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Re: scratch/X_Typedefs 09c65d6 5/7: Introduce Emacs_GC struct and typede


From: Alex Gramiak
Subject: Re: scratch/X_Typedefs 09c65d6 5/7: Introduce Emacs_GC struct and typedef
Date: Wed, 15 May 2019 12:59:28 -0600
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux)

Eli Zaretskii <address@hidden> writes:

> Thanks, it builds now.
>
> Regarding the patch, I have only one comment:
>
>> @@ -1289,7 +1317,7 @@ struct glyph_string
>>    enum glyph_row_area area;
>> 
>>    /* Characters to be drawn, and number of characters.  */
>> -  XChar2b *char2b;
>> +  unsigned short *char2b;
>>    int nchars;
>
> Why use 'unsigned short' and not 'unsigned int'?  The latter is more
> efficient on modern architectures, and in structures you will likely
> have the compiler pad the following 16 bits anyway.

I thought that it would be better to only use a (minimum) 16-bit
unsigned if that's all that is needed. If it's more efficient to use
unsigned then that's even better, since some loops and alloca calls in,
e.g., {x,w32}_compute_glyph_string_overhangs can be removed.

I'll change the type to unsigned and merge the branch later if there are
no objections.



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