no functionality change.

llvm-svn: 91848

two-element arrays.  After restructuring the SROA code, it was not safe to
do this without adding more checking.  It is not clear that this special-case
has really been useful, and removing this simplifies the code quite a bit.

llvm-svn: 91828

the underlying PHI node insertion issue in SSAUpdate is fixed.

llvm-svn: 91821

'GetValueInMiddleOfBlock' case, instead of inserting 
duplicates.

A similar fix is almost certainly needed by the machine-level
SSAUpdate implementation.

llvm-svn: 91820

implement some optimizations for MIN(MIN()) and MAX(MAX()) and 
MIN(MAX()) etc.  This substantially improves the code in PR5822 but
doesn't kick in much elsewhere.  2 max's were optimized in 
pairlocalalign and one in smg2000.

llvm-svn: 91814

Use the presence of NSW/NUW to fold "icmp (x+cst), x" to a constant in
cases where it would otherwise be undefined behavior.

Surprisingly (to me at least), this triggers hundreds of the times in
a few benchmarks: lencode, ldecode, and 466.h264ref seem to *really*
like this.

llvm-svn: 91812

a bunch in lencode, ldecod, spass, 176.gcc, 252.eon, among others.  It is 
also the first part of PR5822

llvm-svn: 91811

llvm-svn: 91764

where instcombine would have to split a critical edge due to a
phi node of an invoke.  Since instcombine can't change the CFG,
it has to bail out from doing the transformation.

llvm-svn: 91763

* change FindElementAndOffset to return a uint64_t instead of unsigned, and
  to identify the type to be used for that result in a GEP instruction.
* move "isa<ConstantInt>" to be first in conditional.
* replace some dyn_casts with casts.
* add a comment about handling mem intrinsics.

llvm-svn: 91762

bootstrap.  This also replaces the WeakVH references that Chris objected to
with normal Value references.

llvm-svn: 91711

multiple uses.  (The construct in question was found in gcc.)

llvm-svn: 91675

llvm-svn: 91666

contains another loop, or an instruction. The loop form is
substantially more efficient on large loops than the typical
code it replaces.

llvm-svn: 91654

llvm-svn: 91653

llvm-svn: 91647

llvm-svn: 91645

of 91296 that caused trouble -- the Processed list needs to be
preserved for the livetime of the pass, as AddUsersIfInteresting
is called from other passes.

llvm-svn: 91641

llvm-svn: 91631

llvm-svn: 91624

to memcpy. (Such a memcpy is technically illegal, but in practice is safe
and is generated by struct self-assignment in C code.)

llvm-svn: 91621

llvm-svn: 91607

Revert 91280-91283, 91286-91289, 91291, 91293, 91295-91296. It apparently introduced a non-deterministic behavior in the optimizer somewhere.

llvm-svn: 91598

Reapply r91459, it was only unmasking the bug, and since TOT is still broken having it reverted does no good.

llvm-svn: 91559

problem", this broke llvm-gcc bootstrap for release builds on
x86_64-apple-darwin10.

This reverts commit db22309800b224a9f5f51baf76071d7a93ce59c9.

llvm-svn: 91534

miscompile (i386.o miscompares) but it happens both with and without
this patch.

llvm-svn: 91532

Will reapply with a fix when I get a chance.

llvm-svn: 91486

found last time.  Instead of trying to modify the IR while iterating over it,
I've change it to keep a list of WeakVH references to dead instructions, and
then delete those instructions later.  I also added some special case code to
detect and handle the situation when both operands of a memcpy intrinsic are
referencing the same alloca.

llvm-svn: 91459

llvm-svn: 91438

llvm-svn: 91432

llvm-svn: 91428

isPodLike type trait.  This is a generally useful type trait for
more than just DenseMap, and we really care about whether something
acts like a pod, not whether it really is a pod.

llvm-svn: 91421

condition was inverted when the code was converted to contains().

llvm-svn: 91295

llvm-svn: 91293

the ScalarEvolution pointer into the functions which need it.

llvm-svn: 91289

llvm-svn: 91288

llvm-svn: 91287

llvm-svn: 91283

llvm-svn: 91282

SCEVExpander does this automatically.

llvm-svn: 91281