ConstantFoldLoadThroughGEPConstantExpr.

llvm-svn: 83311

llvm-svn: 83310

the new predicates I added) instead of going through a context and doing a
pointer comparison.  Besides being cheaper, this allows a smart compiler
to turn the if sequence into a switch.

llvm-svn: 83297

This fixes PR5130.

llvm-svn: 83290

llvm-svn: 83194

Ok'd by Owen.

llvm-svn: 83193

phi nodes.  Make sure to phi translate from the right block. 

This fixes a llvm-building-llvm failure on GVN-PRE.cpp

llvm-svn: 82970

llvm-svn: 82936

The bitcast case is not needed here: instcombine turns icmp(bitcast(x), null) -> icmp(x, null) already.  

llvm-svn: 82935

llvm-svn: 82933

malloc isn't needed.

llvm-svn: 82932

llvm-svn: 82929

These are important to push up to encourage jump threading.  This shrinks 176.gcc a bit.

llvm-svn: 82923

simple constants for the true/false value of the select.  We now
do phi translation etc.  This really fixes PR4895 :)

llvm-svn: 82917

that are phi nodes.  Also tighten up FoldOpIntoPhi to treat constantexpr
operands to phis just like other variables, avoiding moving constantexpr
computations around.

Patch by Daniel Dunbar.

llvm-svn: 82913

that is deleted in some situations. This fixes a use-after-free.

llvm-svn: 82903

rotating the loop, since loop rotation is a very significant change.

llvm-svn: 82901

update all the callers.

llvm-svn: 82889

calls, since direct calls don't always reflect the attributes of their
callees.

llvm-svn: 82867

llvm-svn: 82823

typically faster then doing a general pow.

llvm-svn: 82819

llvm-svn: 82700

rather structs passed by value.
This fixes PR5038.

llvm-svn: 82689

bootstrap problems.

llvm-svn: 82464

by setPreservesCFG().

llvm-svn: 82463

helpful, and it didn't correctly handle the case of constants input
to PHIs for backedges.

llvm-svn: 82462

arrays and structs, which cannot be bitcast to integers.

llvm-svn: 82460

This doesn't kick in too much because of phi translation issues,
but this can be resolved in the future.

llvm-svn: 82447

llvm-svn: 82446

llvm-svn: 82444

analysis, one that does the xform.

llvm-svn: 82443

from a piece of a large store when both are in the same block.

This allows clang to compile the testcase in PR4216 to this code:

_test_bitfield:
	movl	4(%esp), %eax
	movl	%eax, %ecx
	andl	$-65536, %ecx
	orl	$32962, %eax
	andl	$40186, %eax
	orl	%ecx, %eax
	ret

This is not ideal, but is a whole lot better than the code produced
by llvm-gcc:

_test_bitfield:
	movw	$-32574, %ax
	orw	4(%esp), %ax
	andw	$-25350, %ax
	movw	%ax, 4(%esp)
	movw	7(%esp), %cx
	shlw	$8, %cx
	movzbl	6(%esp), %edx
	orw	%cx, %dx
	movzwl	%dx, %ecx
	shll	$16, %ecx
	movzwl	%ax, %eax
	orl	%ecx, %eax
	ret

and dramatically better than that produced by gcc 4.2:

_test_bitfield:
	pushl	%ebx
	call	L3
"L00000000001$pb":
L3:
	popl	%ebx
	movl	8(%esp), %eax
	leal	0(,%eax,4), %edx
	sarb	$7, %dl
	movl	%eax, %ecx
	andl	$7168, %ecx
	andl	$-7201, %ebx
	movzbl	%dl, %edx
	andl	$1, %edx
	sall	$5, %edx
	orl	%ecx, %ebx
	orl	%edx, %ebx
	andl	$24, %eax
	andl	$-58336, %ebx
	orl	%eax, %ebx
	orl	$32962, %ebx
	movl	%ebx, %eax
	popl	%ebx
	ret

llvm-svn: 82439

llvm-svn: 82426

so that nonlocal and partially redundant loads can use it as well.
The testcase shows examples of craziness this can handle.  This triggers
*many* times in 176.gcc.

llvm-svn: 82403

more generic.

llvm-svn: 82402

(and load -> load) when the base pointers must alias but when
they are different types.  This occurs very very frequently in
176.gcc and other code that uses bitfields a lot.

llvm-svn: 82399

llvm-svn: 82355

Reviewed by Dan Gohman.

llvm-svn: 82300

llvm-svn: 82097

constants out of loops. These aren't covered by the regular LICM
pass, because in LLVM IR constants don't require separate
instructions. They're not always covered by the MachineLICM pass
either, because it doesn't know how to unfold folded constant-pool
loads. This is somewhat experimental at this point, and off by
default.

llvm-svn: 82076