configure.target: Fix comment for mips atomicity.

2002-07-08  Eric Christopher  <echristo@redhat.com>

	* configure.target: Fix comment for mips atomicity. Add
	mips*-*-linux* target, enable atomic operations there.
	* config/cpu/mips/atomicity.h: Fix comments, remove
	#ifndef/#endif. Add push/pop mips2.

From-SVN: r55331

libstdc++-v3/config/cpu/mips/atomicity.h

-// Low-level functions for atomic operations. MIPS II version.
+// Low-level functions for atomic operations.
 
-// Copyright (C) 2001 Free Software Foundation, Inc.
+// Copyright (C) 2001, 2002 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
@@ -27,12 +27,9 @@
 // invalidate any other reasons why the executable file might be covered by
 // the GNU General Public License.
 
-#ifndef _BITS_ATOMICITY_H 
+#ifndef _BITS_ATOMICITY_H
 #define _BITS_ATOMICITY_H 1
 
-// #include <sgidefs.h>
-// #ifdef (_MIPS_ISA_MIPS2)
-
 typedef int _Atomic_word;
 
 static inline int
@@ -44,9 +41,12 @@ __exchange_and_add (volatile _Atomic_word *__mem, int __val)
   __asm__ __volatile__
     ("/* Inline exchange & add */\n\t"
      "1:\n\t"
+     ".set	push\n\t"
+     ".set	mips2\n\t"
      "ll	%0,%3\n\t"
      "addu	%1,%4,%0\n\t"
      "sc	%1,%2\n\t"
+     ".set	pop\n\t"
      "beqz	%1,1b\n\t"
      "/* End exchange & add */"
      : "=&r"(__result), "=&r"(__tmp), "=m"(*__mem)
@@ -65,9 +65,12 @@ __atomic_add (volatile _Atomic_word *__mem, int __val)
   __asm__ __volatile__
     ("/* Inline atomic add */\n\t"
      "1:\n\t"
+     ".set	push\n\t"
+     ".set	mips2\n\t"
      "ll	%0,%2\n\t"
      "addu	%0,%3,%0\n\t"
      "sc	%0,%1\n\t"
+     ".set	pop\n\t"
      "beqz	%0,1b\n\t"
      "/* End atomic add */"
      : "=&r"(__result), "=m"(*__mem)

libstdc++-v3/configure.target

@@ -28,7 +28,7 @@
 #
 #   c_model                the model to use for "C" headers, defaults to c_std.
 #
-#   c_compatibility        if "C" compatibility headers are necessary, 
+#   c_compatibility        if "C" compatibility headers are necessary,
 #                              defaults to no.
 #
 # It possibly modifies the following variables:
@@ -58,10 +58,10 @@ c_model=c_std
 c_compatibility=no
 
 
-# TARGET-SPECIFIC OVERRIDES 
+# TARGET-SPECIFIC OVERRIDES
 # Set any CPU-dependent bits.
 # Here we override defaults and catch more general cases due to naming
-# conventions (e.g., chip_name* to catch all variants).  
+# conventions (e.g., chip_name* to catch all variants).
 # THIS TABLE IS SORTED.  KEEP IT THAT WAY.
 case "${target_cpu}" in
   alpha*)
@@ -77,8 +77,9 @@ case "${target_cpu}" in
   m68k | m680[246]0)
     cpu_include_dir="cpu/m68k"
     ;;
-  mips)
-    # This is only until the mips routines are fixed.
+  mips*)
+    # MIPS chips are unreliable as to sc/ll support. By default
+    # don't use atomic instructions and override for the OS.
     cpu_include_dir="cpu/generic"
     ;;
   mmix)
@@ -123,7 +124,7 @@ unset _cpu_incdir_fullpath
 
 
 # Set any OS-dependent bits.
-# Set the os_include_dir.  
+# Set the os_include_dir.
 # Set c_model, c_compatibility here.
 # If atomic ops and/or numeric limits are OS-specific rather than
 # CPU-specifc, set those here too.
@@ -202,5 +203,7 @@ case "${target}" in
   alpha*-*-*osf5*)
     CPULIMITSH="os/osf/osf5.0"
     ;;
+  mips*-*-linux*)
+    ATOMICITYH="cpu/mips"
+    ;;
 esac
-