noop.
llvm-svn: 51636
2008-05-28 05:30:41 +00:00
Nick Lewycky
744dad8004 "ret (constexpr)" can't be folded into a Constant. Add a method to
Analysis/ConstantFolding to fold ConstantExpr's, then make instcombine use it
to try to use targetdata to fold constant expressions on void instructions.

Also extend the icmp(inttoptr, inttoptr) folding to handle the case where
int size != ptr size.

llvm-svn: 51559
2008-05-25 20:56:15 +00:00
Chris Lattner
3def8b4e53 Fix a serious brain-o. Obviously no-one reviewed my patch :(
This fixes PR2359

llvm-svn: 51536
2008-05-24 04:06:28 +00:00
Dan Gohman
8b6f4366ae Tidy up BasicBlock::getFirstNonPHI, and change a bunch of places to
use it instead of duplicating its functionality.

llvm-svn: 51499
2008-05-23 21:05:58 +00:00
Matthijs Kooijman
e9217fe486 Replace some weird usage of UserOp1 introduced in r49492 by a plain if.
llvm-svn: 51482
2008-05-23 16:17:48 +00:00
Nick Lewycky
6a16ace643 Constant integer vectors may also be negated.
llvm-svn: 51476
2008-05-23 04:54:45 +00:00
Nick Lewycky
16773d5239 Typo.
llvm-svn: 51475
2008-05-23 04:39:38 +00:00
Nick Lewycky
bd2da8098d Revert X + X --> X * 2 optz'n which pessimizes heavily on x86.
llvm-svn: 51474
2008-05-23 04:34:58 +00:00
Nick Lewycky
427209006f Implement X + X for vectors.
llvm-svn: 51472
2008-05-23 04:14:51 +00:00
Nick Lewycky
e62259c369 Fix a recently added optimization to not crash on vectors.
llvm-svn: 51471
2008-05-23 03:26:47 +00:00
Dan Gohman
67e1a58e22 Generalize the new code in instcombine's ComputeNumSignBits for handling
and/or to handle more cases (such as this add-sitofp.ll testcase), and
port it to selectiondag's ComputeNumSignBits.

llvm-svn: 51469
2008-05-23 02:28:01 +00:00
Dan Gohman
eafccb7d8f Use isSingleValueType instead of isFirstClassType to
exclude struct and array types.

llvm-svn: 51467
2008-05-23 01:52:21 +00:00
Dan Gohman
b48d4a75f6 Port SelectionDAG's ComputeNumSignBits-using code to instcombine,
now that instcombine also has ComputeNumSignBits.

llvm-svn: 51350
2008-05-20 21:01:12 +00:00
Chris Lattner
b387fd90fc Teach instcombine 4 new xforms:
(add (sext x), cst) --> (sext (add x, cst'))
  (add (sext x), (sext y)) --> (sext (add int x, y))
  (add double (sitofp x), fpcst) --> (sitofp (add int x, intcst))
  (add double (sitofp x), (sitofp y)) --> (sitofp (add int x, y))

This generally reduces conversions.  For example MiBench/telecomm-gsm
gets these simplifications:

HACK2: 	%tmp67.i142.i.i = sext i16 %tmp6.i141.i.i to i32		; <i32> [#uses=1]
	%tmp23.i139.i.i = sext i16 %tmp2.i138.i.i to i32		; <i32> [#uses=1]
	%tmp8.i143.i.i = add i32 %tmp67.i142.i.i, %tmp23.i139.i.i		; <i32> [#uses=3]
HACK2: 	%tmp67.i121.i.i = sext i16 %tmp6.i120.i.i to i32		; <i32> [#uses=1]
	%tmp23.i118.i.i = sext i16 %tmp2.i117.i.i to i32		; <i32> [#uses=1]
	%tmp8.i122.i.i = add i32 %tmp67.i121.i.i, %tmp23.i118.i.i		; <i32> [#uses=3]
HACK2: 	%tmp67.i.i190.i = sext i16 %tmp6.i.i189.i to i32		; <i32> [#uses=1]
	%tmp23.i.i187.i = sext i16 %tmp2.i.i186.i to i32		; <i32> [#uses=1]
	%tmp8.i.i191.i = add i32 %tmp67.i.i190.i, %tmp23.i.i187.i		; <i32> [#uses=3]
HACK2: 	%tmp67.i173.i.i.i = sext i16 %tmp6.i172.i.i.i to i32		; <i32> [#uses=1]
	%tmp23.i170.i.i.i = sext i16 %tmp2.i169.i.i.i to i32		; <i32> [#uses=1]
	%tmp8.i174.i.i.i = add i32 %tmp67.i173.i.i.i, %tmp23.i170.i.i.i		; <i32> [#uses=3]
HACK2: 	%tmp67.i152.i.i.i = sext i16 %tmp6.i151.i.i.i to i32		; <i32> [#uses=1]
	%tmp23.i149.i.i.i = sext i16 %tmp2.i148.i.i.i to i32		; <i32> [#uses=1]
	%tmp8.i153.i.i.i = add i32 %tmp67.i152.i.i.i, %tmp23.i149.i.i.i		; <i32> [#uses=3]
HACK2: 	%tmp67.i.i.i.i = sext i16 %tmp6.i.i.i.i to i32		; <i32> [#uses=1]
	%tmp23.i.i5.i.i = sext i16 %tmp2.i.i.i.i to i32		; <i32> [#uses=1]
	%tmp8.i.i7.i.i = add i32 %tmp67.i.i.i.i, %tmp23.i.i5.i.i		; <i32> [#uses=3]


This also fixes a bug in ComputeNumSignBits handling select and
makes it more aggressive with and/or.

llvm-svn: 51302
2008-05-20 05:46:13 +00:00
Chris Lattner
323a985507 fix two issues Neil noticed, thanks!
llvm-svn: 51296
2008-05-20 03:50:52 +00:00
Dan Gohman
3f6b53dba0 Make AssociativeOpt static.
llvm-svn: 51290
2008-05-20 01:14:05 +00:00
Dan Gohman
2d2351f037 Add a ComputeNumSignBits function for use by instcombine, based on the
code in SelectionDAG.

llvm-svn: 51279
2008-05-19 22:14:15 +00:00
Chris Lattner
859485412b switch to Type::getFPMantissaWidth instead of reinventing it.
llvm-svn: 51275
2008-05-19 21:17:23 +00:00
Chris Lattner
92599bcc72 minor cleanups, teach instcombine that sitofp/uitofp cannot
produce a negative zero.

llvm-svn: 51272
2008-05-19 20:27:56 +00:00
Chris Lattner
63c384df1e convert fptosi(sitofp x) -> x if the fp value has enough bits in its mantissa
to accurately represent the integer.  This triggers 9 times in 471.omnetpp,
though 8 of those seem to be inlined from the same place.

llvm-svn: 51271
2008-05-19 20:25:04 +00:00
Chris Lattner
1435b94f62 Fold FP comparisons where one operand is converted from an integer
type and the other operand is a constant into integer comparisons.
This happens surprisingly frequently (e.g. 10 times in 471.omnetpp),
which are things like this:

	%tmp8283 = sitofp i32 %tmp82 to double	
	%tmp1013 = fcmp ult double %tmp8283, 0.0

Clearly comparing tmp82 against i32 0 is cheaper here.

this also triggers 8 times in gobmk, including this one:

	%tmp375376 = sitofp i32 %tmp375 to double
	%tmp377 = fcmp ogt double %tmp375376, 8.150000e+01

which is comparing an integer against 81.5 :).

llvm-svn: 51268
2008-05-19 20:18:56 +00:00
Chris Lattner
ad02ff166e remove debug output
llvm-svn: 51264
2008-05-19 20:03:53 +00:00
Chris Lattner
510a6b249c be more aggressive about transforming add -> or when the operands have no
intersecting bits.  This triggers all over the place, for example in lencode,
with adds of stuff like:

	%tmp580 = mul i32 %tmp579, 2	
	%tmp582 = and i32 %b8, 1
and

	%tmp28 = shl i32 %abs.i, 1		
	%sign.0 = select i1 %tmp23, i32 1, i32 0
and
	%tmp344 = shl i32 %tmp343, 2	
	%tmp346 = and i32 %tmp96, 3

etc.

llvm-svn: 51263
2008-05-19 20:01:56 +00:00
Chris Lattner
8c0f0a0e6c Fix PR2339
llvm-svn: 51226
2008-05-18 04:11:26 +00:00
Nick Lewycky
6f3744c685 Move isTrueWhenEqual to ICmpInst.
llvm-svn: 51215
2008-05-17 07:33:39 +00:00
Gabor Greif
d61f20217a API change for {BinaryOperator|CmpInst|CastInst}::create*() --> Create. Legacy interfaces will be in place for some time. (Merge from use-diet branch.)
llvm-svn: 51200
2008-05-16 19:29:10 +00:00
Chris Lattner
00e8e1e258 implement PR2328.
llvm-svn: 51176
2008-05-16 02:59:42 +00:00
Gabor Greif
48ffb6c7dc Fix a bunch of 80col violations that arose from the Create API change. Tweak makefile targets to find these better.
llvm-svn: 51143
2008-05-15 10:04:30 +00:00
Bill Wendling
c1d9f9604b Situations can arise when you have a function called that returns a 'void', but
is bitcast to return a floating point value. The result of the instruction may
not be used by the program afterwards, and LLVM will happily remove all
instructions except the call. But, on some platforms, if a value is returned as
a floating point, it may need to be removed from the stack (like x87). Thus, we
can't get rid of the bitcast even if there isn't a use of the value.

llvm-svn: 51134
2008-05-14 22:45:20 +00:00
Dan Gohman
bab18cae46 Clean up the use of static and anonymous namespaces. This turned up
several things that were neither in an anonymous namespace nor static
but not intended to be global.

llvm-svn: 51017
2008-05-13 00:00:25 +00:00
Chris Lattner
b6db834a47 don't sink invokes, even if they are readonly. This fixes a
crash on kimwitu++.

llvm-svn: 50901
2008-05-09 15:07:33 +00:00
Chris Lattner
02ca137915 Implement PR2298. This transforms:
~x < ~y --> y < x
   -x == -y --> x == y

llvm-svn: 50882
2008-05-09 05:19:28 +00:00
Chris Lattner
4c1ef3628b More than just loads can read from memory: readonly calls like strlen
also need to be checked for memory modifying instructions before we
can sink them.  THis fixes the second half of PR2297.

llvm-svn: 50860
2008-05-08 17:37:37 +00:00
Chris Lattner
cba8b4c7e8 Make instcombine's DSE respect loads as well as stores. It is not safe to
delete the first store in:

store x -> p
load p
store y -> p

This is for PR2297.

llvm-svn: 50859
2008-05-08 17:20:30 +00:00
Anton Korobeynikov
ddb93e7a02 Turn StripPointerCast() into a method
llvm-svn: 50836
2008-05-07 22:54:15 +00:00
Dan Gohman
6ea87fa437 Fix a bug in the ComputeMaskedBits logic for multiply.
llvm-svn: 50793
2008-05-07 00:35:55 +00:00
Anton Korobeynikov
90ee6d6616 Make StripPointerCast a common function (should we mak it method of Value instead?)
llvm-svn: 50775
2008-05-06 22:52:30 +00:00
Devang Patel
c5aee6c84d Fix typo.
llvm-svn: 50713
2008-05-06 05:40:11 +00:00
Dan Gohman
faf9df7227 Correct the value of LowBits in srem and urem handling in
ComputeMaskedBits.

llvm-svn: 50692
2008-05-06 00:51:48 +00:00
Devang Patel
b3112b4417 Do not sink getresult.
llvm-svn: 50600
2008-05-03 00:36:30 +00:00
Dan Gohman
27156711ef Fix a mistake in the computation of leading zeros for udiv.
llvm-svn: 50591
2008-05-02 21:30:02 +00:00
Dan Gohman
793c9fed45 Fix an overaggressive SimplifyDemandedBits optimization on urem. This
fixes the 254.gap regression on x86 and the 403.gcc regression on x86-64.

llvm-svn: 50537
2008-05-01 19:13:24 +00:00
Chris Lattner
15195e00ee move lowering of llvm.memset -> store from simplify libcalls
to instcombine.

llvm-svn: 50472
2008-04-30 06:39:11 +00:00
Chris Lattner
5bd55b0885 don't eliminate load from volatile value on paths where the load is dead.
This fixes the second half of PR2262

llvm-svn: 50430
2008-04-29 17:28:22 +00:00
Chris Lattner
7099f3c400 fix a subtle volatile handling bug.
llvm-svn: 50428
2008-04-29 17:13:43 +00:00
Chris Lattner
51fe8415da don't delete the last store to an alloca if the store is volatile.
llvm-svn: 50390
2008-04-29 04:58:38 +00:00
Dan Gohman
1b7238e6e4 Teach InstCombine's ComputeMaskedBits what SelectionDAG's
ComputeMaskedBits knows about cttz, ctlz, and ctpop. Teach
SelectionDAG's ComputeMaskedBits what InstCombine's knows
about SRem. And teach them both some things about high bits
in Mul, UDiv, URem, and Sub. This allows instcombine and
dagcombine to eliminate sign-extension operations in
several new cases.

llvm-svn: 50358
2008-04-28 17:02:21 +00:00
Dale Johannesen
cfba8d51b8 change comments per review
llvm-svn: 50300
2008-04-25 21:16:07 +00:00
Nick Lewycky
1f831c0f57 Remove 'unwinds to' support from mainline. This patch undoes r47802 r47989
r48047 r48084 r48085 r48086 r48088 r48096 r48099 r48109 and r48123.

llvm-svn: 50265
2008-04-25 16:53:59 +00:00
Dale Johannesen
d70ea13581 Rewrite previous patch to suit Chris's preference.
llvm-svn: 50174
2008-04-23 18:34:37 +00:00
Dale Johannesen
3007fc4e1b Do not change the type of a ByVal argument to a
type of a different size.

llvm-svn: 50121
2008-04-23 01:03:05 +00:00
Evan Cheng
680839e258 Don't do: "(X & 4) >> 1 == 2 --> (X & 4) == 4" if there are more than one uses of the shift result.
llvm-svn: 50118
2008-04-23 00:38:06 +00:00
Chris Lattner
8837037473 remove dead code.
llvm-svn: 50080
2008-04-22 03:21:48 +00:00
Chris Lattner
14be19cf1e optimize "p != gep p, ..." better. This allows us to compile
getelementptr-seteq.ll into:

define i1 @test(i64 %X, %S* %P) {
	%C = icmp eq i64 %X, -1		; <i1> [#uses=1]
	ret i1 %C
}

instead of:

define i1 @test(i64 %X, %S* %P) {
	%A.idx.mask = and i64 %X, 4611686018427387903		; <i64> [#uses=1]
	%C = icmp eq i64 %A.idx.mask, 4611686018427387903		; <i1> [#uses=1]
	ret i1 %C
}

And fixes the second half of PR2235.  This speeds up the insertion sort
case by 45%, from 1.12s to 0.77s.  In practice, this will significantly
speed up for loops structured like:

for (double *P = Base + N; P != Base; --P)
  ...

Which happens frequently for C++ iterators.

llvm-svn: 50079
2008-04-22 02:53:33 +00:00
Torok Edwin
e038c595c1 g++-4.3 build-fix: CHAR_BIT requires <climits>.
llvm-svn: 49989
2008-04-20 08:33:11 +00:00
Chris Lattner
f390d62b7f Switch to using Simplified ConstantFP::get API.
llvm-svn: 49977
2008-04-20 00:41:09 +00:00
Dan Gohman
318d9a6605 Teach InstCombine's ComputeMaskedBits to handle pointer expressions
in addition to integer expressions. Rewrite GetOrEnforceKnownAlignment
as a ComputeMaskedBits problem, moving all of its special alignment
knowledge to ComputeMaskedBits as low-zero-bits knowledge.

Also, teach ComputeMaskedBits a few basic things about Mul and PHI
instructions.

This improves ComputeMaskedBits-based simplifications in a few cases,
but more noticeably it significantly improves instcombine's alignment
detection for loads, stores, and memory intrinsics.

llvm-svn: 49492
2008-04-10 18:43:06 +00:00
Gabor Greif
6c6b8a57f3 API changes for class Use size reduction, wave 1.
Specifically, introduction of XXX::Create methods
for Users that have a potentially variable number of
Uses.

llvm-svn: 49277
2008-04-06 20:25:17 +00:00
Nate Begeman
610aa2511c Don't eliminate bitcast instructions that change the type of a pointer
llvm-svn: 48971
2008-03-31 00:22:16 +00:00
Evan Cheng
563b265f37 Handle a special case xor undef, undef -> 0. Technically this should be transformed to undef. But this is such a common idiom (misuse) we are going to handle it.
llvm-svn: 48791
2008-03-25 20:07:13 +00:00
Evan Cheng
1d63708523 Transform (zext (or (icmp), (icmp))) to (or (zext (cimp), (zext icmp))) if at least one of the (zext icmp) can be transformed to eliminate an icmp.
llvm-svn: 48715
2008-03-24 00:21:34 +00:00
Duncan Sands
530554ab0a Fix the build for gcc-4.2.
llvm-svn: 48639
2008-03-21 08:32:17 +00:00
Chris Lattner
96cdf21ed4 Teach masked value is zero about add and sub, and use MVIZ to
simplify things like (X & 4) >> 1 == 2  --> (X & 4) == 4.

since it is obvious that the shift doesn't remove any bits.

llvm-svn: 48631
2008-03-21 05:19:58 +00:00
Bill Wendling
7d054f8b3f The inst combining of inttoptr into GEP with one index was using the bit size of
the type instead of the byte size. This was causing troublesome mis-compilations.

True to form, this took 2 days to find and is a one-line fix. :-P

llvm-svn: 48354
2008-03-14 05:12:19 +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
Devang Patel
0c7fb89803 Skip functions that return multiple values.
llvm-svn: 48233
2008-03-11 18:04:06 +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
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
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
Bill Wendling
bd1f1ae160 De-tabify.
llvm-svn: 47599
2008-02-26 10:53:30 +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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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