On Sun, Feb 17, 2019 at 6:15 PM H.J. Lu <hjl.to...@gmail.com> wrote:
> > > > On Sat, Feb 16, 2019 at 11:46 PM H.J. Lu <hjl.to...@gmail.com> wrote:
> > > > >
> > > > > PR target/89021
> > > > > * config/i386/i386.c (ix86_expand_vector_init_duplicate): Set
> > > > > mmx_ok to true if TARGET_MMX_WITH_SSE is true.
> > > > > (ix86_expand_vector_init_one_nonzero): Likewise.
> > > > > (ix86_expand_vector_init_one_var): Likewise.
> > > > > (ix86_expand_vector_init_general): Likewise.
> > > > > (ix86_expand_vector_init): Likewise.
> > > > > (ix86_expand_vector_set): Likewise.
> > > > > (ix86_expand_vector_extract): Likewise.
> > > >
> > > > Please move this initialization to .md files. We don't support V2SF, so
> > > >
> > > > (define_expand "vec_setv2sf"
> > > > [(match_operand:V2SF 0 "register_operand")
> > > > (match_operand:SF 1 "register_operand")
> > > > (match_operand 2 "const_int_operand")]
> > > > "TARGET_MMX"
> > > > {
> > > > ix86_expand_vector_set (false, operands[0], operands[1],
> > > > INTVAL (operands[2]));
> > > > DONE;
> > > > })
> > > >
> > > > should remain false, while in:
> > > >
> > > > (define_expand "vec_setv2si"
> > > > [(match_operand:V2SI 0 "register_operand")
> > > > (match_operand:SI 1 "register_operand")
> > > > (match_operand 2 "const_int_operand")]
> > > > "TARGET_MMX"
> > > > {
> > > > ix86_expand_vector_set (false, operands[0], operands[1],
> > > > INTVAL (operands[2]));
> > > > DONE;
> > > > })
> > > >
> > > > we should use TARGET_MMX_WITH_SSE instead of false in the call to
> > > > ix86_expand_vector_set. The same change for the other MMX modes: V4HI
> > > > and V8QI.
> > > >
> > > > Same for other exported vector initializers: ix86_expand_vector_init
> > > > and ix86_expand_vector_extract. We support V2SI, V4HI and V8QI, but
> > > > not V2SF (non-MMX modes are agnostic to mmx_ok argument).
> > > >
> > >
> > > There is limited support for V2SF with MMX. My goal is to emulate
> > > all MMX features with SSE so that -msse2 -mno-mmx works for all
> > > MMX codes which don't use MMX inline asm. Leaving out V2SF
> > > emulation creates a hole in my implementation. Do you have testcases
> > > to show issues with V2SF emulation?
> >
> > No, but V2SF should be avoided from emulation.
>
> Then -msse2 -mno-mmx won't work on some MMX codes like:
>
> #include <mmintrin.h>
>
> float
> foo (__m64 x)
> {
> return ((__v2sf) x)[0];
> }
>
> Is there any reason why it shouldn't work for -msse2 -mno-mmx?
Does this require 3DNOW insn? If not, it is OK also for V2SF.
Uros.
