--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tango/std/intrinsic.di	Fri Jan 11 17:57:40 2008 +0100
@@ -0,0 +1,176 @@
+/**
+ * These functions are built-in intrinsics to the compiler.
+ *
+ * Intrinsic functions are functions built in to the compiler, usually to take
+ * advantage of specific CPU features that are inefficient to handle via
+ * external functions.  The compiler's optimizer and code generator are fully
+ * integrated in with intrinsic functions, bringing to bear their full power on
+ * them. This can result in some surprising speedups.
+ *
+ * Copyright: Public Domain
+ * License:   Public Domain
+ * Authors:   Walter Bright
+ */
+module std.intrinsic;
+
+
+/**
+ * Scans the bits in v starting with bit 0, looking
+ * for the first set bit.
+ * Returns:
+ *	The bit number of the first bit set.
+ *	The return value is undefined if v is zero.
+ */
+int bsf( uint v );
+
+
+/**
+ * Scans the bits in v from the most significant bit
+ * to the least significant bit, looking
+ * for the first set bit.
+ * Returns:
+ *	The bit number of the first bit set.
+ *	The return value is undefined if v is zero.
+ * Example:
+ * ---
+ * import std.intrinsic;
+ *
+ * int main()
+ * {
+ *     uint v;
+ *     int x;
+ *
+ *     v = 0x21;
+ *     x = bsf(v);
+ *     printf("bsf(x%x) = %d\n", v, x);
+ *     x = bsr(v);
+ *     printf("bsr(x%x) = %d\n", v, x);
+ *     return 0;
+ * }
+ * ---
+ * Output:
+ *  bsf(x21) = 0<br>
+ *  bsr(x21) = 5
+ */
+int bsr( uint v );
+
+
+/**
+ * Tests the bit.
+ */
+int bt( uint* p, uint bitnum );
+
+
+/**
+ * Tests and complements the bit.
+ */
+int btc( uint* p, uint bitnum );
+
+
+/**
+ * Tests and resets (sets to 0) the bit.
+ */
+int btr( uint* p, uint bitnum );
+
+
+/**
+ * Tests and sets the bit.
+ * Params:
+ * p = a non-NULL pointer to an array of uints.
+ * index = a bit number, starting with bit 0 of p[0],
+ * and progressing. It addresses bits like the expression:
+---
+p[index / (uint.sizeof*8)] & (1 << (index & ((uint.sizeof*8) - 1)))
+---
+ * Returns:
+ * 	A non-zero value if the bit was set, and a zero
+ *	if it was clear.
+ *
+ * Example:
+ * ---
+import std.intrinsic;
+
+int main()
+{
+    uint array[2];
+
+    array[0] = 2;
+    array[1] = 0x100;
+
+    printf("btc(array, 35) = %d\n", <b>btc</b>(array, 35));
+    printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);
+
+    printf("btc(array, 35) = %d\n", <b>btc</b>(array, 35));
+    printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);
+
+    printf("bts(array, 35) = %d\n", <b>bts</b>(array, 35));
+    printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);
+
+    printf("btr(array, 35) = %d\n", <b>btr</b>(array, 35));
+    printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);
+
+    printf("bt(array, 1) = %d\n", <b>bt</b>(array, 1));
+    printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);
+
+    return 0;
+}
+ * ---
+ * Output:
+<pre>
+btc(array, 35) = 0
+array = [0]:x2, [1]:x108
+btc(array, 35) = -1
+array = [0]:x2, [1]:x100
+bts(array, 35) = 0
+array = [0]:x2, [1]:x108
+btr(array, 35) = -1
+array = [0]:x2, [1]:x100
+bt(array, 1) = -1
+array = [0]:x2, [1]:x100
+</pre>
+ */
+int bts( uint* p, uint bitnum );
+
+
+/**
+ * Swaps bytes in a 4 byte uint end-to-end, i.e. byte 0 becomes
+ * byte 3, byte 1 becomes byte 2, byte 2 becomes byte 1, byte 3
+ * becomes byte 0.
+ */
+uint bswap( uint v );
+
+
+/**
+ * Reads I/O port at port_address.
+ */
+ubyte inp( uint port_address );
+
+
+/**
+ * ditto
+ */
+ushort inpw( uint port_address );
+
+
+/**
+ * ditto
+ */
+uint inpl( uint port_address );
+
+
+/**
+ * Writes and returns value to I/O port at port_address.
+ */
+ubyte outp( uint port_address, ubyte value );
+
+
+/**
+ * ditto
+ */
+ushort outpw( uint port_address, ushort value );
+
+
+/**
+ * ditto
+ */
+uint outpl( uint port_address, uint value );
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