there are clearly no stores between the load and the store. This fixes
this miscompile reported as PR7833.

This breaks the test/CodeGen/X86/narrow_op-2.ll optimization, which is
safe, but awkward to prove safe. Move it to X86's README.txt.

llvm-svn: 112861

llvm-svn: 112411

for lowering without sse2.  Add a couple of new testcases.

Fixes a few libgomp tests and latent bugs.  Remove a few todos.

llvm-svn: 109078

llvm-svn: 105375

llvm-svn: 97450

code with lots of bitfields.

llvm-svn: 95809

llvm-svn: 93373

llvm-svn: 93372

llvm-svn: 92511

llvm-svn: 91823

llvm-svn: 85334

llvm-svn: 85332

llvm-svn: 85331

llvm-svn: 85329

llvm-svn: 77584

llvm-svn: 74509

llvm-svn: 74508

llvm-svn: 73472

llvm-svn: 73471

add a few suggestions from looking at some assembly code.

llvm-svn: 73210

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

llvm-svn: 72396

llvm-svn: 72387

related transformations out of target-specific dag combine into the
ARM backend.  These were added by Evan in r37685 with no testcases
and only seems to help ARM (e.g. test/CodeGen/ARM/select_xform.ll).

Add some simple X86-specific (for now) DAG combines that turn things
like cond ? 8 : 0  -> (zext(cond) << 3).  This happens frequently
with the recently added cp constant select optimization, but is a
very general xform.  For example, we now compile the second example
in const-select.ll to:

_test:
        movsd   LCPI2_0, %xmm0
        ucomisd 8(%esp), %xmm0
        seta    %al
        movzbl  %al, %eax
        movl    4(%esp), %ecx
        movsbl  (%ecx,%eax,4), %eax
        ret

instead of:

_test:
        movl    4(%esp), %eax
        leal    4(%eax), %ecx
        movsd   LCPI2_0, %xmm0
        ucomisd 8(%esp), %xmm0
        cmovbe  %eax, %ecx
        movsbl  (%ecx), %eax
        ret

This passes multisource and dejagnu.

llvm-svn: 66779

llvm-svn: 66515

llvm-svn: 66508

llvm-svn: 66360

llvm-svn: 66359

llvm-svn: 64719

llvm-svn: 64620

llvm-svn: 64093

llvm-svn: 60632

llvm-svn: 60286

llvm-svn: 59052

llvm-svn: 58104

llvm-svn: 57733

llvm-svn: 55348

llvm-svn: 53722

llvm-svn: 52663

llvm-svn: 50681

llvm-svn: 50029