Hi!
On Wed, Mar 16, 2022 at 12:20:18PM -0500, will schmidt wrote:
> For PR100693, we currently provide an addg6s builtin using unsigned
> int arguments, but we are missing an unsigned long long argument
> equivalent. This patch adds an overload to provide the long long
> version of the builtin.
>
> unsigned long long __builtin_addg6s (unsigned long long, unsigned long long);
>
> RFC/concerns: This patch works, but looking briefly at intermediate stages
> is not behaving quite as I expected. Looking at the intermediate dumps, I
> see in pr100693.original that calls I expect to be routed to the internal
> __builtin_addg6s_si() that uses (unsigned int) arguments are instead being
> handled by __builtin_addg6s_di() with casts that convert the arguments to
> (unsigned long long).
Did you test with actual 32-bit variables, instead of just function
arguments? Function arguments are always passed in (sign-extended)
registers.
Like,
unsigned int f(unsigned int *a, unsigned int *b)
{
return __builtin_addg6s(*a, *b);
}
> As a test, I see if I swap the order of the builtins in rs6000-overload.def
> I end up with code casting the ULL values to UI, which provides truncated
> results, and is similar to what occurs today without this patch.
>
> All that said, this patch seems to work. OK for next stage 1?
> Tested on power8BE as well as LE power8,power9,power10.
Please ask again when stage 1 has started?
> gcc/
> PR target/100693
> * config/rs6000/rs600-builtins.def: Remove entry for __builtin_addgs()
> and add entries for __builtin_addg6s_di() and __builtin_addg6s_si().
Indent of second and further lines should be at the "*", not two spaces
after that.
> - UNSPEC_ADDG6S
> + UNSPEC_ADDG6S_SI
> + UNSPEC_ADDG6S_DI
You do not need multiple unspec numbers. You can differentiate them
based on the modes of the arguments, already :-)
> ;; Miscellaneous ISA 2.06 (power7) instructions
> -(define_insn "addg6s"
> +(define_insn "addg6s_si"
> [(set (match_operand:SI 0 "register_operand" "=r")
> (unspec:SI [(match_operand:SI 1 "register_operand" "r")
> (match_operand:SI 2 "register_operand" "r")]
> - UNSPEC_ADDG6S))]
> + UNSPEC_ADDG6S_SI))]
> + "TARGET_POPCNTD"
> + "addg6s %0,%1,%2"
> + [(set_attr "type" "integer")])
> +
> +(define_insn "addg6s_di"
> + [(set (match_operand:DI 0 "register_operand" "=r")
> + (unspec:DI [(match_operand:DI 1 "register_operand" "r")
> + (match_operand:DI 2 "register_operand" "r")]
> + UNSPEC_ADDG6S_DI))]
> "TARGET_POPCNTD"
> "addg6s %0,%1,%2"
> [(set_attr "type" "integer")])
(define_insn "addg6s"
[(set (match_operand:GPR 0 "register_operand" "=r")
(unspec:GPR [(match_operand:GPR 1 "register_operand" "r")
(match_operand:GPR 2 "register_operand" "r")]
UNSPEC_ADDG6S))]
"TARGET_POPCNTD"
"addg6s %0,%1,%2"
[(set_attr "type" "integer")])
We do not want DI (here, and in most places) for -m32!
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/pr100693.c
> @@ -0,0 +1,68 @@
> +/* { dg-do compile { target { powerpc*-*-linux* } } } */
Why only on Linux?
> +/* { dg-skip-if "" { powerpc*-*-darwin* } } */
Why not on Darwin? And why skip it anyway, given the previous line :-)
> +/* { dg-require-effective-target powerpc_vsx_ok } */
That is the wrong requirement. You want to test for Power7, not for
VSX. I realise you probably copied this from elsewhere :-( (If from
another addg6s testcase, just keep it).
Segher
