Mesa (master): gallium/util: fix u_bit_scan_consecutive_range for mask == 0xffffffff

[Marek Olšák]

Module: Mesa
Branch: master
Commit: 9434aa8103e93c9a80421b20f04b526ef543d46e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=9434aa8103e93c9a80421b20f04b526ef543d46e

Author: Marek Olšák <marek.olsak at amd.com>
Date:   Fri Apr 15 22:08:57 2016 +0200

gallium/util: fix u_bit_scan_consecutive_range for mask == 0xffffffff

The second ffs returns 0, yielding count == -1.

v2: change 1 to 1u

Reviewed-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>

---

 src/gallium/auxiliary/util/u_math.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h
index b4ac0db..0a82915 100644
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -518,9 +518,15 @@ 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);
+   *mask &= ~(((1u << *count) - 1) << *start);
 }
 
 /**