[Mesa-dev] [PATCH] gallium/util: fix u_bit_scan_consecutive_range for mask == 0xffffffff

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

The second ffs returns 0, yielding count == -1.
---
 src/gallium/auxiliary/util/u_math.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h
index b4ac0db..2880eea 100644
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -518,6 +518,12 @@ u_bit_scan64(uint64_t *mask)
 static inline void
 u_bit_scan_consecutive_range(unsigned *mask, int *start, int *count)
 {
+   if (*mask == 0xffffffff) {
+      *start = 0;
+      *count = 32;
+      *mask = 0;
+      return;
+   }
    *start = ffs(*mask) - 1;
    *count = ffs(~(*mask >> *start)) - 1;
    *mask &= ~(((1 << *count) - 1) << *start);
-- 
2.5.0