diff options
Diffstat (limited to 'target-alpha/fpu_helper.c')
| -rw-r--r-- | target-alpha/fpu_helper.c | 822 |
1 files changed, 822 insertions, 0 deletions
diff --git a/target-alpha/fpu_helper.c b/target-alpha/fpu_helper.c new file mode 100644 index 0000000000..dda110352e --- /dev/null +++ b/target-alpha/fpu_helper.c @@ -0,0 +1,822 @@ +/* + * 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 "cpu.h" +#include "helper.h" +#include "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); +} + +void helper_fp_exc_clear(CPUAlphaState *env) +{ + set_float_exception_flags(0, &FP_STATUS); +} + +uint32_t helper_fp_exc_get(CPUAlphaState *env) +{ + return get_float_exception_flags(&FP_STATUS); +} + +static inline void inline_fp_exc_raise(CPUAlphaState *env, void *retaddr, + uint32_t exc, uint32_t regno) +{ + if (exc) { + uint32_t hw_exc = 0; + + if (exc & float_flag_invalid) { + hw_exc |= EXC_M_INV; + } + if (exc & float_flag_divbyzero) { + hw_exc |= EXC_M_DZE; + } + if (exc & float_flag_overflow) { + hw_exc |= EXC_M_FOV; + } + if (exc & float_flag_underflow) { + hw_exc |= EXC_M_UNF; + } + if (exc & float_flag_inexact) { + hw_exc |= EXC_M_INE; + } + + 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 exc, uint32_t regno) +{ + inline_fp_exc_raise(env, GETPC(), exc, regno); +} + +/* Raise exceptions for ieee fp insns with software completion. */ +void helper_fp_exc_raise_s(CPUAlphaState *env, uint32_t exc, uint32_t regno) +{ + if (exc) { + env->fpcr_exc_status |= exc; + exc &= ~env->fpcr_exc_mask; + inline_fp_exc_raise(env, GETPC(), exc, regno); + } +} + +/* 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 DNZ set raise an exception. */ + if (frac != 0 && !env->fp_status.flush_inputs_to_zero) { + arith_excp(env, GETPC(), EXC_M_UNF, 0); + } + } else if (exp == 0x7ff) { + /* Infinity or NaN. */ + /* ??? I'm not sure these exception bit flags are correct. I do + know that the Linux kernel, at least, doesn't rely on them and + just emulates the insn to figure out what exception to use. */ + arith_excp(env, GETPC(), frac ? EXC_M_INV : EXC_M_FOV, 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 DNZ set raise an exception. */ + if (frac != 0 && !env->fp_status.flush_inputs_to_zero) { + arith_excp(env, GETPC(), EXC_M_UNF, 0); + } + } else if (exp == 0x7ff && frac) { + /* NaN. */ + arith_excp(env, GETPC(), EXC_M_INV, 0); + } +} + +/* F floating (VAX) */ +static uint64_t float32_to_f(float32 fa) +{ + uint64_t r, exp, mant, sig; + CPU_FloatU a; + + a.f = fa; + sig = ((uint64_t)a.l & 0x80000000) << 32; + exp = (a.l >> 23) & 0xff; + mant = ((uint64_t)a.l & 0x007fffff) << 29; + + if (exp == 255) { + /* NaN or infinity */ + r = 1; /* VAX dirty zero */ + } else if (exp == 0) { + if (mant == 0) { + /* Zero */ + r = 0; + } else { + /* Denormalized */ + r = sig | ((exp + 1) << 52) | mant; + } + } else { + if (exp >= 253) { + /* Overflow */ + r = 1; /* VAX dirty zero */ + } else { + r = sig | ((exp + 2) << 52); + } + } + + return r; +} + +static float32 f_to_float32(CPUAlphaState *env, void *retaddr, uint64_t a) +{ + uint32_t exp, mant_sig; + CPU_FloatU r; + + exp = ((a >> 55) & 0x80) | ((a >> 52) & 0x7f); + mant_sig = ((a >> 32) & 0x80000000) | ((a >> 29) & 0x007fffff); + + if (unlikely(!exp && mant_sig)) { + /* Reserved operands / Dirty zero */ + dynamic_excp(env, retaddr, EXCP_OPCDEC, 0); + } + + if (exp < 3) { + /* Underflow */ + r.l = 0; + } else { + r.l = ((exp - 2) << 23) | mant_sig; + } + + return r.f; +} + +uint32_t helper_f_to_memory(uint64_t a) +{ + uint32_t r; + r = (a & 0x00001fffe0000000ull) >> 13; + r |= (a & 0x07ffe00000000000ull) >> 45; + r |= (a & 0xc000000000000000ull) >> 48; + return r; +} + +uint64_t helper_memory_to_f(uint32_t a) +{ + uint64_t r; + r = ((uint64_t)(a & 0x0000c000)) << 48; + r |= ((uint64_t)(a & 0x003fffff)) << 45; + r |= ((uint64_t)(a & 0xffff0000)) << 13; + if (!(a & 0x00004000)) { + r |= 0x7ll << 59; + } + return r; +} + +/* ??? Emulating VAX arithmetic with IEEE arithmetic is wrong. We should + either implement VAX arithmetic properly or just signal invalid opcode. */ + +uint64_t helper_addf(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float32 fa, fb, fr; + + fa = f_to_float32(env, GETPC(), a); + fb = f_to_float32(env, GETPC(), b); + fr = float32_add(fa, fb, &FP_STATUS); + return float32_to_f(fr); +} + +uint64_t helper_subf(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float32 fa, fb, fr; + + fa = f_to_float32(env, GETPC(), a); + fb = f_to_float32(env, GETPC(), b); + fr = float32_sub(fa, fb, &FP_STATUS); + return float32_to_f(fr); +} + +uint64_t helper_mulf(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float32 fa, fb, fr; + + fa = f_to_float32(env, GETPC(), a); + fb = f_to_float32(env, GETPC(), b); + fr = float32_mul(fa, fb, &FP_STATUS); + return float32_to_f(fr); +} + +uint64_t helper_divf(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float32 fa, fb, fr; + + fa = f_to_float32(env, GETPC(), a); + fb = f_to_float32(env, GETPC(), b); + fr = float32_div(fa, fb, &FP_STATUS); + return float32_to_f(fr); +} + +uint64_t helper_sqrtf(CPUAlphaState *env, uint64_t t) +{ + float32 ft, fr; + + ft = f_to_float32(env, GETPC(), t); + fr = float32_sqrt(ft, &FP_STATUS); + return float32_to_f(fr); +} + + +/* G floating (VAX) */ +static uint64_t float64_to_g(float64 fa) +{ + uint64_t r, exp, mant, sig; + CPU_DoubleU a; + + a.d = fa; + sig = a.ll & 0x8000000000000000ull; + exp = (a.ll >> 52) & 0x7ff; + mant = a.ll & 0x000fffffffffffffull; + + if (exp == 2047) { + /* NaN or infinity */ + r = 1; /* VAX dirty zero */ + } else if (exp == 0) { + if (mant == 0) { + /* Zero */ + r = 0; + } else { + /* Denormalized */ + r = sig | ((exp + 1) << 52) | mant; + } + } else { + if (exp >= 2045) { + /* Overflow */ + r = 1; /* VAX dirty zero */ + } else { + r = sig | ((exp + 2) << 52); + } + } + + return r; +} + +static float64 g_to_float64(CPUAlphaState *env, void *retaddr, uint64_t a) +{ + uint64_t exp, mant_sig; + CPU_DoubleU r; + + exp = (a >> 52) & 0x7ff; + mant_sig = a & 0x800fffffffffffffull; + + if (!exp && mant_sig) { + /* Reserved operands / Dirty zero */ + dynamic_excp(env, retaddr, EXCP_OPCDEC, 0); + } + + if (exp < 3) { + /* Underflow */ + r.ll = 0; + } else { + r.ll = ((exp - 2) << 52) | mant_sig; + } + + return r.d; +} + +uint64_t helper_g_to_memory(uint64_t a) +{ + uint64_t r; + r = (a & 0x000000000000ffffull) << 48; + r |= (a & 0x00000000ffff0000ull) << 16; + r |= (a & 0x0000ffff00000000ull) >> 16; + r |= (a & 0xffff000000000000ull) >> 48; + return r; +} + +uint64_t helper_memory_to_g(uint64_t a) +{ + uint64_t r; + r = (a & 0x000000000000ffffull) << 48; + r |= (a & 0x00000000ffff0000ull) << 16; + r |= (a & 0x0000ffff00000000ull) >> 16; + r |= (a & 0xffff000000000000ull) >> 48; + return r; +} + +uint64_t helper_addg(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb, fr; + + fa = g_to_float64(env, GETPC(), a); + fb = g_to_float64(env, GETPC(), b); + fr = float64_add(fa, fb, &FP_STATUS); + return float64_to_g(fr); +} + +uint64_t helper_subg(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb, fr; + + fa = g_to_float64(env, GETPC(), a); + fb = g_to_float64(env, GETPC(), b); + fr = float64_sub(fa, fb, &FP_STATUS); + return float64_to_g(fr); +} + +uint64_t helper_mulg(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb, fr; + + fa = g_to_float64(env, GETPC(), a); + fb = g_to_float64(env, GETPC(), b); + fr = float64_mul(fa, fb, &FP_STATUS); + return float64_to_g(fr); +} + +uint64_t helper_divg(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb, fr; + + fa = g_to_float64(env, GETPC(), a); + fb = g_to_float64(env, GETPC(), b); + fr = float64_div(fa, fb, &FP_STATUS); + return float64_to_g(fr); +} + +uint64_t helper_sqrtg(CPUAlphaState *env, uint64_t a) +{ + float64 fa, fr; + + fa = g_to_float64(env, GETPC(), a); + fr = float64_sqrt(fa, &FP_STATUS); + return float64_to_g(fr); +} + + +/* 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); + 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); + 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); + 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); + 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); + 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); + 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); + 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); + 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); + 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); + return float64_to_t(fr); +} + +/* Comparisons */ +uint64_t helper_cmptun(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb; + + fa = t_to_float64(a); + fb = t_to_float64(b); + + if (float64_unordered_quiet(fa, fb, &FP_STATUS)) { + return 0x4000000000000000ULL; + } else { + return 0; + } +} + +uint64_t helper_cmpteq(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb; + + fa = t_to_float64(a); + fb = t_to_float64(b); + + if (float64_eq_quiet(fa, fb, &FP_STATUS)) { + return 0x4000000000000000ULL; + } else { + return 0; + } +} + +uint64_t helper_cmptle(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb; + + fa = t_to_float64(a); + fb = t_to_float64(b); + + if (float64_le(fa, fb, &FP_STATUS)) { + return 0x4000000000000000ULL; + } else { + return 0; + } +} + +uint64_t helper_cmptlt(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb; + + fa = t_to_float64(a); + fb = t_to_float64(b); + + if (float64_lt(fa, fb, &FP_STATUS)) { + return 0x4000000000000000ULL; + } else { + return 0; + } +} + +uint64_t helper_cmpgeq(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb; + + fa = g_to_float64(env, GETPC(), a); + fb = g_to_float64(env, GETPC(), b); + + if (float64_eq_quiet(fa, fb, &FP_STATUS)) { + return 0x4000000000000000ULL; + } else { + return 0; + } +} + +uint64_t helper_cmpgle(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb; + + fa = g_to_float64(env, GETPC(), a); + fb = g_to_float64(env, GETPC(), b); + + if (float64_le(fa, fb, &FP_STATUS)) { + return 0x4000000000000000ULL; + } else { + return 0; + } +} + +uint64_t helper_cmpglt(CPUAlphaState *env, uint64_t a, uint64_t b) +{ + float64 fa, fb; + + fa = g_to_float64(env, GETPC(), a); + fb = g_to_float64(env, GETPC(), b); + + if (float64_lt(fa, fb, &FP_STATUS)) { + return 0x4000000000000000ULL; + } else { + return 0; + } +} + +/* 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); + 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); + return float64_to_t(fr); +} + +uint64_t helper_cvtqs(CPUAlphaState *env, uint64_t a) +{ + float32 fr = int64_to_float32(a, &FP_STATUS); + return float32_to_s(fr); +} + +/* Implement float64 to uint64 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. + + The VI flag is set when overflow or inexact exceptions should be raised. */ + +static inline uint64_t inline_cvttq(CPUAlphaState *env, uint64_t a, + int roundmode, int VI) +{ + 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)) { + goto do_underflow; + } + } else if (exp == 0x7ff) { + exc = (frac ? float_flag_invalid : VI ? float_flag_overflow : 0); + } 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 < 63) { + ret = frac << shift; + if (VI && (ret >> shift) != frac) { + exc = float_flag_overflow; + } + } + } 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 = (VI ? float_flag_inexact : 0); + 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; + } + } + if (unlikely(exc)) { + float_raise(exc, &FP_STATUS); + } + + return ret; +} + +uint64_t helper_cvttq(CPUAlphaState *env, uint64_t a) +{ + return inline_cvttq(env, a, FP_STATUS.float_rounding_mode, 1); +} + +uint64_t helper_cvttq_c(CPUAlphaState *env, uint64_t a) +{ + return inline_cvttq(env, a, float_round_to_zero, 0); +} + +uint64_t helper_cvttq_svic(CPUAlphaState *env, uint64_t a) +{ + return inline_cvttq(env, a, float_round_to_zero, 1); +} + +uint64_t helper_cvtqt(CPUAlphaState *env, uint64_t a) +{ + float64 fr = int64_to_float64(a, &FP_STATUS); + return float64_to_t(fr); +} + +uint64_t helper_cvtqf(CPUAlphaState *env, uint64_t a) +{ + float32 fr = int64_to_float32(a, &FP_STATUS); + return float32_to_f(fr); +} + +uint64_t helper_cvtgf(CPUAlphaState *env, uint64_t a) +{ + float64 fa; + float32 fr; + + fa = g_to_float64(env, GETPC(), a); + fr = float64_to_float32(fa, &FP_STATUS); + return float32_to_f(fr); +} + +uint64_t helper_cvtgq(CPUAlphaState *env, uint64_t a) +{ + float64 fa = g_to_float64(env, GETPC(), a); + return float64_to_int64_round_to_zero(fa, &FP_STATUS); +} + +uint64_t helper_cvtqg(CPUAlphaState *env, uint64_t a) +{ + float64 fr; + fr = int64_to_float64(a, &FP_STATUS); + return float64_to_g(fr); +} |