Hi,
The attached patch does some cleanup and a check for trailing zeros to decide
whether or not to round.
I have added the additional test cases posted on the bugzilla to the existing
test case round_3.f08.
Regression tested on x86-64.
OK for trunk and then I will back port the whole enchilada to 4.6.1 in a few
weeks. Please consider the starting point of the zero scan carefully. I have
not convinced myself that the d * p covers all cases, but it works for all cases
I have tried.
Regards,
Jerry
2011-04-29 Jerry DeLisle <jvdeli...@gcc.gnu.org>
PR libgfortran/48787
* io/write_float.def (output_float): Gather up integer declarations and
add new 'p' for scale factor. Use 'p' in place of the 'dtp' reference
everywhere. For ROUND_UP scan the digit string and only perform
rounding if something other than '0' is found.
Index: gcc/testsuite/gfortran.dg/round_3.f08
===================================================================
--- gcc/testsuite/gfortran.dg/round_3.f08 (revision 173197)
+++ gcc/testsuite/gfortran.dg/round_3.f08 (working copy)
@@ -4,10 +4,17 @@
program pr48615
call checkfmt("(RU,F17.0)", 2.5, " 3.")
call checkfmt("(RU,-1P,F17.1)", 2.5, " 0.3")
- call checkfmt("(RU,E17.1)", 2.5, " 0.3E+01") ! 0.2E+01
+ call checkfmt("(RU,E17.1)", 2.5, " 0.3E+01")
call checkfmt("(RU,1P,E17.0)", 2.5, " 3.E+00")
- call checkfmt("(RU,ES17.0)", 2.5, " 3.E+00") ! 2.E+00
+ call checkfmt("(RU,ES17.0)", 2.5, " 3.E+00")
call checkfmt("(RU,EN17.0)", 2.5, " 3.E+00")
+ call checkfmt("(RU,F2.0)", 2.0, "2.")
+ call checkfmt("(RU,F6.4)", 2.0, "2.0000")
+ call checkfmt("(RU,1P,E6.0E2)", 2.0, "2.E+00")
+ call checkfmt("(RU,1P,E7.1E2)", 2.5, "2.5E+00")
+ call checkfmt("(RU,1P,E10.4E2)", 2.5, "2.5000E+00")
+ call checkfmt("(RU,1P,G6.0E2)", 2.0, "2.E+00")
+ call checkfmt("(RU,1P,G10.4E2)", 2.3456e5, "2.3456E+05")
call checkfmt("(RD,F17.0)", 2.5, " 2.")
call checkfmt("(RD,-1P,F17.1)", 2.5, " 0.2")
@@ -18,9 +25,9 @@ program pr48615
call checkfmt("(RC,F17.0)", 2.5, " 3.")
call checkfmt("(RC,-1P,F17.1)", 2.5, " 0.3")
- call checkfmt("(RC,E17.1)", 2.5, " 0.3E+01") ! 0.2E+01
+ call checkfmt("(RC,E17.1)", 2.5, " 0.3E+01")
call checkfmt("(RC,1P,E17.0)", 2.5, " 3.E+00")
- call checkfmt("(RC,ES17.0)", 2.5, " 3.E+00") ! 2.E+00
+ call checkfmt("(RC,ES17.0)", 2.5, " 3.E+00")
call checkfmt("(RC,EN17.0)", 2.5, " 3.E+00")
call checkfmt("(RN,F17.0)", 2.5, " 2.")
@@ -53,20 +60,20 @@ program pr48615
call checkfmt("(RC,F17.0)", -2.5, " -3.")
call checkfmt("(RC,-1P,F17.1)", -2.5, " -0.3")
- call checkfmt("(RC,E17.1)", -2.5, " -0.3E+01") ! -0.2E+01
+ call checkfmt("(RC,E17.1)", -2.5, " -0.3E+01")
call checkfmt("(RC,1P,E17.0)", -2.5, " -3.E+00")
- call checkfmt("(RC,ES17.0)", -2.5, " -3.E+00") ! -2.E+00
+ call checkfmt("(RC,ES17.0)", -2.5, " -3.E+00")
call checkfmt("(RC,EN17.0)", -2.5, " -3.E+00")
- call checkfmt("(RU,E17.1)", nearest(2.0, 1.0), " 0.3E+01") ! 0.2E+01
- call checkfmt("(RD,E17.1)", nearest(3.0, -1.0), " 0.2E+01") ! 0.3E+01
+ call checkfmt("(RU,E17.1)", nearest(2.0, 1.0), " 0.3E+01")
+ call checkfmt("(RD,E17.1)", nearest(3.0, -1.0), " 0.2E+01")
contains
subroutine checkfmt(fmt, x, cmp)
character(len=*), intent(in) :: fmt
real, intent(in) :: x
character(len=*), intent(in) :: cmp
- character(len=40) :: s
+ character(len=20) :: s
write(s, fmt) x
if (s /= cmp) call abort
Index: libgfortran/io/write_float.def
===================================================================
--- libgfortran/io/write_float.def (revision 173197)
+++ libgfortran/io/write_float.def (working copy)
@@ -67,11 +67,9 @@ output_float (st_parameter_dt *dtp, const fnode *f
{
char *out;
char *digits;
- int e;
+ int e, w, d, p, i;
char expchar, rchar;
format_token ft;
- int w;
- int d;
/* Number of digits before the decimal point. */
int nbefore;
/* Number of zeros after the decimal point. */
@@ -82,12 +80,12 @@ output_float (st_parameter_dt *dtp, const fnode *f
int nzero_real;
int leadzero;
int nblanks;
- int i;
sign_t sign;
ft = f->format;
w = f->u.real.w;
d = f->u.real.d;
+ p = dtp->u.p.scale_factor;
rchar = '5';
nzero_real = -1;
@@ -119,14 +117,14 @@ output_float (st_parameter_dt *dtp, const fnode *f
switch (ft)
{
case FMT_F:
- if (d == 0 && e <= 0 && dtp->u.p.scale_factor == 0)
+ if (d == 0 && e <= 0 && p == 0)
{
memmove (digits + 1, digits, ndigits - 1);
digits[0] = '0';
e++;
}
- nbefore = e + dtp->u.p.scale_factor;
+ nbefore = e + p;
if (nbefore < 0)
{
nzero = -nbefore;
@@ -147,13 +145,13 @@ output_float (st_parameter_dt *dtp, const fnode *f
case FMT_E:
case FMT_D:
i = dtp->u.p.scale_factor;
- if (d <= 0 && i == 0)
+ if (d <= 0 && p == 0)
{
generate_error (&dtp->common, LIBERROR_FORMAT, "Precision not "
"greater than zero in format specifier 'E' or 'D'");
return FAILURE;
}
- if (i <= -d || i >= d + 2)
+ if (p <= -d || p >= d + 2)
{
generate_error (&dtp->common, LIBERROR_FORMAT, "Scale factor "
"out of range in format specifier 'E' or 'D'");
@@ -161,20 +159,20 @@ output_float (st_parameter_dt *dtp, const fnode *f
}
if (!zero_flag)
- e -= i;
- if (i < 0)
+ e -= p;
+ if (p < 0)
{
nbefore = 0;
- nzero = -i;
- nafter = d + i;
+ nzero = -p;
+ nafter = d + p;
}
- else if (i > 0)
+ else if (p > 0)
{
- nbefore = i;
+ nbefore = p;
nzero = 0;
- nafter = (d - i) + 1;
+ nafter = (d - p) + 1;
}
- else /* i == 0 */
+ else /* p == 0 */
{
nbefore = 0;
nzero = 0;
@@ -233,7 +231,13 @@ output_float (st_parameter_dt *dtp, const fnode *f
if (sign_bit)
goto skip;
rchar = '0';
- break;
+ /* Scan for trailing zeros to see if we really need to round it. */
+ for(i = 1 + d * p ; i < ndigits; i++)
+ {
+ if (digits[i] != '0')
+ goto do_rnd;
+ }
+ goto skip;
case ROUND_DOWN:
if (!sign_bit)
goto skip;
@@ -290,8 +294,6 @@ output_float (st_parameter_dt *dtp, const fnode *f
else if (nbefore + nafter < ndigits)
{
i = ndigits = nbefore + nafter;
- if (d == 0 && digits[1] == '0')
- goto skip;
if (digits[i] >= rchar)
{
/* Propagate the carry. */
