msvcrt: Implement wcstod without using 'long double'.

Fix for the wide equivalent of strtod (see commit
c22af971c2).

Signed-off-by: Erich E. Hoover <erich.e.hoover@gmail.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
This commit is contained in:
Erich E. Hoover 2019-12-19 10:37:13 -07:00 committed by Alexandre Julliard
parent 296a1eb77b
commit a6734f549f

View file

@ -381,20 +381,30 @@ int CDECL MSVCRT__wcsncoll(const MSVCRT_wchar_t* str1, const MSVCRT_wchar_t* str
return MSVCRT__wcsncoll_l(str1, str2, count, NULL);
}
static double MSVCRT_mul_pow10(double x, int exp)
{
BOOL negexp = (exp < 0);
double ret;
if(negexp)
exp = -exp;
ret = pow(10.0, exp);
return (negexp ? x/ret : x*ret);
}
/*********************************************************************
* _wcstod_l (MSVCRT.@)
*/
double CDECL MSVCRT__wcstod_l(const MSVCRT_wchar_t* str, MSVCRT_wchar_t** end,
MSVCRT__locale_t locale)
{
BOOL found_digit = FALSE, overflow, underflow;
int exp1=0, exp2=0, exp3=0, sign=1;
MSVCRT_pthreadlocinfo locinfo;
unsigned __int64 d=0, hlp;
unsigned fpcontrol;
int exp=0, sign=1;
const MSVCRT_wchar_t *p;
double ret;
long double lret=1, expcnt = 10;
BOOL found_digit = FALSE, negexp;
if (!MSVCRT_CHECK_PMT(str != NULL)) return 0;
@ -417,13 +427,13 @@ double CDECL MSVCRT__wcstod_l(const MSVCRT_wchar_t* str, MSVCRT_wchar_t** end,
found_digit = TRUE;
hlp = d*10+*(p++)-'0';
if(d>MSVCRT_UI64_MAX/10 || hlp<d) {
exp++;
exp1++;
break;
} else
d = hlp;
}
while(*p>='0' && *p<='9') {
exp++;
exp1++;
p++;
}
if(*p == *locinfo->lconv->decimal_point)
@ -436,7 +446,7 @@ double CDECL MSVCRT__wcstod_l(const MSVCRT_wchar_t* str, MSVCRT_wchar_t** end,
break;
d = hlp;
exp--;
exp1--;
}
while(*p>='0' && *p<='9')
p++;
@ -465,9 +475,9 @@ double CDECL MSVCRT__wcstod_l(const MSVCRT_wchar_t* str, MSVCRT_wchar_t** end,
}
e *= s;
if(exp<0 && e<0 && exp+e>=0) exp = INT_MIN;
else if(exp>0 && e>0 && exp+e<0) exp = INT_MAX;
else exp += e;
if(exp1<0 && e<0 && exp1+e>=0) exp1 = INT_MIN;
else if(exp1>0 && e>0 && exp1+e<0) exp1 = INT_MAX;
else exp3 += e;
} else {
if(*p=='-' || *p=='+')
p--;
@ -477,20 +487,31 @@ double CDECL MSVCRT__wcstod_l(const MSVCRT_wchar_t* str, MSVCRT_wchar_t** end,
fpcontrol = _control87(0, 0);
_control87(MSVCRT__EM_DENORMAL|MSVCRT__EM_INVALID|MSVCRT__EM_ZERODIVIDE
|MSVCRT__EM_OVERFLOW|MSVCRT__EM_UNDERFLOW|MSVCRT__EM_INEXACT, 0xffffffff);
|MSVCRT__EM_OVERFLOW|MSVCRT__EM_UNDERFLOW|MSVCRT__EM_INEXACT|MSVCRT__PC_64,
MSVCRT__MCW_EM | MSVCRT__MCW_PC );
negexp = (exp < 0);
if(negexp)
exp = -exp;
while(exp) {
if(exp & 1)
lret *= expcnt;
exp /= 2;
expcnt = expcnt*expcnt;
/* if we have a simple case then just calculate the result directly */
overflow = (exp3-exp1 > MSVCRT_DBL_MAX_10_EXP);
underflow = (exp3-exp1 < MSVCRT_DBL_MIN_10_EXP);
if(!overflow && !underflow) {
exp1 += exp3;
exp3 = 0;
}
ret = (long double)sign * (negexp ? d/lret : d*lret);
/* take the number without exponent and convert it into a double */
ret = MSVCRT_mul_pow10(d, exp1);
/* shift the number to the representation where the first non-zero digit is in the ones place */
if(overflow || underflow)
exp2 = (ret != 0.0 ? (int)log10(ret) : 0);
/* incorporate an additional shift to deal with floating point denormal values (if necessary) */
if(exp3-exp2 < MSVCRT_DBL_MIN_10_EXP)
exp2 += exp3-exp2-MSVCRT_DBL_MIN_10_EXP;
ret = MSVCRT_mul_pow10(ret, exp2);
/* apply the exponent (and undo any shift) */
ret = MSVCRT_mul_pow10(ret, exp3-exp2);
/* apply the sign bit */
ret *= sign;
_control87(fpcontrol, 0xffffffff);
_control87( fpcontrol, MSVCRT__MCW_EM | MSVCRT__MCW_PC );
if((d && ret==0.0) || isinf(ret))
*MSVCRT__errno() = MSVCRT_ERANGE;