llvm-svn: 72411

low-level alias() method, allowing it to reason more aggressively
about pointers into constant memory.  PR4189

llvm-svn: 72403

or use labels as members of structures for example. Also included a couple of
whitespace fixes.

llvm-svn: 72402

even on Core2, not just AMD processors which was a surprise to me.

llvm-svn: 72396

llvm-svn: 72395

llvm-svn: 72387

llvm-svn: 72376

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

bit clearer.

llvm-svn: 72374

corresponding integer type is legal.

llvm-svn: 72373

one of the RecursivelyDeleteTriviallyDeadInstructions.
Add a comment explaining why the cache needs to be cleared.

llvm-svn: 72372

Also fix 80 column violation.

llvm-svn: 72371

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

Use &Ops[0] instead, which is safe since Ops will never be empty here.

llvm-svn: 72368

comparison, use takeName to give the integer comparison a name.

llvm-svn: 72367

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

of low bits of the other operand are preserved in the output.

llvm-svn: 72365

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

it's late, and I don't have any better ideas at the moment.  Fixes PR4257.

llvm-svn: 72363

llvm-svn: 72360

all results and all operands are legal, so this change shouldn't affect 
behavior at all.

llvm-svn: 72359

This leaves around 4000 lines of dead code; I'll clean that up 
in subsequent commits.

llvm-svn: 72358

nodes it generates.

llvm-svn: 72356

ExpandExtractFromVectorThroughStack.

llvm-svn: 72351

moment.

llvm-svn: 72350

doesn't split legal vector operands.  This is necessary because the 
type legalization (and therefore, vector splitting) code will be going 
away soon.

llvm-svn: 72349

llvm-svn: 72337

llvm-svn: 72336

llvm-svn: 72335

llvm-svn: 72332

The DAGCombiner created a negative shiftamount, stored in an
unsigned variable. Later the optimizer eliminated the shift entirely as being
undefined.
Example: (srl (shl X, 56) 48). ShiftAmt is 4294967288.
Fix it by checking that the shiftamount is positive, and storing in a signed
variable.

llvm-svn: 72331

llvm-svn: 72329

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

will allow simplifying LegalizeDAG to eliminate type legalization.  (I 
have a patch to do that, but it's not quite finished; I'll commit it 
once it's finished and I've fixed any review comments for this patch.)  
See the comment at the beginning of 
lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp for more details on the
motivation for this patch.

llvm-svn: 72325

systems instead of attempting to promote them to a 64-bit SINT_TO_FP or 
FP_TO_SINT.  This is in preparation for removing the type legalization 
code from LegalizeDAG: once type legalization is gone from LegalizeDAG, 
it won't be able to handle the i64 operand/result correctly.

This isn't quite ideal, but I don't think any other operation for any 
target ends up in this situation, so treating this case specially seems 
reasonable.

llvm-svn: 72324

Fix bug in FoldFCmp_IntToFP_Cst. If inttofp is a uintofp, use unsigned instead of signed integer constant.

llvm-svn: 72300

files for PIC16 target.

llvm-svn: 72277

code in preparation for code generation.  The main thing it does
is handle the case when eh.exception calls (and, in a future
patch, eh.selector calls) are far away from landing pads.  Right
now in practice you only find eh.exception calls close to landing
pads: either in a landing pad (the common case) or in a landing
pad successor, due to loop passes shifting them about.  However
future exception handling improvements will result in calls far
from landing pads:
(1) Inlining of rewinds.  Consider the following case:
In function @f:
...
  invoke @g to label %normal unwind label %unwinds
...
unwinds:
  %ex = call i8* @llvm.eh.exception()
...

In function @g:
...
  invoke @something to label %continue unwind label %handler
...
handler:
  %ex = call i8* @llvm.eh.exception()
... perform cleanups ...
  "rethrow exception"

Now inline @g into @f.  Currently this is turned into:
In function @f:
...
  invoke @something to label %continue unwind label %handler
...
handler:
  %ex = call i8* @llvm.eh.exception()
... perform cleanups ...
  invoke "rethrow exception" to label %normal unwind label %unwinds
unwinds:
  %ex = call i8* @llvm.eh.exception()
...

However we would like to simplify invoke of "rethrow exception" into
a branch to the %unwinds label.  Then %unwinds is no longer a landing
pad, and the eh.exception call there is then far away from any landing
pads.

(2) Using the unwind instruction for cleanups.
It would be nice to have codegen handle the following case:
  invoke @something to label %continue unwind label %run_cleanups
...
handler:
... perform cleanups ...
  unwind

This requires turning "unwind" into a library call, which
necessarily takes a pointer to the exception as an argument
(this patch also does this unwind lowering).  But that means
you are using eh.exception again far from a landing pad.

(3) Bugpoint simplifications.  When bugpoint is simplifying
exception handling code it often generates eh.exception calls
far from a landing pad, which then causes codegen to assert.
Bugpoint then latches on to this assertion and loses sight
of the original problem.

Note that it is currently rare for this pass to actually do
anything.  And in fact it normally shouldn't do anything at
all given the code coming out of llvm-gcc!  But it does fire
a few times in the testsuite.  As far as I can see this is
almost always due to the LoopStrengthReduce codegen pass
introducing pointless loop preheader blocks which are landing
pads and only contain a branch to another block.  This other
block contains an eh.exception call.  So probably by tweaking
LoopStrengthReduce a bit this can be avoided.

llvm-svn: 72276

for ARM.  This fixes rdar://6908807.

llvm-svn: 72269

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