Commit Graph

289 Commits

Author SHA1 Message Date
Dan Gohman
91380b7239 Fix a bug in the trip-count computation with And/Or. If either of the
sides is CouldNotCompute, the resulting exact count must be CouldNotCompute.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73920 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 23:28:56 +00:00
Dan Gohman
bd5ce52740 Fix llvm::ComputeNumSignBits to handle pointer types
conservatively correctly, instead of aborting.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73908 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 22:02:32 +00:00
Dan Gohman
a334aa7a10 Teach ScalarEvolution how to analyze loops with multiple exit
blocks, and also exit blocks with multiple conditions (combined
with (bitwise) ands and ors). It's often infeasible to compute an
exact trip count in such cases, but a useful upper bound can often
be found.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73866 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 00:31:57 +00:00
Dan Gohman
51f53b7f5a Fix ScalarEvolution's backedge-taken count computations to check for
overflow when computing a integer division to round up.

Thanks to Nick Lewycky for noticing this!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73862 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-21 23:46:38 +00:00
Dan Gohman
820528331f Teach ScalarEvolution how to recognize another xor(and(x, C), C) case.
If C is a single bit and the and gets analyzed as a truncate and
zero-extend, the xor can be represnted as an add.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73664 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 00:00:20 +00:00
Dan Gohman
559254b697 Add -disable-output to a bunch of tests that don't care about the output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73633 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-17 20:56:26 +00:00
Dan Gohman
3034c10675 Fix ScalarEvolution's Xor handling to not assume that an And
that gets recognized with a SCEVZeroExtendExpr must be an And
with a low-bits mask. With r73540, this is no longer the case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73594 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-17 01:22:39 +00:00
Dan Gohman
ae3a0be92e Split the Add, Sub, and Mul instruction opcodes into separate
integer and floating-point opcodes, introducing
FAdd, FSub, and FMul.

For now, the AsmParser, BitcodeReader, and IRBuilder all preserve
backwards compatability, and the Core LLVM APIs preserve backwards
compatibility for IR producers. Most front-ends won't need to change
immediately.

This implements the first step of the plan outlined here:
http://nondot.org/sabre/LLVMNotes/IntegerOverflow.txt


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72897 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-04 22:49:04 +00:00
Dan Gohman
72776d2190 Teach BasicAliasAnalysis to understand constant gep indices that fall
beyond their associated static array type.

I believe that this fixes a legitimate bug, because BasicAliasAnalysis
already has code to check for this condition that works for non-constant
indices, however it was missing the case of constant indices. With this
change, it checks for both.

This fixes PR4267, and miscompiles of SPEC 188.ammp and 464.h264.href.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72451 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-27 01:48:27 +00:00
Dan Gohman
10978bd591 Teach ScalarEvolution to recognize x^-1 in the case where non-demanded
bits have been stripped out by instcombine.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72010 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 16:29:04 +00:00
Dan Gohman
859b4824ee Make ScalarEvolution::isLoopGuardedByCond work even when the edge
entering a loop is a non-split critical edge.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72004 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 15:36:09 +00:00
Dan Gohman
04623272d2 Add nounwind to a few tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72002 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 15:16:49 +00:00
Eli Friedman
361e54d433 Allow scalar evolution to compute iteration counts for loops with a
pointer-based condition.  This fixes PR3171.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71354 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-09 12:32:42 +00:00
Dan Gohman
b0285932ab Fix bogus overflow checks by replacing them with actual
overflow checks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71284 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 23:11:16 +00:00
Dan Gohman
728c7f3059 Fold trunc casts into add-recurrence expressions, allowing the
add-recurrence to be exposed. Add a new SCEV folding rule to
help simplify expressions in the presence of these extra truncs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71264 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 21:03:19 +00:00
Dan Gohman
9032b78c98 When printing a SCEVUnknown with pointer type, don't print an
artificial "ptrtoint", as it tends to clutter up complicated
expressions. The cast operators now print both source and
destination types, which is usually sufficient.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70554 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-01 17:02:22 +00:00
Dan Gohman
a1af757e0a Extend ScalarEvolution's getBackedgeTakenCount to be able to
compute an upper-bound value for the trip count, in addition to
the actual trip count. Use this to allow getZeroExtendExpr and
getSignExtendExpr to fold casts in more cases.

This may eventually morph into a more general value-range
analysis capability; there are certainly plenty of places where
more complete value-range information would allow more folding.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70509 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-30 20:47:05 +00:00
Dan Gohman
ac70ceafbc Generalize the cast-of-addrec folding to handle folding of SCEVs like
(sext i8 {-128,+,1} to i64) to i64 {-128,+,1}, where the iteration
crosses from negative to positive, but is still safe if the trip
count is within range.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70421 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-29 22:28:28 +00:00
Dan Gohman
3e0e31b261 Fix this test to match the new output from scalar-evolution.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70410 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-29 21:06:20 +00:00
Dan Gohman
36b8e53fe0 Include the source type in SCEV cast expression debug output, and
print sext, zext, and trunc, instead of signextend, zeroextend,
and truncate, respectively, for consistency with the main IR.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70405 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-29 20:27:52 +00:00
Dan Gohman
87d2fe5143 Fix a grammaro in a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70331 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-28 21:54:23 +00:00
Nick Lewycky
5cd28fad15 Simplify trunc(extend(x)) in SCEVs, just for completeness. Also fix some odd
whitespace in the same file.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69870 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-23 05:15:08 +00:00
Owen Anderson
03dac74d40 Testcase for PR3909.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69868 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-23 04:33:42 +00:00
Dan Gohman
578ccf81e5 When turning (ashr(shl(x, n), n)) into sext(trunc(x)), the width of the
type to truncate to should be the number of bits of the value that are
preserved, not the number that are clobbered with sign-extension.
This fixes regressions in ldecod.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69704 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-21 20:18:36 +00:00
Chris Lattner
56cb12c9a7 change this to test for an alias result more directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67046 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-16 18:28:27 +00:00
Nick Lewycky
b24e6c4dd3 Add a replacement for 2009-02-12-GEPNoalias.ll that works without -debug.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67011 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-14 19:40:09 +00:00
Chris Lattner
6dc3a8fd40 remove a buggy test, it is not ok to use -debug in RUN line.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66918 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-13 18:19:34 +00:00
Dan Gohman
d4b3a37f96 Update this test for the LoopInfo::print changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65597 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-27 00:17:49 +00:00
Dan Gohman
46bdfb0e6b Rename ScalarEvolution's getIterationCount to getBackedgeTakenCount,
to more accurately describe what it does. Expand its doxygen comment
to describe what the backedge-taken count is and how it differs
from the actual iteration count of the loop. Adjust names and
comments in associated code accordingly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65382 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-24 18:55:53 +00:00
Nick Lewycky
826f7cebfd BasicAA was making the assumption that a local allocation which hadn't escaped
couldn't ever be the return of call instruction. However, it's quite possible
that said local allocation is itself the return of a function call. That's
what malloc and calloc are for, actually.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64442 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-13 07:06:27 +00:00
Owen Anderson
fe9388ccb4 Finish making AliasAnalysis aware of the fact that most atomic intrinsics only dereference their arguments, and enhance
BasicAA to make use of this fact when computing ModRef info.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63718 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-04 05:16:46 +00:00
Nick Lewycky
789558db70 Wind SCEV back in time, to Nov 18th. This 'fixes' PR3275, PR3294, PR3295,
PR3296 and PR3302.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62160 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-13 09:18:58 +00:00
Nick Lewycky
ae285bf5a6 Don't try to analyze this "backward" case. This is overly conservative
pending a correct solution.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61589 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-02 18:54:17 +00:00
Nick Lewycky
3037eda1ef Check that the function prototypes are correct before assuming that the
parameters are pointers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61451 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-27 16:20:53 +00:00
Nick Lewycky
f23d0d392a Resubmit support for the 'nocapture' attribute.
The problematic part of this patch is that we were out of attribute bits,
requiring some fancy bit hacking to make it fit (by shrinking alignment)
without breaking existing users or the file format.

This change will require users to rebuild llvm-gcc to match llvm.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61239 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-19 06:39:12 +00:00
Bill Wendling
43445c153c Remove empty test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61095 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-16 19:07:17 +00:00
Bill Wendling
6fa311c233 Temporarily revert r61019, r61030, and r61040. These were breaking LLVM Release
builds.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61094 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-16 19:06:48 +00:00
Nick Lewycky
1447f5ca1f Generalize support for analyzing loops to include SLE/SGE loop exit conditions
and support for non-unit strides with signed exit conditions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61082 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-16 08:30:01 +00:00
Chris Lattner
1314f20283 Teach basicaa to use the nocapture attribute when possible. When the
intrinsics are properly marked nocapture, the fixme should be addressed.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61040 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-15 18:59:22 +00:00
Nick Lewycky
8bdc6920cd Revert my re-instated reverted commit, fixes the bootstrap build on x86-64 linux.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60951 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-12 17:09:07 +00:00
Nick Lewycky
277a147f87 Sneaky, sneaky: move the -1 to the outside of the SMax. Reinstate the
optimization of SGE/SLE with unit stride, now that it works properly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60881 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-11 17:40:14 +00:00
Chris Lattner
b957bda0bc Allow basicaa to walk through geps with identical indices in
parallel, allowing it to decide that P/Q must alias if A/B
must alias in things like:
 P = gep A, 0, i, 1
 Q = gep B, 0, i, 1

This allows GVN to delete 62 more instructions out of 403.gcc.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60820 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-10 01:04:47 +00:00
Evan Cheng
28575f2113 xfail this for now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60777 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 18:43:00 +00:00
Nick Lewycky
0bed364307 It's easy to handle SLE/SGE when the loop has a unit stride.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60748 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 07:25:04 +00:00
Nick Lewycky
02ff308aa1 Extend the 'noalias' attribute to function return values. This is intended to
indicate functions that allocate, such as operator new, or list::insert. The
actual definition is slightly less strict (for now).

No changes to the bitcode reader/writer, asm printer or verifier were needed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59934 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-24 03:41:24 +00:00
Nick Lewycky
dd643f26c4 Add a utility function that detects whether a loop is guaranteed to be finite.
Use it to safely handle less-than-or-equals-to exit conditions in loops. These
also occur when the loop exit branch is exit on true because SCEV inverses the
icmp predicate.

Use it again to handle non-zero strides, but only with an unsigned comparison
in the exit condition.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59528 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-18 15:10:54 +00:00
Nick Lewycky
d72a81ee64 Don't brute-force analyze cubic or higher polynomials.
If this patch causes a performance regression for anyone, please let me know,
and it can be fixed in a different way with much more effort.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59384 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-16 04:14:25 +00:00
Nick Lewycky
8f4d5eb9e5 Don't crash analyzing certain quadratics (addrec of {X,+,Y,+,1}).
We're still waiting on code that actually analyzes them properly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58592 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-03 02:43:49 +00:00
Duncan Sands
3ee8fc9649 Rationalize the names of passes that print information:
-callgraph => print-callgraph
    -callscc   => print-callgraph-sccs
    -cfgscc    => print-cfg-sccs
    -externalfnconstants => print-externalfnconstants
    -print               => print-function
    -print-alias-sets (no change)
    -print-callgraph     => dot-callgraph
    -print-cfg           => dot-cfg
    -print-cfg-only      => dot-cfg-only
    -print-dom-info (no change)
    -printm              => print-module
    -printusedtypes      => print-used-types


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56487 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-23 12:47:39 +00:00
Duncan Sands
acdb2eeb45 Remove the MarkModRef pass (use AddReadAttrs instead).
Unfortunately this means removing one regression test
of GlobalsModRef because I couldn't work out how to
perform it without MarkModRef.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56342 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-19 08:23:44 +00:00