2162 Commits

Author SHA1 Message Date
Dan Gohman
5003d0ee42 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
fb34a67498 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
8f4210d099 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
621071c6c4 Various comment fixes.
llvm-svn: 72376
2009-05-24 23:45:28 +00:00
Dan Gohman
19be1fa810 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
aca641232c 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
942daf73f8 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
fdba9c8fce 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
378152d9d0 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
8936fc2e28 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
82df35a657 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
16d48d2595 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
fc28858d91 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
18580e593a 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
be817680b8 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
f61ddb4c06 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
922033d119 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
7c5aee4f79 Silence Release-Asserts warnings.
llvm-svn: 72011
2009-05-18 16:43:04 +00:00
Dan Gohman
592d65ba06 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
09726e69b9 Delete a redundant 'else'.
llvm-svn: 72009
2009-05-18 16:17:44 +00:00
Dan Gohman
e50a960c5a 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
153b5acb45 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
b24fd61296 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
2c9bd7e0cb 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
560da2a066 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
78f6980946 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
3449db3f16 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
6f8d5b489a 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
Chris Lattner
a5add81e91 add IVUsers.cpp
llvm-svn: 71646
2009-05-13 06:28:04 +00:00
Dan Gohman
32cd719eba Add three new helper routines, getNoopOrZeroExtend,
getNoopOrSignExtend, and getTruncateOrNoop. These are similar
to getTruncateOrZeroExtend etc., except that they assert that
the conversion is either not widening or narrowing, as
appropriate. These will be used in some upcoming fixes.

llvm-svn: 71632
2009-05-13 03:46:30 +00:00
Dan Gohman
d13f674130 Factor the code for collecting IV users out of LSR into an IVUsers class,
and generalize it so that it can be used by IndVarSimplify. Implement the
base IndVarSimplify transformation code using IVUsers. This removes
TestOrigIVForWrap and associated code, as ScalarEvolution now has enough
builtin overflow detection and folding logic to handle all the same cases,
and more. Run "opt -iv-users -analyze -disable-output" on your favorite
loop for an example of what IVUsers does.

This lets IndVarSimplify eliminate IV casts and compute trip counts in
more cases. Also, this happens to finally fix the remaining testcases
in PR1301.

Now that IndVarSimplify is being more aggressive, it occasionally runs
into the problem where ScalarEvolutionExpander's code for avoiding
duplicate expansions makes it difficult to ensure that all expanded
instructions dominate all the instructions that will use them. As a
temporary measure, IndVarSimplify now uses a FixUsesBeforeDefs function
to fix up instructions inserted by SCEVExpander. Fortunately, this code
is contained, and can be easily removed once a more comprehensive
solution is available.

llvm-svn: 71535
2009-05-12 02:17:14 +00:00
Dan Gohman
cac9b5c5be When forgetting SCEVs for loop PHIs, don't forget SCEVUnknown values.
These values aren't analyzable, so they don't care if more information
about the loop trip count can be had. Also, SCEVUnknown is used for
a PHI while the PHI itself is being analyzed, so it needs to be left
in the Scalars map. This fixes a variety of subtle issues.

llvm-svn: 71533
2009-05-12 01:27:58 +00:00
Dan Gohman
e55d6c4c8a Fix GetMinTrailingZeros for SCEVSignExtend and SCEVZeroExtendExpr to
return the correct value when the cast operand is all zeros. This ought
to be pretty rare, because it would mean that the regular SCEV folding
routines missed a case, though there are cases they might legitimately
miss. Also, it's unlikely anything currently using GetMinTrailingZeros
cares about this case.

llvm-svn: 71532
2009-05-12 01:23:18 +00:00
Eli Friedman
aec1764402 Allow scalar evolution to compute iteration counts for loops with a
pointer-based condition.  This fixes PR3171.

llvm-svn: 71354
2009-05-09 12:32:42 +00:00
Duncan Sands
f7af13b2d4 Rename PaddedSize to AllocSize, in the hope that this
will make it more obvious what it represents, and stop
it being confused with the StoreSize.

llvm-svn: 71349
2009-05-09 07:06:46 +00:00
Dan Gohman
3de703ce43 Don't attempt to handle unsized types in ScalarEvolution's GEP analyzer.
llvm-svn: 71302
2009-05-09 00:14:52 +00:00
Dan Gohman
141989d3c2 Fix bogus overflow checks by replacing them with actual
overflow checks.

llvm-svn: 71284
2009-05-08 23:11:16 +00:00
Dan Gohman
603f022049 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.

llvm-svn: 71264
2009-05-08 21:03:19 +00:00
Dan Gohman
6eaf7850d8 Fix another bug in r71252. This code supports GetElementPtr
constant exprs as well as instructions.

llvm-svn: 71262
2009-05-08 20:58:38 +00:00
Dan Gohman
f3461c73e8 Add memoization for getSCEVAtScope results for instructions
which are not analyzed with SCEV techniques, which can require
brute-forcing through a large number of instructions. This
fixes a massive compile-time issue on 400.perlbench (in
particular, the loop in MD5Transform).

llvm-svn: 71259
2009-05-08 20:47:27 +00:00
Dan Gohman
1307f44388 Make the SCEV* form of getSCEVAtScope public, to allow ScalarEvolution
clients to use it.

llvm-svn: 71258
2009-05-08 20:38:54 +00:00
Dan Gohman
6d21c4110b Fix an error from r71252.
llvm-svn: 71255
2009-05-08 20:36:47 +00:00
Bill Wendling
5de4207c68 Print out nicer dump info for DIDescriptor.
llvm-svn: 71253
2009-05-08 20:28:06 +00:00
Dan Gohman
afd53ad1a3 Factor out the code for creating SCEVs for GEPs into a
separate function.

llvm-svn: 71252
2009-05-08 20:26:55 +00:00
Dan Gohman
34a6d38d54 Implement several new SCEV folding rules for UDiv SCEVs.
This fixes an old FIXME, and is needed by some upcoming changes.

llvm-svn: 71247
2009-05-08 20:18:49 +00:00
Dan Gohman
ebacd61d7d Revert 71165. It did more than just revert 71158 and it introduced
several regressions. The problem due to 71158 is now fixed.

llvm-svn: 71176
2009-05-07 19:46:24 +00:00
Dan Gohman
93c518ffe9 SCEVComplexityCompare's new code was missing SCEVUDivExpr. Implement
the SCEVUDivExpr case.

llvm-svn: 71173
2009-05-07 19:23:21 +00:00
Duncan Sands
e90202e388 Revert r70876 and add a testcase (@c7) showing the problem:
bits captured, but the pointer marked nocapture.  In fact
I now recall that this problem is why only readnone functions
returning void were considered before!  However keep a small
fix that was also in r70876: a readnone function returning
void can result in bits being captured if it unwinds, so
test for this.

llvm-svn: 71168
2009-05-07 18:08:34 +00:00
Bill Wendling
9f97e4a3dc Temporarily revert r71158. It was causing a failure during a full bootstrap:
checking for bcopy... no
checking for getc_unlocked... Assertion failed: (0 && "Unknown SCEV kind!"), function operator(), file /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmCore.roots/llvmCore~obj/src/lib/Analysis/ScalarEvolution.cpp, line 511.
/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmgcc42.roots/llvmgcc42~obj/src/libdecnumber/decUtility.c:360: internal compiler error: Abort trap
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://developer.apple.com/bugreporter> for instructions.
make[4]: *** [decUtility.o] Error 1
make[4]: *** Waiting for unfinished jobs....
Assertion failed: (0 && "Unknown SCEV kind!"), function operator(), file /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmCore.roots/llvmCore~obj/src/lib/Analysis/ScalarEvolution.cpp, line 511.
/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmgcc42.roots/llvmgcc42~obj/src/libdecnumber/decNumber.c:5591: internal compiler error: Abort trap
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://developer.apple.com/bugreporter> for instructions.
make[4]: *** [decNumber.o] Error 1
make[3]: *** [all-stage2-libdecnumber] Error 2
make[3]: *** Waiting for unfinished jobs....

llvm-svn: 71165
2009-05-07 17:26:14 +00:00
Dan Gohman
99b6edddf3 Make ScalarEvolution's GroupByComplexity more thorough. In addition
to sorting SCEVs by their kind, sort SCEVs of the same kind according
to their operands. This helps avoid things like (a+b) being a distinct
expression from (b+a).

llvm-svn: 71160
2009-05-07 14:39:04 +00:00