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authorLennart Poettering <lennart@poettering.net>2009-08-26 01:41:34 +0200
committerLennart Poettering <lennart@poettering.net>2009-08-26 01:41:34 +0200
commit827ae07c1ec73c8fe48dc4182726c38c3e9c992f (patch)
treeed18d2469babaefe1665e6132aa50fd9ec7d4863 /src/pulsecore
parent457b973ba69d1a417d438b8716389464eb62e049 (diff)
macro: add PA_CLIP_SUB() for saturated subtraction
Diffstat (limited to 'src/pulsecore')
-rw-r--r--src/pulsecore/macro.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/src/pulsecore/macro.h b/src/pulsecore/macro.h
index ce88c1b9..87684ad3 100644
--- a/src/pulsecore/macro.h
+++ b/src/pulsecore/macro.h
@@ -157,6 +157,17 @@ static inline size_t PA_PAGE_ALIGN(size_t l) {
#define PA_ROUND_DOWN(a, b) (((a) / (b)) * (b))
#endif
+#ifdef __GNUC__
+#define PA_CLIP_SUB(a, b) \
+ __extension__ ({ \
+ typeof(a) _a = (a); \
+ typeof(b) _b = (b); \
+ _a > _b ? _a - _b : 0; \
+ })
+#else
+#define PA_CLIP_SUB(a, b) ((a) > (b) ? (a) - (b) : 0)
+#endif
+
/* This type is not intended to be used in exported APIs! Use classic "int" there! */
#ifdef HAVE_STD_BOOL
typedef _Bool pa_bool_t;