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 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 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 > > wrote: > > > > > > On Mon, 4 Feb 2019 at 21:27, Tejas Joshi 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 > > > > wrote: > > > > > > > > > > On Mon, 4 Feb 2019 at 20:10, Tejas Joshi 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 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 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 > > > > > > > > joseph@codesourcery.com