[src/trunk]: src/lib/libc/arch/aarch64/gen Update comments to help explain wh...

[skrll <skrll%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/157d764fb030
branches:  trunk
changeset: 994821:157d764fb030
user:      skrll <skrll%NetBSD.org@localhost>
date:      Fri Nov 23 12:39:18 2018 +0000

description:
Update comments to help explain what's going on

diffstat:

 lib/libc/arch/aarch64/gen/swapcontext.S |  8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diffs (33 lines):

diff -r a97a7b508443 -r 157d764fb030 lib/libc/arch/aarch64/gen/swapcontext.S
--- a/lib/libc/arch/aarch64/gen/swapcontext.S   Fri Nov 23 12:15:14 2018 +0000
+++ b/lib/libc/arch/aarch64/gen/swapcontext.S   Fri Nov 23 12:39:18 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: swapcontext.S,v 1.3 2018/11/23 11:38:07 skrll Exp $ */
+/* $NetBSD: swapcontext.S,v 1.4 2018/11/23 12:39:18 skrll Exp $ */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -33,7 +33,7 @@
 #include "assym.h"
 
 #if defined(LIBC_SCCS) && !defined(lint)
-        RCSID("$NetBSD: swapcontext.S,v 1.3 2018/11/23 11:38:07 skrll Exp $")
+        RCSID("$NetBSD: swapcontext.S,v 1.4 2018/11/23 12:39:18 skrll Exp $")
 #endif /* LIBC_SCCS && !lint */
 
 /* LINTSTUB: int swapcontext(ucontext_t * restrict, ucontext_t * restrict); */
@@ -42,12 +42,12 @@
        sub     sp, sp, #32             /* allocate stack frame */
        stp     x29, x30, [sp, #16]     /* save FP & LR */
        add     x29, sp, #16            /* new FP */
-       stp     x0, x1, [sp, #0]        /* save oucp & ucp */
+       stp     x0, x1, [sp, #0]        /* save oucp (x0) & ucp (x1) */
 
        bl      _C_LABEL(_getcontext)   /* getcontext(oucp) */
        mov     x3, x0                  /* save return value */
 
-       ldp     x2, x0, [sp, #0]        /* restore oucp & ucp */
+       ldp     x2, x0, [sp, #0]        /* load oucp (x2) & ucp (x0) */
        ldp     x29, x30, [sp, #16]     /* restore FP & LR */
        add     sp, sp, #32             /* free stack frame */