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Re: real_from_string fails to convert negative values
On Sun, Sep 29, 2002 at 10:45:44AM -0700, Richard Henderson wrote:
> On Sat, Sep 28, 2002 at 10:37:21PM +0100, Paul Brook wrote:
> > The real_from_string function in real.c doesn't seem to convert negative
> > numbers correctly. It seems to return the absolute (ie. positive) value of
> > the value, and ignore any preceeding - signs.
>
> Sure enough. The existing code only works for -0. I'll have it fixed
> in a moment.
Like so.
r~
* real.c (real_from_string): Apply sign last. Tidy exponent handling.
Index: real.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/real.c,v
retrieving revision 1.94
diff -c -p -d -u -r1.94 real.c
--- real.c 29 Sep 2002 21:23:45 -0000 1.94
+++ real.c 30 Sep 2002 05:59:36 -0000
@@ -1579,12 +1579,13 @@ real_from_string (r, str)
const char *str;
{
int exp = 0;
+ bool sign = false;
get_zero (r, 0);
if (*str == '-')
{
- r->sign = 1;
+ sign = true;
str++;
}
else if (*str == '+')
@@ -1616,6 +1617,11 @@ real_from_string (r, str)
if (*str == '.')
{
str++;
+ if (pos == SIGNIFICAND_BITS - 4)
+ {
+ while (*str == '0')
+ str++, exp -= 4;
+ }
while (1)
{
d = hex_value (*str);
@@ -1632,12 +1638,12 @@ real_from_string (r, str)
}
if (*str == 'p' || *str == 'P')
{
- int exp_neg = 0;
+ bool exp_neg = false;
str++;
if (*str == '-')
{
- exp_neg = 1;
+ exp_neg = true;
str++;
}
else if (*str == '+')
@@ -1646,10 +1652,9 @@ real_from_string (r, str)
d = 0;
while (ISDIGIT (*str))
{
- int t = d;
d *= 10;
d += *str - '0';
- if (d < t)
+ if (d > MAX_EXP)
{
/* Overflowed the exponent. */
if (exp_neg)
@@ -1667,13 +1672,6 @@ real_from_string (r, str)
r->class = rvc_normal;
r->exp = exp;
- if (r->exp != exp)
- {
- if (exp < 0)
- goto underflow;
- else
- goto overflow;
- }
normalize (r);
}
@@ -1695,6 +1693,11 @@ real_from_string (r, str)
if (*str == '.')
{
str++;
+ if (r->class == rvc_zero)
+ {
+ while (*str == '0')
+ str++, exp--;
+ }
while (ISDIGIT (*str))
{
d = *str++ - '0';
@@ -1707,12 +1710,12 @@ real_from_string (r, str)
if (*str == 'e' || *str == 'E')
{
- int exp_neg = 0;
+ bool exp_neg = false;
str++;
if (*str == '-')
{
- exp_neg = 1;
+ exp_neg = true;
str++;
}
else if (*str == '+')
@@ -1721,10 +1724,9 @@ real_from_string (r, str)
d = 0;
while (ISDIGIT (*str))
{
- int t = d;
d *= 10;
d += *str - '0';
- if (d < t)
+ if (d > MAX_EXP)
{
/* Overflowed the exponent. */
if (exp_neg)
@@ -1754,14 +1756,15 @@ real_from_string (r, str)
}
}
+ r->sign = sign;
return;
underflow:
- get_zero (r, r->sign);
+ get_zero (r, sign);
return;
overflow:
- get_inf (r, r->sign);
+ get_inf (r, sign);
return;
}