Before:
_main:
        subq    $8, %rsp
        leaq    _X(%rip), %rax
        movsd   8(%rax), %xmm1
        movss   _X(%rip), %xmm0
        call    _t
        xorl    %ecx, %ecx
        movl    %ecx, %eax
        addq    $8, %rsp
        ret
Now:
_main:
        subq    $8, %rsp
        movsd   _X+8(%rip), %xmm1
        movss   _X(%rip), %xmm0
        call    _t
        xorl    %ecx, %ecx
        movl    %ecx, %eax
        addq    $8, %rsp
        ret

Notice there is another idiotic codegen issue that needs to be fixed asap:
xorl    %ecx, %ecx
movl    %ecx, %eax

llvm-svn: 46850

llvm-svn: 46681

precision integers.  This won't actually work
(and most of the code is dead) unless the new
legalization machinery is turned on.  While
there, I rationalized the handling of i1, and
removed some bogus (and unused) sextload patterns.
For i1, this could result in microscopically
better code for some architectures (not X86).
It might also result in worse code if annotating
with AssertZExt nodes turns out to be more harmful
than helpful.

llvm-svn: 46280

1. Legalize now always promotes truncstore of i1 to i8. 
2. Remove patterns and gunk related to truncstore i1 from targets.
3. Rename the StoreXAction stuff to TruncStoreAction in TLI.
4. Make the TLI TruncStoreAction table a 2d table to handle from/to conversions.
5. Mark a wide variety of invalid truncstores as such in various targets, e.g.
   X86 currently doesn't support truncstore of any of its integer types.
6. Add legalize support for truncstores with invalid value input types.
7. Add a dag combine transform to turn store(truncate) into truncstore when
   safe.

The later allows us to compile CodeGen/X86/storetrunc-fp.ll to:

_foo:
	fldt	20(%esp)
	fldt	4(%esp)
	faddp	%st(1)
	movl	36(%esp), %eax
	fstps	(%eax)
	ret

instead of:

_foo:
	subl	$4, %esp
	fldt	24(%esp)
	fldt	8(%esp)
	faddp	%st(1)
	fstps	(%esp)
	movl	40(%esp), %eax
	movss	(%esp), %xmm0
	movss	%xmm0, (%eax)
	addl	$4, %esp
	ret

llvm-svn: 46140

Move definition of 'trap' sdnode up from x86 instrinfo to targetselectiondag.td.

llvm-svn: 46017

llvm-svn: 46015

llvm-svn: 46012

as well as PPC codegen

llvm-svn: 46001

llvm-svn: 45870

llvm-svn: 45860

llvm-svn: 45838

x86 backend where instructions were not marked maystore/mayload, and perf issues where
instructions were not marked neverHasSideEffects.  It would be really nice if we could
write patterns for copy instructions.

I have audited all the x86 instructions down to MOVDQAmr.  The flags on others and on
other targets are probably not right in all cases, but no clients currently use this
info that are enabled by default.

llvm-svn: 45829

llvm-svn: 45826

inferred from the instr patterns.

llvm-svn: 45824

llvm-svn: 45821

llvm-svn: 45668

llvm-svn: 45667

llvm-svn: 45618

llvm-svn: 45605

llvm-svn: 45418

llvm-svn: 45307

based what flag to set on whether it was already marked as
"isRematerializable". If there was a further check to determine if it's "really"
rematerializable, then I marked it as "mayHaveSideEffects" and created a check
in the X86 back-end similar to the remat one.

llvm-svn: 45132

llvm-svn: 45037

llvm-svn: 45030

Fix ctlz and cttz. llvm definition requires them to return number of bits in of the src type when value is zero.

llvm-svn: 45029

llvm-svn: 45024

llvm-svn: 44970

Implicit def instructions, e.g. X86::IMPLICIT_DEF_GR32, are always re-materializable and they should not be spilled.

llvm-svn: 44960

llvm-svn: 44045

adjustment fields, and an optional flag. If there is a "dynamic_stackalloc" in
the code, make sure that it's bracketed by CALLSEQ_START and CALLSEQ_END. If
not, then there is the potential for the stack to be changed while the stack's
being used by another instruction (like a call).

This can only result in tears...

llvm-svn: 44037

Target maintainers: please check that the instructions for your target are correctly marked.

llvm-svn: 44012

Turn a store folding instruction into a load folding instruction. e.g.
     xorl  %edi, %eax
     movl  %eax, -32(%ebp)
     movl  -36(%ebp), %eax
     orl   %eax, -32(%ebp)
=>
     xorl  %edi, %eax
     orl   -36(%ebp), %eax
     mov   %eax, -32(%ebp)
This enables the unfolding optimization for a subsequent instruction which will
also eliminate the newly introduced store instruction.

llvm-svn: 43192

for fastcc from X86CallingConv.td.  This means that nested functions
are not supported for calling convention 'fastcc'.

llvm-svn: 42934

enabled by passing -tailcallopt to llc.  The optimization is
performed if the following conditions are satisfied:
* caller/callee are fastcc
* elf/pic is disabled OR
  elf/pic enabled + callee is in module + callee has
  visibility protected or hidden

llvm-svn: 42870

to its inverse.
Testing this as llcbeta

llvm-svn: 42661

llvm-svn: 42640

llvm-svn: 42459

llvm-svn: 42429

llvm-svn: 42426

Some assemblers do not recognize aliases pushfd, pushfq, popfd, and popfq. Just emit them as pushf and popf.

llvm-svn: 42371