Superoptimizing an FPU Emulator(purplesyringa.moe)

39 points by dverlaeckt80 10 days ago | 6 comments

Blog post on using superoptimization to find an optimal instruction sequence for a floating-point emulator function returning a float's lowest set bit.

Vectorized CLZ and CTZ(purplesyringa.moe)

47 points by zX41ZdbW 15 days ago | 5 comments

Blog post on purplesyringa explaining how to implement vectorized count-leading-zeros and count-trailing-zeros using floating-point tricks.

Who is vfmaddrnd231pd?(purplesyringa.moe)

243 points by pngmangi 13 days ago | 21 comments

Blog post examining the x86 FMA instruction vfmaddrnd231pd, which performs fused multiply-add with per-instruction rounding control.

Quadrupling code performance with a "useless" if(purplesyringa.moe)

76 points by birdculture 3 months ago | 11 comments

Simplest Hash Functions(purplesyringa.moe)

44 points by ibobev 6 months ago | 39 comments

Log is non-monotonic in PHP and Lua(purplesyringa.moe)

59 points by ibobev 3 months ago | 39 comments