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9<title>OSSetGQR[n]</title>
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13
14<h1>OSSetGQR[n]</h1>
15
16<h2>Syntax</h2>
17<dl><dd><pre class="construction">
18#include &lt;revolution/os.h&gt;
19
20// GQR type formats
21#define OS_GQR_F32 0x0000
22#define OS_GQR_U8  0x0004
23#define OS_GQR_U16 0x0005
24#define OS_GQR_S8  0x0006
25#define OS_GQR_S16 0x0007
26
27// GQR scale factors
28#define OS_GQR_SCALE_NONE   0
29#define OS_GQR_SCALE_2      1
30#define OS_GQR_SCALE_4      2
31#define OS_GQR_SCALE_8      3
32#define OS_GQR_SCALE_16     4
33#define OS_GQR_SCALE_32     5
34#define OS_GQR_SCALE_64     6
35#define OS_GQR_SCALE_128    7
36#define OS_GQR_SCALE_256    8
37#define OS_GQR_SCALE_512    9
38#define OS_GQR_SCALE_1024   10
39#define OS_GQR_SCALE_2048   11
40#define OS_GQR_SCALE_4096   12
41#define OS_GQR_SCALE_8192   13
42#define OS_GQR_SCALE_16384  14
43#define OS_GQR_SCALE_32768  15
44#define OS_GQR_SCALE_65536  16
45#define OS_GQR_SCALE_MAX    31
46
47#define OS_GQR_DIVIDE_2     63
48#define OS_GQR_DIVIDE_4     62
49#define OS_GQR_DIVIDE_8     61
50#define OS_GQR_DIVIDE_16    60
51#define OS_GQR_DIVIDE_32    59
52#define OS_GQR_DIVIDE_64    58
53#define OS_GQR_DIVIDE_128   57
54#define OS_GQR_DIVIDE_256   56
55#define OS_GQR_DIVIDE_512   55
56#define OS_GQR_DIVIDE_1024  54
57#define OS_GQR_DIVIDE_2048  53
58#define OS_GQR_DIVIDE_4096  52
59#define OS_GQR_DIVIDE_8192  51
60#define OS_GQR_DIVIDE_16384 50
61#define OS_GQR_DIVIDE_32768 49
62#define OS_GQR_DIVIDE_65536 48
63#define OS_GQR_DIVIDE_MAX   32
64
65inline void OSSetGQR2(u32 type, u32 scale);
66inline void OSSetGQR3(u32 type, u32 scale);
67inline void OSSetGQR4(u32 type, u32 scale);
68inline void OSSetGQR5(u32 type, u32 scale);
69inline void OSSetGQR6(u32 type, u32 scale);
70inline void OSSetGQR7(u32 type, u32 scale);
71</pre></dd></dl>
72
73<h2>Arguments</h2>
74<TABLE class="arguments" border="1" >
75  <tr>
76<TH>type</TH>
77<TD>Data Types. The specifiable values are: <code>OS_GQR_F32, OS_GQR_S8, OS_GQR_S16, OS_GQR_U8, OS_GQR_U16</code>.</TD>
78  </tr>
79  <tr>
80<TH><STRONG><EM><CODE>scale</CODE></EM></STRONG></TH>
81<TD>Scaling coefficient. The specifiable values are: <code>OS_GQR_SCALE_* or OS_GQR_DIVIDE_*</code>.</TD>
82  </tr>
83</TABLE>
84
85<h2>Return Values</h2>
86<P>None.</P>
87
88<h2>Description</h2>
89<P>Sets a value to a GQR (quantization register) in the Broadway CPU. These register values are used to convert from floating-point to integer or vice versa with a paired single floating-point load/store instruction.</P>
90<P>The <SPAN class="argument">type</SPAN> argument defines the data type used to load floating-point values from memory or store floating-point values into memory. The <SPAN class="argument">scale</SPAN> argument defines the scale factor when a value is stored into memory as an integer value. For loading a value from memory, the inverted scale factor is applied. For example, If you use <code>OS_GQR_SCALE_4</code>,&nbsp;the value will be scaled by 4 when stored, and divided by 4 when loaded.)</P>
91<P>The Broadway CPU has 8 GQRs. Since GQR0 and GQR1 are reserved for the system, no APIs to modify them are available.</P>
92<P>Note: OS fast cast functions use GQR2 to GQR5. If you change them after <a href="OSInitFastCast.html"><code>OSInitFastCast</code></a> is called, such OS fast-cast functions as <a href="OSf32tos16.html"><CODE>OSf32tos16</CODE></a> and <a href="OSf32tos8.html"><CODE>OSf32tos8</CODE></a> will not behave correctly. In such a case, call the <A href="OSInitFastCast.html"><code>OSInitFastCast</code></A> function again to re-initialize the four registers.</P>
93
94<h2>See Also</h2>
95<P class="reference">
96<a href="OSInitFastCast.html">OSInitFastCast</a>,
97<a href="OSf32tos16.html">OSf32tos16</a>,
98<a href="OSf32tos8.html">OSf32tos8</a>,
99<a href="OSf32tou16.html">OSf32tou16</a>,
100<a href="OSf32tou8.html">OSf32tou8</a>,
101<a href="OSs16tof32.html">OSs16tof32</a>,
102<a href="OSs8tof32.html">OSs8tof32</a>,
103<a href="OSu16tof32.html">OSu16tof32</a>,
104<a href="OSu8tof32.html">OSu8tof32</a>
105</p>
106
107<H2>Revision History</H2>
108<P>
1092006/03/01 Initial version.<br>
110</P>
111
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