Commit Graph

155 Commits

Author SHA1 Message Date
Andrew Trick 443332deca Test case pasto (failed when run with IR verifier).
llvm-svn: 132516
2011-06-02 23:57:27 +00:00
Andrew Trick 812276eed4 scev: Better sign-extend removal. Normalize postincrement recurrences
so that their sign extended forms are congruent when no overflow occurs.

llvm-svn: 132360
2011-05-31 21:17:47 +00:00
Andrew Trick 7fac79e255 indvars: incremental fixes for -disable-iv-rewrite and testcases.
Use a proper worklist for use-def traversal without holding onto an
iterator. Now that we process all IV uses, we need complete logic for
resusing existing derived IV defs. See HoistStep.

llvm-svn: 132103
2011-05-26 00:46:11 +00:00
Andrew Trick eb3c36e69c indvars: fixed IV cloning in -disable-iv-rewrite mode with associated
cleanup and overdue test cases.

llvm-svn: 132038
2011-05-25 04:42:22 +00:00
Andrew Trick 37f0082804 FileCheck-ize a couple of IV unit tests.
llvm-svn: 131946
2011-05-24 01:02:49 +00:00
Andrew Trick 1ea0243bd0 Test case for r130799 - indvars: Added canExpandBackEdgeTakenCount.
llvm-svn: 131939
2011-05-24 00:17:53 +00:00
Andrew Trick 29ac7b8858 Fixes PR9730: indvars: An asserting value handle still pointed to this value
Modified LinearFunctionTestReplace to push the condition on the dead
list instead of eagerly deleting it. This can cause unnecessary
IV rewrites, which should have no effect on codegen and will not be an
issue once we stop generating canonical IVs.

llvm-svn: 130340
2011-04-27 23:00:03 +00:00
Andrew Trick 1c4b42d00f Avoid creating canonical induction variables for non-native types.
For example, on 32-bit architecture, don't promote all uses of the IV
to 64-bits just because one use is a 64-bit cast.
Alternate implementation of the patch by Arnaud de Grandmaison.

llvm-svn: 127884
2011-03-18 16:50:32 +00:00
Devang Patel 57da4caa85 Remove LoopIndexSplit pass. It is neither maintained nor used by anyone.
llvm-svn: 116004
2010-10-07 23:29:37 +00:00
Chris Lattner 65fb25a257 more test cleanup
llvm-svn: 112892
2010-09-02 22:38:56 +00:00
Duncan Sands 8dda07428a Print the number of uses of a function in the .ll since it can be informative
and there seems to be no reason not to.

llvm-svn: 112812
2010-09-02 08:52:23 +00:00
Duncan Sands 68c30907cc Correct bogus module triple specifications.
llvm-svn: 112469
2010-08-30 10:48:29 +00:00
Dan Gohman cd83870faf Fix SCEVExpander::visitAddRecExpr so that it remembers the induction variable
it inserted rather than using LoopInfo::getCanonicalInductionVariable to
rediscover it, since that doesn't work on non-canonical loops. This fixes
infinite recurrsion on such loops; PR7562.

llvm-svn: 109419
2010-07-26 18:28:14 +00:00
Dan Gohman c6eefe4d4e Fix this test.
llvm-svn: 108491
2010-07-16 01:28:45 +00:00
Dan Gohman fbbdfcaea7 Fix the order that SCEVExpander considers add operands in so that
it doesn't miss an opportunity to form a GEP, regardless of the
relative loop depths of the operands. This fixes rdar://8197217.

llvm-svn: 108475
2010-07-15 23:38:13 +00:00
Dan Gohman ae36b1ed42 Fix ScalarEvolution's tripcount computation for chains of loops
where each loop's induction variable's start value is the exit
value of a preceding loop.

llvm-svn: 107224
2010-06-29 23:43:06 +00:00
Dan Gohman f3aea7aecf Disable indvars on loops when LoopSimplify form is not available.
This fixes PR7333.

llvm-svn: 106267
2010-06-18 01:35:11 +00:00
Rafael Espindola 29dda21e96 Remove arm_apcscc from the test files. It is the default and doing this
matches what llvm-gcc and clang now produce.

llvm-svn: 106221
2010-06-17 15:18:27 +00:00
Dan Gohman e637ff5e9a Remove the Expr member from IVUsers. Instead of remembering the expression,
just ask ScalarEvolution for it on demand. This helps IVUsers be more robust
in the case of expressions changing underneath it. This fixes PR6862.

llvm-svn: 101819
2010-04-19 21:48:58 +00:00
Nick Lewycky fbe8d2803d Fix declarations in a few more tests.
llvm-svn: 101676
2010-04-17 21:29:25 +00:00
Dan Gohman 7ef0dc2163 Teach ScalarEvolution to simplify smax and umax when it can prove
that one operand is always greater than another.

llvm-svn: 101142
2010-04-13 16:51:03 +00:00
Dan Gohman 5867a56db8 Teach IndVarSimplify how to eliminate remainder operators where the
numerator is an induction variable. For example, with code like this:

  for (i=0;i<n;++i)
    x[i%n] = 0;

IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the remainder.

llvm-svn: 101113
2010-04-13 01:46:36 +00:00
Dan Gohman 4a645b88ef Suppress LinearFunctionTestReplace when the computed backedge-taken
expression is a UDiv and it doesn't appear that the UDiv came from
the user's source.

ScalarEvolution has recently figured out how to compute a tripcount
expression for the inner loop in
SingleSource/Benchmarks/Shootout/sieve.c, using a udiv. Emitting a
udiv instruction dramatically slows down the enclosing loop.

llvm-svn: 101068
2010-04-12 21:13:43 +00:00
Dan Gohman fa5ad797e3 Re-apply r101000, with a fix: Don't eliminate an icmp which is part of
the loop exit test. This usually doesn't come up for a variety of
reasons, but it isn't impossible, so make IndVarSimplify handle it
conservatively.

llvm-svn: 101008
2010-04-12 02:21:50 +00:00
Dan Gohman c0f1efaf8d Revert 101000, which is breaking self-host builds.
llvm-svn: 101002
2010-04-12 00:17:10 +00:00
Dan Gohman af4ab1b681 Teach IndVarSimplify how to eliminate comparisons involving induction
variables. For example, with code like this:

  for (i=0;i<n;++i)
    if (i<n)
      x[i] = 0;

IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the if.

llvm-svn: 101000
2010-04-11 23:10:12 +00:00
Chris Lattner 3ae2dd2ba5 add newlines at the end of files.
llvm-svn: 100705
2010-04-07 22:53:17 +00:00
Chris Lattner 40060d33f6 add integer overflow check for the fp induction variable
checker.  Amusingly, we already had tests that we should
have rejects because they would be miscompiled in the
testsuite.

The remaining issue with this is that we don't check that
the branch causes us to exit the loop if it fails, so we
don't actually know if we remain in bounds.

llvm-svn: 100284
2010-04-03 07:18:48 +00:00
Chris Lattner 40ea690f39 fix PR6761, a miscompilation due to the fp->int IV conversion
stuff.  More bugs remain though.

llvm-svn: 100282
2010-04-03 06:30:03 +00:00
Chris Lattner 2508bcf176 convert to filecheck
llvm-svn: 100281
2010-04-03 06:27:56 +00:00
Chris Lattner 8ca668497f rename feature test.
llvm-svn: 100279
2010-04-03 06:24:28 +00:00
Chris Lattner fc9e88ae76 actually just remove this, will move the real feature test here.
llvm-svn: 100278
2010-04-03 06:24:03 +00:00
Chris Lattner 290f42a9c3 rename test since it is a feature test.
llvm-svn: 100277
2010-04-03 06:22:52 +00:00
Chris Lattner c558b49f14 first half of a pass through IndVarSimplify::HandleFloatingPointIV,
this cleans up a bunch of code and also fixes several crashes and
miscompiles.  More to come unfortunately, this optimization
is quite broken.

llvm-svn: 100270
2010-04-03 05:54:59 +00:00
Dan Gohman f7239102fe Manually notify ScalarEvolution before making an operand replacement, since
it can't currently observe such changes automatically.

llvm-svn: 100186
2010-04-02 14:48:31 +00:00
Dan Gohman a9c205cc88 Make LoopSimplify change conditional branches in loop exiting blocks
which branch on undef to branch on a boolean constant for the edge
exiting the loop. This helps ScalarEvolution compute trip counts for
loops.

Teach ScalarEvolution to recognize single-value PHIs, when safe, and
ForgetSymbolicName to forget such single-value PHI nodes as apprpriate
in ForgetSymbolicName.

llvm-svn: 97126
2010-02-25 06:57:05 +00:00
Dan Gohman 6b1e2a829d Teach ScalarEvolution how to compute a tripcount for a loop with
true or false as its exit condition. These are usually eliminated by
SimplifyCFG, but the may be left around during a pass which wishes
to preserve the CFG.

llvm-svn: 96683
2010-02-19 18:12:07 +00:00
Dan Gohman 45774ce0ad Reapply the new LoopStrengthReduction code, with compile time and
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.

This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.

llvm-svn: 95975
2010-02-12 10:34:29 +00:00
Dan Gohman 80386c10d4 -disable-output is no longer needed with -analyze.
llvm-svn: 94574
2010-01-26 19:25:59 +00:00
Dan Gohman 51ad99d2c5 Re-implement the main strength-reduction portion of LoopStrengthReduction.
This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also more aggressive about
rewriting induction variables to count down (or up) to zero when doing so
reduces register pressure.

It currently uses fairly simplistic algorithms for finding reuse
opportunities, but it introduces a new framework allows it to combine
multiple strategies at once to form hybrid solutions, instead of doing
all full-reduction or all base+index.

llvm-svn: 94061
2010-01-21 02:09:26 +00:00
Dan Gohman bc694918cc Use WriteAsOperand instead of getName() to print loop header names,
so that unnamed blocks are handled.

llvm-svn: 93059
2010-01-09 18:17:45 +00:00
Dan Gohman f34b289057 Move this test from test/Transforms/IndVarSimplify to
test/CodeGen/X86, as doesn't use -indvars, and it does use
llc -march=x86-64.

llvm-svn: 92799
2010-01-05 22:52:54 +00:00
Dan Gohman 84ba039cf2 Make getUniqueExitBlocks's precondition assert more precise, to
avoid spurious failures. This fixes PR5758.

llvm-svn: 91147
2009-12-11 20:05:23 +00:00
Kenneth Uildriks 90fedc6ef9 Make opt default to not adding a target data string and update tests that depend on target data to supply it within the test
llvm-svn: 85900
2009-11-03 15:29:06 +00:00
Dan Gohman 82ef61857e Add a testcase for r83011.
llvm-svn: 83012
2009-09-28 21:03:02 +00:00
Dan Gohman 5bafe38916 Fix a case where ScalarEvolution was expanding pointer arithmetic
to inttoptr/ptrtoint unnecessarily.

llvm-svn: 82864
2009-09-26 16:11:57 +00:00
Dan Gohman 1880092722 Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.

llvm-svn: 81537
2009-09-11 18:01:28 +00:00
Dan Gohman 22f339010c Use "opt < %s" instead of "opt %s" so that opt doesn't print the test
filename in the output, which interferes with the tests' grep lines.

llvm-svn: 81263
2009-09-08 22:57:49 +00:00
Dan Gohman 4f2527cd6d Convert a few more opt | llvm-dis to opt -S.
llvm-svn: 81261
2009-09-08 22:41:33 +00:00
Dan Gohman 72a13d2476 Use opt -S instead of piping bitcode output through llvm-dis.
llvm-svn: 81257
2009-09-08 22:34:10 +00:00
Dan Gohman 9737a63ed8 Change these tests to feed the assembly files to opt directly, instead
of using llvm-as, now that opt supports this.

llvm-svn: 81226
2009-09-08 16:50:01 +00:00
Daniel Dunbar b9ea94c990 Eliminate uses of %prcontext.
- I'd appreciate it if someone else eyeballs my changes to make sure I captured
   the intent of the test.

llvm-svn: 81083
2009-09-05 11:35:16 +00:00
Dan Gohman 337d56110e Special-case static allocas in IndVarSimplify's loop invariant
sinking code, since they are special. If the loop preheader happens
to be the entry block of a function, don't sink static allocas
out of it. This fixes PR4775.

llvm-svn: 80010
2009-08-25 17:42:10 +00:00
Dan Gohman bf2a9aedca Generalize ScalarEvolution to be able to analyze GEPs when
TargetData is not present. It still uses TargetData when available.
This generalization also fixed some limitations in the TargetData
case; the attached testcase covers this.

llvm-svn: 79344
2009-08-18 16:46:41 +00:00
Dan Gohman 1a7ab9473f The upper argument of ConstantRange is exclusive, not inclusive.
llvm-svn: 76492
2009-07-20 22:34:18 +00:00
Dan Gohman 33a3fd0b9c Revert the addition of hasNoPointerOverflow to GEPOperator.
Getelementptrs that are defined to wrap are virtually useless to
optimization, and getelementptrs that are undefined on any kind
of overflow are too restrictive -- it's difficult to ensure that
all intermediate addresses are within bounds. I'm going to take
a different approach.

Remove a few optimizations that depended on this flag.

llvm-svn: 76437
2009-07-20 17:43:30 +00:00
Dan Gohman 8c129d7687 Fill in some holes in ScalarEvolution's loop iteration condition
analysis. This allows indvars to emit a simpler loop trip count
expression.

llvm-svn: 76085
2009-07-16 17:34:36 +00:00
Eli Friedman 662da55c5f Switch invars away from using isTrapping when it really shouldn't be
using it.

llvm-svn: 75852
2009-07-15 22:48:29 +00:00
Dan Gohman 92b969ba80 Fix the expansion of umax and smax in the case where one or more of
the operands have pointer type, so that the resulting type matches
the original SCEV type, and so that unnecessary ptrtoints are
avoided in common cases.

llvm-svn: 75680
2009-07-14 20:57:04 +00:00
Dan Gohman 69ddd05329 Add a testcase for a bug fixed by r75634.
llvm-svn: 75644
2009-07-14 18:15:00 +00:00
Dan Gohman 4d6149f356 Update LoopSimplify and LoopUnswitch to use the new makeLoopInvariant
function.

llvm-svn: 75584
2009-07-14 01:37:59 +00:00
Dan Gohman 03d5d0f451 Fix indvars to not assume that a loop with a single unique exit
block has a single unique exiting block.

llvm-svn: 75579
2009-07-14 01:09:02 +00:00
Dan Gohman e65c917ecf Reapply 75252, with a fix to avoid the infinite recursion case. The
check for avoiding re-analyzing a widening cast needed to happen
earlier, as getSCEV itself may result in a isLoopGuardedByCond query.

llvm-svn: 75511
2009-07-13 21:35:55 +00:00
Nick Lewycky c0bf46b226 Revert r75252 which was causing some crashes at compile time.
llvm-svn: 75384
2009-07-11 20:38:25 +00:00
Dan Gohman a9938d8226 Generalize ScalarEvolution's cast-folding code to support more kinds
of loops. Add several new functions to for working with ScalarEvolution's
add-hoc value-range analysis functionality.

llvm-svn: 75252
2009-07-10 16:42:52 +00:00
Dan Gohman 19d2417c90 Don't cache PHI exit values from exhaustive evaluations, because
an individual exhaustive evaluation reflects only the exit value
implied by an individual exit, which may differ from the actual
exit value of the loop if there are other exits. This fixes PR4477.

llvm-svn: 74447
2009-06-29 20:34:13 +00:00
Dan Gohman fe174b6952 When a value is used multiple times within a single PHI, instructions
inserted to replace that value must dominate all of of the basic
blocks associated with the uses of the value in the PHI, not just
one of them.

llvm-svn: 74376
2009-06-27 05:16:57 +00:00
Dan Gohman d3b930d426 Add some testcases for some of the recent ScalarEvolution bug fixes.
llvm-svn: 74353
2009-06-26 22:54:11 +00:00
Dan Gohman f57bdb75d4 Simplify [su]max(MAX, n) to MAX. This comes up in loop tripcount
computations in loops with multiple exits.

Adjust the testcase for PR4436 so that the relevant portion isn't
optimized away.

llvm-svn: 74073
2009-06-24 14:46:22 +00:00
Dan Gohman 929fa7b0f4 When inserting code into a loop preheader, insert it before the
terminator, instead of after the last phi. This fixes a bug
exposed by ScalarEvolution analyzing more kinds of loops.
This fixes PR4436.

llvm-svn: 74072
2009-06-24 14:31:06 +00:00
Dan Gohman 0104842ee3 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!

llvm-svn: 73862
2009-06-21 23:46:38 +00:00
Dan Gohman 450f4e0fa9 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.

llvm-svn: 73807
2009-06-20 00:35:32 +00:00
Dan Gohman a0348809b6 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.

llvm-svn: 73706
2009-06-18 16:54:06 +00:00
Dan Gohman 432af7ace0 Add -disable-output to a bunch of tests that don't care about the output.
llvm-svn: 73633
2009-06-17 20:56:26 +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 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 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 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 c380cca7ae Don't attempt to simplify an non-affine IV expression if it can't
be simplified to a loop-invariant value. This fixes PR4315.

llvm-svn: 72798
2009-06-03 19:11:31 +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 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
Dan Gohman 4486da5b78 When rewriting the loop exit test with the canonical induction variable,
leave the original comparison in place if it has other uses, since the
other uses won't be dominated by the new comparison instruction.

llvm-svn: 72369
2009-05-24 19:11:38 +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
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 781b75a7df Teach IndVarSimplify's FixUsesBeforeDefs to handle InvokeInsts by
assuming that the use of the value is in a block dominated by the
"normal" destination. LangRef.html and other documentation sources
don't explicitly guarantee this, but it seems to be assumed in
other places in LLVM at least.

This fixes an assertion failure on the included testcase, which
is derived from the Ada testsuite.

FixUsesBeforeDefs is a temporary measure which I'm looking to
replace with a more capable solution.

llvm-svn: 72266
2009-05-22 16:47:11 +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
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
Dan Gohman b81dd48fd2 Add nounwind to a few tests.
llvm-svn: 72002
2009-05-18 15:16:49 +00:00
Dan Gohman d76d71a291 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 ae451600fa 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 2625f2cb80 Make this testcase slightly less trivial, so that it doesn't fail
if indvars happens to optimize away the unused primary induction
variable.

llvm-svn: 70333
2009-04-28 22:03:26 +00:00
Dale Johannesen 27b4f222cf Fix PR 4086, a bug in FP IV elimination.
llvm-svn: 70247
2009-04-27 21:03:15 +00:00
Dan Gohman 05c1d372b7 Handle ands with ~0 correctly too. This fixes PR4052.
llvm-svn: 70176
2009-04-27 01:41:10 +00:00
Dan Gohman df19948ea7 Handle ands with 0 and shifts by 0 correctly. These aren't
common, but indvars shouldn't crash on them. This fixes PR4054.

llvm-svn: 70051
2009-04-25 17:05:40 +00:00
Dan Gohman d6f9713634 Fix an error in this test.
llvm-svn: 69893
2009-04-23 15:22:28 +00:00
Dan Gohman 86bcd97014 Change SCEVExpander's expandCodeFor to provide more flexibility
with the persistent insertion point, and change IndVars to make
use of it. This fixes a bug where IndVars was holding on to a
stale insertion point and forcing the SCEVExpander to continue to
use it.

This fixes PR4038.

llvm-svn: 69892
2009-04-23 15:16:49 +00:00
Evan Cheng d8174d3d09 Make sure both operands have binary instructions have the same type.
llvm-svn: 69844
2009-04-22 23:39:28 +00:00
Evan Cheng cbfe9df096 Avoid deferencing use_begin() if value does not have a use.
llvm-svn: 69836
2009-04-22 22:45:37 +00:00
Dan Gohman 54fd2869a3 SCEVExpander's InsertCastOfTo knows how to move existing cast
instructions in order to avoid inserting new ones. However, if
the cast instruction is the SCEVExpander's InsertPt, this
causes subsequently emitted instructions to be inserted near
the cast, and not at the location of the original insert point.
Fix this by adjusting the insert point in such cases.
This fixes PR4009.

llvm-svn: 69808
2009-04-22 16:11:16 +00:00
Dale Johannesen 8958f4f30f Another testcase for IV shortening.
llvm-svn: 69247
2009-04-16 00:45:21 +00:00