[(set (subreg:SI (match_operand:DI 0 "register_operand") 0)
(unspec [...] SUPER_LD32_LO))
(set (subreg:SI (match_operand:DI 0 "register_operand") 4)
(unspec [...] SUPER_LD32_HI))]
I finally looked at my code instead of going by memory. :-)
I think you should turn what you have now into a define_expand, and make
a separate define_insn which does not see the subregs but only SImode
operands:
(define_insn "*super_ld32_internal"
[(set (match_operand:SI 0 "s_register_operand" "=r")
(unspec:SI [(match_operand:SI 1 "s_register_operand" "r")
(match_operand:SI 2 "s_register_operand" "r")]
SUPER_LD32_LO))
(set (match_operand:SI 3 "s_register_operand" "=r")
(unspec:SI [(match_dup 1)
(match_dup 2)]
SUPER_LD32_HI))]
"TARGET_ARM"
"*
{
return \"superld32 %0, %1, %2\";
}"
[]
)
The way you were doing it until now, when lower-subreg tried to replace
the DImode pseudo with two SImode pseudos, the insn wasn't recognized
anymore and so the substitution failed.
Paolo
