Re: commutative asm operands

[Alan Modra <amodra at bigpond dot net dot au>]

On Sun, Aug 04, 2002 at 06:29:19PM +0200, Roman Zippel wrote:
> Alan Modra wrote:
> >         * recog.c (constrain_operands): Handle commutative operands.
> 
> What exactly does this patch fix?

The ICE reported at the beginning of this thread, and the following
similar one.

> What is the assembly output for this test case (register names might
> need a change):

Thanks, this testcase is useful.

void f (void)
{
  register int a asm ("%r3");
  register int b asm ("%r4");
  register int c asm ("%r5");
  register int d asm ("%r6");

  asm volatile ("addc %0, %2, %3\n\tadde %1, %4, %5"
		: "=r" (a), "=r" (b)
		: "%0" (a), "r" (c), "%1" (b), "r" (d));
  asm volatile ("addc %0, %2, %3\n\tadde %1, %4, %5"
		: "=r" (a), "=r" (b)
		: "%0" (c), "r" (a), "%1" (d), "r" (b));
}

produces, with my patch:

.f:
#APP
        addc 3, 3, 5
        adde 4, 4, 6
        addc 3, 5, 3
        adde 4, 4, 6
#NO_APP
        blr

and without:

addc.c: In function `f':
addc.c:14: error: unrecognizable insn:
(insn:HI 14 12 22 0 0x4012c0c0 (parallel [
            (set (reg/v:SI 3 r3)
                (asm_operands/v:SI ("addc %0, %2, %3
        adde %1, %4, %5") ("=r") 0 [
                        (reg/v:SI 5 r5)
                        (reg/v:SI 3 r3)
                        (reg/v:SI 4 r4)
                        (reg/v:SI 6 r6)
                    ]
                     [
                        (asm_input:SI ("%0"))
                        (asm_input:SI ("r"))
                        (asm_input:SI ("%1"))
                        (asm_input:SI ("r"))
                    ] ("addc.c") 11))
            (set (reg/v:SI 4 r4)
                (asm_operands/v:SI ("addc %0, %2, %3
        adde %1, %4, %5") ("=r") 1 [
                        (reg/v:SI 5 r5)
                        (reg/v:SI 3 r3)
                        (reg/v:SI 4 r4)
                        (reg/v:SI 6 r6)
                    ]
                     [
                        (asm_input:SI ("%0"))
                        (asm_input:SI ("r"))
                        (asm_input:SI ("%1"))
                        (asm_input:SI ("r"))
                    ] ("addc.c") 11))
        ]) -1 (insn_list 12 (nil))
    (nil))
addc.c:14: internal compiler error: Internal compiler error in reload_cse_simplify_operands, at reload1.c:8308

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre