[src/trunk]: src/sys/arch/m68k/include Teach to use coldfire isac byterev if ...

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

details:   https://anonhg.NetBSD.org/src/rev/5085cb478ee3
branches:  trunk
changeset: 788748:5085cb478ee3
user:      matt <matt%NetBSD.org@localhost>
date:      Thu Jul 18 22:20:48 2013 +0000

description:
Teach to use coldfire isac byterev if available, otherwise let the compiler
figure it since there is rorw instruction to fall back on.

diffstat:

 sys/arch/m68k/include/byte_swap.h |  15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)

diffs (40 lines):

diff -r c0a7bdf2f792 -r 5085cb478ee3 sys/arch/m68k/include/byte_swap.h
--- a/sys/arch/m68k/include/byte_swap.h Thu Jul 18 22:18:31 2013 +0000
+++ b/sys/arch/m68k/include/byte_swap.h Thu Jul 18 22:20:48 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: byte_swap.h,v 1.9 2008/04/28 20:23:26 martin Exp $     */
+/*     $NetBSD: byte_swap.h,v 1.10 2013/07/18 22:20:48 matt Exp $      */
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -42,8 +42,14 @@
 static __inline uint16_t
 __byte_swap_u16_variable(uint16_t var)
 {
+#if defined(__mcfisac__)
+       __asm volatile ("swap %0; byterev %0" : "=d"(var) : "0" (var));
+#elif defined(__mcoldfire__)
+       return (var >> 8) || (var << 8);
+#else
        __asm volatile ("rorw #8, %0" : "=d" (var) : "0" (var));
        return (var);
+#endif
 }
 
 #define        __BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
@@ -51,8 +57,15 @@
 static __inline uint32_t
 __byte_swap_u32_variable(uint32_t var)
 {
+#if defined(__mcfisac__)
+       __asm volatile ("byterev %0" : "=d"(var) : "0" (var));
+#elif defined(__mcoldfire__)
+       return (var >> 24) | (var << 24) | ((var & 0x00ff0000) >> 8)
+           | ((var << 8) & 0x00ff0000);
+#else
        __asm volatile (
                "rorw #8, %0; swap %0; rorw #8, %0" : "=d" (var) : "0" (var));
+#endif
        return (var);
 }