[src/netbsd-6]: src/sys/arch/arm/include Pull up following revision(s) (reque...

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

details:   https://anonhg.NetBSD.org/src/rev/a178dca1fd90
branches:  netbsd-6
changeset: 774596:a178dca1fd90
user:      riz <riz%NetBSD.org@localhost>
date:      Thu Sep 13 20:28:15 2012 +0000

description:
Pull up following revision(s) (requested by martin in ticket #542):
        sys/arch/arm/include/byte_swap.h: revision 1.12
Disable arm32 __asm for _byte_swap_u16_variable since gcc4.5 produces
decent code for it.  Fixes PR/46898.

diffstat:

 sys/arch/arm/include/byte_swap.h |  40 +++++++++++++++++++++++++---------------
 1 files changed, 25 insertions(+), 15 deletions(-)

diffs (69 lines):

diff -r 6fa1bcf72ae7 -r a178dca1fd90 sys/arch/arm/include/byte_swap.h
--- a/sys/arch/arm/include/byte_swap.h  Thu Sep 13 20:20:15 2012 +0000
+++ b/sys/arch/arm/include/byte_swap.h  Thu Sep 13 20:28:15 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: byte_swap.h,v 1.8 2008/04/28 20:23:14 martin Exp $     */
+/*     $NetBSD: byte_swap.h,v 1.8.40.1 2012/09/13 20:28:15 riz Exp $   */
 
 /*-
  * Copyright (c) 1997, 1999, 2002 The NetBSD Foundation, Inc.
@@ -40,16 +40,20 @@
 static __inline uint32_t
 __byte_swap_u32_variable(uint32_t v)
 {
+       uint32_t t1;
+
 #ifdef _ARM_ARCH_6
-       __asm("rev\t%0, %1" : "=r" (v) : "0" (v));
-#else
-       uint32_t t1;
+       if (!__builtin_constant_p(v)) {
+               __asm("rev\t%0, %1" : "=r" (v) : "0" (v));
+               return v;
+       }
+#endif
 
        t1 = v ^ ((v << 16) | (v >> 16));
        t1 &= 0xff00ffffU;
        v = (v >> 8) | (v << 24);
        v ^= (t1 >> 8);
-#endif
+
        return (v);
 }
 
@@ -59,18 +63,24 @@
 {
 
 #ifdef _ARM_ARCH_6
-       __asm("rev16\t%0, %1" : "=r" (v) : "0" (v));
-#elif !defined(__thumb__)
-       __asm volatile(
-               "mov    %0, %1, ror #8\n"
-               "orr    %0, %0, %0, lsr #16\n"
-               "bic    %0, %0, %0, lsl #16"
-       : "=r" (v)
-       : "0" (v));
-#else
+       if (!__builtin_constant_p(v)) {
+               __asm("rev16\t%0, %1" : "=r" (v) : "0" (v));
+               return v;
+       }
+#elif !defined(__thumb__) && 0 /* gcc produces decent code for this */
+       if (!__builtin_constant_p(v)) {
+               uint32_t v0 = v;
+               __asm volatile(
+                       "mov    %0, %1, ror #8\n"
+                       "orr    %0, %0, %0, lsr #16\n"
+                       "bic    %0, %0, %0, lsl #16"
+               : "=&r" (v0)
+               : "0" (v0));
+               return v0;
+       }
+#endif
        v &= 0xffff;
        v = (v >> 8) | (v << 8);
-#endif
 
        return (v);
 }