Re: [LAD] Floating point Denormals: C++ and Waf

Hi, that's my solution regardless of CPU type: // // DENORMALS ARE EVIL // // 32 bit float // SEEEEEEEEMMMMMMMMMMMMMMMMMMMMMMM // E = 0, M != 0 -> denormal // processing denormals uses lot of cpu. // problem: an IIR feeds back 0.7*y. // a value > 0 will decay until the smallest float is reached: // 00000000000000000000000000000001 // multiplying with 0.7 and rounding (to nearest, default) gives again: // 00000000000000000000000000000001 // this value circulates forever and consumes lot of cpu cycles :( // even with "round to zero" - set in main() - // it takes about 5 seconds until the denorm fades to zero... // // solution: // "it's better to burn out than to fade away" // // denormals are zero static inline float daz( float f ) { // define an aliasing type to perform a "reinterpret cast" typedef __u32 __attribute__ (( __may_alias__ )) u32bit; if ( *( (u32bit*)&f ) & 0x7F000000 ) // E > 1 : normal. return f; else // E <= 1 : zero or _almost_ denormal // (may become denormal with next operation) return 0.0; } Ciao, Martin -- View this message in context: http://old.nabble.com/Floating-point-Denormals%3A-C%2B%2B-and-Waf-tp3424522… Sent from the linux-audio-dev mailing list archive at Nabble.com.