OLD | NEW |
(Empty) | |
| 1 <html> |
| 2 <head> |
| 3 <script src="../htmlrunner.js"></script> |
| 4 <script> |
| 5 // Copyright (c) 2004 by Arthur Langereis (arthur_ext at domain xfinitegames, tl
d com |
| 6 |
| 7 // 1 op = 6 ANDs, 3 SHRs, 3 SHLs, 4 assigns, 2 ADDs |
| 8 // O(1) |
| 9 function fast3bitlookup(b) { |
| 10 var c, bi3b = 0xE994; // 0b1110 1001 1001 0100; // 3 2 2 1 2 1 1 0 |
| 11 c = 3 & (bi3b >> ((b << 1) & 14)); |
| 12 c += 3 & (bi3b >> ((b >> 2) & 14)); |
| 13 c += 3 & (bi3b >> ((b >> 5) & 6)); |
| 14 return c; |
| 15 |
| 16 /* |
| 17 lir4,0xE994; 9 instructions, no memory access, minimal register dependence, 6 sh
ifts, 2 adds, 1 inline assign |
| 18 rlwinmr5,r3,1,28,30 |
| 19 rlwinmr6,r3,30,28,30 |
| 20 rlwinmr7,r3,27,29,30 |
| 21 rlwnmr8,r4,r5,30,31 |
| 22 rlwnmr9,r4,r6,30,31 |
| 23 rlwnmr10,r4,r7,30,31 |
| 24 addr3,r8,r9 |
| 25 addr3,r3,r10 |
| 26 */ |
| 27 } |
| 28 |
| 29 |
| 30 function TimeFunc(func) { |
| 31 var x, y, t; |
| 32 for(var x=0; x<250; x++) |
| 33 for(var y=0; y<256; y++) func(y); |
| 34 } |
| 35 |
| 36 window.onload = function(){ startTest("sunspider-bitops-3bit-bits-in-byte", ''); |
| 37 |
| 38 test("3bit bits in byte", function(){ |
| 39 TimeFunc(fast3bitlookup); |
| 40 }); |
| 41 |
| 42 endTest(); }; |
| 43 </script> |
| 44 </head> |
| 45 <body></body> |
| 46 </html> |
OLD | NEW |