float expansion (and sometimes vector splitting too).

llvm-svn: 52548

integer of the same type.  Before it was "promotion",
but this is confusing because it is quite different
to promotion of integers.  Call it "softening" instead,
inspired by "soft float".

llvm-svn: 52546

llvm-svn: 52545

llvm-svn: 52522

llvm-svn: 52517

llvm-svn: 52516

llvm-svn: 52508

llvm-svn: 52495

llvm-svn: 52487

llvm-svn: 52485

llvm-svn: 52480

llvm-svn: 52479

llvm-svn: 52477

add new instructions.

llvm-svn: 52475

According to DWARF-2 specification, the line information is provided through an offset in the .debug_line section.
Replace the label reference that is used with a section offset.

llvm-svn: 52468

llvm-svn: 52452

llvm-svn: 52450

llvm-svn: 52431

llvm-svn: 52430

It's not safe to remove SUBREG_TO_REG that looks like identity copies, e.g. movl %eax, %eax on x86-64 actually does a zero-extend.

llvm-svn: 52421

rather than bundling them together.  Rename FloatToInt
to PromoteFloat (better, if not perfect).  Reorganize
files by types rather than by operations.

llvm-svn: 52408

of value info (sign/zero ext info) from one MBB to another.  This doesn't
handle much right now because of two limitations:

1) only handles zext/sext, not random bit propagation (no assert exists 
   for this)
2) doesn't handle phis.

llvm-svn: 52383

llvm-svn: 52381

llvm-svn: 52373

llvm-svn: 52345

impact on code quality or compile time.

llvm-svn: 52329

still excluding types like i1 (not byte sized)
and i120 (loading an i120 requires loading an i64,
an i32, an i16 and an i8, which is expensive). 

llvm-svn: 52310

llvm-svn: 52309

llvm-svn: 52308

llvm-svn: 52306

Assign indices to empty basic blocks.  This will be necessary for StrongPHIElimination in the near future.

llvm-svn: 52300

not valid if the load is volatile.  Hopefully
all wrong DAG combiner transforms of volatile
loads and stores have now been caught.

llvm-svn: 52293

a non-constant index.

llvm-svn: 52292

on some code when !AfterLegalize - but since
this whole code section is turned off by an
"if (0)" it's not really turning anything on.

llvm-svn: 52276

llvm-svn: 52270

Teach the spiller to commute instructions in order to fold a reload. This hits 410 times on 444.namd and 122 times on 252.eon.

llvm-svn: 52266

wrong for volatile loads and stores.  In fact this
is almost all of them!  There are three types of
problems: (1) it is wrong to change the width of
a volatile memory access.  These may be used to
do memory mapped i/o, in which case a load can have
an effect even if the result is not used.  Consider
loading an i32 but only using the lower 8 bits.  It
is wrong to change this into a load of an i8, because
you are no longer tickling the other three bytes.  It
is also unwise to make a load/store wider.  For
example, changing an i16 load into an i32 load is
wrong no matter how aligned things are, since the
fact of loading an additional 2 bytes can have
i/o side-effects.  (2) it is wrong to change the
number of volatile load/stores: they may be counted
by the hardware.  (3) it is wrong to change a volatile
load/store that requires one memory access into one
that requires several.  For example on x86-32, you
can store a double in one processor operation, but to
store an i64 requires two (two i32 stores).  In a
multi-threaded program you may want to bitcast an i64
to a double and store as a double because that will
occur atomically, and be indivisible to other threads.
So it would be wrong to convert the store-of-double
into a store of an i64, because this will become two
i32 stores - no longer atomic.  My policy here is
to say that the number of processor operations for
an illegal operation is undefined.  So it is alright
to change a store of an i64 (requires at least two
stores; but could be validly lowered to memcpy for
example) into a store of double (one processor op).
In short, if the new store is legal and has the same
size then I say that the transform is ok.  It would
also be possible to say that transforms are always
ok if before they were illegal, whether after they
are illegal or not, but that's more awkward to do
and I doubt it buys us anything much.
However this exposed an interesting thing - on x86-32
a store of i64 is considered legal!  That is because
operations are marked legal by default, regardless of
whether the type is legal or not.  In some ways this
is clever: before type legalization this means that
operations on illegal types are considered legal;
after type legalization there are no illegal types
so now operations are only legal if they really are.
But I consider this to be too cunning for mere mortals.
Better to do things explicitly by testing AfterLegalize.
So I have changed things so that operations with illegal
types are considered illegal - indeed they can never
map to a machine operation.  However this means that
the DAG combiner is more conservative because before
it was "accidentally" performing transforms where the
type was illegal because the operation was nonetheless
marked legal.  So in a few such places I added a check
on AfterLegalize, which I suppose was actually just
forgotten before.  This causes the DAG combiner to do
slightly more than it used to, which resulted in the X86
backend blowing up because it got a slightly surprising
node it wasn't expecting, so I tweaked it.

llvm-svn: 52254

maps can be deleted.  This happens when RAUW
replaces a node N with another equivalent node
E, deleting the first node.  Solve this by
adding (N, E) to ReplacedNodes, which is already
used to remap nodes to replacements.  This means
that deleted nodes are being allowed in maps,
which can be delicate: the memory may be reused
for a new node which might get confused with the
old deleted node pointer hanging around in the
maps, so detect this and flush out maps if it
occurs (ExpungeNode).  The expunging operation
is expensive, however it never occurs during
a llvm-gcc bootstrap or anywhere in the nightly
testsuite.  It occurs three times in "make check":
Alpha/illegal-element-type.ll,
PowerPC/illegal-element-type.ll and
X86/mmx-shift.ll.  If expunging proves to be too
expensive then there are other more complicated
ways of solving the problem.
In the normal case this patch adds the overhead
of a few more map lookups, which is hopefully
negligable.

llvm-svn: 52214

value, which is something that apparently isn't used much.

llvm-svn: 52158

llvm-svn: 52156