Recent content by bitbank

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    Mame4all For Gp2x V1.2

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    Mame4all For Gp2x V1.2

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    Mame Gp2x Inline Assembler For Vector Games

    Here's some off the cuff code to quickly determine if your divisor is a simple power of 2 R0 = divisor R1 = dividend CLZ r4,r0 MOV r5,r0,LSL r4 ; shift it up to compare with 0x80000000 CMP r5,#0x80000000 ; is it a simple power of 2? RSBEQ r6,r4,#31 ; get the shift amount...
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    Mame Gp2x Inline Assembler For Vector Games

    if you're forced into the shift and subtract method, hopefully you can use ARMv5 instructions such as CLZ to save a few instructions in aligning the divisor with the dividend. With CLZ (count leading zeros) you can quickly determine if the divisor is a simple power of 2 (1 bit set) and then...
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    GP2X Nes Tile Optimization

    This may have been done already, but I came up with a good ARM optimized way of taking NES tile data and converting it into 1 byte per pixel. The NES tile data is stored as bitplanes with each byte containing all 8 pixels for a single bit plane. Here's my code for converting the 2 bit planes...
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    GP2X Clever Idea For 6502 Emulators

    I started a blog about ARM and optimization related topics. Today I released one of my many cpu emulator optmization ideas. Have a look: Larry's Personal & Tech Ramblings L.B.
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    Getting Started With Asm?

    Have a look at my blog: Larry's Personal & Tech Ramblings I cover a bunch of ARM optimization issues from the perspective of C and ASM. L.B.
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