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Testing Inline ASM-VB
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Testing Inline ASM-VB
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Using inline ASM
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SinCos instruction vs VB Sin and CosWith ASM the instruction fSinCos is available. It calculates both Sin and Cos for the same argument.
Often you use Sin and Cos with the same angle (in radians). And this function will perform it one time as quick as VB's separate Sin and Cos.
User contributed notes:
Often you use Sin and Cos with the same angle (in radians). And this function will perform it one time as quick as VB's separate Sin and Cos.
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'//How-to use: '//Simply Call: '//Call asmSinCosPointer(sngCos, sngSin) '//With: sngCos As Single, sngSin As Single '//The first argument will be used for the calculation! '//So only use this if sin and cos need to use the same angle (in radians!) '//You will get the result of cos in the first argument and Sin in the second '//50% faster than normal Sin+Cos in VB Public Sub asmSinCosPointer(ByRef sngCosAngle As Single, ByRef sngSinAngle As Single) '#ASM_START '.MMX ' push ebp ' mov ebp, esp ' mov eax, DWORD PTR [ebp+8] ;'//First argument, store in eax (= value now!) ' fld dword ptr [eax] ;'//Get value for cos ' fsincos ;'//Execute sin/cos instruction ' fstp dword ptr [eax] ;'//Store cos in eax (1st param pointer!) ' mov eax, DWORD PTR [ebp+12] ;'//Second argument, store in eax (=value now!) ' fstp dword ptr [eax] ;'//Store sin in eax (2nd param pointer!) ' mov esp, ebp ;'//MOV/POP is much faster ' pop ebp ;'//on 486 and Pentium than Leave ' ret 8 '#ASM_END End Sub |
| VBSinCos % faster than ASMSinCos | VBSinCos (sec) | ASMSinCos (sec) |
| 2149.6% | 0.002583 | 0.000115 |
| 3530.7% | 0.004169 | 0.000115 |
| 2238.9% | 0.00247 | 0.000106 |
| 2466.4% | 0.002689 | 0.000105 |
| 2419.2% | 0.002639 | 0.000105 |
| VBSinCos % faster than ASMSinCos | VBSinCos (sec) | ASMSinCos (sec) |
| 2106.3% | 0.004956 | 0.000225 |
| 3689.2% | 0.008511 | 0.000225 |
| 2556.1% | 0.005988 | 0.000225 |
| 1971.6% | 0.005191 | 0.000251 |
| 2285.1% | 0.005357 | 0.000225 |
User contributed notes:
| Author: cjb0087 () | Date: 11:03 03/03/2004 |
| i gotta get me this!! | |
| Author: Kristian () | Date: 03:07 31/07/2004 |
| uhh... this will really speed up my game, thanx! | |
| Author: Tom (hurendo_kun at hotmail dot com) | Date: 16:06 08/06/2005 |
| Yikes, that's fast. Anybody know why the VB versions would be so slow? | |
| Author: Steven (steven at uplinklabs dot net) | Date: 18:07 15/07/2005 |
| Because it's VB. VB is a *very* high level language, and as such is very slow. | |
| Author: Tom (hurendo_kun at hotmail dot com) | Date: 05:09 23/09/2005 |
| Okay, but does it have its own implementation of Sin/Cos, whereas the ASM listing uses special CPU hardware? Because with normal operations, VB delegates to the FPU, and the speed difference is negligible. | |