Re: [PATCH 1/5] sim: Allow toggling of quiet NaN-bit semantics

[Mike Frysinger <vapier@gentoo.org>]

On 20 May 2021 13:15, Faraz Shahbazker wrote:
> IEEE754-1985 specifies the top bit of the mantissa as an indicator
> of signalling vs. quiet NaN, but does not define the precise semantics.
> Most architectures treat this bit as indicating quiet NaN, but legacy
> (pre-R6) MIPS goes the other way and treats it as signalling NaN.
> 
> This used to be controlled by a macro that was only defined for MIPS.
> This patch replaces the macro with a variable to track the current
> semantics of the NaN bit and allows differentiation between older
> (pre-R6) and and newer MIPS cores.

looks good ... minor style nits

> --- a/sim/common/sim-fpu.c
> +++ b/sim/common/sim-fpu.c
> 
> +/* IEEE 754-1985 specifies the top bit of the mantissa as an indicator
> +   of signalling vs. quiet NaN, but does not specify the semantics.
> +   Most architectures treat this bit as quiet NaN, but legacy (pre-R6)
> +   MIPS goes the other way and treats it as signalling.  This variable
> +   tracks the current semantics of the NaN bit and allows differentiation
> +   between pre-R6 and R6 MIPS cores.  */
> +int sim_fpu_quiet_nan_inverted = 0;

we're C11 now, so we can assume stdbool.h.  so switch to bool/true/false.

> --- a/sim/common/sim-fpu.h
> +++ b/sim/common/sim-fpu.h
>  
> +/* Toggle quiet NaN semantics.  */
>  
> +extern int sim_fpu_quiet_nan_inverted;

omit the blank line between the two lines
-mike