calls. Before arguments that could overwrite each other were
explicitly lowered to a stack slot, not giving the register allocator
a chance to optimize. Now a sequence of copyto/copyfrom virtual
registers ensures that arguments are loaded in (virtual) registers
before they are lowered to the stack slot (and might overwrite each
other). Also parameter stack slots are marked mutable for
(potentially) tail calling functions.

llvm-svn: 47593

pointed out that this isn't correct at -O0.

llvm-svn: 47575

llvm-svn: 47573

{S,U}MUL_LOHI with an unused high value.

llvm-svn: 47569

result into a MUL late in the X86 codegen process. ISD::MUL is
once again Legal on X86, so this is no longer needed. And, the
hack was suboptimal; see PR1874 for details.

llvm-svn: 47567

a SignBitIsZero function to simplify a common use case.

llvm-svn: 47561

of TokenFactor underneath chain (seems to be enough)

llvm-svn: 47554

llvm-svn: 47524

No need recognize load from a fixed argument slot as re-materializable. LiveIntervalAnalysis already handles it as a special case.

llvm-svn: 47522

stuff into ParamAttrsList.h.  Per feedback from
ParamAttrs changes.

llvm-svn: 47504

llvm-svn: 47483

llvm-svn: 47476

instead of with mmx registers.  This horribleness is apparently
done by gcc to avoid having to insert emms in places that really 
should have it.  This is the second half of rdar://5741668.

llvm-svn: 47474

GCC apparently does this, and code depends on not having to do
emms when this happens.  This is x86-64 only so far, second half
should handle x86-32.

rdar://5741668

llvm-svn: 47470

new things.

llvm-svn: 47458

llvm-svn: 47431

Atomic op support.  If any gcc test uses __sync builtins, it might start failing on archs that haven't implemented them yet

llvm-svn: 47430

llvm-svn: 47400

llvm-svn: 47375

llvm-svn: 47369

llvm-svn: 47367

llvm-svn: 47354

llvm-svn: 47351

This compiles test-nofold.ll into:

_test:
	movl	$15, %ecx
	andl	4(%esp), %ecx
	testl	%ecx, %ecx
	movl	$42, %eax
	cmove	%ecx, %eax
	ret

instead of:
_test:
	movl	4(%esp), %eax
	movl	%eax, %ecx
	andl	$15, %ecx
	testl	$15, %eax
	movl	$42, %eax
	cmove	%ecx, %eax
	ret

llvm-svn: 47330

llvm-svn: 47300

- When DAG combiner is folding a bit convert into a BUILD_VECTOR, it should check if it's essentially a SCALAR_TO_VECTOR. Avoid turning (v8i16) <10, u, u, u> to <10, 0, u, u, u, u, u, u>. Instead, simply convert it to a SCALAR_TO_VECTOR of the proper type.
- X86 now normalize SCALAR_TO_VECTOR to (BIT_CONVERT (v4i32 SCALAR_TO_VECTOR)). Get rid of X86ISD::S2VEC.

llvm-svn: 47290

on x86-32 since i64 itself is not a Legal type. And, update some
comments.

llvm-svn: 47282

llvm-svn: 47278

has plain one-result scalar integer multiplication instructions.
This avoids expanding such instructions into MUL_LOHI sequences that
must be special-cased at isel time, and avoids the problem with that
code that provented memory operands from being folded.

This fixes PR1874, addressesing the most common case. The uncommon
cases of optimizing multiply-high operations will require work
in DAGCombiner.

llvm-svn: 47277

llvm-svn: 47237

I cannot find a libgcc function for this builtin.  Therefor expanding it to a noop (which is how it use to be treated).  If someone who knows the x86 backend better than me could tell me how to get a lock prefix on an instruction, that would be nice to complete x86 support.

llvm-svn: 47213

llvm-svn: 47204

really really really need refactoring :(

llvm-svn: 47171

the global comment.  This prevents printing things like:

...  # foo
bar

when the name is "foo\nbar".

llvm-svn: 47170

that doesn't support it.  Per Chris.

llvm-svn: 47162

llvm-svn: 47149

the return value is zero-extended if it isn't
sign-extended.  It may also be any-extended.
Also, if a floating point value was returned
in a larger floating point type, pass 1 as the
second operand to FP_ROUND, which tells it
that all the precision is in the original type.
I think this is right but I could be wrong.
Finally, when doing libcalls, set isZExt on
a parameter if it is "unsigned".  Currently
isSExt is set when signed, and nothing is
set otherwise.  This should be right for all
calls to standard library routines.

llvm-svn: 47122

1) ConstantFP is now expand by default
2) ConstantFP is not turned into TargetConstantFP during Legalize
   if it is legal.

This allows ConstantFP to be handled like Constant, allowing for 
targets that can encode FP immediates as MachineOperands.

As a bonus, fix up Itanium FP constants, which now correctly match,
and match more constants!  Hooray.

llvm-svn: 47121

llvm-svn: 47109

llvm-svn: 47108