Since mem2reg isn't run at -O0, we get a ton of reloads from the stack,
for example, before, this code:

int foo(int x, int y, int z) {
  return x+y+z;
}

used to compile into:

_foo:                                   ## @foo
	subq	$12, %rsp
	movl	%edi, 8(%rsp)
	movl	%esi, 4(%rsp)
	movl	%edx, (%rsp)
	movl	8(%rsp), %edx
	movl	4(%rsp), %esi
	addl	%edx, %esi
	movl	(%rsp), %edx
	addl	%esi, %edx
	movl	%edx, %eax
	addq	$12, %rsp
	ret

Now we produce:

_foo:                                   ## @foo
	subq	$12, %rsp
	movl	%edi, 8(%rsp)
	movl	%esi, 4(%rsp)
	movl	%edx, (%rsp)
	movl	8(%rsp), %edx
	addl	4(%rsp), %edx    ## Folded load
	addl	(%rsp), %edx     ## Folded load
	movl	%edx, %eax
	addq	$12, %rsp
	ret

Fewer instructions and less register use = faster compiles.

llvm-svn: 113102

solve the root problem, but it corrects the bug in the code I added to
support legalizing in the case where the non-extended type is also legal.

llvm-svn: 112997

llvm-svn: 112864

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: 112858

llvm-svn: 112659

llvm-svn: 112631

Remember byval argument's frame index during argument lowering and use this info to emit debug info.
Fixes Radar 8367011.

llvm-svn: 112623

llvm-svn: 112584

llvm-svn: 112571

llvm-svn: 112463

said (physical) register.

llvm-svn: 112461

being actively maintained, improved, or extended.

llvm-svn: 112356

doesn't currently support dealing with this.

llvm-svn: 112341

llvm-svn: 112340

llvm-svn: 112305

llvm-svn: 112242

llvm-svn: 112238

llvm-svn: 112216

llvm-svn: 112215

llvm-svn: 112213

Donot forget to resolve dangling debug info in a case where virtual register, used for a value, is initialized after a dbg intrinsic is seen.

llvm-svn: 112207

llvm-svn: 112175

llvm-svn: 112171

llvm-svn: 112155

llvm-svn: 112104

expanding: e.g. <2 x float> -> <4 x float> instead of -> 2 floats.  This
affects two places in the code: handling cross block values and handling
function return and arguments.  Since vectors are already widened by 
legalizetypes, this gives us much better code and unblocks x86-64 abi
and SPU abi work.

For example, this (which is a silly example of a cross-block value):
define <4 x float> @test2(<4 x float> %A) nounwind {
 %B = shufflevector <4 x float> %A, <4 x float> undef, <2 x i32> <i32 0, i32 1>
 %C = fadd <2 x float> %B, %B
  br label %BB
BB:
 %D = fadd <2 x float> %C, %C
 %E = shufflevector <2 x float> %D, <2 x float> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
 ret <4 x float> %E
}

Now compiles into:

_test2:                                 ## @test2
## BB#0:
 addps %xmm0, %xmm0
 addps %xmm0, %xmm0
 ret

previously it compiled into:

_test2:                                 ## @test2
## BB#0:
 addps %xmm0, %xmm0
 pshufd $1, %xmm0, %xmm1
                                        ## kill: XMM0<def> XMM0<kill> XMM0<def>
 insertps $0, %xmm0, %xmm0
 insertps $16, %xmm1, %xmm0
 addps %xmm0, %xmm0
 ret

This implements rdar://8230384

llvm-svn: 112101

llvm-svn: 112086

llvm-svn: 112085

no functionality change.

llvm-svn: 111994

functionality change.

llvm-svn: 111990

llvm-svn: 111982

hierarchy with virtual methods and using llvm_unreachable to properly indicate
unreachable states which would otherwise leave variables uninitialized.

llvm-svn: 111803

it involves specific floating-point types, legalize should expand an
extending load to a non-extending load followed by a separate extend operation.
For example, we currently expand SEXTLOAD to EXTLOAD+SIGN_EXTEND_INREG (and
assert that EXTLOAD should always be supported).  Now we can expand that to
LOAD+SIGN_EXTEND.  This is needed to allow vector SIGN_EXTEND and ZERO_EXTEND
to be used for NEON.

llvm-svn: 111586

PR 7882.  Follows suggestion by Amaury Pouly, thanks.

llvm-svn: 111306

llvm-svn: 111223

llvm-svn: 110649

llvm-svn: 110460

llvm-svn: 110410

ID member as the sole unique type identifier.  Clean up APIs related to this change.

llvm-svn: 110396