exposed:

GAS doesn't accept "fcomip %st(1)", it requires "fcomip %st(1), %st(0)"
even though st(0) is implicit in all other fp stack instructions.

Fortunately, there is an alias for fcomip named "fcompi" and gas does
accept the default argument for the alias (boggle!).

As such, switch the canonical form of this instruction to "pi" instead
of "ip".  This makes the code generator and disassembler generate pi,
avoiding the gas bug.

llvm-svn: 118356

shift-by-1 instructions, where the asmstring doesn't contain
the implicit 1.  It turns out that a bunch of these rotate
instructions were completely broken because they used 1 
instead of $1.

This fixes assembly mismatches on "rclb	$1, %bl" and friends,
where we used to generate the 3 byte form, we now generate the
proper 2-byte form.

llvm-svn: 118355

listed in its asm string, for consistency with the other similar
instructions.

llvm-svn: 118354

llvm-svn: 118353

fixed physical registers.  Start moving fp comparison
aliases to the .td file (which default to using %st1 if
nothing is specified).

llvm-svn: 118352

(surprise!) a list of registers. Register lists are consecutive, so we only need
to record the start register plus the number of registers.

llvm-svn: 118351

add fixed immediate values.  Move the aad and aam aliases to
use this, and document it.

llvm-svn: 118350

llvm-svn: 118349

llvm-svn: 118348

llvm-svn: 118347

floating point stack instructions instead of looking for b/w/l/q.

This fixes issues where we'd accidentally match fistp to fistpl,
when it is in fact an ambiguous instruction.

This changes the behavior of llvm-mc to reject fstp, which was the
correct fix for rdar://8456389:
t.s:1:1: error: ambiguous instructions require an explicit suffix (could be 'fstps', 'fstpl', or 'fstpt')
fstp	(%rax)

it also causes us to correctly reject fistp and fist, which addresses
PR8528:

t.s:2:1: error: ambiguous instructions require an explicit suffix (could be 'fistps', or 'fistpl')
fistp (%rax)
^
t.s:3:1: error: ambiguous instructions require an explicit suffix (could be 'fists', or 'fistl')
fist (%rax)
^

Thanks to Ismail Donmez for tracking down the issue here!

llvm-svn: 118346

llvm-svn: 118342

llvm-svn: 118341

llvm-svn: 118340

llvm-svn: 118339

while the latter doesn't.

llvm-svn: 118338

llvm-svn: 118337

result instruction operand numbering matched the result pattern.

Fixing this allows us to move the xchg/test aliases to the .td file.

llvm-svn: 118334

Fixes 8559.

llvm-svn: 118333

llvm-svn: 118332

tidy up the movsx and movzx aliases.

llvm-svn: 118331

from c++ hacks to proper .td InstAlias definitions.  Change them!

llvm-svn: 118330

operand list instead of the operand list redundantly declared on the alias
or instruction.

With this change, we finally remove the ins/outs list on the alias.  Before:
  def : InstAlias<(outs GR16:$dst), (ins GR8 :$src),
                  "movsx $src, $dst",
                  (MOVSX16rr8W GR16:$dst, GR8:$src)>;
After:
  def : InstAlias<"movsx $src, $dst",
                  (MOVSX16rr8W GR16:$dst, GR8:$src)>;

This also makes the alias mechanism more general and powerful, which will
be exploited in subsequent patches.

llvm-svn: 118329

llvm-svn: 118310

llvm-svn: 118309

llvm-svn: 118307

llvm-svn: 118304

llvm-svn: 118301

llvm-svn: 118300

llvm-svn: 118295

llvm-svn: 118294

llvm-svn: 118291

(relocations, e.g.), but this will allow simple things to flow through.

llvm-svn: 118289

llvm-svn: 118288

llvm-svn: 118287

llvm-svn: 118280

to perform the copy, which may be of lots of memory [*].  It would be good if the
fall-back code generated something reasonable, i.e. did the copy in a loop, rather
than vast numbers of loads and stores.  Add a note about this.  Currently target
specific code seems to always kick in so this is more of a theoretical issue rather
than a practical one now that X86 has been fixed.
[*] It's amazing how often people pass mega-byte long arrays by copy...

llvm-svn: 118275

llvm-svn: 118272

sequence of loads and stores was being generated to perform the
copy on the x86 targets if the parameter was less than 4 byte
aligned, causing llc to use up vast amounts of memory and time.
Use a "rep movs" form instead.  PR7170.

llvm-svn: 118260

llvm-svn: 118257