Commit Graph

2184 Commits

Author SHA1 Message Date
Dan Gohman b50f5a46e0 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.

llvm-svn: 73594
2009-06-17 01:22:39 +00:00
Dan Gohman 1ee696d8fc 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.

llvm-svn: 73540
2009-06-16 19:52:01 +00:00
Dan Gohman 7ccc52f131 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.

llvm-svn: 73431
2009-06-15 22:12:54 +00:00
Dan Gohman 19f8b0c3e0 Code cleanups. getSCEVAtScope no longer uses SCEVCouldNotCompute.
llvm-svn: 73401
2009-06-15 18:38:59 +00:00
Dan Gohman 4fe64deb7b Fix old-style type names in comments.
llvm-svn: 73362
2009-06-14 23:30:43 +00:00
Dan Gohman 038d02e74e 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.

llvm-svn: 73361
2009-06-14 22:58:51 +00:00
Dan Gohman 011cf687d7 Check for the short-circuiting condition before performing
the potentially expensive erase.

llvm-svn: 73359
2009-06-14 22:53:57 +00:00
Dan Gohman 862b7d98d1 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.

llvm-svn: 73358
2009-06-14 22:51:25 +00:00
Dan Gohman 0652fd59ff Convert several parts of the ScalarEvolution framework to use
SmallVector instead of std::vector.

llvm-svn: 73357
2009-06-14 22:47:23 +00:00
Dan Gohman 426901aa19 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.

llvm-svn: 73294
2009-06-13 16:25:49 +00:00
Dan Gohman 8db2edcf7f Add a ScalarEvolution::getAnyExtendExpr utility function for performing
extension with unspecified bits.

llvm-svn: 73293
2009-06-13 15:56:47 +00:00
Dan Gohman b8597bd097 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.

llvm-svn: 73137
2009-06-09 17:18:38 +00:00
Dan Gohman 4c720c07bb Rename UnknownValue to CouldNotCompute, since it holds an instance of
SCEVCouldNotCompute, and not SCEVUnknown.

llvm-svn: 72999
2009-06-06 14:37:11 +00:00
Devang Patel afa8a1592f Simplify.
llvm-svn: 72970
2009-06-05 23:08:56 +00:00
Dan Gohman 63964b5821 Move SCEVExpander::getOrInsertCanonicalInductionVariable out of line.
llvm-svn: 72949
2009-06-05 16:35:53 +00:00
Dan Gohman d9ef48a73e Remove some unnecessary #includes.
llvm-svn: 72948
2009-06-05 16:32:58 +00:00
Dan Gohman a5b9645c4b 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

llvm-svn: 72897
2009-06-04 22:49:04 +00:00
Dan Gohman 136bd719f0 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.

llvm-svn: 72741
2009-06-02 21:48:15 +00:00
Dan Gohman 2299d2ba2f Delete an obsolete sentance from a comment.
llvm-svn: 72667
2009-05-31 16:18:57 +00:00
Dan Gohman 28a9f80811 Add braces around an array initializer.
llvm-svn: 72453
2009-05-27 02:07:15 +00:00
Dan Gohman 1789362d70 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

llvm-svn: 72452
2009-05-27 02:00:53 +00:00
Dan Gohman 776e4c8d35 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.

llvm-svn: 72451
2009-05-27 01:48:27 +00:00
Dan Gohman 2a6606ca20 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.

llvm-svn: 72424
2009-05-26 17:44:05 +00:00
Dan Gohman 9fe212806b 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.

llvm-svn: 72422
2009-05-26 17:41:16 +00:00
Chris Lattner 02274a7171 make memdep use the getModRefInfo method for stores instead of the
low-level alias() method, allowing it to reason more aggressively
about pointers into constant memory.  PR4189

llvm-svn: 72403
2009-05-25 21:28:56 +00:00
Dan Gohman 4d5435d46a Various comment fixes.
llvm-svn: 72376
2009-05-24 23:45:28 +00:00
Dan Gohman 8ca0885d69 Change ScalarEvolution::getSCEVAtScope to always return the original value
in the case where a loop exit value cannot be computed, instead of only in
some cases while using SCEVCouldNotCompute in others. This simplifies
getSCEVAtScope's callers.

llvm-svn: 72375
2009-05-24 23:25:42 +00:00
Torok Edwin 5349cf5f4b Instead of clearing the rewriter, don't attempt to rewrite dead phi nodes.
Also fix 80 column violation.

llvm-svn: 72371
2009-05-24 19:36:09 +00:00
Dan Gohman 3cdfe749e0 Fix this code for hosts where std::vector doesn't have .data().
Use &Ops[0] instead, which is safe since Ops will never be empty here.

llvm-svn: 72368
2009-05-24 19:02:45 +00:00
Dan Gohman 291c2e04bd Generalize SCEVExpander::visitAddRecExpr's GEP persuit, and avoid
sending SCEVUnknowns to expandAddToGEP. This avoids the need for
expandAddToGEP to bend the rules and peek into SCEVUnknown
expressions.

Factor out the code for testing whether a SCEV can be factored by
a constant for use in a GEP index. This allows it to handle
SCEVAddRecExprs, by recursing.

As a result, SCEVExpander can now put more things in GEP indices,
so it emits fewer explicit mul instructions.

llvm-svn: 72366
2009-05-24 18:06:31 +00:00
Dan Gohman 071156c19c When the low bits of one operand of an add are zero, that number
of low bits of the other operand are preserved in the output.

llvm-svn: 72365
2009-05-24 18:02:35 +00:00
Torok Edwin d184bc209c The rewriter may hold references to instructions that are deleted because they are trivially dead.
Fix by clearing the rewriter cache before deleting the trivially dead
instructions.
Also make InsertedExpressions use an AssertingVH to catch these
bugs easier.

llvm-svn: 72364
2009-05-24 14:23:16 +00:00
Dan Gohman 88e06db116 Fix a thinko in the code that adapted SCEVMulExpr operands for
use in expanding SCEVAddExprs with GEPs. The operands of a
SCEVMulExpr need to be multiplied together, not added.

llvm-svn: 72250
2009-05-22 07:14:20 +00:00
Jay Foad 7d0479f2c2 Use v.data() instead of &v[0] when SmallVector v might be empty.
llvm-svn: 72210
2009-05-21 09:52:38 +00:00
Dan Gohman bf0002e7c1 Teach ValueTracking a new way to analyze PHI nodes, and and teach
Instcombine to be more aggressive about using SimplifyDemandedBits
on shift nodes. This allows a shift to be simplified to zero in the
included test case.

llvm-svn: 72204
2009-05-21 02:28:33 +00:00
Dan Gohman 9cbf850506 Teach SCEV::isLoopInvariant and SCEV::hasComputableLoopEvolution
about the convention from LoopInfo that a null Loop* means the entire
function body.

llvm-svn: 72152
2009-05-20 01:01:24 +00:00
Dan Gohman d33a090efa Make SCEVCallbackVH a private nested class inside ScalarEvolution, as
it's an implementation detail.

llvm-svn: 72122
2009-05-19 19:22:47 +00:00
Dan Gohman 7a97e933cd Create ConstantExpr GEPs the correct way. This fixes
MultiSource/Benchmarks/Prolangs-C/football and a variety of other
failures.

llvm-svn: 72120
2009-05-19 19:18:01 +00:00
Dan Gohman 2649491f9c Teach SCEVExpander to expand arithmetic involving pointers into GEP
instructions. It attempts to create high-level multi-operand GEPs,
though in cases where this isn't possible it falls back to casting
the pointer to i8* and emitting a GEP with that. Using GEP instructions
instead of ptrtoint+arithmetic+inttoptr helps pointer analyses that
don't use ScalarEvolution, such as BasicAliasAnalysis.

Also, make the AddrModeMatcher more aggressive in handling GEPs.
Previously it assumed that operand 0 of a GEP would require a register
in almost all cases. It now does extra checking and can do more
matching if operand 0 of the GEP is foldable. This fixes a problem
that was exposed by SCEVExpander using GEPs.

llvm-svn: 72093
2009-05-19 02:15:55 +00:00
Daniel Dunbar a8c1658619 Silence Release-Asserts warnings.
llvm-svn: 72011
2009-05-18 16:43:04 +00:00
Dan Gohman 6350296efc Teach ScalarEvolution to recognize x^-1 in the case where non-demanded
bits have been stripped out by instcombine.

llvm-svn: 72010
2009-05-18 16:29:04 +00:00
Dan Gohman d277a1ed49 Delete a redundant 'else'.
llvm-svn: 72009
2009-05-18 16:17:44 +00:00
Dan Gohman 9cf09f8291 Fix ScalarEvolution::isLoopGuardedByCond to accept a null Loop*, for
consistency with other routines that use a null Loop* to mean code
not contained by any loop.

llvm-svn: 72008
2009-05-18 16:03:58 +00:00
Dan Gohman 4fc3668a92 Minor code cleanups. Do more of the work before the if statements
instead of within their controlling expressions.

llvm-svn: 72007
2009-05-18 15:58:39 +00:00
Dan Gohman d33f36e23b Add assertion checks to the SCEV operator creation methods to catch
type mismatches.

llvm-svn: 72006
2009-05-18 15:44:58 +00:00
Dan Gohman 8c77f1a275 Make ScalarEvolution::isLoopGuardedByCond work even when the edge
entering a loop is a non-split critical edge.

llvm-svn: 72004
2009-05-18 15:36:09 +00:00
Dan Gohman ba7f6d8276 Add an isOne() utility function to ScalarEvolution, similar to isZero()
and similar to ConstantInt's isOne().

llvm-svn: 72003
2009-05-18 15:22:39 +00:00
Bill Wendling 6ddc11aedd Non-functionality changes:
- Reformatting.
- Use while() instead of do-while().
- Move simple constructors into .h file.

llvm-svn: 71782
2009-05-14 18:26:15 +00:00
Bill Wendling 3fe4cf745b Clean up this file fixing 80-column violations, bad formatting, etc. No functionality change.
llvm-svn: 71781
2009-05-14 18:16:46 +00:00
Duncan Sands 7e3c9e1bd9 Avoid getting a compiler warning
IVUsers.cpp: In member function ‘bool llvm::IVUsers::AddUsersIfInteresting(llvm::Instruction*)’:
 IVUsers.cpp:221: warning: ‘isSigned’ may be used uninitialized in this function
with gcc-4.3.

llvm-svn: 71654
2009-05-13 12:52:44 +00:00