Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Move some comments from before npxsave1() to before npxsave().

This commit is contained in:
mycroft 1995-05-04 00:00:25 +00:00
parent bfef4c14c5
commit e03a827a0a
1 changed files with 10 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
sys/arch/i386/isa/npx.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: npx.c,v 1.39 1995/05/03 23:09:37 mycroft Exp $ */ /* $NetBSD: npx.c,v 1.40 1995/05/04 00:00:25 mycroft Exp $ */
#if 0 #if 0
#define iprintf(x) printf x #define iprintf(x) printf x
@ -470,12 +470,6 @@ npxintr(arg)
* This routine is always called at spl0. If it might called with the NPX * This routine is always called at spl0. If it might called with the NPX
* interrupt masked, it would be necessary to forcibly unmask the NPX interrupt * interrupt masked, it would be necessary to forcibly unmask the NPX interrupt
* so that it could succeed. * so that it could succeed.
*
* The FNSAVE instruction clears the FPU state. Rather than reloading the FPU
* immediately, we clear npxproc and turn on CR0_TS to force a DNA and a reload
* of the FPU state the next time we try to use it. Since this routine is only
* called when forking, so this algorithm at worst forces us to trap once per
* fork(), and at best saves us a reload once per fork().
*/ */
static inline void static inline void
npxsave1() npxsave1()
@ -543,6 +537,15 @@ npxdna()
return (1); return (1);
} }
/*
* Save npxproc's FPU state.
*
* The FNSAVE instruction clears the FPU state. Rather than reloading the FPU
* immediately, we clear npxproc and turn on CR0_TS to force a DNA and a reload
* of the FPU state the next time we try to use it. This routine is only
* called when forking or core dump, so this algorithm at worst forces us to
* trap once per fork(), and at best saves us a reload once per fork().
*/
void void
npxsave() npxsave()
{ {