Hello. I have developed a fairly working patch for roundeven, attaching herewith. The testcase function as follows :
double f()
{
double x = 4.5;
double ret = __builtin_roundeven (x);
return ret;
}
We can inspect the file foo.c.028t.ccp1, where we can see f() returns
value 4.0e+0.
I am also writing the proposal and make draft ready in couple of days
for community review.
Do roundeven have to be added in internals-fn.def to be called internal?
Thanks,
-Tejas
On Sun, 24 Feb 2019 at 17:39, Tejas Joshi <tejasjoshi9...@gmail.com> wrote:
>
> Hello.
> I had a little pause on roundeven due to seminars in my college. I've
> tried to implement roundeven but can not figure out what are just
> minimal needs to roundeven be called for a test program like
> __builtin_roundeven();
> Also, build exited returning status as:
>
> DEF_INTERNAL_FLT_FN (ROUNDEVEN) has no associated built-in functions
>
> Here is the .diff flie.
>
> Thanks,
> -Tejas
>
> On Mon, 4 Feb 2019 at 22:55, Tejas Joshi <tejasjoshi9...@gmail.com> wrote:
> >
> > Hi.
> > Although now, I am unable to build the compiler.
> > The build exited returning status as:
> >
> > DEF_INTERNAL_FLT_FN (ROUNDEVEN) has no associated built-in functions
> >
> > I have added the entry in fold_const_call_ss() and do not find any
> > other place to add the case.
> > Here is the latest patch.
> >
> > On Mon, 4 Feb 2019 at 22:14, Prathamesh Kulkarni
> > <prathamesh.kulka...@linaro.org> wrote:
> > >
> > > On Mon, 4 Feb 2019 at 21:27, Tejas Joshi <tejasjoshi9...@gmail.com> wrote:
> > > >
> > > > Thanks.
> > > > > Did you add an entry for roundeven in builtins.def ?
> > > > Yes, I did.
> > > >
> > > > Find here the attached patch.diff for which I did the changes to
> > > > implement roundeven. There might be some unnecessary changes and some
> > > > necessary changes which have not been made.
> > > You haven't called roundeven() in the patch. You'll need to add an
> > > entry in fold_const_call_ss()
> > > similar to real_ceil, and probably in other places too.
> > >
> > > Thanks,
> > > Prathamesh
> > > >
> > > > Regards,
> > > > -Tejas
> > > >
> > > > On Mon, 4 Feb 2019 at 20:36, Prathamesh Kulkarni
> > > > <prathamesh.kulka...@linaro.org> wrote:
> > > > >
> > > > > On Mon, 4 Feb 2019 at 20:10, Tejas Joshi <tejasjoshi9...@gmail.com>
> > > > > wrote:
> > > > > >
> > > > > > Hello.
> > > > > > I have implemented roundeven function in real.c as follows: (and
> > > > > > respective changes in real.h)
> > > > > It's a better idea to include all changes in patch instead of
> > > > > copy-pasting.
> > > > > Use the command:
> > > > > git diff > patch.diff
> > > > > which will create a file called "patch.diff" containing the changes
> > > > > and send it as an attachment.
> > > > > >
> > > > > > /* Round X to nearest even integer towards zero. */
> > > > > >
> > > > > > void
> > > > > > real_roundeven (REAL_VALUE_TYPE *r, format_helper fmt,
> > > > > > const REAL_VALUE_TYPE *x)
> > > > > > {
> > > > > > REAL_VALUE_TYPE t;
> > > > > >
> > > > > > do_fix_trunc (&t, x);
> > > > > > HOST_WIDE_INT i = real_to_integer (&t);
> > > > > > if(i % 2)
> > > > > > do_add (r, &t, &dconstm1, 0);
> > > > > > else
> > > > > > *r = t;
> > > > > > }
> > > > > >
> > > > > > Although I cant get it to test like
> > > > > >
> > > > > > int foo()
> > > > > > {
> > > > > > double x = __builtin_roundeven (3.5);
> > > > > > printf("%f",x);
> > > > > > return (int) x;
> > > > > > }
> > > > > > Because I do not know its dependencies through other files. I tried
> > > > > > to
> > > > > > track them down by inspecting real_ceil function, but it also
> > > > > > includes
> > > > > > other optimization procedures like folding. How do I know enough
> > > > > > declarations to be made in respective files?
> > > > > Did you add an entry for roundeven in builtins.def ?
> > > > >
> > > > > Thanks,
> > > > > Prathamesh
> > > > > >
> > > > > > Thanks.
> > > > > > -Tejas
> > > > > >
> > > > > > On Mon, 28 Jan 2019 at 22:33, Tejas Joshi
> > > > > > <tejasjoshi9...@gmail.com> wrote:
> > > > > > >
> > > > > > > Hello.
> > > > > > > Representations of real numbers in real.c are a little complex to
> > > > > > > understand right now for me. I am still trying to understand them
> > > > > > > and
> > > > > > > figure them out using gdb and cscope. Though conventions are
> > > > > > > given in
> > > > > > > comments in real.c, I will still be trying to figure it out. The
> > > > > > > equation and its bitwise representation is not pretty elaborated
> > > > > > > in
> > > > > > > any documentation I could find.
> > > > > > >
> > > > > > > x = s * b^e * \sum_{k=1}^p f_k * b^{-k}
> > > > > > >
> > > > > > > where
> > > > > > > s = sign (+- 1)
> > > > > > > b = base or radix, here always 2
> > > > > > > e = exponent
> > > > > > > p = precision (the number of base-b digits in the
> > > > > > > significand)
> > > > > > > f_k = the digits of the significand.
> > > > > > >
> > > > > > > In mean time, I've tried real_round function to work like
> > > > > > > roundeven. I
> > > > > > > will try to submit a clean patch along with roundeven implemented
> > > > > > > separately with changes like in builtins.def, adding cases, etc.
> > > > > > >
> > > > > > > void
> > > > > > > real_round (REAL_VALUE_TYPE *r, format_helper fmt,
> > > > > > > const REAL_VALUE_TYPE *x)
> > > > > > > {
> > > > > > > #if 0
> > > > > > > do_add (r, x, &dconsthalf, x->sign);
> > > > > > > do_fix_trunc (r, r);
> > > > > > > if (fmt)
> > > > > > > real_convert (r, fmt, r);
> > > > > > > #endif
> > > > > > > fprintf (stderr, "\nhere\n");
> > > > > > > real_value z;
> > > > > > > do_fix_trunc (&z, x);
> > > > > > > HOST_WIDE_INT i = real_to_integer (&z);
> > > > > > > fprintf (stderr, "\n i = %ld\n", i);
> > > > > > > if (i % 2)
> > > > > > > do_add (r, &z, &dconstm1, 0);
> > > > > > > else
> > > > > > > *r = z;
> > > > > > > }
> > > > > > >
> > > > > > > Thanks.
> > > > > > > -Tejas
> > > > > > >
> > > > > > > On Sat, 26 Jan 2019 at 03:02, Joseph Myers
> > > > > > > <jos...@codesourcery.com> wrote:
> > > > > > > >
> > > > > > > > On Sat, 26 Jan 2019, Tejas Joshi wrote:
> > > > > > > >
> > > > > > > > > function with byte-byte comparison which also include mpfr.
> > > > > > > > > (Correct
> > > > > > > > > me if I am wrong.) What is the significance of mpfr related
> > > > > > > > > to these
> > > > > > > > > internal representations?
> > > > > > > >
> > > > > > > > real.c provides a fixed-size representation of floating-point
> > > > > > > > numbers that
> > > > > > > > allows for various non-IEEE formats supported by GCC, and also
> > > > > > > > allows
> > > > > > > > functions from dfp.c to be used for decimal floating-point
> > > > > > > > formats.
> > > > > > > >
> > > > > > > > MPFR is used in GCC to provide operations that are nontrivial to
> > > > > > > > implement, especially those that are nontrivial to implement in
> > > > > > > > such a
> > > > > > > > fixed-size context. real.c operations wrap around MPFR ones
> > > > > > > > where
> > > > > > > > appropriate, doing whatever's needed in cases where there are
> > > > > > > > non-IEEE
> > > > > > > > semantics or sets of values.
> > > > > > > >
> > > > > > > > --
> > > > > > > > Joseph S. Myers
> > > > > > > > jos...@codesourcery.com
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 25e01e4092b..0b2d6bf82f9 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -2067,6 +2067,7 @@ mathfn_built_in_2 (tree type, combined_fn fn)
CASE_MATHFN (REMQUO)
CASE_MATHFN_FLOATN (RINT)
CASE_MATHFN_FLOATN (ROUND)
+ CASE_MATHFN (ROUNDEVEN)
CASE_MATHFN (SCALB)
CASE_MATHFN (SCALBLN)
CASE_MATHFN (SCALBN)
diff --git a/gcc/builtins.def b/gcc/builtins.def
index ef89729fd0c..e1d593a8765 100644
--- a/gcc/builtins.def
+++ b/gcc/builtins.def
@@ -542,6 +542,9 @@ DEF_C99_BUILTIN (BUILT_IN_RINTL, "rintl", BT_FN_LONGDOUBLE_LONGDOUBLE, AT
#define RINT_TYPE(F) BT_FN_##F##_##F
DEF_EXT_LIB_FLOATN_NX_BUILTINS (BUILT_IN_RINT, "rint", RINT_TYPE, ATTR_CONST_NOTHROW_LEAF_LIST)
#undef RINT_TYPE
+DEF_EXT_LIB_BUILTIN (BUILT_IN_ROUNDEVEN, "roundeven", BT_FN_DOUBLE_DOUBLE, ATTR_CONST_NOTHROW_LEAF_LIST)
+DEF_EXT_LIB_BUILTIN (BUILT_IN_ROUNDEVENF, "roundevenf", BT_FN_FLOAT_FLOAT, ATTR_CONST_NOTHROW_LEAF_LIST)
+DEF_EXT_LIB_BUILTIN (BUILT_IN_ROUNDEVENL, "roundevenl", BT_FN_LONGDOUBLE_LONGDOUBLE, ATTR_CONST_NOTHROW_LEAF_LIST)
DEF_C99_BUILTIN (BUILT_IN_ROUND, "round", BT_FN_DOUBLE_DOUBLE, ATTR_CONST_NOTHROW_LEAF_LIST)
DEF_C99_BUILTIN (BUILT_IN_ROUNDF, "roundf", BT_FN_FLOAT_FLOAT, ATTR_CONST_NOTHROW_LEAF_LIST)
DEF_C99_BUILTIN (BUILT_IN_ROUNDL, "roundl", BT_FN_LONGDOUBLE_LONGDOUBLE, ATTR_CONST_NOTHROW_LEAF_LIST)
diff --git a/gcc/fold-const-call.c b/gcc/fold-const-call.c
index 06a420601c0..7eafd91e9a2 100644
--- a/gcc/fold-const-call.c
+++ b/gcc/fold-const-call.c
@@ -792,6 +792,14 @@ fold_const_call_ss (real_value *result, combined_fn fn,
}
return false;
+ case CFN_BUILT_IN_ROUNDEVEN:
+ if (!REAL_VALUE_ISNAN (*arg) || !flag_errno_math)
+ {
+ real_roundeven (result, format, arg);
+ return true;
+ }
+ return false;
+
CASE_CFN_LOGB:
return fold_const_logb (result, arg, format);
@@ -854,6 +862,9 @@ fold_const_call_ss (wide_int *result, combined_fn fn,
return fold_const_conversion (result, real_round, arg,
precision, format);
+ case CFN_BUILT_IN_ROUNDEVEN:
+ return fold_const_conversion (result, real_roundeven, arg, precision, format);
+
CASE_CFN_IRINT:
CASE_CFN_LRINT:
CASE_CFN_LLRINT:
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 59cedeafd71..30c409e95bf 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -329,6 +329,7 @@ negate_mathfn_p (combined_fn fn)
CASE_CFN_LLROUND:
CASE_CFN_LROUND:
CASE_CFN_ROUND:
+ CASE_CFN_ROUNDEVEN:
CASE_CFN_SIN:
CASE_CFN_SINH:
CASE_CFN_TAN:
@@ -13060,6 +13061,8 @@ tree_call_nonnegative_warnv_p (tree type, combined_fn fn, tree arg0, tree arg1,
CASE_CFN_RINT_FN:
CASE_CFN_ROUND:
CASE_CFN_ROUND_FN:
+ CASE_CFN_ROUNDEVEN:
+ CASE_CFN_ROUNDEVEN_FN:
CASE_CFN_SCALB:
CASE_CFN_SCALBLN:
CASE_CFN_SCALBN:
@@ -13583,6 +13586,8 @@ integer_valued_real_call_p (combined_fn fn, tree arg0, tree arg1, int depth)
CASE_CFN_RINT_FN:
CASE_CFN_ROUND:
CASE_CFN_ROUND_FN:
+ CASE_CFN_ROUNDEVEN:
+ CASE_CFN_ROUNDEVEN_FN:
CASE_CFN_TRUNC:
CASE_CFN_TRUNC_FN:
return true;
diff --git a/gcc/real.c b/gcc/real.c
index f822ae82d61..087478841e5 100644
--- a/gcc/real.c
+++ b/gcc/real.c
@@ -5010,6 +5010,22 @@ real_round (REAL_VALUE_TYPE *r, format_helper fmt,
real_convert (r, fmt, r);
}
+/* Round X to nearest even integer towards zero. */
+
+void
+real_roundeven (REAL_VALUE_TYPE *r, format_helper fmt,
+ const REAL_VALUE_TYPE *x)
+{
+ REAL_VALUE_TYPE t;
+
+ do_fix_trunc (&t, x);
+ HOST_WIDE_INT i = real_to_integer (&t);
+ if(i % 2)
+ do_add (r, &t, &dconstm1, 0);
+ else
+ *r = t;
+}
+
/* Set the sign of R to the sign of X. */
void
diff --git a/gcc/real.h b/gcc/real.h
index 0ce42565708..10898eae79e 100644
--- a/gcc/real.h
+++ b/gcc/real.h
@@ -499,6 +499,8 @@ extern void real_ceil (REAL_VALUE_TYPE *, format_helper,
const REAL_VALUE_TYPE *);
extern void real_round (REAL_VALUE_TYPE *, format_helper,
const REAL_VALUE_TYPE *);
+extern void real_roundeven (REAL_VALUE_TYPE *, format_helper,
+ const REAL_VALUE_TYPE *);
/* Set the sign of R to the sign of X. */
extern void real_copysign (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
foo.c.028t.ccp1
Description: Binary data
