diff --git a/qemu/target/m68k/fpu_helper.c b/qemu/target/m68k/fpu_helper.c index 94b95435..ea073629 100644 --- a/qemu/target/m68k/fpu_helper.c +++ b/qemu/target/m68k/fpu_helper.c @@ -583,3 +583,8 @@ void HELPER(flog10)(CPUM68KState *env, FPReg *res, FPReg *val) { res->d = floatx80_log10(val->d, &env->fp_status); } + +void HELPER(flog2)(CPUM68KState *env, FPReg *res, FPReg *val) +{ + res->d = floatx80_log2(val->d, &env->fp_status); +} diff --git a/qemu/target/m68k/helper.h b/qemu/target/m68k/helper.h index e2ebc572..5bc9e4d3 100644 --- a/qemu/target/m68k/helper.h +++ b/qemu/target/m68k/helper.h @@ -72,6 +72,7 @@ DEF_HELPER_4(fscale, void, env, fp, fp, fp) DEF_HELPER_3(flognp1, void, env, fp, fp) DEF_HELPER_3(flogn, void, env, fp, fp) DEF_HELPER_3(flog10, void, env, fp, fp) +DEF_HELPER_3(flog2, void, env, fp, fp) DEF_HELPER_3(mac_move, void, env, i32, i32) DEF_HELPER_3(macmulf, i64, env, i32, i32) diff --git a/qemu/target/m68k/softfloat.c b/qemu/target/m68k/softfloat.c index 22fd7f63..9fa6d6fd 100644 --- a/qemu/target/m68k/softfloat.c +++ b/qemu/target/m68k/softfloat.c @@ -715,3 +715,70 @@ floatx80 floatx80_log10(floatx80 a, float_status *status) return a; } + +/*---------------------------------------------------------------------------- + | Log base 2 + *----------------------------------------------------------------------------*/ + +floatx80 floatx80_log2(floatx80 a, float_status *status) +{ + flag aSign; + int32_t aExp; + uint64_t aSig; + + int8_t user_rnd_mode, user_rnd_prec; + + floatx80 fp0, fp1; + + aSig = extractFloatx80Frac(a); + aExp = extractFloatx80Exp(a); + aSign = extractFloatx80Sign(a); + + if (aExp == 0x7FFF) { + if ((uint64_t) (aSig << 1)) { + propagateFloatx80NaNOneArg(a, status); + } + if (aSign == 0) { + return packFloatx80(0, floatx80_infinity.high, + floatx80_infinity.low); + } + } + + if (aExp == 0) { + if (aSig == 0) { + float_raise(float_flag_divbyzero, status); + return packFloatx80(1, floatx80_infinity.high, + floatx80_infinity.low); + } + normalizeFloatx80Subnormal(aSig, &aExp, &aSig); + } + + if (aSign) { + float_raise(float_flag_invalid, status); + return floatx80_default_nan(status); + } + + user_rnd_mode = status->float_rounding_mode; + user_rnd_prec = status->floatx80_rounding_precision; + status->float_rounding_mode = float_round_nearest_even; + status->floatx80_rounding_precision = 80; + + if (aSig == one_sig) { /* X is 2^k */ + status->float_rounding_mode = user_rnd_mode; + status->floatx80_rounding_precision = user_rnd_prec; + + a = int32_to_floatx80(aExp - 0x3FFF, status); + } else { + fp0 = floatx80_logn(a, status); + fp1 = packFloatx80(0, 0x3FFF, LIT64(0xB8AA3B295C17F0BC)); /* INV_L2 */ + + status->float_rounding_mode = user_rnd_mode; + status->floatx80_rounding_precision = user_rnd_prec; + + a = floatx80_mul(fp0, fp1, status); /* LOGN(X)*INV_L2 */ + } + + float_raise(float_flag_inexact, status); + + return a; +} diff --git a/qemu/target/m68k/softfloat.h b/qemu/target/m68k/softfloat.h index ac29e761..c0b77cf0 100644 --- a/qemu/target/m68k/softfloat.h +++ b/qemu/target/m68k/softfloat.h @@ -30,4 +30,5 @@ floatx80 floatx80_move(floatx80 a, float_status *status); floatx80 floatx80_lognp1(floatx80 a, float_status *status); floatx80 floatx80_logn(floatx80 a, float_status *status); floatx80 floatx80_log10(floatx80 a, float_status *status); +floatx80 floatx80_log2(floatx80 a, float_status *status); #endif diff --git a/qemu/target/m68k/translate.c b/qemu/target/m68k/translate.c index 7e30eb0d..679d44cf 100644 --- a/qemu/target/m68k/translate.c +++ b/qemu/target/m68k/translate.c @@ -5262,6 +5262,9 @@ DISAS_INSN(fpu) case 0x15: /* flog10 */ gen_helper_flog10(tcg_ctx, tcg_ctx->cpu_env, cpu_dest, cpu_src); break; + case 0x16: /* flog2 */ + gen_helper_flog2(tcg_ctx, tcg_ctx->cpu_env, cpu_dest, cpu_src); + break; case 0x18: /* fabs */ gen_helper_fabs(tcg_ctx, tcg_ctx->cpu_env, cpu_dest, cpu_src); break;