On Wed, Jul 29, 2015 at 04:04:28PM -0400, Michael Meissner wrote:
> +;; Return constant 0x80000000000000000000000000000000 in an Altivec register.
> +
> +(define_expand "altivec_high_bit"
> + [(set (match_dup 1)
> + (vec_duplicate:V16QI (const_int 7)))
> + (set (match_dup 2)
> + (ashift:V16QI (match_dup 1)
> + (match_dup 1)))
> + (set (match_dup 3)
> + (match_dup 4))
> + (set (match_operand:V16QI 0 "register_operand" "")
> + (unspec:V16QI [(match_dup 2)
> + (match_dup 3)
> + (const_int 15)] UNSPEC_VSLDOI))]
> + "TARGET_ALTIVEC"
> +{
> + if (can_create_pseudo_p ())
> + {
> + operands[1] = gen_reg_rtx (V16QImode);
> + operands[2] = gen_reg_rtx (V16QImode);
> + operands[3] = gen_reg_rtx (V16QImode);
> + }
> + else
> + operands[1] = operands[2] = operands[3] = operands[0];
This won't work (in the pattern you write to op 3 before reading from op 2).
Do you ever call this expander late, anyway?
Segher
