util/u_atomic: Add new macro p_atomic_add

This provides for atomic addition, which will be used by an upcoming
shader-cache patch. A simple test is added to "make check" as well.

Note: The various O/S functions differ on whether they return the
original value or the value after the addition, so I did not provide
an add_return() macro which would be sensitive to that difference.

Reviewed-by: Matt Turner <[email protected]>
Reviewed-by: Aaron Watry <[email protected]>
Reviewed-by: José Fonseca <[email protected]>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/util/u_atomic_test.c b/src/util/u_atomic_test.c
index 4845e753e6e..c5062750ae4 100644
--- a/src/util/u_atomic_test.c
+++ b/src/util/u_atomic_test.c
@@ -97,6 +97,11 @@
       assert(v == ones && "p_atomic_dec_return"); \
       assert(r == v && "p_atomic_dec_return"); \
       \
+      v = 23; \
+      p_atomic_add(&v, 42); \
+      r = p_atomic_read(&v); \
+      assert(r == 65 && "p_atomic_add"); \
+      \
       (void) r; \
       (void) b; \
    }