From f77442fbd3b539aa3da927630c12c3a1a377f6da Mon Sep 17 00:00:00 2001
From: Alan Hourihane <alanh@tungstengraphics.com>
Date: Mon, 5 May 2008 23:09:38 +0100
Subject: [PATCH] fix _mesa_ffs for alternative compilers

---
 src/mesa/main/imports.c | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/src/mesa/main/imports.c b/src/mesa/main/imports.c
index d8d35af15e2..d798f80e253 100644
--- a/src/mesa/main/imports.c
+++ b/src/mesa/main/imports.c
@@ -542,26 +542,24 @@ int
 _mesa_ffs(int i)
 {
 #if (defined(_WIN32) && !defined(__MINGW32__) ) || defined(__IBMC__) || defined(__IBMCPP__)
-   register int bit = 0;
-   if (i != 0) {
-      if ((i & 0xffff) == 0) {
-         bit += 16;
-         i >>= 16;
-      }
-      if ((i & 0xff) == 0) {
-         bit += 8;
-         i >>= 8;
-      }
-      if ((i & 0xf) == 0) {
-         bit += 4;
-         i >>= 4;
-      }
-      while ((i & 1) == 0) {
-         bit++;
-         i >>= 1;
-      }
+   register int bit = 1;
+   if ((i & 0xffff) == 0) {
+      bit += 16;
+      i >>= 16;
+   }
+   if ((i & 0xff) == 0) {
+      bit += 8;
+      i >>= 8;
+   }
+   if ((i & 0xf) == 0) {
+      bit += 4;
+      i >>= 4;
+   }
+   if ((i & 0x3) == 0) {
+      bit += 2;
+      i >>= 2;
    }
-   return bit;
+   return (i) ? (bit + ((i + 1) & 0x01)) : 0;
 #else
    return ffs(i);
 #endif
-- 
2.30.2