#ifndef _FRACMUL_H #define _FRACMUL_H /** FRACTIONAL MULTIPLICATION - TAKEN FROM apps/dsp.h * Multiply two fixed point numbers with 31 fractional bits: * FRACMUL(x, y) * * Multiply two fixed point numbers with 31 fractional bits, * then shift left by z bits: * FRACMUL_SHL(x, y, z) * NOTE: z must be in the range 1-8 on Coldfire targets. */ /* A bunch of fixed point assembler helper macros */ #if defined(CPU_COLDFIRE) /* These macros use the Coldfire EMAC extension and need the MACSR flags set * to fractional mode with no rounding. */ /* Multiply two S.31 fractional integers and return the sign bit and the * 31 most significant bits of the result. */ #define FRACMUL(x, y) \ ({ \ long t; \ asm ("mac.l %[a], %[b], %%acc0\n\t" \ "movclr.l %%acc0, %[t]\n\t" \ : [t] "=r" (t) : [a] "r" (x), [b] "r" (y)); \ t; \ }) /* Multiply two S.31 fractional integers, and return the 32 most significant * bits after a shift left by the constant z. NOTE: Only works for shifts of * 1 to 8 on Coldfire! */ #define FRACMUL_SHL(x, y, z) \ ({ \ long t, t2; \ asm ("mac.l %[a], %[b], %%acc0\n\t" \ "moveq.l %[d], %[t]\n\t" \ "move.l %%accext01, %[t2]\n\t" \ "and.l %[mask], %[t2]\n\t" \ "lsr.l %[t], %[t2]\n\t" \ "movclr.l %%acc0, %[t]\n\t" \ "asl.l %[c], %[t]\n\t" \ "or.l %[t2], %[t]\n\t" \ : [t] "=&d" (t), [t2] "=&d" (t2) \ : [a] "r" (x), [b] "r" (y), [mask] "d" (0xff), \ [c] "i" ((z)), [d] "i" (8 - (z))); \ t; \ }) #elif defined(CPU_ARM) /* Multiply two S.31 fractional integers and return the sign bit and the * 31 most significant bits of the result. */ #define FRACMUL(x, y) \ ({ \ long t, t2; \ asm ("smull %[t], %[t2], %[a], %[b]\n\t" \ "mov %[t2], %[t2], asl #1\n\t" \ "orr %[t], %[t2], %[t], lsr #31\n\t" \ : [t] "=&r" (t), [t2] "=&r" (t2) \ : [a] "r" (x), [b] "r" (y)); \ t; \ }) /* Multiply two S.31 fractional integers, and return the 32 most significant * bits after a shift left by the constant z. */ #define FRACMUL_SHL(x, y, z) \ ({ \ long t, t2; \ asm ("smull %[t], %[t2], %[a], %[b]\n\t" \ "mov %[t2], %[t2], asl %[c]\n\t" \ "orr %[t], %[t2], %[t], lsr %[d]\n\t" \ : [t] "=&r" (t), [t2] "=&r" (t2) \ : [a] "r" (x), [b] "r" (y), \ [c] "M" ((z) + 1), [d] "M" (31 - (z))); \ t; \ }) #else #define FRACMUL(x, y) (long) (((((long long) (x)) * ((long long) (y))) >> 31)) #define FRACMUL_SHL(x, y, z) \ ((long)(((((long long) (x)) * ((long long) (y))) >> (31 - (z))))) #endif #endif