llvm-svn: 46431

llvm-svn: 46429

way or the other.  Rewriting the code itself prevents subsequent analysis
passes from making contradictory conclusions about the code that could 
cause an infeasible path to be made feasible.

llvm-svn: 46427

llvm-svn: 46424

llvm-svn: 46422

llvm-svn: 46420

llvm-svn: 46417

longer allowed to write through byval arguments.

llvm-svn: 46416

registers if used by a bitconvert or using a bitconvert.  This allows us to
avoid constant pool loads and use cheaper integer instructions when the
values come from or end up in integer regs anyway.  For example, we now 
compile CodeGen/X86/fp-in-intregs.ll to:

_test1:
	movl	$2147483648, %eax
	xorl	4(%esp), %eax
	ret
_test2:
	movl	$1065353216, %eax
	orl	4(%esp), %eax
	andl	$3212836864, %eax
	ret

Instead of:
_test1:
	movss	4(%esp), %xmm0
	xorps	LCPI2_0, %xmm0
	movd	%xmm0, %eax
	ret
_test2:
	movss	4(%esp), %xmm0
	andps	LCPI3_0, %xmm0
	movss	LCPI3_1, %xmm1
	andps	LCPI3_2, %xmm1
	orps	%xmm0, %xmm1
	movd	%xmm1, %eax
	ret

bitconverts can happen due to various calling conventions that require
fp values to passed in integer regs in some cases, e.g. when returning
a complex.

llvm-svn: 46414

llvm-svn: 46413

llvm-svn: 46411

This fixes PR1769.

llvm-svn: 46408

For long double constants, print an approximation of their value to the .s file to make it easier to read.

llvm-svn: 46407

llvm-svn: 46406

llvm-svn: 46405

now that the dag combiner does it.

llvm-svn: 46404

from the stack.  This allows us to compile stack-align.ll to:

_test:
	movsd	LCPI1_0, %xmm0
	movapd	%xmm0, %xmm1
***	andpd	4(%esp), %xmm1
	andpd	_G, %xmm0
	addsd	%xmm1, %xmm0
	movl	20(%esp), %eax
	movsd	%xmm0, (%eax)
	ret

instead of:

_test:
	movsd	LCPI1_0, %xmm0
**	movsd	4(%esp), %xmm1
**	andpd	%xmm0, %xmm1
	andpd	_G, %xmm0
	addsd	%xmm1, %xmm0
	movl	20(%esp), %eax
	movsd	%xmm0, (%eax)
	ret

llvm-svn: 46401

nop. Emit the nop directly for PPC.

llvm-svn: 46398

a "nop" instruction so that we don't have the function's label associated
with something that it's not supposed to be associated with.

llvm-svn: 46394

when inlining a readonly function.

llvm-svn: 46393

void bork() {
  int *address = 0;
  *address = 0;
}

It's compiled into LLVM code that looks like this:

define void @bork() noreturn nounwind  {
entry:
        unreachable
}

This is bad on some platforms (like PPC) because it will generate the label for
the function but no body. The label could end up being associated with some
non-code related stuff, like a section. This places a "trap" instruction if the
SimplifyCFG pass removed all code from the function leaving only one
"unreachable" instruction.

llvm-svn: 46387

delete a node even if it was not dead in some cases.  Instead, just add it to
the worklist.  Also, make sure to use the CombineTo methods, as it was doing
things that were unsafe: the top level combine loop could touch dangling memory.

This fixes CodeGen/Generic/2008-01-25-dag-combine-mul.ll

llvm-svn: 46384

don't bother making x&-1 only to simplify it in dag combine.  This commonly occurs expanding i64 ops.

llvm-svn: 46383

llvm-svn: 46377

llvm-svn: 46369

llvm-svn: 46355

was actually passing a completely incorrect size to sys_icache_invalidate.
Instead of having the JITEmitter do this (which doesn't have the correct 
size), just make the target sync its own stubs.

llvm-svn: 46354

DeadStoreElimination can treat byval parameters as if there were alloca's for the purpose of removing end-of-function stores.

llvm-svn: 46351

we can infer it.  This will eventually help stuff, though it doesn't
do much right now because all fixed FI's have an alignment of 1.

llvm-svn: 46349

a reference to TargetFrameInfo.  Rearrange order of fields in StackObject to
save a word.

llvm-svn: 46348

llvm-svn: 46347

llvm-svn: 46345

us to compile:

double test(double X) {
  return copysign(0.0, X);
}

into:

_test:
	andpd	LCPI1_0(%rip), %xmm0
	ret

instead of:
_test:
	pxor	%xmm1, %xmm1
	andpd	LCPI1_0(%rip), %xmm1
	movapd	%xmm0, %xmm2
	andpd	LCPI1_1(%rip), %xmm2
	movapd	%xmm1, %xmm0
	orpd	%xmm2, %xmm0
	ret

llvm-svn: 46344

This should fix bunch of issues.

llvm-svn: 46337

llvm-svn: 46320

llvm-svn: 46318

can't be aliased to other known objects.  This allows us to know that byval 
pointer args don't alias globals, etc.

llvm-svn: 46315

llvm-svn: 46314

llvm-svn: 46313

This case returns the value in ST(0) and then has to convert it to an SSE
register.  This causes significant codegen ugliness in some cases.  For 
example in the trivial fp-stack-direct-ret.ll testcase we used to generate:

_bar:
	subl	$28, %esp
	call	L_foo$stub
	fstpl	16(%esp)
	movsd	16(%esp), %xmm0
	movsd	%xmm0, 8(%esp)
	fldl	8(%esp)
	addl	$28, %esp
	ret

because we move the result of foo() into an XMM register, then have to
move it back for the return of bar.

Instead of hacking ever-more special cases into the call result lowering code
we take a much simpler approach: on x86-32, fp return is modeled as always 
returning into an f80 register which is then truncated to f32 or f64 as needed.
Similarly for a result, we model it as an extension to f80 + return.

This exposes the truncate and extensions to the dag combiner, allowing target
independent code to hack on them, eliminating them in this case.  This gives 
us this code for the example above:

_bar:
	subl	$12, %esp
	call	L_foo$stub
	addl	$12, %esp
	ret

The nasty aspect of this is that these conversions are not legal, but we want
the second pass of dag combiner (post-legalize) to be able to hack on them.
To handle this, we lie to legalize and say they are legal, then custom expand
them on entry to the isel pass (PreprocessForFPConvert).  This is gross, but
less gross than the code it is replacing :)

This also allows us to generate better code in several other cases.  For 
example on fp-stack-ret-conv.ll, we now generate:

_test:
	subl	$12, %esp
	call	L_foo$stub
	fstps	8(%esp)
	movl	16(%esp), %eax
	cvtss2sd	8(%esp), %xmm0
	movsd	%xmm0, (%eax)
	addl	$12, %esp
	ret

where before we produced (incidentally, the old bad code is identical to what
gcc produces):

_test:
	subl	$12, %esp
	call	L_foo$stub
	fstpl	(%esp)
	cvtsd2ss	(%esp), %xmm0
	cvtss2sd	%xmm0, %xmm0
	movl	16(%esp), %eax
	movsd	%xmm0, (%eax)
	addl	$12, %esp
	ret

Note that we generate slightly worse code on pr1505b.ll due to a scheduling 
deficiency that is unrelated to this patch.

llvm-svn: 46307