On Mon, Mar 23, 2020 at 06:00:06PM -0600, Jeff Law via Gcc-patches wrote:
> +/* Return true if CODE is valid for comparisons of mode MODE, false
> + otherwise.
> +
> + It is always safe to return false, even if the code was valid for the
> + given mode as that will merely suppress optimizations. */
> +
> +static bool
> +comparison_code_valid_for_mode (enum rtx_code code, enum machine_mode mode)
> +{
> + switch (code)
> + {
> + /* These are valid for integral, floating and vector modes. */
> + case NE:
> + case EQ:
> + case GE:
> + case GT:
> + case LE:
> + case LT:
> + return (INTEGRAL_MODE_P (mode)
> + || FLOAT_MODE_P (mode)
> + || VECTOR_MODE_P (mode));
I'm not sure I understand the VECTOR_MODE_P cases.
INTEGRAL_MODE_P or FLOAT_MODE_P already do include vector modes with the
corresponding element types.
And if you want the {,u}{fract,accum} modes for some of these, shouldn't
they apply to both scalar and vector modes thereof?
So, either drop the || VECTOR_MODE_P (mode), or use
|| ALL_FRACT_MODE_P (mode) || ALL_ACCUM_MODE_P (mode)
instead?
> +
> + /* These are valid for floating point modes. */
> + case LTGT:
> + case UNORDERED:
> + case ORDERED:
> + case UNEQ:
> + case UNGE:
> + case UNGT:
> + case UNLE:
> + case UNLT:
> + return FLOAT_MODE_P (mode);
This will do the right thing, i.e. allow it for both floating scalar and
vector modes.
> + /* These are filtered out in simplify_logical_operation, but
> + we check for them too as a matter of safety. They are valid
> + for integral and vector modes. */
> + case GEU:
> + case GTU:
> + case LEU:
> + case LTU:
> + return INTEGRAL_MODE_P (mode) || VECTOR_MODE_P (mode);
This doesn't look right. I don't know what the fract/accum modes want, but
you don't want to return true for GET_MODE_CLASS (mode) ==
MODE_VECTOR_FLOAT, do you?
Jakub
