llvm-svn: 72604

llvm-svn: 72557

This patch removes some special cases for opcodes and does a bit of 
cleanup.

llvm-svn: 72536

llvm-svn: 72533

failure during llvm-gcc bootstrap:

Assertion failed: (!Tmp2.getNode() && "Can't legalize BR_CC with legal condition!"), function ExpandNode, file /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmCore.roots/llvmCore~obj/src/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp, line 2923.
/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmgcc42.roots/llvmgcc42~obj/src/gcc/libgcc2.c:1727: 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.

llvm-svn: 72530

llvm-svn: 72516

This is basically the end of this series of patches for LegalizeDAG; the 
remaining special cases can't be removed without more infrastructure 
work.  There's a FIXME for each relevant opcode near the beginning of
SelectionDAGLegalize::LegalizeOp.

llvm-svn: 72514

some special cases are necessary.

llvm-svn: 72511

llvm-svn: 72509

Added optimization that narrow load / op / store and the 'op' is a bit twiddling instruction and its second operand is an immediate. If bits that are touched by 'op' can be done with a narrower instruction, reduce the width of the load and store as well. This happens a lot with bitfield manipulation code.
e.g.
orl     $65536, 8(%rax)
=>
orb     $1, 10(%rax)

Since narrowing is not always a win, e.g. i32 -> i16 is a loss on x86, dag combiner consults with the target before performing the optimization.

llvm-svn: 72507

BUILD_VECTOR.

llvm-svn: 72469

llvm-svn: 72468

llvm-svn: 72467

llvm-svn: 72465

llvm-svn: 72464

llvm-svn: 72456

llvm-svn: 72455

llvm-svn: 72454

handling for every single opcode.

llvm-svn: 72447

entries as there are basic blocks in the function.  LiveVariables::getVarInfo
creates a VarInfo struct for every register in the function, leading to
quadratic space use.  This patch changes the BitVector to a SparseBitVector,
which doesn't help the worst-case memory use but does reduce the actual use in
very long functions with short-lived variables.

llvm-svn: 72426

llvm-svn: 72414

llvm-svn: 72411

bit clearer.

llvm-svn: 72374

corresponding integer type is legal.

llvm-svn: 72373

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

ExpandExtractFromVectorThroughStack.

llvm-svn: 72351

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

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

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

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

llvm-svn: 72210

bootstrapping.

llvm-svn: 72200

llvm-svn: 72198

llvm-svn: 72197

llvm-svn: 72196

llvm-svn: 72195

llvm-svn: 72194