Commit Graph

2249 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
Owen Anderson
e7b6118a51 Remove unneeded #include.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73911 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 22:09:07 +00:00
Dan Gohman
469f3cdc13 Fix a few minor issues that were exposed by the removal of SCEVHandle.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73910 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 22:08:45 +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
Owen Anderson
753ad615f9 Remove the parent pointer from SCEV, since it did not end up being needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73907 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 21:57:23 +00:00
Owen Anderson
372b46cad9 SCEVHandle is no more!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73906 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 21:39:50 +00:00
Dan Gohman
d32f5bf22d Fix some typos that Duncan noticed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73903 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 21:10:22 +00:00
Owen Anderson
08367b6163 Banish global state from ScalarEvolution! SCEV uniquing is now done by tables attached to the ScalarEvolution pass.
This also throws out the SCEV reference counting scheme, as the the SCEVs now have a lifetime controlled by the
ScalarEvolution pass.

Note that SCEVHandle is now a no-op, and will be remove in a future commit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73892 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 18:25:46 +00:00
Dan Gohman
60e9b0708a Make use of getUMinFromMismatchedTypes when computing backedge-taken
counts for loops with multiple exits, replacing more conservative code
which only handled constants. This is derived from a patch by
Nick Lewycky.

This also fixes llc aborts in ClamAV and others, as
getUMinFromMismatchedTypes takes care of balancing the types before
working with them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73884 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 15:09:28 +00:00
Dan Gohman
c9759e80f4 Add a getUMinFromMismatchedTypes helper function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73883 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 15:03:27 +00:00
Dan Gohman
f9a9a9928c Factor out code for computing umin and smin for SCEV expressions into
helper functions. Based on a patch by Nick Lewycky.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73869 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 03:18:45 +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
743ab498d8 Delete an unused variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73865 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 00:19:17 +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
763bad1a2b Generalize isLoopGuardedByCond's checking to consider two
SCEVUnknowns with identical Instructions to be equal. This allows
it to analze cases such as the attached testcase, where the front-end
has cloned the loop controlling expression. Along with r73805, this
lets IndVarSimplify eliminate all the sign-extend casts in the
loop in the attached testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73807 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-20 00:35:32 +00:00
Dan Gohman
3964acc2f4 Use ScalarEvolution's new GetMinSignBits and GetMinLeadingZeros
in the loop backedge-taken count computation of the maximum
possible trip count.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73805 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-20 00:32:22 +00:00
Dan Gohman
2c364ad4a6 Make GetMinTrailingZeros a member function of ScalarEvolution,
so that it can access the TargetData member (when available) and
use ValueTracking.h information to compute information for
SCEVUnknown Values.

Also add GetMinLeadingZeros and GetMinSignBits functions,
with minimal implementations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73794 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-19 23:29:04 +00:00
Dan Gohman
0c689c5e05 Make ScalarEvolution::print print getSCEVAtScope values for
expressions, when interesting.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73776 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-19 17:49:54 +00:00
Dan Gohman
958e292c7a Don't (unconditionally) use getSCEVAtScope to simplify the step
expression in IVUsers, because in the case of a use of a non-linear
addrec outside of a loop, this causes the addrec to be evaluated as
a linear addrec.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73774 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-19 17:33:15 +00:00
Owen Anderson
4a7893b452 Add a parent pointer to SCEV, in preparation for getting rid of the global uniquing tables. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73728 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 22:25:12 +00:00
Dan Gohman
30fb512e95 Recognize n != 0 ? n : 1 as umax(n, 1). Previously only ULT/UGT/ULE/UGE
comparisons were recognized for umax, but instcombine canonicalizes
unsigned comparisons with zero to this simpler form.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73717 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 20:21:07 +00:00
Dan Gohman
4e8a98519e Remove the code from IVUsers that attempted to handle
casted induction variables in cases where the cast
isn't foldable. It ended up being a pessimization in
many cases. This could be fixed, but it would require
a bunch of complicated code in IVUsers' clients. The
advantages of this approach aren't visible enough to
justify it at this time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73706 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 16:54:06 +00:00
Dan Gohman
6864db6fac Update a comment to reflect the code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73704 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 16:24:47 +00:00
Dan Gohman
9e7d9883b0 Fix trailing whitespace from ScalarEvolution::print.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73666 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 00:37:45 +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
fc3641b07a Delete unnecessary braces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73663 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-17 23:54:37 +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
61ffa8e373 Instcombine's ShrinkDemandedConstant may strip bits out of constants,
obscuring what would otherwise be a low-bits mask.  Use ComputeMaskedBits
to compute what ShrinkDemandedConstant knew about to reconstruct a
low-bits mask value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73540 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-16 19:52:01 +00:00
Dan Gohman
6de29f8d96 Support vector casts in more places, fixing a variety of assertion
failures.

To support this, add some utility functions to Type to help support
vector/scalar-independent code. Change ConstantInt::get and
ConstantFP::get to support vector types, and add an overload to
ConstantInt::get that uses a static IntegerType type, for
convenience.

Introduce a new getConstant method for ScalarEvolution, to simplify
common use cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73431 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-15 22:12:54 +00:00
Dan Gohman
743e41eae1 Code cleanups. getSCEVAtScope no longer uses SCEVCouldNotCompute.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73401 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-15 18:38:59 +00:00
Dan Gohman
a119de86a0 Fix old-style type names in comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73362 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 23:30:43 +00:00
Dan Gohman
bd59d7b603 Implement more aggressive folding of add operand lists when
they contain multiplications of constants with add operations.
This helps simplify several kinds of things; in particular it
helps simplify expressions like ((-1 * (%a + %b)) + %a) to %b,
as expressions like this often come up in loop trip count
computations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73361 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 22:58:51 +00:00
Dan Gohman
7f7c4366ca Check for the short-circuiting condition before performing
the potentially expensive erase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73359 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 22:53:57 +00:00
Dan Gohman
4dfad29547 Do compare constant SCEV values in SCEVComplexityCompare, because
even though the order doesn't matter at the top level of an expression,
it does matter when the constant is a subexpression of an n-ary
expression, because n-ary expressions are sorted lexicographically.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73358 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 22:51:25 +00:00
Dan Gohman
a82752c9eb Convert several parts of the ScalarEvolution framework to use
SmallVector instead of std::vector.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73357 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 22:47:23 +00:00
Dan Gohman
4d8414f420 Teach SCEVExpander's visitAddRecExpr to reuse an existing canonical
induction variable when the addrec to be expanded does not require
a wider type. This eliminates the need for IndVarSimplify to
micro-manage SCEV expansions, because SCEVExpander now
automatically expands them in the form that IndVarSimplify considers
to be canonical. (LSR still micro-manages its SCEV expansions,
because it's optimizing for the target, rather than for
other optimizations.)

Also, this uses the new getAnyExtendExpr, which has more clever
expression simplification logic than the IndVarSimplify code it
replaces, and this cleans up some ugly expansions in code such as
the included masked-iv.ll testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73294 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-13 16:25:49 +00:00
Dan Gohman
2ce84c8d47 Add a ScalarEvolution::getAnyExtendExpr utility function for performing
extension with unspecified bits.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73293 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-13 15:56:47 +00:00
Dan Gohman
92fcdcac54 Use expandCodeFor instead of expand when the result will be
immediately casted. At present, this is just a minor code
simplification. In the future, the expansion code may be able
to make better choices if it knows what the desired result
type will be.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73137 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-09 17:18:38 +00:00
Dan Gohman
86fbf2fe4c Rename UnknownValue to CouldNotCompute, since it holds an instance of
SCEVCouldNotCompute, and not SCEVUnknown.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72999 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-06 14:37:11 +00:00
Devang Patel
5c06f61e57 Simplify.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72970 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-05 23:08:56 +00:00
Dan Gohman
1d09de3eca Move SCEVExpander::getOrInsertCanonicalInductionVariable out of line.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72949 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-05 16:35:53 +00:00
Dan Gohman
c965ee223c Remove some unnecessary #includes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72948 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-05 16:32:58 +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
7714285efd Change ConstantFoldConstantExpression to accept a null
TargetData pointer. The only thing it's used for are
calls to ConstantFoldCompareInstOperands and
ConstantFoldInstOperands, which both already accept a
null TargetData pointer. This makes
ConstantFoldConstantExpression easier to use in clients
where TargetData is optional.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72741 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-02 21:48:15 +00:00
Dan Gohman
18a69c5a36 Delete an obsolete sentance from a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72667 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-31 16:18:57 +00:00
Dan Gohman
f1a80489d6 Add braces around an array initializer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72453 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-27 02:07:15 +00:00
Dan Gohman
4a4f767235 Teach SCEVExpander to avoid creating over-indexed GEP indices when
possible. For example, it now emits

  %p.2.ip.1 = getelementptr [3 x [3 x double]]* %p, i64 2, i64 %tmp, i64 1

instead of the equivalent but less obvious

  %p.2.ip.1 = getelementptr [3 x [3 x double]]* %p, i64 0, i64 %tmp, i64 19


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72452 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-27 02:00:53 +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
91bb61a1e2 For the return type of SCEVUDivExpr, use the RHS' type instead of
that of the LHS. It doesn't matter for correctness, but the LHS
is more likely than the RHS to be a pointer type in exotic cases,
and it's more tidy to have it return the integer type.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72424 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-26 17:44:05 +00:00
Dan Gohman
f876ad0a70 In cases where a pointer value is an operand of a multiplication or
division operation, don't attempt to use the operation's value as
the base of a getelementptr. This fixes PR4271.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72422 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-26 17:41:16 +00:00