llvm-svn: 122795

llvm-svn: 122794

FunctionPass. It probably doesn't have a reason to be a LoopPass, as it will
probably drop the simple fixed point and either use RPO iteration or Duncan's
approach in instsimplify of only revisiting instructions that have changed.

The next step is to preserve LoopSimplify. This looks like it won't be too hard,
although the pass manager doesn't actually seem to respect when non-loop passes
claim to preserve LCSSA or LoopSimplify. This will have to be fixed.

llvm-svn: 122791

stop setting NSW: signed overflow is possible.  Thanks to Dan
for pointing these out.

llvm-svn: 122790

llvm-svn: 122789

llvm-svn: 122788

Use the new addEscapingValue callback to update GlobalsModRef when GVN adds PHIs of GEPs. For the moment,
have GlobalsModRef handle this conservatively by simply removing the value from its maps.

llvm-svn: 122787

invalidated by stores, so they can be handled as 'simple'
operations.

llvm-svn: 122785

prologue and epilogue if the adjustment is 8. Similarly, use pushl / popl if
the adjustment is 4 in 32-bit mode.

In the epilogue, takes care to pop to a caller-saved register that's not live
at the exit (either return or tailcall instruction).
rdar://8771137

llvm-svn: 122783

llvm-svn: 122778

a pointer value has potentially become escaping.  Implementations can choose to either fall back to
conservative responses for that value, or may recompute their analysis to accomodate the change.

llvm-svn: 122777

exposed.  It turns out to be a latent bug in basicaa, scary.

llvm-svn: 122772

almost-but-not-quite-identical code.  No intended functionality change.

llvm-svn: 122760

that are allowed to have metadata operands are intrinsic calls,
and the only ones that take metadata currently return void.
Just reject all void instructions, which should not be value
numbered anyway.  To future proof things, add an assert to the
getHashValue impl for calls to check that metadata operands 
aren't present.

llvm-svn: 122759

nested values, so they can change and drop to null, which can
change the hash and cause havok.

It turns out that it isn't a good idea to value number stuff
with metadata operands anyway, so... don't.

llvm-svn: 122758

InstructionSimplify on instructions that didn't change since the
last time round the loop.

llvm-svn: 122745

capacity on the Visited SmallPtrSet. On 403.gcc, this is about a 4.5% speedup of
CodeGenPrepare time (which itself is 10% of time spent in the backend).

This is progress towards PR8889.

llvm-svn: 122741

elimination as well.  This deletes 60 stores in 176.gcc
that largely come from bitfield code.

llvm-svn: 122736

a 28% speedup of MachineCSE time on 403.gcc.

llvm-svn: 122735

speeding earlycse up by 6%.

llvm-svn: 122733

store->load forwarding.  This allows EarlyCSE to zap 600 more
loads from 176.gcc.

llvm-svn: 122732

by their pointer instead of using MemoryValue to wrap it.

llvm-svn: 122731

llvm-svn: 122729

update a callGraph when performing the common operation of splicing the body to
a new function and updating all callers (such as via RAUW).

No users yet, though this is intended for DeadArgumentElimination as part of
PR8887.

llvm-svn: 122728

On 176.gcc, this catches 13090 loads and calls, and increases the
number of simple instructions CSE'd from 29658 to 36208.

llvm-svn: 122727

llvm-svn: 122725

llvm-svn: 122724

allocator.  This speeds up early cse by about 20%

llvm-svn: 122723

llvm-svn: 122720

of instcombine that is currently in the middle of the loop pass pipeline. This
commit only checks in the pass; it will hopefully be enabled by default later.

llvm-svn: 122719

llvm-svn: 122718

Teach it to CSE the rest of the non-side-effecting instructions.

llvm-svn: 122716

Add a testcase.

llvm-svn: 122715

so that Dominators.h is *just* domtree.  Also prune #includes a bit.

llvm-svn: 122714

llvm-svn: 122713

sure that the loop we're promoting into a memcpy doesn't mutate the input
of the memcpy.  Before we were just checking that the dest of the memcpy
wasn't mod/ref'd by the loop.

llvm-svn: 122712

mess with it.  We'd rather peel/unroll it than convert all of its 
stores into memsets.

llvm-svn: 122711

This allows us to compile:
  void test(char *s, int a) {
    __builtin_memset(s, a, 15);
  }
into 1 mul + 3 stores instead of 3 muls + 3 stores.

llvm-svn: 122710

Lower the i8 extension in memset to a multiply instead of a potentially long series of shifts and ors.

We could implement a DAGCombine to turn x * 0x0101 back into logic operations
on targets that doesn't support the multiply or it is slow (p4) if someone cares
enough.

Example code:
  void test(char *s, int a) {
      __builtin_memset(s, a, 4);
  }
before:
  _test:                                  ## @test
    movzbl  8(%esp), %eax
    movl  %eax, %ecx
    shll  $8, %ecx
    orl %eax, %ecx
    movl  %ecx, %eax
    shll  $16, %eax
    orl %ecx, %eax
    movl  4(%esp), %ecx
    movl  %eax, 4(%ecx)
    movl  %eax, (%ecx)
    ret
after:
  _test:                                  ## @test
    movzbl  8(%esp), %eax
    imull $16843009, %eax, %eax   ## imm = 0x1010101
    movl  4(%esp), %ecx
    movl  %eax, 4(%ecx)
    movl  %eax, (%ecx)
    ret

llvm-svn: 122707

llvm-svn: 122706