From e7c7150d6395c1e31f4e73e0e43dc6bb7e6dfacd Mon Sep 17 00:00:00 2001
From: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Date: Fri, 19 Feb 2021 14:43:59 -0500
Subject: [PATCH] util/bitscan: add u_foreach_bit macros

this is a standardized (and very slightly improved for usability) version
of the macro that has been copied into every vulkan driver

includes fixup from Rob Clark <robclark@freedesktop.org>

Reviewed-by: Rob Clark <robclark@freedesktop.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9191>
---
 src/util/bitscan.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/util/bitscan.h b/src/util/bitscan.h
index 895a1e7a372..1ea7b07359f 100644
--- a/src/util/bitscan.h
+++ b/src/util/bitscan.h
@@ -104,6 +104,11 @@ u_bit_scan(unsigned *mask)
    return i;
 }
 
+#define u_foreach_bit(b, dword)                          \
+   for (uint32_t __dword = (dword), b;                     \
+        ((b) = ffs(__dword) - 1, __dword);      \
+        __dword &= ~(1 << (b)))
+
 static inline int
 u_bit_scan64(uint64_t *mask)
 {
@@ -112,6 +117,11 @@ u_bit_scan64(uint64_t *mask)
    return i;
 }
 
+#define u_foreach_bit64(b, dword)                          \
+   for (uint64_t __dword = (dword), b;                     \
+        ((b) = ffsll(__dword) - 1, __dword);      \
+        __dword &= ~(1ull << (b)))
+
 /* Determine if an unsigned value is a power of two.
  *
  * \note