used to tack a register number onto the node.

Instead of doing this, make a new node, RegisterSDNode, which is a leaf
containing a register number.  These three operations just become normal
DAG nodes now, instead of requiring special handling.

Note that with this change, it is no longer correct to make illegal
CopyFromReg/CopyToReg nodes.  The legalizer will not touch them, and this
is bad, so don't do it. :)

llvm-svn: 22806

fixme from the PowerPC backend.  Emit slightly better code for legalizing
select_cc.

llvm-svn: 22805

when printing a node, use it to render target operations with their
target instruction name instead of "<<unknown>>".

llvm-svn: 22804

llvm-svn: 22802

Split RemoveNodeFromCSEMaps out of DeleteNodesIfDead to do it.

llvm-svn: 22801

1. Not selecting the false value of a select_cc in the false arm, which
   isn't legal for nested selects.
2. Actually returning the node we created and Legalized in the FP_TO_UINT
   Expander.

llvm-svn: 22789

Teach the legalizer to promote FP_TO_UINT to FP_TO_SINT if the wider
  FP_TO_UINT is also illegal.  This allows us on PPC to codegen
  unsigned short foo(float a) { return a; }

as:
_foo:
.LBB_foo_0:     ; entry
        fctiwz f0, f1
        stfd f0, -8(r1)
        lwz r2, -4(r1)
        rlwinm r3, r2, 0, 16, 31
        blr

instead of:
_foo:
.LBB_foo_0:     ; entry
        fctiwz f0, f1
        stfd f0, -8(r1)
        lwz r2, -4(r1)
        lis r3, ha16(.CPI_foo_0)
        lfs f0, lo16(.CPI_foo_0)(r3)
        fcmpu cr0, f1, f0
        blt .LBB_foo_2  ; entry
.LBB_foo_1:     ; entry
        fsubs f0, f1, f0
        fctiwz f0, f0
        stfd f0, -16(r1)
        lwz r2, -12(r1)
        xoris r2, r2, 32768
.LBB_foo_2:     ; entry
        rlwinm r3, r2, 0, 16, 31
        blr

llvm-svn: 22785

assert when creating a select_cc node.

llvm-svn: 22780

out into SimplifySelectCC.  This allows both ISD::SELECT and ISD::SELECT_CC
to use the same set of simplifying folds.

llvm-svn: 22779

e.g.  (X & 7) >> 3   -> 0

llvm-svn: 22774

integer MPEG encoding loop by a factor of two.

llvm-svn: 22758

1. move assertions for node creation to getNode()
2. legalize the values returned in ExpandOp immediately
3. Move select_cc optimizations from SELECT's getNode() to SELECT_CC's,
   allowing them to be cleaned up significantly.

This paves the way to pick up additional optimizations on SELECT_CC, such
as sum-of-absolute-differences.

llvm-svn: 22757

implement SELECT.

llvm-svn: 22755

llvm-svn: 22753

llvm-svn: 22734

llvm-svn: 22731

CC out of the SetCC operation, making SETCC a standard ternary operation and
CC's a standard DAG leaf.  This will make it possible for other node to use
CC's as operands in the future...

llvm-svn: 22728

llvm-svn: 22691

avoid revisiting nodes more than once.  This eliminates a source of
potentially exponential behavior.  For a small function in 191.fma3d
(hexah_stress_divergence_), this speeds up isel from taking > 20mins to
taking 0.07s.

llvm-svn: 22680

llvm-svn: 22679

yesterday.  This fixes whetstone and a bunch of programs in the External tests.

llvm-svn: 22678

llvm-svn: 22661

* Add comments to #endif pragmas for readability

llvm-svn: 22647

the sequence used for integer ops

llvm-svn: 22629

Patch contributed by Jim Laskey!

llvm-svn: 22594

llvm-svn: 22570

llvm-svn: 22565

llvm-svn: 22563

both the src and dest values are legal

llvm-svn: 22555

llvm-svn: 22548

a larger integer destination.

llvm-svn: 22547

subcases inside, break things out earlier.

llvm-svn: 22546

llvm-svn: 22523

llvm-svn: 22469

expand the code to work for all integer datatypes.  This should unbreak
alpha.

llvm-svn: 22464

the target natively supports.  This eliminates some special-case code from
the x86 backend and generates better code as well.

For an i8 to f64 conversion, before & after:

_x87 before:
        subl $2, %esp
        movb 6(%esp), %al
        movsbw %al, %ax
        movw %ax, (%esp)
        filds (%esp)
        addl $2, %esp
        ret

_x87 after:
        subl $2, %esp
        movsbw 6(%esp), %ax
        movw %ax, (%esp)
        filds (%esp)
        addl $2, %esp
        ret

_sse before:
        subl $12, %esp
        movb 16(%esp), %al
        movsbl %al, %eax
        cvtsi2sd %eax, %xmm0
        addl $12, %esp
        ret

_sse after:
        subl $12, %esp
        movsbl 16(%esp), %eax
        cvtsi2sd %eax, %xmm0
        addl $12, %esp
        ret

llvm-svn: 22452

SelectionDAGLegalize::ExpandLegalUINT_TO_FP method.

Add a new method, PromoteLegalUINT_TO_FP, which allows targets to request
that UINT_TO_FP operations be promoted to a larger input type.  This is
useful for targets that have some UINT_TO_FP or SINT_TO_FP operations but
not all of them (like X86).

The same should be done with SINT_TO_FP, but this patch does not do that
yet.

llvm-svn: 22447

llvm-svn: 22446

gv and Graphviz.

llvm-svn: 22434

llvm-svn: 22432