From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58906) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1euIyq-0000vd-0Q for qemu-devel@nongnu.org; Fri, 09 Mar 2018 09:26:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1euIyo-0007CP-6n for qemu-devel@nongnu.org; Fri, 09 Mar 2018 09:26:43 -0500 Received: from mout.kundenserver.de ([217.72.192.75]:45337) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1euIyn-0007CE-Sk for qemu-devel@nongnu.org; Fri, 09 Mar 2018 09:26:42 -0500 From: Laurent Vivier Date: Fri, 9 Mar 2018 15:26:27 +0100 Message-Id: <20180309142630.2170-6-laurent@vivier.eu> In-Reply-To: <20180309142630.2170-1-laurent@vivier.eu> References: <20180309142630.2170-1-laurent@vivier.eu> Subject: [Qemu-devel] [PULL 5/8] target/m68k: implement flog2 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Laurent Vivier Using a local m68k floatx80_log2() [copied from previous: Written by Andreas Grabher for Previous, NeXT Computer Emulator.] Signed-off-by: Laurent Vivier Message-Id: <20180305203910.10391-6-laurent@vivier.eu> --- target/m68k/fpu_helper.c | 5 ++++ target/m68k/helper.h | 1 + target/m68k/softfloat.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++ target/m68k/softfloat.h | 1 + target/m68k/translate.c | 3 +++ 5 files changed, 77 insertions(+) diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c index 2628534136..97a4501126 100644 --- a/target/m68k/fpu_helper.c +++ b/target/m68k/fpu_helper.c @@ -572,3 +572,8 @@ 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/target/m68k/helper.h b/target/m68k/helper.h index d1f38f260f..15f63b353f 100644 --- a/target/m68k/helper.h +++ b/target/m68k/helper.h @@ -71,6 +71,7 @@ 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/target/m68k/softfloat.c b/target/m68k/softfloat.c index 22fd7f6341..9fa6d6fd05 100644 --- a/target/m68k/softfloat.c +++ b/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/target/m68k/softfloat.h b/target/m68k/softfloat.h index ac29e76189..c0b77cf01b 100644 --- a/target/m68k/softfloat.h +++ b/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/target/m68k/translate.c b/target/m68k/translate.c index f1130df314..189b23d38d 100644 --- a/target/m68k/translate.c +++ b/target/m68k/translate.c @@ -5063,6 +5063,9 @@ DISAS_INSN(fpu) case 0x15: /* flog10 */ gen_helper_flog10(cpu_env, cpu_dest, cpu_src); break; + case 0x16: /* flog2 */ + gen_helper_flog2(cpu_env, cpu_dest, cpu_src); + break; case 0x18: /* fabs */ gen_helper_fabs(cpu_env, cpu_dest, cpu_src); break; -- 2.14.3