* sysdeps/sh/bits/atomic.h: Moved to ...

	* sysdeps/unix/sysv/linux/sh/bits/atomic.h: ... here.  Add comments.
	(__arch_compare_and_exchange_val_*_acq): Add parens around macro
        arguments.
	(atomic_bit_set, atomic_bit_test_set): Likewise.
	(atomic_exchange_and_add): Likewise.  Don't evaluate VALUE argument
	twice.
	(atomic_add, atomic_add_negative, atomic_add_zero): Likewise.

2 files changed, 74 insertions, 46 deletions

diff --git a/ChangeLog b/ChangeLog
index 3f054f8..e8d73f6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2002-04-06  Kaz Kojima  <kkojima@rr.iij4u.or.jp>
+
+	* sysdeps/sh/bits/atomic.h: Moved to ...
+	* sysdeps/unix/sysv/linux/sh/bits/atomic.h: ... here.  Add comments.
+	(__arch_compare_and_exchange_val_*_acq): Add parens around macro
+        arguments.
+	(atomic_bit_set, atomic_bit_test_set): Likewise.
+	(atomic_exchange_and_add): Likewise.  Don't evaluate VALUE argument
+	twice.
+	(atomic_add, atomic_add_negative, atomic_add_zero): Likewise.
+
 2003-04-06  Roland McGrath  <roland@redhat.com>
 
 	* sysdeps/unix/sysv/linux/i386/swapcontext.S: Rewrite register
diff --git a/sysdeps/sh/bits/atomic.h b/sysdeps/unix/sysv/linux/sh/bits/atomic.h
index d3725fc..e692595 100644
--- a/sysdeps/sh/bits/atomic.h
+++ b/sysdeps/unix/sysv/linux/sh/bits/atomic.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 2003 Free Software Foundation, Inc.
+/* Atomic operations used inside libc.  Linux/SH version.
+   Copyright (C) 2003 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -44,9 +45,28 @@ typedef uintptr_t uatomicptr_t;
 typedef intmax_t atomic_max_t;
 typedef uintmax_t uatomic_max_t;
 
+/* SH kernel has implemented a gUSA ("g" User Space Atomicity) support
+   for the user space atomicity. The atomicity macros use this scheme.
+
+  Reference:
+    Niibe Yutaka, "gUSA: Simple and Efficient User Space Atomicity
+    Emulation with Little Kernel Modification", Linux Conference 2002,
+    Japan. http://lc.linux.or.jp/lc2002/papers/niibe0919h.pdf (in
+    Japanese).
+
+    B.N. Bershad, D. Redell, and J. Ellis, "Fast Mutual Exclusion for
+    Uniprocessors",  Proceedings of the Fifth Architectural Support for
+    Programming Languages and Operating Systems (ASPLOS), pp. 223-233,
+    October 1992. http://www.cs.washington.edu/homes/bershad/Papers/Rcs.ps
+
+  SuperH ABI:
+      r15:    -(size of atomic instruction sequence) < 0
+      r0:     end point
+      r1:     saved stack pointer
+*/
 
 #define __arch_compare_and_exchange_val_8_acq(mem, newval, oldval) \
-  ({ __typeof (*mem) __result; \
+  ({ __typeof (*(mem)) __result; \
      __asm __volatile ("\
 	.align 2\n\
 	mova 1f,r0\n\
@@ -63,7 +83,7 @@ typedef uintmax_t uatomic_max_t;
      __result; })
 
 #define __arch_compare_and_exchange_val_16_acq(mem, newval, oldval) \
-  ({ __typeof (*mem) __result; \
+  ({ __typeof (*(mem)) __result; \
      __asm __volatile ("\
 	.align 2\n\
 	mova 1f,r0\n\
@@ -80,7 +100,7 @@ typedef uintmax_t uatomic_max_t;
      __result; })
 
 #define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \
-  ({ __typeof (*mem) __result; \
+  ({ __typeof (*(mem)) __result; \
      __asm __volatile ("\
 	.align 2\n\
 	mova 1f,r0\n\
@@ -105,9 +125,8 @@ typedef uintmax_t uatomic_max_t;
   (abort (), 0)
 
 #define atomic_exchange_and_add(mem, value) \
-  ({ __typeof (*mem) __result; \
-     __typeof (value) __value; \
-     if (sizeof (*mem) == 1) \
+  ({ __typeof (*(mem)) __result, __tmp, __value = (value); \
+     if (sizeof (*(mem)) == 1) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -117,9 +136,9 @@ typedef uintmax_t uatomic_max_t;
 	  add %0,%1\n\
 	  mov.b %1,@%2\n\
        1: mov r1,r15"\
-	: "=&r" (__result), "=&r" (__value) : "r" (mem), "1" (value) \
+	: "=&r" (__result), "=&r" (__tmp) : "r" (mem), "1" (__value) \
 	: "r0", "r1", "memory"); \
-     else if (sizeof (*mem) == 2) \
+     else if (sizeof (*(mem)) == 2) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -129,9 +148,9 @@ typedef uintmax_t uatomic_max_t;
 	  add %0,%1\n\
 	  mov.w %1,@%2\n\
        1: mov r1,r15"\
-	: "=&r" (__result), "=&r" (__value) : "r" (mem), "1" (value) \
+	: "=&r" (__result), "=&r" (__tmp) : "r" (mem), "1" (__value) \
 	: "r0", "r1", "memory"); \
-     else if (sizeof (*mem) == 4) \
+     else if (sizeof (*(mem)) == 4) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -141,23 +160,22 @@ typedef uintmax_t uatomic_max_t;
 	  add %0,%1\n\
 	  mov.l %1,@%2\n\
        1: mov r1,r15"\
-	: "=&r" (__result), "=&r" (__value) : "r" (mem), "1" (value) \
+	: "=&r" (__result), "=&r" (__tmp) : "r" (mem), "1" (__value) \
 	: "r0", "r1", "memory"); \
      else \
        { \
-	 __typeof (value) addval = (value); \
 	 __typeof (mem) memp = (mem); \
 	 do \
 	   __result = *memp; \
 	 while (__arch_compare_and_exchange_val_64_acq \
-		 (memp,	__result + addval, __result) == __result); \
-	 (void) addval; \
+		 (memp,	__result + __value, __result) == __result); \
+	 (void) __value; \
        } \
      __result; })
 
 #define atomic_add(mem, value) \
-  (void) ({ __typeof (value) __value; \
-	    if (sizeof (*mem) == 1) \
+  (void) ({ __typeof (*(mem)) __tmp, __value = (value); \
+	    if (sizeof (*(mem)) == 1) \
 	      __asm __volatile ("\
 		.align 2\n\
 		mova 1f,r0\n\
@@ -167,9 +185,9 @@ typedef uintmax_t uatomic_max_t;
 		add r2,%0\n\
 		mov.b %0,@%1\n\
 	     1: mov r1,r15"\
-		: "=&r" (__value) : "r" (mem), "0" (value) \
+		: "=&r" (__tmp) : "r" (mem), "0" (__value) \
 		: "r0", "r1", "r2", "memory"); \
-	    else if (sizeof (*mem) == 2) \
+	    else if (sizeof (*(mem)) == 2) \
 	      __asm __volatile ("\
 		.align 2\n\
 		mova 1f,r0\n\
@@ -179,9 +197,9 @@ typedef uintmax_t uatomic_max_t;
 		add r2,%0\n\
 		mov.w %0,@%1\n\
 	     1: mov r1,r15"\
-		: "=&r" (__value) : "r" (mem), "0" (value) \
+		: "=&r" (__tmp) : "r" (mem), "0" (__value) \
 		: "r0", "r1", "r2", "memory"); \
-	    else if (sizeof (*mem) == 4) \
+	    else if (sizeof (*(mem)) == 4) \
 	      __asm __volatile ("\
 		.align 2\n\
 		mova 1f,r0\n\
@@ -191,25 +209,24 @@ typedef uintmax_t uatomic_max_t;
 		add r2,%0\n\
 		mov.l %0,@%1\n\
 	     1: mov r1,r15"\
-		: "=&r" (__value) : "r" (mem), "0" (value) \
+		: "=&r" (__tmp) : "r" (mem), "0" (__value) \
 		: "r0", "r1", "r2", "memory"); \
 	    else \
 	      { \
-		__typeof (value) addval = (value); \
-		__typeof (*mem) oldval; \
+		__typeof (*(mem)) oldval; \
 		__typeof (mem) memp = (mem); \
 		do \
 		  oldval = *memp; \
 		while (__arch_compare_and_exchange_val_64_acq \
-			(memp, oldval + addval, oldval) == oldval); \
-		(void) addval; \
+			(memp, oldval + __value, oldval) == oldval); \
+		(void) __value; \
 	      } \
 	    })
 
 #define atomic_add_negative(mem, value) \
   ({ unsigned char __result; \
-     __typeof (value) __value; \
-     if (sizeof (*mem) == 1) \
+     __typeof (*(mem)) __tmp, __value = (value); \
+     if (sizeof (*(mem)) == 1) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -221,9 +238,9 @@ typedef uintmax_t uatomic_max_t;
        1: mov r1,r15\n\
 	  shal %1\n\
 	  movt %0"\
-	: "=r" (__result), "=&r" (__value) : "r" (mem), "1" (value) \
+	: "=r" (__result), "=&r" (__tmp) : "r" (mem), "1" (__value) \
 	: "r0", "r1", "r2", "t", "memory"); \
-     else if (sizeof (*mem) == 2) \
+     else if (sizeof (*(mem)) == 2) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -235,9 +252,9 @@ typedef uintmax_t uatomic_max_t;
        1: mov r1,r15\n\
 	  shal %1\n\
 	  movt %0"\
-	: "=r" (__result), "=&r" (__value) : "r" (mem), "1" (value) \
+	: "=r" (__result), "=&r" (__tmp) : "r" (mem), "1" (__value) \
 	: "r0", "r1", "r2", "t", "memory"); \
-     else if (sizeof (*mem) == 4) \
+     else if (sizeof (*(mem)) == 4) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -249,7 +266,7 @@ typedef uintmax_t uatomic_max_t;
        1: mov r1,r15\n\
 	  shal %1\n\
 	  movt %0"\
-	: "=r" (__result), "=&r" (__value) : "r" (mem), "1" (value) \
+	: "=r" (__result), "=&r" (__tmp) : "r" (mem), "1" (__value) \
 	: "r0", "r1", "r2", "t", "memory"); \
      else \
        abort (); \
@@ -257,8 +274,8 @@ typedef uintmax_t uatomic_max_t;
 
 #define atomic_add_zero(mem, value) \
   ({ unsigned char __result; \
-     __typeof (value) __value; \
-     if (sizeof (*mem) == 1) \
+     __typeof (*(mem)) __tmp, __value = (value); \
+     if (sizeof (*(mem)) == 1) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -270,9 +287,9 @@ typedef uintmax_t uatomic_max_t;
        1: mov r1,r15\n\
 	  tst %1,%1\n\
 	  movt %0"\
-	: "=r" (__result), "=&r" (__value) : "r" (mem), "1" (value) \
+	: "=r" (__result), "=&r" (__tmp) : "r" (mem), "1" (__value) \
 	: "r0", "r1", "r2", "t", "memory"); \
-     else if (sizeof (*mem) == 2) \
+     else if (sizeof (*(mem)) == 2) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -284,9 +301,9 @@ typedef uintmax_t uatomic_max_t;
        1: mov r1,r15\n\
 	  tst %1,%1\n\
 	  movt %0"\
-	: "=r" (__result), "=&r" (__value) : "r" (mem), "1" (value) \
+	: "=r" (__result), "=&r" (__tmp) : "r" (mem), "1" (__value) \
 	: "r0", "r1", "r2", "t", "memory"); \
-     else if (sizeof (*mem) == 4) \
+     else if (sizeof (*(mem)) == 4) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -298,7 +315,7 @@ typedef uintmax_t uatomic_max_t;
        1: mov r1,r15\n\
 	  tst %1,%1\n\
 	  movt %0"\
-	: "=r" (__result), "=&r" (__value) : "r" (mem), "1" (value) \
+	: "=r" (__result), "=&r" (__tmp) : "r" (mem), "1" (__value) \
 	: "r0", "r1", "r2", "t", "memory"); \
      else \
        abort (); \
@@ -309,7 +326,7 @@ typedef uintmax_t uatomic_max_t;
 
 #define atomic_bit_set(mem, bit) \
   (void) ({ unsigned int __mask = 1 << (bit); \
-	    if (sizeof (*mem) == 1) \
+	    if (sizeof (*(mem)) == 1) \
 	      __asm __volatile ("\
 		.align 2\n\
 		mova 1f,r0\n\
@@ -321,7 +338,7 @@ typedef uintmax_t uatomic_max_t;
 	     1: mov r1,r15"\
 		: : "r" (mem), "r" (__mask) \
 		: "r0", "r1", "r2", "memory"); \
-	    else if (sizeof (*mem) == 2) \
+	    else if (sizeof (*(mem)) == 2) \
 	      __asm __volatile ("\
 		.align 2\n\
 		mova 1f,r0\n\
@@ -333,7 +350,7 @@ typedef uintmax_t uatomic_max_t;
 	     1: mov r1,r15"\
 		: : "r" (mem), "r" (__mask) \
 		: "r0", "r1", "r2", "memory"); \
-	    else if (sizeof (*mem) == 4) \
+	    else if (sizeof (*(mem)) == 4) \
 	      __asm __volatile ("\
 		.align 2\n\
 		mova 1f,r0\n\
@@ -352,7 +369,7 @@ typedef uintmax_t uatomic_max_t;
 #define atomic_bit_test_set(mem, bit) \
   ({ unsigned int __mask = 1 << (bit); \
      unsigned int __result = __mask; \
-     if (sizeof (*mem) == 1) \
+     if (sizeof (*(mem)) == 1) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -367,7 +384,7 @@ typedef uintmax_t uatomic_max_t;
 	: "=&r" (__result), "=&r" (__mask) \
 	: "r" (mem), "0" (__result), "1" (__mask) \
 	: "r0", "r1", "r2", "memory"); \
-     else if (sizeof (*mem) == 2) \
+     else if (sizeof (*(mem)) == 2) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\
@@ -382,7 +399,7 @@ typedef uintmax_t uatomic_max_t;
 	: "=&r" (__result), "=&r" (__mask) \
 	: "r" (mem), "0" (__result), "1" (__mask) \
 	: "r0", "r1", "r2", "memory"); \
-     else if (sizeof (*mem) == 4) \
+     else if (sizeof (*(mem)) == 4) \
        __asm __volatile ("\
 	  .align 2\n\
 	  mova 1f,r0\n\