and simplify code that was fallout from the separation of memcpyopt and gvn.

llvm-svn: 50034

llvm-svn: 49971

from transforming loops and adding a separate loop pass for removing
loops with know trip counts.  Until that happens, ADCE is miscompiling this code.

llvm-svn: 49769

llvm-svn: 49517

in addition to integer expressions. Rewrite GetOrEnforceKnownAlignment
as a ComputeMaskedBits problem, moving all of its special alignment
knowledge to ComputeMaskedBits as low-zero-bits knowledge.

Also, teach ComputeMaskedBits a few basic things about Mul and PHI
instructions.

This improves ComputeMaskedBits-based simplifications in a few cases,
but more noticeably it significantly improves instcombine's alignment
detection for loads, stores, and memory intrinsics.

llvm-svn: 49492

figuring out the suffix to use.  implement pow(2,x) -> exp2(x).

llvm-svn: 49437

llvm-svn: 49436

GVN and into its own pass.

llvm-svn: 49419

add support for  pow(x, 2.0) -> x*x.

llvm-svn: 49411

llvm-svn: 49382

llvm-svn: 48938

Handle a special case xor undef, undef -> 0. Technically this should be transformed to undef. But this is such a common idiom (misuse) we are going to handle it.

llvm-svn: 48791

llvm-svn: 48762

llvm-svn: 48738

llvm-svn: 48732

llvm-svn: 48731

Transform (zext (or (icmp), (icmp))) to (or (zext (cimp), (zext icmp))) if at least one of the (zext icmp) can be transformed to eliminate an icmp.

llvm-svn: 48715

llvm-svn: 48693

This fires dozens of times across spec and multisource, but I don't know
if it actually speeds stuff up.  Hopefully the testers will show something
nice :)

llvm-svn: 48680

simplify things like (X & 4) >> 1 == 2  --> (X & 4) == 4.

since it is obvious that the shift doesn't remove any bits.

llvm-svn: 48631

llvm-svn: 48538

llvm-svn: 48536

llvm-svn: 48530

llvm-svn: 48529

llvm-svn: 48527

llvm-svn: 48484

llvm-svn: 48483

the type instead of the byte size. This was causing troublesome mis-compilations.

True to form, this took 2 days to find and is a one-line fix. :-P

llvm-svn: 48354

pointer bitcast when performing return slot optimization.

llvm-svn: 48343

Improve the return slot optimization to be both more aggressive (not limited to sret parameters), and 
safer (when the passed pointer might be invalid).  Thanks to Duncan and Chris for the idea behind this, 
and extra thanks to Duncan for helping me work out the trap-safety.

llvm-svn: 48280

llvm-svn: 48262

llvm-svn: 48254

before trying to merge the block into its predecessors.
This allows two-entry-phi-return.ll to be simplified
into a single basic block.

llvm-svn: 48252

optimized away before it tests what it is intended to test.

llvm-svn: 48251

llvm-svn: 48210

llvm-svn: 48207

llvm-svn: 48163

llvm-svn: 48137

llvm-svn: 48123

llvm-svn: 48103