Compute max depth

diff --git a/MagickCore/quantum-private.h b/MagickCore/quantum-private.h
index 405c3810e6089a14823c427f66eaf12fad0f0e19..695b8df124b962a1b839fe71f7fa993b472727ab 100644 (file)
--- a/MagickCore/quantum-private.h
+++ b/MagickCore/quantum-private.h
@@ -93,13 +93,15 @@ extern MagickPrivate void
 static inline MagickSizeType GetQuantumRange(const size_t depth)
 {
   MagickSizeType
+    max_depth,
     one;
 
   if (depth == 0)
     return(0);
   one=1;
-  return((MagickSizeType) ((one << (MagickMin(depth,64)-1))+
-    ((one << (MagickMin(depth,64)-1))-1)));
+  max_depth=8*sizeof(MagickSizeType);
+  return((MagickSizeType) ((one << (MagickMin(depth,max_depth)-1))+
+    ((one << (MagickMin(depth,max_depth)-1))-1)));
 }
 
 static inline float HalfToSinglePrecision(const unsigned short half)