Work in progress. This patch *fixes* x86-64 calls which are modelled as StructRet but really should be return in registers, e.g. _Complex long double, some 128-bit aggregates. This is a short term solution that is necessary only because llvm, for now, cannot model i128 nor call's with multiple results.
Status: This only works for direct calls, and only the caller side is done. Disabled for now.

llvm-svn: 46527

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

llvm-svn: 45870

llvm-svn: 45861

llvm-svn: 45860

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: 45667

llvm-svn: 45418

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: 45041

Fix (mem) <-> low 64-bits of xmm bugs pointed out by David Greene. Mac OS X Leopard assembler recognizes movq.

llvm-svn: 45040

llvm-svn: 45037

llvm-svn: 45036

llvm-svn: 45030

llvm-svn: 45024

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

llvm-svn: 44960

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: 42642

llvm-svn: 42640

llvm-svn: 42459

llvm-svn: 42413

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

llvm-svn: 42371

llvm-svn: 42348

llvm-svn: 42335

Added support for new condition code modeling scheme (i.e. physical register dependency). These are a bunch of instructions that are duplicated so the x86 backend can support both the old and new schemes at the same time. They will be deleted after
all the kinks are worked out.

llvm-svn: 42285

llvm-svn: 42027

previously only done for 32-bit and smaller operands.

llvm-svn: 42024

llvm-svn: 41975

llvm-svn: 41962

llvm-svn: 41863

by flagging the associated instructions as being trivially rematerializable.

llvm-svn: 41775

llvm-svn: 41595

llvm-svn: 40702

mnemonics from their operands instead of single spaces. This makes the
assembly output a little more consistent with various other compilers
(f.e. GCC), and slightly easier to read. Also, update the regression
tests accordingly.

llvm-svn: 40648