Fix: x86 and s390: uatomic __hp() macro clang support

[urcu.git] / include / urcu / uatomic / s390.h

diff --git a/include/urcu/uatomic/s390.h b/include/urcu/uatomic/s390.h
index 62561e000224ccb4c71e244a239eab5ac730f70b..d7d545ad8f869ede493edef727233d7e9edc42ad 100644 (file)
--- a/include/urcu/uatomic/s390.h
+++ b/include/urcu/uatomic/s390.h
@@ -61,10 +61,15 @@ extern "C" {
 
 #endif /* !COMPILER_HAVE_SHORT_MEM_OPERAND */
 
-struct __uatomic_dummy {
-       unsigned long v[10];
-};
-#define __hp(x)        ((struct __uatomic_dummy *)(x))
+/*
+ * The __hp() macro casts the void pointer @x to a pointer to a structure
+ * containing an array of char of the specified size. This allows passing the
+ * @addr arguments of the following inline functions as "m" and "+m" operands
+ * to the assembly. The @size parameter should be a constant to support
+ * compilers such as clang which do not support VLA.
+ */
+
+#define __hp(size, x)  ((struct { char v[size]; } *)(x))
 
 /* xchg */
 
@@ -79,8 +84,8 @@ unsigned long _uatomic_exchange(volatile void *addr, unsigned long val, int len)
                __asm__ __volatile__(
                        "0:     cs %0,%2," MEMOP_REF(%3) "\n"
                        "       brc 4,0b\n"
-                       : "=&r" (old_val), MEMOP_OUT (__hp(addr))
-                       : "r" (val), MEMOP_IN (__hp(addr))
+                       : "=&r" (old_val), MEMOP_OUT (__hp(4, addr))
+                       : "r" (val), MEMOP_IN (__hp(4, addr))
                        : "memory", "cc");
                return old_val;
        }
@@ -92,8 +97,8 @@ unsigned long _uatomic_exchange(volatile void *addr, unsigned long val, int len)
                __asm__ __volatile__(
                        "0:     csg %0,%2," MEMOP_REF(%3) "\n"
                        "       brc 4,0b\n"
-                       : "=&r" (old_val), MEMOP_OUT (__hp(addr))
-                       : "r" (val), MEMOP_IN (__hp(addr))
+                       : "=&r" (old_val), MEMOP_OUT (__hp(8, addr))
+                       : "r" (val), MEMOP_IN (__hp(8, addr))
                        : "memory", "cc");
                return old_val;
        }
@@ -123,8 +128,8 @@ unsigned long _uatomic_cmpxchg(void *addr, unsigned long old,
 
                __asm__ __volatile__(
                        "       cs %0,%2," MEMOP_REF(%3) "\n"
-                       : "+r" (old_val), MEMOP_OUT (__hp(addr))
-                       : "r" (_new), MEMOP_IN (__hp(addr))
+                       : "+r" (old_val), MEMOP_OUT (__hp(4, addr))
+                       : "r" (_new), MEMOP_IN (__hp(4, addr))
                        : "memory", "cc");
                return old_val;
        }
@@ -133,8 +138,8 @@ unsigned long _uatomic_cmpxchg(void *addr, unsigned long old,
        {
                __asm__ __volatile__(
                        "       csg %0,%2," MEMOP_REF(%3) "\n"
-                       : "+r" (old), MEMOP_OUT (__hp(addr))
-                       : "r" (_new), MEMOP_IN (__hp(addr))
+                       : "+r" (old), MEMOP_OUT (__hp(8, addr))
+                       : "r" (_new), MEMOP_IN (__hp(8, addr))
                        : "memory", "cc");
                return old;
        }