llvm-svn: 44671

Simpler and safer.

llvm-svn: 44663

llvm-svn: 44660

only disable it if we don't know it will be obviously profitable.
Still fixme, but less so. :)

llvm-svn: 44658

the X86 backend are needed before this should be enabled by default.

llvm-svn: 44657

_foo:
	movl	$12, %eax
	andl	4(%esp), %eax
	movl	_array(%eax), %eax
	ret

instead of:

_foo:
	movl	4(%esp), %eax
	shrl	$2, %eax
	andl	$3, %eax
	movl	_array(,%eax,4), %eax
	ret

As it turns out, this triggers all the time, in a wide variety of
situations, for example, I see diffs like this in various programs:

-       movl    8(%eax), %eax
-       shll    $2, %eax
-       andl    $1020, %eax
-       movl    (%esi,%eax), %eax
+       movzbl  8(%eax), %eax
+       movl    (%esi,%eax,4), %eax


-       shll    $2, %edx
-       andl    $1020, %edx
-       movl    (%edi,%edx), %edx
+       andl    $255, %edx
+       movl    (%edi,%edx,4), %edx

Unfortunately, I also see stuff like this, which can be fixed in the
X86 backend:

-       andl    $85, %ebx
-       addl    _bit_count(,%ebx,4), %ebp
+       shll    $2, %ebx
+       andl    $340, %ebx
+       addl    _bit_count(%ebx), %ebp

llvm-svn: 44656

llvm-svn: 44654

llvm-svn: 44649

Fix for PR1831: if all defs of an interval are re-materializable, then it's a preferred spill candiate.

llvm-svn: 44644

llvm-svn: 44612

llvm-svn: 44611

llvm-svn: 44610

llvm-svn: 44609

llvm-svn: 44608

llvm-svn: 44607

  This allows an important optimization to be re-enabled.
- If all uses / defs of a split interval can be folded, give the interval a
  low spill weight so it would not be picked in case spilling is needed (avoid
  pushing other intervals in the same BB to be spilled).

llvm-svn: 44601

the stored register is killed.

llvm-svn: 44600

llvm-svn: 44587

Spiller unfold optimization bug: do not clobber a reusable stack slot value unless it can be modified.

llvm-svn: 44575

to codegen this:

define float @test_extract_elt(<1 x float> * %P) {
	%p = load <1 x float>* %P
	%R = extractelement <1 x float> %p, i32 0
	ret float %R
}

llvm-svn: 44570

llvm-svn: 44569

llvm-svn: 44565

llvm-svn: 44549

throw exceptions", just mark intrinsics with the nounwind
attribute.  Likewise, mark intrinsics as readnone/readonly
and get rid of special aliasing logic (which didn't use
anything more than this anyway).

llvm-svn: 44544

llvm-svn: 44532

llvm-svn: 44531

llvm-svn: 44517

llvm-svn: 44482

llvm-svn: 44479

llvm-svn: 44467

llvm-svn: 44446

llvm-svn: 44443

in the middle of a split basic block, create a new live interval starting at
the def. This avoid artifically extending the live interval over a number of
cycles where it is dead. e.g.

bb1:
       = vr1204   (use / kill) <= new interval starts and ends here.
...
...
vr1204 =          (new def)   <= start a new interval here.
       = vr1204   (use)

llvm-svn: 44436

llvm-svn: 44434

llvm-svn: 44428

llvm-svn: 44427

use them.

llvm-svn: 44403

llvm-svn: 44399

llvm-svn: 44386

llvm-svn: 44384