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Re: Rewrite some jump.c routines to use flags
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: Richard Sandiford <richard dot sandiford at arm dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Fri, 12 Jul 2019 11:30:43 +0200
- Subject: Re: Rewrite some jump.c routines to use flags
- References: <mptsgrbhdzt.fsf@arm.com>
> +/* Invoke T (CODE, ORDER, SIGNEDNESS, CAN_TRAP) for each comparison, where:
> +
> + - CODE is the rtl comparison code
> + - ORDER is the OR of the conditions under which CODE returns true
> + - SIGNEDNESS is the signedness of COND, or 0 if it is sign-agnostic
> + - CAN_TRAP is true if CODE can trap on some forms of NaN. */
Are you talking about any NaNs here or just quiet NaNs? If the former, what's
the point to encode anything for signaling NaNs?
> +#define FOR_MAPPING(T) \
> + T (EQ, FLAGS_EQ, 0, true) \
> + T (NE, ~FLAGS_EQ, 0, true) \
This doesn't look correct: EQ and NE do not trap on quiet NaNs, unlike GT/LT.
--
Eric Botcazou