Filter: keep aliased ax and bx registers

[lttng-ust.git] / liblttng-ust / lttng-filter.h

diff --git a/liblttng-ust/lttng-filter.h b/liblttng-ust/lttng-filter.h
index 4ca8dfc6fbaca0a1370ac4c8ba7256ab084da9cf..8a40d16f740a5f8d75a4d513f789954ab51f0387 100644 (file)
--- a/liblttng-ust/lttng-filter.h
+++ b/liblttng-ust/lttng-filter.h
@@ -37,7 +37,8 @@
 #include "filter-bytecode.h"
 
 /* Filter stack length, in number of entries */
-#define FILTER_STACK_LEN       8
+#define FILTER_STACK_LEN       10      /* includes 2 dummy */
+#define FILTER_STACK_EMPTY     1
 
 #ifndef min_t
 #define min_t(type, a, b)      \
@@ -138,8 +139,8 @@ struct estack_entry {
 
                struct {
                        const char *str;
-               size_t seq_len;
-               int literal;            /* is string literal ? */
+                       size_t seq_len;
+                       int literal;            /* is string literal ? */
                } s;
        } u;
 };
@@ -149,39 +150,36 @@ struct estack {
        struct estack_entry e[FILTER_STACK_LEN];
 };
 
-static inline
-void estack_init(struct estack *stack)
-{
-       stack->top = -1;
-}
-
-static inline
-struct estack_entry *estack_ax(struct estack *stack)
-{
-       assert(stack->top >= 0);
-       return &stack->e[stack->top];
-}
-
-static inline
-struct estack_entry *estack_bx(struct estack *stack)
-{
-       assert(stack->top >= 1);
-       return &stack->e[stack->top - 1];
-}
-
-static inline
-void estack_push(struct estack *stack)
-{
-       assert(stack->top < FILTER_STACK_LEN - 1);
-       ++stack->top;
-}
-
-static inline
-void estack_pop(struct estack *stack)
-{
-       assert(stack->top >= 0);
-       stack->top--;
-}
+#define estack_ax_v    ax
+#define estack_bx_v    bx
+
+#define estack_ax(stack, top)                                  \
+       ({                                                      \
+               assert((top) > FILTER_STACK_EMPTY);             \
+               &(stack)->e[top];                               \
+       })
+
+#define estack_bx(stack, top)                                  \
+       ({                                                      \
+               assert((top) > FILTER_STACK_EMPTY + 1);         \
+               &(stack)->e[(top) - 1];                         \
+       })
+
+#define estack_push(stack, top, ax, bx)                                \
+       do {                                                    \
+               assert((top) < FILTER_STACK_LEN - 1);           \
+               (stack)->e[(top) - 1].u.v = (bx);               \
+               (bx) = (ax);                                    \
+               ++(top);                                        \
+       } while (0)
+
+#define estack_pop(stack, top, ax, bx)                         \
+       do {                                                    \
+               assert((top) > FILTER_STACK_EMPTY);             \
+               (ax) = (bx);                                    \
+               (bx) = (stack)->e[(top) - 2].u.v;               \
+               (top)--;                                        \
+       } while (0)
 
 const char *print_op(enum filter_op op);