diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c index 20496497f1..a9b7f73bb0 100644 --- a/target-ppc/op_helper.c +++ b/target-ppc/op_helper.c @@ -1865,30 +1865,16 @@ void helper_rfsvc (void) /* 602 specific instructions */ /* mfrom is the most crazy instruction ever seen, imho ! */ /* Real implementation uses a ROM table. Do the same */ +/* Extremly decomposed: + * -arg / 256 + * return 256 * log10(10 + 1.0) + 0.5 + */ #if !defined (CONFIG_USER_ONLY) -#define USE_MFROM_ROM_TABLE target_ulong helper_602_mfrom (target_ulong arg) { if (likely(arg < 602)) { -#if defined(USE_MFROM_ROM_TABLE) #include "mfrom_table.c" return mfrom_ROM_table[arg]; -#else - double d; - /* Extremly decomposed: - * -arg / 256 - * return 256 * log10(10 + 1.0) + 0.5 - */ - d = arg; - d = float64_div(d, 256, &env->fp_status); - d = float64_chs(d); - d = exp10(d); // XXX: use float emulation function - d = float64_add(d, 1.0, &env->fp_status); - d = log10(d); // XXX: use float emulation function - d = float64_mul(d, 256, &env->fp_status); - d = float64_add(d, 0.5, &env->fp_status); - return float64_round_to_int(d, &env->fp_status); -#endif } else { return 0; }