Commit Graph

693 Commits

Author SHA1 Message Date
Nick Lewycky
8e39432ea9 Fix demanded bits analysis with srem by negative number. Based on a patch
by Richard Osborne.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58555 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-02 02:41:50 +00:00
Dan Gohman
21440acc06 Fix this recently moved code to use the correct type. CI is now a
ConstantInt, and SI is the original cast instruction. This fixes
PR2996.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58549 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-02 00:17:33 +00:00
Dan Gohman
1975d03183 Canonicalize sext(i1) to i1?-1:0, and update various instcombine
optimizations accordingly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58457 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-30 20:40:10 +00:00
Dan Gohman
b493b2774c (A & sext(C)) | (B & ~sext(C) -> C ? A : B
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58351 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-28 22:38:57 +00:00
Nick Lewycky
04aa2c3520 Don't try to create a mask when we don't need one. Fixes a crash.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58075 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-24 06:14:27 +00:00
Dan Gohman
2276a7bc8e 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57608 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-15 23:19:35 +00:00
Evan Cheng
403006205f Combine (fcmp cc0 x, y) | (fcmp cc1 x, y) into a single fcmp when possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57515 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-14 18:44:08 +00:00
Evan Cheng
4990b257dd - Somehow I forgot about one / une.
- Renumber fcmp predicates to match their icmp counterparts.
- Try swapping operands to expose more optimization opportunities.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57513 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-14 18:13:38 +00:00
Evan Cheng
8db90725cb 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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57507 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-14 17:15:11 +00:00
Chris Lattner
a6321b40c2 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!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57387 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-11 22:55:00 +00:00
Chris Lattner
8c34cd287a 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57095 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-05 02:13:19 +00:00
Nick Lewycky
a06cf82a7b Fix misoptimization of: xor i1 (icmp eq (X, C1), icmp s[lg]t (X, C2))
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56834 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-30 06:08:34 +00:00
Dan Gohman
81b28ceab6 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56246 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-16 18:46:06 +00:00
Dan Gohman
4f833d4351 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56133 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-11 23:06:38 +00:00
Dan Gohman
3139ff8f7b Fix a vectorshuffle instcombine bug introduced by r55995.
Patch by Nicolas Capens!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56129 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-11 22:47:57 +00:00
Dan Gohman
1df3fd6683 Fix an icmp+sdiv optimization to check for and handle an overflow
condition. This fixes PR2740.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56076 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-10 23:30:57 +00:00
Dan Gohman
488fbfc69e 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55995 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-09 18:11:14 +00:00
Nick Lewycky
83c05e5d30 Don't crash when trying to constant fold a vector with some elements that can't
be folded. Instead, fail to fold the entire vector.

We could also return a vector with some elements folded and some not. If anyone
thinks that's a better approach, please speak up!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55689 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-03 05:54:33 +00:00
Nick Lewycky
5d52c4501a Revert r54876 r54877 r54906 and r54907. Evan found that these caused a 20%
slowdown in bzip2.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55113 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-21 05:56:10 +00:00
Nick Lewycky
91a0f78265 Consider the case where xor by -1 and xor by 128 have been combined already to
produce an xor by 127.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54906 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-17 19:58:24 +00:00
Nick Lewycky
1b344bc986 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54876 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-17 07:34:14 +00:00
Owen Anderson
7c856c09cd Remove GCSE and LoadVN from the testsuite.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54832 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-16 00:00:54 +00:00
Dan Gohman
a60832b018 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54767 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-13 23:12:35 +00:00
Chris Lattner
b8cd4d3d49 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54653 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-11 22:06:05 +00:00
Dan Gohman
4ce9627e97 Fix a shufflevector instcombine that was emitting invalid masks indices
when it meant to be emitting undef indices.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54417 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 18:17:32 +00:00
Chris Lattner
46bbad217b optimize a common idiom generated by clang for bitfield access, PR2638.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54408 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 07:35:52 +00:00
Chris Lattner
5af5f463e1 Zap sitofp/fptoui pairs. In all cases when the sign difference
matters, the result is undefined anyway.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54396 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 05:13:06 +00:00
Nick Lewycky
b30591ec64 Reinstate this optimization, but without the miscompile. Thanks to Bill for
tracking down that this was breaking llvm-gcc bootstrap on Linux.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54394 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 04:54:03 +00:00
Bill Wendling
5226698f67 Just grep for through the LL code instead of the ASM code
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54389 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 00:10:32 +00:00
Bill Wendling
201bf25f83 Add default architecture.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54384 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-05 23:36:00 +00:00
Bill Wendling
0b101b0399 Testcase for PR2629.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54377 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-05 22:23:59 +00:00
Bill Wendling
021507be82 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54372 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-05 21:23:45 +00:00
Chris Lattner
d137ab4783 Fix PR2553
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53715 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-17 06:07:20 +00:00
Matthijs Kooijman
d8b4d60490 Add a few cases to instcombine's extractvalue testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53675 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-16 12:57:25 +00:00
Evan Cheng
be8efa54b6 Fix PR2296. Do not transform x86_sse2_storel_dq into a full-width store.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53666 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-16 07:28:14 +00:00
Chris Lattner
fdb19e5887 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
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53534 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-14 00:15:52 +00:00
Nick Lewycky
3ac9e109b2 Enhance analysis of srem.
Remove dead code analyzing urem. 'urem' of power-of-2 is canonicalized to an
'and' instruction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53506 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-12 05:04:38 +00:00
Nick Lewycky
4bf1e59819 Add another optimization from PR2330. Also catch some missing cases that are
similar.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53451 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-11 07:20:53 +00:00
Chris Lattner
85b5eb0505 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53444 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-11 04:20:58 +00:00
Chris Lattner
f299184565 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)




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53443 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-11 04:09:09 +00:00
Chris Lattner
99672cb130 make this condition more precise.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53442 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-11 03:54:57 +00:00
Nick Lewycky
5dcc41f5b3 Fix overzealous optimization. Thanks to Duncan Sands for pointing out my error!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53393 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-10 05:51:40 +00:00
Nick Lewycky
9ee863ecc0 Fold (a < 8) && (b < 8) into (a|b) < 8 for unsigned less or greater than.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53282 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-09 07:29:11 +00:00
Nick Lewycky
d1f77bf931 Fold ((1 << a) & 1) to (a == 0).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53276 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-09 05:20:13 +00:00
Chris Lattner
2782ed1f14 Fix a broken test. Neither load is eliminable without changing the CFG.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53273 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-09 05:01:02 +00:00
Nick Lewycky
b4d1bc989e Reduce x - y to -y when we know the 'x' part will get masked off anyways.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53271 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-09 04:32:37 +00:00
Chris Lattner
895860e27b new testcase for PR2496
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53239 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-08 17:18:05 +00:00
Nick Lewycky
b8cd6a49b5 Fix missed optimization opportunity when analyzing cast of mul and select.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53151 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-05 21:19:34 +00:00
Chris Lattner
aa0bf52625 Fix PR2488, a case where we deleted stack restores too aggressively.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52702 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-25 05:59:28 +00:00
Eli Friedman
5c1f172213 Fix for PR2479: correctly optimize expressions like (a > 13) & (a ==
15).

See also PR1800, which is about the signed case.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52608 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-21 23:36:13 +00:00