Changeset 1289 for trunk/src/emx/include/386/builtin.h

Timestamp:

Mar 15, 2004, 2:50:57 AM (21 years ago)

Author:

bird

Message:

o Logging and strict features.
o #967: TLS implementation.

File:

• trunk/src/emx/include/386/builtin.h (modified) (1 diff, 1 prop)

trunk/src/emx/include/386/builtin.h ¶

@@ -39 +39 @@
   __asm__ __volatile__ ("cli");
 }
+
+/**
+ * Atomically sets a bit and return the old one.
+ *
+ * @returns 1 if the bit was set, 0 if it was clear.
+ * @param   pv      Pointer to base of bitmap.
+ * @param   uBit    Bit in question.
+ */
+static __inline__ int __atomic_set_bit(__volatile__ void *pv, unsigned uBit)
+{
+    int rc;
+    __asm__ __volatile__("lock btsl %2, %1\n\t"
+                         "sbbl %0,%0"
+                         : "=r" (rc),
+                           "=m" (*(__volatile__ unsigned *)pv)
+                         : "r" (uBit)
+                         : "memory");
+    return rc;
+}
+
+
+/**
+ * Atomically clears a bit.
+ *
+ * @param   pv      Pointer to base of bitmap.
+ * @param   uBit    Bit in question.
+ */
+static __inline__ void __atomic_clear_bit(__volatile__ void *pv, unsigned uBit)
+{
+    __asm__ __volatile__("lock btrl %1, %0"
+                         : "=m" (*(__volatile__ unsigned *)pv)
+                         : "r" (uBit));
+}
+
+
+/**
+ * Atomically (er?) tests if a bit is set.
+ *
+ * @returns non zero if the bit was set.
+ * @returns 0 if the bit was clear.
+ * @param   pv      Pointer to base of bitmap.
+ * @param   uBit    Bit in question.
+ */
+static __inline__ int __atomic_test_bit(const __volatile__ void *pv, unsigned uBit)
+{
+    __asm__ __volatile__("btl %0, %1\n\t"
+                         "sbbl %0, %0\t\n"
+                         : "=r" (uBit)
+                         : "m"  (*(const __volatile__ unsigned *)pv));
+    return uBit;
+}
+
+
+/**
+ * Atomically increments a 32-bit unsigned value.
+ *
+ * @param   pu      Pointer to the value to increment.
+ */
+static __inline__ void __atomic_increment(__volatile__ unsigned *pu)
+{
+    __asm__ __volatile__("lock incl %0"
+                         : "=m" (*pu));
+}
+
+/**
+ * Atomically decrements a 32-bit unsigned value.
+ *
+ * @param   pu      Pointer to the value to decrement.
+ */
+static __inline__ void __atomic_decrement(__volatile__ unsigned *pu)
+{
+    __asm__ __volatile__("lock decl %0"
+                         : "=m" (*pu));
+}
+
+/**
+ * Atomically increments a 32-bit unsigned value if less than max.
+ *
+ * @returns 0 if incremented.
+ * @returns *pu + 1 when not updated.
+ * @param   pu      Pointer to the value to increment.
+ * @param   uMax    *pu must not be above this value.
+ */
+static __inline__ int __atomic_increment_max(__volatile__ unsigned *pu, unsigned uMax)
+{
+    unsigned rc;
+    __asm__ __volatile__("movl  %1, %%eax\n"
+                         "1:\n\t"
+                         "lea   1(%%eax), %0\n\t"
+                         "cmpl  %0, %2\n\t"
+                         "jna   2f\n\t"
+                         "jmp   4f\n"
+                         "2:\n\t"
+                         "lock  cmpxchgl %0, %1\n\t"
+                         "jz    3f\n\t"
+                         "jmp   1b\n"
+                         "3:"
+                         "xorl  %0, %0\n\t"
+                         "4:"
+                         : "=r" (rc),
+                           "=m" (pu)
+                         : "r"  (uMax)
+                         : "%eax");
+    return rc;
+}
+
+
+/**
+ * Atomically decrements a 32-bit unsigned value if greater than a min.
+ *
+ * @returns 0 if incremented.
+ * @returns *pu + 1 when not updated.
+ * @param   pu      Pointer to the value to decrement.
+ * @param   uMin    *pu must not be below this value.
+ */
+static __inline__ int __atomic_increment_min(__volatile__ unsigned *pu, unsigned uMin)
+{
+    unsigned rc;
+    __asm__ __volatile__("movl  %1, %%eax\n"
+                         "1:\n\t"
+                         "lea   -1(%%eax), %0\n\t"
+                         "cmpl  %0, %2\n\t"
+                         "jnb   2f\n\t"
+                         "jmp   4f\n"
+                         "2:\n\t"
+                         "lock  cmpxchgl %0, %1\n\t"
+                         "jz    3f\n\t"
+                         "jmp   1b\n"
+                         "3:"
+                         "xorl  %0, %0\n\t"
+                         "4:"
+                         : "=r" (rc),
+                           "=m" (*pu)
+                         : "r"  (uMin)
+                         : "%eax");
+    return rc;
+}
+
 
 #define __ROTATE_FUN(F,I,T) \