Added 'math.c' for optimized math and bit operations

include/math.h

@@ -0,0 +1,8 @@
+#ifndef _QUARK_UTIL_H
+#define _QUARK_UTIL_H
+
+int ilog2(unsigned int x);
+
+int llog2(unsigned long x);
+
+#endif

src/heap.c

@@ -1,6 +1,7 @@
 #include <stdbool.h>
 #include "heap.h"
 #include "mmgr.h"
+#include "math.h"
 #include "types/status.h"
 
 #define AVAIL 0
@@ -23,23 +24,6 @@ struct heap_node_t
     size_t state : 2;
 } __attribute__ ((packed));
 
-size_t ilog2(size_t n)
-{
-	size_t m = n;
-	size_t count = 0;
-	bool isPowerOfTwo = true;
-	while(m)
-	{
-		if((m & 1) == 1 && m > 1)
-		{
-			isPowerOfTwo = false;
-		}
-		count++;
-		m >>= 1;
-	}
-	return count - (isPowerOfTwo ? 1 : 0);
-}
-
 size_t find_free_block(struct heap_t *heap, size_t height)
 {
     if(height > heap->tree_height)
@@ -95,7 +79,7 @@ int heap_contruct(struct heap_t *heap, void *base, void *start, size_t heap_size
     heap->header = (struct heap_node_t*) start;
     heap->heap_size = heap_size;
     heap->block_size = block_size;
-    heap->tree_height = ilog2(heap_size / block_size);
+    heap->tree_height = llog2(heap_size / block_size);
     size_t header_size = (heap_size / block_size) << 1;
     for(size_t i = 1; i <= (heap_size / block_size) * 2; i++)
     {
@@ -136,7 +120,7 @@ void *heap_allocate(struct heap_t *heap, size_t size)
 {
     size += heap->block_size - 1;
     size -= size % heap->block_size;
-    size_t height = ilog2(size / heap->block_size);
+    size_t height = llog2(size / heap->block_size);
     size_t index = find_free_block(heap, height);
     if(index)
     {

src/math.c

@@ -0,0 +1,66 @@
+#include "math.h"
+
+int ilog2(unsigned int x)
+{
+#if defined __GNUC__
+    if(x <= 1)
+        return 0;
+    return 32 - __builtin_clzl(x - 1);
+#else
+    static const int table[32] = {
+        0,  9,  1, 10, 13, 21,  2, 29,
+        11, 14, 16, 18, 22, 25,  3, 30,
+        8, 12, 20, 28, 15, 17, 24,  7,
+        19, 27, 23,  6, 26,  5,  4, 31};
+    
+    x |= x >> 1;
+    x |= x >> 2;
+    x |= x >> 4;
+    x |= x >> 8;
+    x |= x >> 16;
+
+    return table[(x * 0x07C4ACDD) >> 27];
+#endif
+}
+
+int llog2(unsigned long x)
+{
+#if (defined __GNUC__) && (__SIZEOF_LONG__ == 4)
+    if(x <= 1)
+        return 0;
+    return 32 - __builtin_clzl(x - 1);
+#elif (defined __GNUC__) && (__SIZEOF_LONG__ == 8)
+    if(x <= 1)
+        return 0;
+    return 64 - __buildin_clzl(x - 1);
+#elif __SIZEOF_LONG__ == 8
+    static const int table[64] = {
+        0, 58, 1, 59, 47, 53, 2, 60, 39, 48, 27, 54, 33, 42, 3, 61,
+        51, 37, 40, 49, 18, 28, 20, 55, 30, 34, 11, 43, 14, 22, 4, 62,
+        57, 46, 52, 38, 26, 32, 41, 50, 36, 17, 19, 29, 10, 13, 21, 56,
+        45, 25, 31, 35, 16, 9, 12, 44, 24, 15, 8, 23, 7, 6, 5, 63};
+
+    x |= x >> 1;
+    x |= x >> 2;
+    x |= x >> 4;
+    x |= x >> 8;
+    x |= x >> 16;
+    x |= x >> 32;
+
+    return table[(x * 0x03f6eaf2cd271461) >> 58];
+#else
+    static const int table[32] = {
+        0,  9,  1, 10, 13, 21,  2, 29,
+        11, 14, 16, 18, 22, 25,  3, 30,
+        8, 12, 20, 28, 15, 17, 24,  7,
+        19, 27, 23,  6, 26,  5,  4, 31};
+    
+    x |= x >> 1;
+    x |= x >> 2;
+    x |= x >> 4;
+    x |= x >> 8;
+    x |= x >> 16;
+
+    return table[(x * 0x07C4ACDD) >> 27];
+#endif
+}