Erich E. Hoover : msvcrt: Implement wcstod without using 'long double'.
Alexandre Julliard
julliard at winehq.org
Fri Dec 20 14:07:23 CST 2019
Module: wine
Branch: master
Commit: a6734f549fc6f5d0a93364d159519a5d6d0b5f38
URL: https://source.winehq.org/git/wine.git/?a=commit;h=a6734f549fc6f5d0a93364d159519a5d6d0b5f38
Author: Erich E. Hoover <erich.e.hoover at gmail.com>
Date: Thu Dec 19 10:37:13 2019 -0700
msvcrt: Implement wcstod without using 'long double'.
Fix for the wide equivalent of strtod (see commit
c22af971c287933a137c9fbecc81823812e12b7a).
Signed-off-by: Erich E. Hoover <erich.e.hoover at gmail.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>
---
dlls/msvcrt/wcs.c | 65 ++++++++++++++++++++++++++++++++++++-------------------
1 file changed, 43 insertions(+), 22 deletions(-)
diff --git a/dlls/msvcrt/wcs.c b/dlls/msvcrt/wcs.c
index 8b240e97c0..855e3d8593 100644
--- a/dlls/msvcrt/wcs.c
+++ b/dlls/msvcrt/wcs.c
@@ -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);
-
- negexp = (exp < 0);
- if(negexp)
- exp = -exp;
- while(exp) {
- if(exp & 1)
- lret *= expcnt;
- exp /= 2;
- expcnt = expcnt*expcnt;
+ |MSVCRT__EM_OVERFLOW|MSVCRT__EM_UNDERFLOW|MSVCRT__EM_INEXACT|MSVCRT__PC_64,
+ MSVCRT__MCW_EM | MSVCRT__MCW_PC );
+
+ /* 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);
-
- _control87(fpcontrol, 0xffffffff);
+ /* 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, MSVCRT__MCW_EM | MSVCRT__MCW_PC );
if((d && ret==0.0) || isinf(ret))
*MSVCRT__errno() = MSVCRT_ERANGE;
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