| /* |
| * Helpers for floating point instructions. |
| * |
| * Copyright (c) 2007 Jocelyn Mayer |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "cpu.h" |
| #include "exec/exec-all.h" |
| #include "exec/helper-proto.h" |
| #include "fpu/softfloat.h" |
| |
| #define FP_STATUS (env->fp_status) |
| |
| |
| void helper_setroundmode(CPUAlphaState *env, uint32_t val) |
| { |
| set_float_rounding_mode(val, &FP_STATUS); |
| } |
| |
| void helper_setflushzero(CPUAlphaState *env, uint32_t val) |
| { |
| set_flush_to_zero(val, &FP_STATUS); |
| } |
| |
| #define CONVERT_BIT(X, SRC, DST) \ |
| (SRC > DST ? (X) / (SRC / DST) & (DST) : ((X) & SRC) * (DST / SRC)) |
| |
| static uint32_t soft_to_fpcr_exc(CPUAlphaState *env) |
| { |
| uint8_t exc = get_float_exception_flags(&FP_STATUS); |
| uint32_t ret = 0; |
| |
| if (unlikely(exc)) { |
| set_float_exception_flags(0, &FP_STATUS); |
| ret |= CONVERT_BIT(exc, float_flag_invalid, FPCR_INV); |
| ret |= CONVERT_BIT(exc, float_flag_divbyzero, FPCR_DZE); |
| ret |= CONVERT_BIT(exc, float_flag_overflow, FPCR_OVF); |
| ret |= CONVERT_BIT(exc, float_flag_underflow, FPCR_UNF); |
| ret |= CONVERT_BIT(exc, float_flag_inexact, FPCR_INE); |
| } |
| |
| return ret; |
| } |
| |
| static void fp_exc_raise1(CPUAlphaState *env, uintptr_t retaddr, |
| uint32_t exc, uint32_t regno, uint32_t hw_exc) |
| { |
| hw_exc |= CONVERT_BIT(exc, FPCR_INV, EXC_M_INV); |
| hw_exc |= CONVERT_BIT(exc, FPCR_DZE, EXC_M_DZE); |
| hw_exc |= CONVERT_BIT(exc, FPCR_OVF, EXC_M_FOV); |
| hw_exc |= CONVERT_BIT(exc, FPCR_UNF, EXC_M_UNF); |
| hw_exc |= CONVERT_BIT(exc, FPCR_INE, EXC_M_INE); |
| hw_exc |= CONVERT_BIT(exc, FPCR_IOV, EXC_M_IOV); |
| |
| arith_excp(env, retaddr, hw_exc, 1ull << regno); |
| } |
| |
| /* Raise exceptions for ieee fp insns without software completion. |
| In that case there are no exceptions that don't trap; the mask |
| doesn't apply. */ |
| void helper_fp_exc_raise(CPUAlphaState *env, uint32_t ignore, uint32_t regno) |
| { |
| uint32_t exc = env->error_code; |
| if (exc) { |
| env->fpcr |= exc; |
| exc &= ~ignore; |
| if (exc) { |
| fp_exc_raise1(env, GETPC(), exc, regno, 0); |
| } |
| } |
| } |
| |
| /* Raise exceptions for ieee fp insns with software completion. */ |
| void helper_fp_exc_raise_s(CPUAlphaState *env, uint32_t ignore, uint32_t regno) |
| { |
| uint32_t exc = env->error_code & ~ignore; |
| if (exc) { |
| env->fpcr |= exc; |
| exc &= ~ignore; |
| if (exc) { |
| exc &= env->fpcr_exc_enable; |
| fp_exc_raise1(env, GETPC(), exc, regno, EXC_M_SWC); |
| } |
| } |
| } |
| |
| /* Input handing without software completion. Trap for all |
| non-finite numbers. */ |
| void helper_ieee_input(CPUAlphaState *env, uint64_t val) |
| { |
| uint32_t exp = (uint32_t)(val >> 52) & 0x7ff; |
| uint64_t frac = val & 0xfffffffffffffull; |
| |
| if (exp == 0) { |
| /* Denormals without /S raise an exception. */ |
| if (frac != 0) { |
| arith_excp(env, GETPC(), EXC_M_INV, 0); |
| } |
| } else if (exp == 0x7ff) { |
| /* Infinity or NaN. */ |
| env->fpcr |= FPCR_INV; |
| arith_excp(env, GETPC(), EXC_M_INV, 0); |
| } |
| } |
| |
| /* Similar, but does not trap for infinities. Used for comparisons. */ |
| void helper_ieee_input_cmp(CPUAlphaState *env, uint64_t val) |
| { |
| uint32_t exp = (uint32_t)(val >> 52) & 0x7ff; |
| uint64_t frac = val & 0xfffffffffffffull; |
| |
| if (exp == 0) { |
| /* Denormals without /S raise an exception. */ |
| if (frac != 0) { |
| arith_excp(env, GETPC(), EXC_M_INV, 0); |
| } |
| } else if (exp == 0x7ff && frac) { |
| /* NaN. */ |
| env->fpcr |= FPCR_INV; |
| arith_excp(env, GETPC(), EXC_M_INV, 0); |
| } |
| } |
| |
| /* Input handing with software completion. Trap for denorms, unless DNZ |
| is set. If we try to support DNOD (which none of the produced hardware |
| did, AFAICS), we'll need to suppress the trap when FPCR.DNOD is set; |
| then the code downstream of that will need to cope with denorms sans |
| flush_input_to_zero. Most of it should work sanely, but there's |
| nothing to compare with. */ |
| void helper_ieee_input_s(CPUAlphaState *env, uint64_t val) |
| { |
| if (unlikely(2 * val - 1 < 0x1fffffffffffffull) |
| && !env->fp_status.flush_inputs_to_zero) { |
| arith_excp(env, GETPC(), EXC_M_INV | EXC_M_SWC, 0); |
| } |
| } |
| |
| /* S floating (single) */ |
| |
| /* Taken from linux/arch/alpha/kernel/traps.c, s_mem_to_reg. */ |
| static inline uint64_t float32_to_s_int(uint32_t fi) |
| { |
| uint32_t frac = fi & 0x7fffff; |
| uint32_t sign = fi >> 31; |
| uint32_t exp_msb = (fi >> 30) & 1; |
| uint32_t exp_low = (fi >> 23) & 0x7f; |
| uint32_t exp; |
| |
| exp = (exp_msb << 10) | exp_low; |
| if (exp_msb) { |
| if (exp_low == 0x7f) { |
| exp = 0x7ff; |
| } |
| } else { |
| if (exp_low != 0x00) { |
| exp |= 0x380; |
| } |
| } |
| |
| return (((uint64_t)sign << 63) |
| | ((uint64_t)exp << 52) |
| | ((uint64_t)frac << 29)); |
| } |
| |
| static inline uint64_t float32_to_s(float32 fa) |
| { |
| CPU_FloatU a; |
| a.f = fa; |
| return float32_to_s_int(a.l); |
| } |
| |
| static inline uint32_t s_to_float32_int(uint64_t a) |
| { |
| return ((a >> 32) & 0xc0000000) | ((a >> 29) & 0x3fffffff); |
| } |
| |
| static inline float32 s_to_float32(uint64_t a) |
| { |
| CPU_FloatU r; |
| r.l = s_to_float32_int(a); |
| return r.f; |
| } |
| |
| uint32_t helper_s_to_memory(uint64_t a) |
| { |
| return s_to_float32_int(a); |
| } |
| |
| uint64_t helper_memory_to_s(uint32_t a) |
| { |
| return float32_to_s_int(a); |
| } |
| |
| uint64_t helper_adds(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float32 fa, fb, fr; |
| |
| fa = s_to_float32(a); |
| fb = s_to_float32(b); |
| fr = float32_add(fa, fb, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float32_to_s(fr); |
| } |
| |
| uint64_t helper_subs(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float32 fa, fb, fr; |
| |
| fa = s_to_float32(a); |
| fb = s_to_float32(b); |
| fr = float32_sub(fa, fb, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float32_to_s(fr); |
| } |
| |
| uint64_t helper_muls(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float32 fa, fb, fr; |
| |
| fa = s_to_float32(a); |
| fb = s_to_float32(b); |
| fr = float32_mul(fa, fb, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float32_to_s(fr); |
| } |
| |
| uint64_t helper_divs(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float32 fa, fb, fr; |
| |
| fa = s_to_float32(a); |
| fb = s_to_float32(b); |
| fr = float32_div(fa, fb, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float32_to_s(fr); |
| } |
| |
| uint64_t helper_sqrts(CPUAlphaState *env, uint64_t a) |
| { |
| float32 fa, fr; |
| |
| fa = s_to_float32(a); |
| fr = float32_sqrt(fa, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float32_to_s(fr); |
| } |
| |
| |
| /* T floating (double) */ |
| static inline float64 t_to_float64(uint64_t a) |
| { |
| /* Memory format is the same as float64 */ |
| CPU_DoubleU r; |
| r.ll = a; |
| return r.d; |
| } |
| |
| static inline uint64_t float64_to_t(float64 fa) |
| { |
| /* Memory format is the same as float64 */ |
| CPU_DoubleU r; |
| r.d = fa; |
| return r.ll; |
| } |
| |
| uint64_t helper_addt(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float64 fa, fb, fr; |
| |
| fa = t_to_float64(a); |
| fb = t_to_float64(b); |
| fr = float64_add(fa, fb, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float64_to_t(fr); |
| } |
| |
| uint64_t helper_subt(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float64 fa, fb, fr; |
| |
| fa = t_to_float64(a); |
| fb = t_to_float64(b); |
| fr = float64_sub(fa, fb, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float64_to_t(fr); |
| } |
| |
| uint64_t helper_mult(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float64 fa, fb, fr; |
| |
| fa = t_to_float64(a); |
| fb = t_to_float64(b); |
| fr = float64_mul(fa, fb, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float64_to_t(fr); |
| } |
| |
| uint64_t helper_divt(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float64 fa, fb, fr; |
| |
| fa = t_to_float64(a); |
| fb = t_to_float64(b); |
| fr = float64_div(fa, fb, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float64_to_t(fr); |
| } |
| |
| uint64_t helper_sqrtt(CPUAlphaState *env, uint64_t a) |
| { |
| float64 fa, fr; |
| |
| fa = t_to_float64(a); |
| fr = float64_sqrt(fa, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float64_to_t(fr); |
| } |
| |
| /* Comparisons */ |
| uint64_t helper_cmptun(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float64 fa, fb; |
| uint64_t ret = 0; |
| |
| fa = t_to_float64(a); |
| fb = t_to_float64(b); |
| |
| if (float64_unordered_quiet(fa, fb, &FP_STATUS)) { |
| ret = 0x4000000000000000ULL; |
| } |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return ret; |
| } |
| |
| uint64_t helper_cmpteq(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float64 fa, fb; |
| uint64_t ret = 0; |
| |
| fa = t_to_float64(a); |
| fb = t_to_float64(b); |
| |
| if (float64_eq_quiet(fa, fb, &FP_STATUS)) { |
| ret = 0x4000000000000000ULL; |
| } |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return ret; |
| } |
| |
| uint64_t helper_cmptle(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float64 fa, fb; |
| uint64_t ret = 0; |
| |
| fa = t_to_float64(a); |
| fb = t_to_float64(b); |
| |
| if (float64_le(fa, fb, &FP_STATUS)) { |
| ret = 0x4000000000000000ULL; |
| } |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return ret; |
| } |
| |
| uint64_t helper_cmptlt(CPUAlphaState *env, uint64_t a, uint64_t b) |
| { |
| float64 fa, fb; |
| uint64_t ret = 0; |
| |
| fa = t_to_float64(a); |
| fb = t_to_float64(b); |
| |
| if (float64_lt(fa, fb, &FP_STATUS)) { |
| ret = 0x4000000000000000ULL; |
| } |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return ret; |
| } |
| |
| /* Floating point format conversion */ |
| uint64_t helper_cvtts(CPUAlphaState *env, uint64_t a) |
| { |
| float64 fa; |
| float32 fr; |
| |
| fa = t_to_float64(a); |
| fr = float64_to_float32(fa, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float32_to_s(fr); |
| } |
| |
| uint64_t helper_cvtst(CPUAlphaState *env, uint64_t a) |
| { |
| float32 fa; |
| float64 fr; |
| |
| fa = s_to_float32(a); |
| fr = float32_to_float64(fa, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float64_to_t(fr); |
| } |
| |
| uint64_t helper_cvtqs(CPUAlphaState *env, uint64_t a) |
| { |
| float32 fr = int64_to_float32(a, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| |
| return float32_to_s(fr); |
| } |
| |
| /* Implement float64 to uint64_t conversion without saturation -- we must |
| supply the truncated result. This behaviour is used by the compiler |
| to get unsigned conversion for free with the same instruction. */ |
| |
| static uint64_t do_cvttq(CPUAlphaState *env, uint64_t a, int roundmode) |
| { |
| uint64_t frac, ret = 0; |
| uint32_t exp, sign, exc = 0; |
| int shift; |
| |
| sign = (a >> 63); |
| exp = (uint32_t)(a >> 52) & 0x7ff; |
| frac = a & 0xfffffffffffffull; |
| |
| if (exp == 0) { |
| if (unlikely(frac != 0) && !env->fp_status.flush_inputs_to_zero) { |
| goto do_underflow; |
| } |
| } else if (exp == 0x7ff) { |
| exc = FPCR_INV; |
| } else { |
| /* Restore implicit bit. */ |
| frac |= 0x10000000000000ull; |
| |
| shift = exp - 1023 - 52; |
| if (shift >= 0) { |
| /* In this case the number is so large that we must shift |
| the fraction left. There is no rounding to do. */ |
| if (shift < 64) { |
| ret = frac << shift; |
| } |
| /* Check for overflow. Note the special case of -0x1p63. */ |
| if (shift >= 11 && a != 0xC3E0000000000000ull) { |
| exc = FPCR_IOV | FPCR_INE; |
| } |
| } else { |
| uint64_t round; |
| |
| /* In this case the number is smaller than the fraction as |
| represented by the 52 bit number. Here we must think |
| about rounding the result. Handle this by shifting the |
| fractional part of the number into the high bits of ROUND. |
| This will let us efficiently handle round-to-nearest. */ |
| shift = -shift; |
| if (shift < 63) { |
| ret = frac >> shift; |
| round = frac << (64 - shift); |
| } else { |
| /* The exponent is so small we shift out everything. |
| Leave a sticky bit for proper rounding below. */ |
| do_underflow: |
| round = 1; |
| } |
| |
| if (round) { |
| exc = FPCR_INE; |
| switch (roundmode) { |
| case float_round_nearest_even: |
| if (round == (1ull << 63)) { |
| /* Fraction is exactly 0.5; round to even. */ |
| ret += (ret & 1); |
| } else if (round > (1ull << 63)) { |
| ret += 1; |
| } |
| break; |
| case float_round_to_zero: |
| break; |
| case float_round_up: |
| ret += 1 - sign; |
| break; |
| case float_round_down: |
| ret += sign; |
| break; |
| } |
| } |
| } |
| if (sign) { |
| ret = -ret; |
| } |
| } |
| env->error_code = exc; |
| |
| return ret; |
| } |
| |
| uint64_t helper_cvttq(CPUAlphaState *env, uint64_t a) |
| { |
| return do_cvttq(env, a, FP_STATUS.float_rounding_mode); |
| } |
| |
| uint64_t helper_cvttq_c(CPUAlphaState *env, uint64_t a) |
| { |
| return do_cvttq(env, a, float_round_to_zero); |
| } |
| |
| uint64_t helper_cvtqt(CPUAlphaState *env, uint64_t a) |
| { |
| float64 fr = int64_to_float64(a, &FP_STATUS); |
| env->error_code = soft_to_fpcr_exc(env); |
| return float64_to_t(fr); |
| } |
| |
| uint64_t helper_cvtql(CPUAlphaState *env, uint64_t val) |
| { |
| uint32_t exc = 0; |
| if (val != (int32_t)val) { |
| exc = FPCR_IOV | FPCR_INE; |
| } |
| env->error_code = exc; |
| |
| return ((val & 0xc0000000) << 32) | ((val & 0x3fffffff) << 29); |
| } |