diff options
Diffstat (limited to 'target-arm/helper.c')
| -rw-r--r-- | target-arm/helper.c | 133 |
1 files changed, 106 insertions, 27 deletions
diff --git a/target-arm/helper.c b/target-arm/helper.c index 535fc8f35e..55077ed1b6 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -4721,12 +4721,12 @@ float64 HELPER(recpe_f64)(float64 input, void *fpstp) /* The algorithm that must be used to calculate the estimate * is specified by the ARM ARM. */ -static float64 recip_sqrt_estimate(float64 a, CPUARMState *env) +static float64 recip_sqrt_estimate(float64 a, float_status *real_fp_status) { /* These calculations mustn't set any fp exception flags, * so we use a local copy of the fp_status. */ - float_status dummy_status = env->vfp.standard_fp_status; + float_status dummy_status = *real_fp_status; float_status *s = &dummy_status; float64 q; int64_t q_int; @@ -4773,49 +4773,64 @@ static float64 recip_sqrt_estimate(float64 a, CPUARMState *env) return float64_div(int64_to_float64(q_int, s), float64_256, s); } -float32 HELPER(rsqrte_f32)(float32 a, CPUARMState *env) +float32 HELPER(rsqrte_f32)(float32 input, void *fpstp) { - float_status *s = &env->vfp.standard_fp_status; + float_status *s = fpstp; + float32 f32 = float32_squash_input_denormal(input, s); + uint32_t val = float32_val(f32); + uint32_t f32_sbit = 0x80000000 & val; + int32_t f32_exp = extract32(val, 23, 8); + uint32_t f32_frac = extract32(val, 0, 23); + uint64_t f64_frac; + uint64_t val64; int result_exp; float64 f64; - uint32_t val; - uint64_t val64; - val = float32_val(a); - - if (float32_is_any_nan(a)) { - if (float32_is_signaling_nan(a)) { + if (float32_is_any_nan(f32)) { + float32 nan = f32; + if (float32_is_signaling_nan(f32)) { float_raise(float_flag_invalid, s); + nan = float32_maybe_silence_nan(f32); } - return float32_default_nan; - } else if (float32_is_zero_or_denormal(a)) { - if (!float32_is_zero(a)) { - float_raise(float_flag_input_denormal, s); + if (s->default_nan_mode) { + nan = float32_default_nan; } + return nan; + } else if (float32_is_zero(f32)) { float_raise(float_flag_divbyzero, s); - return float32_set_sign(float32_infinity, float32_is_neg(a)); - } else if (float32_is_neg(a)) { + return float32_set_sign(float32_infinity, float32_is_neg(f32)); + } else if (float32_is_neg(f32)) { float_raise(float_flag_invalid, s); return float32_default_nan; - } else if (float32_is_infinity(a)) { + } else if (float32_is_infinity(f32)) { return float32_zero; } - /* Normalize to a double-precision value between 0.25 and 1.0, + /* Scale and normalize to a double-precision value between 0.25 and 1.0, * preserving the parity of the exponent. */ - if ((val & 0x800000) == 0) { - f64 = make_float64(((uint64_t)(val & 0x80000000) << 32) + + f64_frac = ((uint64_t) f32_frac) << 29; + if (f32_exp == 0) { + while (extract64(f64_frac, 51, 1) == 0) { + f64_frac = f64_frac << 1; + f32_exp = f32_exp-1; + } + f64_frac = extract64(f64_frac, 0, 51) << 1; + } + + if (extract64(f32_exp, 0, 1) == 0) { + f64 = make_float64(((uint64_t) f32_sbit) << 32 | (0x3feULL << 52) - | ((uint64_t)(val & 0x7fffff) << 29)); + | f64_frac); } else { - f64 = make_float64(((uint64_t)(val & 0x80000000) << 32) + f64 = make_float64(((uint64_t) f32_sbit) << 32 | (0x3fdULL << 52) - | ((uint64_t)(val & 0x7fffff) << 29)); + | f64_frac); } - result_exp = (380 - ((val & 0x7f800000) >> 23)) / 2; + result_exp = (380 - f32_exp) / 2; - f64 = recip_sqrt_estimate(f64, env); + f64 = recip_sqrt_estimate(f64, s); val64 = float64_val(f64); @@ -4824,6 +4839,69 @@ float32 HELPER(rsqrte_f32)(float32 a, CPUARMState *env) return make_float32(val); } +float64 HELPER(rsqrte_f64)(float64 input, void *fpstp) +{ + float_status *s = fpstp; + float64 f64 = float64_squash_input_denormal(input, s); + uint64_t val = float64_val(f64); + uint64_t f64_sbit = 0x8000000000000000ULL & val; + int64_t f64_exp = extract64(val, 52, 11); + uint64_t f64_frac = extract64(val, 0, 52); + int64_t result_exp; + uint64_t result_frac; + + if (float64_is_any_nan(f64)) { + float64 nan = f64; + if (float64_is_signaling_nan(f64)) { + float_raise(float_flag_invalid, s); + nan = float64_maybe_silence_nan(f64); + } + if (s->default_nan_mode) { + nan = float64_default_nan; + } + return nan; + } else if (float64_is_zero(f64)) { + float_raise(float_flag_divbyzero, s); + return float64_set_sign(float64_infinity, float64_is_neg(f64)); + } else if (float64_is_neg(f64)) { + float_raise(float_flag_invalid, s); + return float64_default_nan; + } else if (float64_is_infinity(f64)) { + return float64_zero; + } + + /* Scale and normalize to a double-precision value between 0.25 and 1.0, + * preserving the parity of the exponent. */ + + if (f64_exp == 0) { + while (extract64(f64_frac, 51, 1) == 0) { + f64_frac = f64_frac << 1; + f64_exp = f64_exp - 1; + } + f64_frac = extract64(f64_frac, 0, 51) << 1; + } + + if (extract64(f64_exp, 0, 1) == 0) { + f64 = make_float64(f64_sbit + | (0x3feULL << 52) + | f64_frac); + } else { + f64 = make_float64(f64_sbit + | (0x3fdULL << 52) + | f64_frac); + } + + result_exp = (3068 - f64_exp) / 2; + + f64 = recip_sqrt_estimate(f64, s); + + result_frac = extract64(float64_val(f64), 0, 52); + + return make_float64(f64_sbit | + ((result_exp & 0x7ff) << 52) | + result_frac); +} + uint32_t HELPER(recpe_u32)(uint32_t a, void *fpstp) { float_status *s = fpstp; @@ -4841,8 +4919,9 @@ uint32_t HELPER(recpe_u32)(uint32_t a, void *fpstp) return 0x80000000 | ((float64_val(f64) >> 21) & 0x7fffffff); } -uint32_t HELPER(rsqrte_u32)(uint32_t a, CPUARMState *env) +uint32_t HELPER(rsqrte_u32)(uint32_t a, void *fpstp) { + float_status *fpst = fpstp; float64 f64; if ((a & 0xc0000000) == 0) { @@ -4857,7 +4936,7 @@ uint32_t HELPER(rsqrte_u32)(uint32_t a, CPUARMState *env) | ((uint64_t)(a & 0x3fffffff) << 22)); } - f64 = recip_sqrt_estimate(f64, env); + f64 = recip_sqrt_estimate(f64, fpst); return 0x80000000 | ((float64_val(f64) >> 21) & 0x7fffffff); } |