Commit Graph

5251 Commits

Author SHA1 Message Date
Bill Wendling 006459ecd4 Enable GVN Load PRE.
llvm-svn: 72589
2009-05-29 20:38:16 +00:00
Torok Edwin 0b0ddb21fe just show the instruction, its not that slow.
llvm-svn: 72577
2009-05-29 16:58:36 +00:00
Torok Edwin 6a94624a1b for instructions with void type we have no choice but print the instruction as
is, otherwise we get a <badref>.

llvm-svn: 72567
2009-05-29 10:28:44 +00:00
Torok Edwin 72070282eb Add a DEBUG() output to GVN that prints the instruction clobbering a load.
This is useful when trying to figure out why GVN didn't eliminate redundant
loads.

llvm-svn: 72565
2009-05-29 09:46:03 +00:00
Owen Anderson 04cfdd38a2 Fix an issue where phiMap was not being updated properly when doing load PRE.
Diagnosis and patch thanks to Jakub Staszak.

llvm-svn: 72562
2009-05-29 05:37:54 +00:00
Nick Lewycky 206876e2da Use Operands.data() instead of &Operands[0] where Operands is a potentially
empty SmallVector.

llvm-svn: 72512
2009-05-28 04:08:10 +00:00
Dan Gohman 4d1823680d Revert 72493 and replace it with a more conservative fix, for now: don't
rewrite the comparison if there is any implicit extension or truncation
on the induction variable. I'm planning for IVUsers to eventually take
over some of the work of this code, and for it to be generalized.

llvm-svn: 72496
2009-05-27 21:10:47 +00:00
Dan Gohman f4d85325c0 In ChangeCompareStride, when the stride to be reused is truncated to
a smaller type, promoted its offset back up to the type of the new
comparison. This fixes PR4222.

llvm-svn: 72493
2009-05-27 20:00:18 +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 26895b518b Move Rewriter.clear() earlier, to avoid triggerring the AssertingVH by
one of the RecursivelyDeleteTriviallyDeadInstructions.
Add a comment explaining why the cache needs to be cleared.

llvm-svn: 72372
2009-05-24 20:08:21 +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 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 fb56cf1b1d When replacing a floating-point comparison with an integer
comparison, use takeName to give the integer comparison a name.

llvm-svn: 72367
2009-05-24 18:09:01 +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
Torok Edwin 7996339dd8 available_externall linkage is not local, this was confusing the codegenerator,
and it wasn't generating calls through @PLT for these functions.
hasLocalLinkage() is now false for available_externally,
I attempted to fix the inliner and dce to handle available_externally properly.
It passed make check.

llvm-svn: 72328
2009-05-23 14:06:57 +00:00
Evan Cheng a838a40bc4 Fix bug in FoldFCmp_IntToFP_Cst. If inttofp is a uintofp, use unsigned instead of signed integer constant.
llvm-svn: 72300
2009-05-22 23:10:53 +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
Eli Friedman 0cf811df82 Fix loop-index-split to correctly preserve dominance frontiers. Part of
PR4238.

llvm-svn: 72244
2009-05-22 03:22:46 +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 7248923a5d Suppress the IV reversal transformation in the case that the RHS
of the comparison is defined inside the loop. This fixes a
use-before-def problem, because the transformation puts a use
of the RHS outside the loop.

llvm-svn: 72149
2009-05-20 00:34:08 +00:00
Dan Gohman 67587ce2e9 Remove an irrelevant comment.
llvm-svn: 72132
2009-05-19 20:38:47 +00:00
Dan Gohman 97f70add3c Add some more comments to the top of this file.
llvm-svn: 72131
2009-05-19 20:37:36 +00:00
Dan Gohman adc70d6806 Trim unneeded #includes.
llvm-svn: 72130
2009-05-19 20:35:26 +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 14d1339579 Rename UseTy to AccessTy, for consistency with getAccessType, and to
avoid ambiguity with the word "use" in IVStrideUse.

llvm-svn: 72012
2009-05-18 16:45:28 +00:00
Dale Johannesen 1ac1969e09 Reuse existing getUnderlyingObject instead of
adding another copy.

llvm-svn: 71783
2009-05-14 18:41:18 +00:00
Dale Johannesen f241df9abe Use abs64 in one more place.
llvm-svn: 71775
2009-05-14 16:47:34 +00:00
Dale Johannesen 3181652363 Handle some additonal cases of external weak globals.
llvm-svn: 71717
2009-05-13 20:55:30 +00:00
Dale Johannesen 69921959b4 Don't generate a select whose operand is load of a weak
external.  These may have address 0 and are not safe
to execute unconditionally.

llvm-svn: 71688
2009-05-13 18:25:07 +00:00
Chris Lattner 149546a6a0 calls in nothrow functions can be marked nothrow even if the callee
is not known to be nothrow.  This allows readnone/readonly functions
to be deleted even if we don't know whether the callee can throw.

llvm-svn: 71676
2009-05-13 17:39:14 +00:00
Chris Lattner 7e335a763a Fix PR4206 - crash in simplify lib calls
llvm-svn: 71644
2009-05-13 06:26:11 +00:00
Dale Johannesen 536de01bcf Add an int64_t variant of abs, for host environments
without one.  Use it where we were using abs on
int64_t objects.
(I strongly suspect the casts to unsigned in the
fragments in LoopStrengthReduce are not doing whatever
the original intent was, but the obvious change to
uint64_t doesn't work.  Maybe later.)

llvm-svn: 71612
2009-05-13 00:24:22 +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
Evan Cheng 78a4eb844b Teach LSR to optimize more loop exit compares, i.e. change them to use postinc iv value. Previously LSR would only optimize those which are in the loop latch block. However, if LSR can prove it is safe (and profitable), it's now possible to change those not in the latch blocks to use postinc values.
Also, if the compare is the only use, LSR would place the iv increment instruction before the compare instead in the latch.

llvm-svn: 71485
2009-05-11 22:33:01 +00:00
Dale Johannesen 02cb2bf2e3 Reverse a loop that is counting up to a maximum to
count down to 0 instead, under very restricted
circumstances.  Adjust 4 testcases in which this
optimization fires.

llvm-svn: 71439
2009-05-11 17:15:42 +00:00
Duncan Sands af9eaa830a 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
Evan Cheng b9dcc2c0c9 Factor out code that optimize loop terminating condition.
llvm-svn: 71305
2009-05-09 01:08:24 +00:00
Chris Lattner c48091f141 fix RewriteStoreUserOfWholeAlloca to use the correct type size
method, fixing a crash on PR4146.  While the store will 
ultimately overwrite the "padded size" number of bits in memory,
the stored value may be a subset of this size.  This function
only wants to handle the case where all bits are stored.

llvm-svn: 71224
2009-05-08 15:54:41 +00:00
Nick Lewycky 702fbf94a0 This transform requires valid TargetData info. Wrap it in 'if (TD)' in
preparation for the day we use null TargetData when no target is specified.

llvm-svn: 71210
2009-05-08 06:47:37 +00:00
Eli Friedman 36b9026fa7 PR4123: don't crash when inlining a call which uses its own result.
llvm-svn: 71199
2009-05-08 00:22:04 +00:00
Dan Gohman 140a6f24f0 Perform constant folding on operands of instructions with non-void
types, such as loads and calls.

llvm-svn: 71175
2009-05-07 19:43:39 +00:00
Evan Cheng 342053cd27 Unbreak the build.
llvm-svn: 71091
2009-05-06 18:00:56 +00:00
David Greene 0dec5b9a75 Make sure to use signed arithmetic in APInt to fix a regression.
llvm-svn: 71090
2009-05-06 17:39:26 +00:00
Dan Gohman 9a6fef0a52 Simplify code by using SmallVector's pop_back_val() instead of
separate back() and pop_back() calls.

llvm-svn: 71089
2009-05-06 17:22:41 +00:00
Duncan Sands 9759f2e063 Fix PR3754: don't mark functions that wrap MallocInst with
the readnone.  Since MallocInst is scheduled for deletion
it doesn't seem worth doing anything more subtle, such as
having mayWriteToMemory return true for MallocInst.

llvm-svn: 71077
2009-05-06 08:42:00 +00:00
Duncan Sands 1efabaaa2a Allow readonly functions to unwind exceptions. Teach
the optimizers about this.  For example, a readonly
function with no uses cannot be removed unless it is
also marked nounwind.

llvm-svn: 71071
2009-05-06 06:49:50 +00:00
Dan Gohman e58fc20f8d Fix a copy+pasto in a comment.
llvm-svn: 71035
2009-05-05 23:02:38 +00:00
Dan Gohman 96b18ccdd3 Delete a FIXME which is no longer relevant, and add a FIXME that is.
llvm-svn: 71033
2009-05-05 22:59:55 +00:00
Bill Wendling 5e2ac0cd9c Temporarily reverting r71008. It was causing this failure:
Running /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/
CodeGen/X86/dg.exp ...
FAIL: /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/
CodeGen/X86/change-compare-stride-1.ll
Failed with exit(1) at line 2
while running: grep {cmpq       $-478,} change-compare-stride-1.ll.tmp
child process exited abnormally

llvm-svn: 71013
2009-05-05 20:49:46 +00:00
David Greene 246a3dfb10 Handle overflow of 64-bit loop conditions.
llvm-svn: 71008
2009-05-05 20:22:36 +00:00