diff options
Diffstat (limited to 'misc')
| -rw-r--r-- | misc/efgcvt_r.c | 94 |
1 files changed, 71 insertions, 23 deletions
diff --git a/misc/efgcvt_r.c b/misc/efgcvt_r.c index e6030c8543..69caef01d7 100644 --- a/misc/efgcvt_r.c +++ b/misc/efgcvt_r.c @@ -37,6 +37,7 @@ #define FLOOR APPEND(floor, FLOAT_NAME_EXT) #define FABS APPEND(fabs, FLOAT_NAME_EXT) #define LOG10 APPEND(log10, FLOAT_NAME_EXT) +#define EXP APPEND(exp, FLOAT_NAME_EXT) int @@ -54,9 +55,12 @@ APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign, buf, len) return -1; } - *sign = value < 0.0; - if (*sign) - value = - value; + if (isfinite (value)) + { + *sign = signbit (value) != 0; + if (*sign) + value = -value; + } n = snprintf (buf, len, "%.*" FLOAT_FMT_FLAG "f", ndigit, value); if (n < 0) @@ -66,16 +70,29 @@ APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign, buf, len) while (i < n && isdigit (buf[i])) ++i; *decpt = i; - do - ++i; - while (! isdigit (buf[i])); - memmove (&buf[i - *decpt], buf, n - (i - *decpt)); + + if (i == 0) + { + /* Value is Inf or NaN. */ + *sign = 0; + return 0; + } + + if (i < n) + { + do + ++i; + while (i < n && !isdigit (buf[i])); + memmove (&buf[*decpt], &buf[i], n - i); + buf[n - (i - *decpt)] = 0; + } return 0; } #define weak_extern2(name) weak_extern (name) weak_extern2 (FLOOR) weak_extern2 (LOG10) weak_extern2 (FABS) +weak_extern2 (EXP) int APPEND (FUNC_PREFIX, ecvt_r) (value, ndigit, decpt, sign, buf, len) @@ -84,24 +101,55 @@ APPEND (FUNC_PREFIX, ecvt_r) (value, ndigit, decpt, sign, buf, len) char *buf; size_t len; { - FLOAT_TYPE (*log10_function) (FLOAT_TYPE) = &LOG10; + int exponent = 0; - if (log10_function) - { - /* Use the reasonable code if -lm is included. */ - ndigit -= (int) FLOOR (LOG10 (FABS (value))); - if (ndigit < 0) - ndigit = 0; - } - else + if (isfinite (value) && value != 0.0) { - /* Slow code that doesn't require -lm functions. */ - FLOAT_TYPE d; - for (d = value < 0.0 ? - value : value; - ndigit > 0 && d >= 10.0; - d *= 0.1) - --ndigit; + FLOAT_TYPE (*log10_function) (FLOAT_TYPE) = &LOG10; + + if (log10_function) + { + /* Use the reasonable code if -lm is included. */ + FLOAT_TYPE dexponent; + dexponent = FLOOR (LOG10 (FABS (value))); + value *= EXP (dexponent * -M_LN10); + exponent = (int) dexponent; + } + else + { + /* Slow code that doesn't require -lm functions. */ + FLOAT_TYPE d; + if (value < 0.0) + d = -value; + else + d = value; + if (d < 1.0) + { + do + { + d *= 10.0; + exponent--; + } + while (d < 1.0); + } + else if (d >= 10.0) + { + do + { + d *= 0.1; + exponent++; + } + while (d >= 10.0); + } + if (value < 0.0) + value = -d; + else + value = d; + } } - return APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit, decpt, sign, buf, len); + if (APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit - 1, decpt, sign, buf, len)) + return -1; + *decpt += exponent; + return 0; } |