/* * Helpers for vax 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) /* 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, uintptr_t 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, uintptr_t 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); } 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; } } 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); }