Hi,
I have attached a patch for NSObject.m which adds the GCC atomic
increment/decrement operations, and also renames the 'modified:' labels in
the existing PPC assembly increment/decrement functions so that they will
now compile if they happen to be needed.
Eric
On Mon, Apr 13, 2009 at 5:58 AM, David Chisnall <[email protected]> wrote:
> Ooops, this one is my fault.
>
> Recent versions of GCC (and llvm-gcc / clang) support portable atomic
> intrinsics. I've checked these on x86 and x86-64, and they generate the
> same code that my inline asm uses. If you add this after the Windows bit
> (it will probably work on Windows too, but I'm not completely sure) then we
> will gain fast atomic operations on all platforms (e.g. SPARC / ARM) that
> support them when compiling with a recent compiler.
>
> David
>
> #elif __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)
> /* Use the GCC atomic operations with recent GCC versions */
>
> typedef int32_t volatile *gsatomic_t;
> #define GSATOMICREAD(X) (*(X))
> #define GSAtomicIncrement(X) __sync_fetch_and_add(X, 1)
> #define GSAtomicDecrement(X) __sync_fetch_and_sub(X, 1)
>
>
>
> On 13 Apr 2009, at 10:19, Eric Wasylishen wrote:
>
> Hi,
>> I ran in to a small problem when compiling GNUstep (svn trunk) on
>> Debian testing for PowerPC. GCC is "gcc (Debian 4.3.2-1.1) 4.3.2"
>>
>> Compiling file NSObject.m ...
>> /tmp/ccF8zgwE.s: Assembler messages:
>> /tmp/ccF8zgwE.s:730: Error: symbol `modified' is already defined
>> make[3]: *** [obj/NSObject.m.o] Error 1
>>
>> The PPC atomic increment and decrement functions starting at line 254
>> of NSObject.m both use the label 'modified:' in their asm code. I
>> found that by changing the labels in one of the functions to something
>> else ("modified2"), this error disappeared.
>>
>> I'm not sure if GCC is correct in reporting this as an error or not,
>> but it's easy to fix.
>> -Eric
>>
>>
>> _______________________________________________
>> Gnustep-dev mailing list
>> [email protected]
>> http://lists.gnu.org/mailman/listinfo/gnustep-dev
>>
>
>
Index: Source/NSObject.m
===================================================================
--- Source/NSObject.m (revision 28264)
+++ Source/NSObject.m (working copy)
@@ -218,7 +218,14 @@
#define GSAtomicIncrement(X) InterlockedIncrement((LONG volatile*)X)
#define GSAtomicDecrement(X) InterlockedDecrement((LONG volatile*)X)
+#elif __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)
+/* Use the GCC atomic operations with recent GCC versions */
+typedef int32_t volatile *gsatomic_t;
+#define GSATOMICREAD(X) (*(X))
+#define GSAtomicIncrement(X) __sync_fetch_and_add(X, 1)
+#define GSAtomicDecrement(X) __sync_fetch_and_sub(X, 1)
+
#elif defined(__linux__) && (defined(__i386__) || defined(__x86_64__))
/* Set up atomic read, increment and decrement for intel style linux
*/
@@ -256,11 +263,11 @@
{
int tmp;
__asm__ __volatile__ (
- "modified:"
+ "incmodified:"
"lwarx %0,0,%1 \n"
"addic %0,%0,1 \n"
"stwcx. %0,0,%1 \n"
- "bne- modified \n"
+ "bne- incmodified \n"
:"=&r" (tmp)
:"r" (X)
:"cc", "memory");
@@ -272,11 +279,11 @@
{
int tmp;
__asm__ __volatile__ (
- "modified:"
+ "decmodified:"
"lwarx %0,0,%1 \n"
"addic %0,%0,-1 \n"
"stwcx. %0,0,%1 \n"
- "bne- modified \n"
+ "bne- decmodified \n"
:"=&r" (tmp)
:"r" (X)
:"cc", "memory");
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