X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=includes%2FSMP.h;h=b7538424b9aa6d9050a55347ec81ccb3b1193661;hb=f4e682c8f54a70cacbc412c1bd24cf619e1023e7;hp=c851054cd90d3f2adc685a7d02756a32f83f8fca;hpb=a67183b75f1527edd88b071b879c2d07e8ac7653;p=ghc-hetmet.git

diff --git a/includes/SMP.h b/includes/SMP.h
index c851054..b753842 100644
--- a/includes/SMP.h
+++ b/includes/SMP.h
@@ -18,7 +18,7 @@
 
 #if defined(THREADED_RTS)
 
-#if  defined(TICKY_TICKY)
+#if defined(TICKY_TICKY)
 #error Build options incompatible with THREADED_RTS.
 #endif
 
@@ -52,6 +52,24 @@ EXTERN_INLINE StgWord xchg(StgPtr p, StgWord w);
  */
 EXTERN_INLINE StgWord cas(StgVolatilePtr p, StgWord o, StgWord n);
 
+/*
+ * Atomic increment
+ *
+ * atomic_inc(p) {
+ *   return ++(*p);
+ * }
+ */
+EXTERN_INLINE StgWord atomic_inc(StgVolatilePtr p);
+
+/*
+ * Atomic decrement
+ *
+ * atomic_dec(p) {
+ *   return --(*p);
+ * }
+ */
+EXTERN_INLINE StgWord atomic_dec(StgVolatilePtr p);
+
 #endif // !IN_STG_CODE
 
 /*
@@ -164,6 +182,48 @@ cas(StgVolatilePtr p, StgWord o, StgWord n)
 #endif
 }
 
+EXTERN_INLINE StgWord
+atomic_inc(StgVolatilePtr p)
+{
+#if defined(i386_HOST_ARCH) || defined(x86_64_HOST_ARCH)
+    StgWord r;
+    r = 1;
+    __asm__ __volatile__ (
+        "lock\nxadd %0,%1":
+            "+r" (r), "+m" (*p):
+    );
+    return r+1;
+#else
+    StgWord old, new;
+    do {
+        old = *p;
+        new = old + 1;
+    } while (cas(p, old, new) != old);
+    return new;
+#endif
+}
+
+EXTERN_INLINE StgWord
+atomic_dec(StgVolatilePtr p)
+{
+#if defined(i386_HOST_ARCH) || defined(x86_64_HOST_ARCH)
+    StgWord r;
+    r = (StgWord)-1;
+    __asm__ __volatile__ (
+        "lock\nxadd %0,%1":
+            "+r" (r), "+m" (*p):
+    );
+    return r-1;
+#else
+    StgWord old, new;
+    do {
+        old = *p;
+        new = old - 1;
+    } while (cas(p, old, new) != old);
+    return new;
+#endif
+}
+
 #endif // !IN_STG_CODE
 
 /*
@@ -179,7 +239,7 @@ write_barrier(void) {
 #elif powerpc_HOST_ARCH
     __asm__ __volatile__ ("lwsync" : : : "memory");
 #elif sparc_HOST_ARCH
-    /* Sparc in TSO mode does not require write/write barriers. */
+    /* Sparc in TSO mode does not require store/store barriers. */
     __asm__ __volatile__ ("" : : : "memory");
 #elif !defined(WITHSMP)
     return;
@@ -195,10 +255,9 @@ store_load_barrier(void) {
 #elif x86_64_HOST_ARCH
     __asm__ __volatile__ ("lock; addq $0,0(%%rsp)" : : : "memory");
 #elif powerpc_HOST_ARCH
-    __asm__ __volatile__ ("msync" : : : "memory");
+    __asm__ __volatile__ ("sync" : : : "memory");
 #elif sparc_HOST_ARCH
-    /* Sparc in TSO mode does not require write/write barriers. */
-    __asm__ __volatile__ ("membar" : : : "memory");
+    __asm__ __volatile__ ("membar #StoreLoad" : : : "memory");
 #elif !defined(WITHSMP)
     return;
 #else
@@ -215,7 +274,7 @@ load_load_barrier(void) {
 #elif powerpc_HOST_ARCH
     __asm__ __volatile__ ("lwsync" : : : "memory");
 #elif sparc_HOST_ARCH
-    /* Sparc in TSO mode does not require write/write barriers. */
+    /* Sparc in TSO mode does not require load/load barriers. */
     __asm__ __volatile__ ("" : : : "memory");
 #elif !defined(WITHSMP)
     return;
@@ -250,6 +309,18 @@ cas(StgVolatilePtr p, StgWord o, StgWord n)
     return result;
 }
 
+INLINE_HEADER StgWord
+atomic_inc(StgVolatilePtr p)
+{
+    return ++(*p);
+}
+
+INLINE_HEADER StgWord
+atomic_dec(StgVolatilePtr p)
+{
+    return --(*p);
+}
+
 #endif /* !THREADED_RTS */
 
 #endif /* SMP_H */