diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2018-10-11 16:41:55 -0700 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2018-11-08 12:04:40 +1100 |
| commit | 0394d7a68474f4144d7e2f5eb9dd8e6a87d01bef (patch) | |
| tree | 8f4077981d5cfb78ba24d585b7c2123c38f98dd7 /target/ppc/fpu_helper.c | |
| parent | 6525aadc1201ae55e18cedaa8a9f2d1831e700f8 (diff) | |
target/ppc: Introduce fp number classification
Having a separate, logical classifiation of numbers will
unify more error paths for different formats.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'target/ppc/fpu_helper.c')
| -rw-r--r-- | target/ppc/fpu_helper.c | 94 |
1 files changed, 51 insertions, 43 deletions
diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c index c9198f826d..9ae55b1e93 100644 --- a/target/ppc/fpu_helper.c +++ b/target/ppc/fpu_helper.c @@ -114,54 +114,62 @@ static inline int ppc_float64_get_unbiased_exp(float64 f) return ((f >> 52) & 0x7FF) - 1023; } -#define COMPUTE_FPRF(tp) \ -void helper_compute_fprf_##tp(CPUPPCState *env, tp arg) \ +/* Classify a floating-point number. */ +enum { + is_normal = 1, + is_zero = 2, + is_denormal = 4, + is_inf = 8, + is_qnan = 16, + is_snan = 32, + is_neg = 64, +}; + +#define COMPUTE_CLASS(tp) \ +static int tp##_classify(tp arg) \ { \ - int isneg; \ - int fprf; \ - \ - isneg = tp##_is_neg(arg); \ + int ret = tp##_is_neg(arg) * is_neg; \ if (unlikely(tp##_is_any_nan(arg))) { \ - if (tp##_is_signaling_nan(arg, &env->fp_status)) { \ - /* Signaling NaN: flags are undefined */ \ - fprf = 0x00; \ - } else { \ - /* Quiet NaN */ \ - fprf = 0x11; \ - } \ + float_status dummy = { }; /* snan_bit_is_one = 0 */ \ + ret |= (tp##_is_signaling_nan(arg, &dummy) \ + ? is_snan : is_qnan); \ } else if (unlikely(tp##_is_infinity(arg))) { \ - /* +/- infinity */ \ - if (isneg) { \ - fprf = 0x09; \ - } else { \ - fprf = 0x05; \ - } \ + ret |= is_inf; \ + } else if (tp##_is_zero(arg)) { \ + ret |= is_zero; \ + } else if (tp##_is_zero_or_denormal(arg)) { \ + ret |= is_denormal; \ } else { \ - if (tp##_is_zero(arg)) { \ - /* +/- zero */ \ - if (isneg) { \ - fprf = 0x12; \ - } else { \ - fprf = 0x02; \ - } \ - } else { \ - if (tp##_is_zero_or_denormal(arg)) { \ - /* Denormalized numbers */ \ - fprf = 0x10; \ - } else { \ - /* Normalized numbers */ \ - fprf = 0x00; \ - } \ - if (isneg) { \ - fprf |= 0x08; \ - } else { \ - fprf |= 0x04; \ - } \ - } \ + ret |= is_normal; \ } \ - /* We update FPSCR_FPRF */ \ - env->fpscr &= ~(0x1F << FPSCR_FPRF); \ - env->fpscr |= fprf << FPSCR_FPRF; \ + return ret; \ +} + +COMPUTE_CLASS(float16) +COMPUTE_CLASS(float32) +COMPUTE_CLASS(float64) +COMPUTE_CLASS(float128) + +static void set_fprf_from_class(CPUPPCState *env, int class) +{ + static const uint8_t fprf[6][2] = { + { 0x04, 0x08 }, /* normalized */ + { 0x02, 0x12 }, /* zero */ + { 0x14, 0x18 }, /* denormalized */ + { 0x05, 0x09 }, /* infinity */ + { 0x11, 0x11 }, /* qnan */ + { 0x00, 0x00 }, /* snan -- flags are undefined */ + }; + bool isneg = class & is_neg; + + env->fpscr &= ~(0x1F << FPSCR_FPRF); + env->fpscr |= fprf[ctz32(class)][isneg] << FPSCR_FPRF; +} + +#define COMPUTE_FPRF(tp) \ +void helper_compute_fprf_##tp(CPUPPCState *env, tp arg) \ +{ \ + set_fprf_from_class(env, tp##_classify(arg)); \ } COMPUTE_FPRF(float16) |