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. 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..25282d2122d 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_FLOATN (ROUNDEVEN) CASE_MATHFN (SCALB) CASE_MATHFN (SCALBLN) CASE_MATHFN (SCALBN) diff --git a/gcc/builtins.def b/gcc/builtins.def index ef89729fd0c..f1b6830a49c 100644 --- a/gcc/builtins.def +++ b/gcc/builtins.def @@ -308,6 +308,7 @@ DEF_C99_BUILTIN (BUILT_IN_CBRT, "cbrt", BT_FN_DOUBLE_DOUBLE, ATTR_MATHFN_ DEF_C99_BUILTIN (BUILT_IN_CBRTF, "cbrtf", BT_FN_FLOAT_FLOAT, ATTR_MATHFN_FPROUNDING) DEF_C99_BUILTIN (BUILT_IN_CBRTL, "cbrtl", BT_FN_LONGDOUBLE_LONGDOUBLE, ATTR_MATHFN_FPROUNDING) DEF_LIB_BUILTIN (BUILT_IN_CEIL, "ceil", BT_FN_DOUBLE_DOUBLE, ATTR_CONST_NOTHROW_LEAF_LIST) +DEF_EXT_LIB_BUILTIN (BUILT_IN_ROUNDEVEN, "roundeven", BT_FN_DOUBLE_DOUBLE, ATTR_CONST_NOTHROW_LEAF_LIST) DEF_C99_C90RES_BUILTIN (BUILT_IN_CEILF, "ceilf", BT_FN_FLOAT_FLOAT, ATTR_CONST_NOTHROW_LEAF_LIST) DEF_C99_C90RES_BUILTIN (BUILT_IN_CEILL, "ceill", BT_FN_LONGDOUBLE_LONGDOUBLE, ATTR_CONST_NOTHROW_LEAF_LIST) #define CEIL_TYPE(F) BT_FN_##F##_##F diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def index cda314e1121..b89918815f9 100644 --- a/gcc/internal-fn.def +++ b/gcc/internal-fn.def @@ -224,6 +224,7 @@ DEF_INTERNAL_FLT_FLOATN_FN (FLOOR, ECF_CONST, floor, unary) DEF_INTERNAL_FLT_FLOATN_FN (NEARBYINT, ECF_CONST, nearbyint, unary) DEF_INTERNAL_FLT_FLOATN_FN (RINT, ECF_CONST, rint, unary) DEF_INTERNAL_FLT_FLOATN_FN (ROUND, ECF_CONST, round, unary) +DEF_INTERNAL_FLT_FLOATN_FN (ROUNDEVEN, ECF_CONST, roundeven, unary) DEF_INTERNAL_FLT_FLOATN_FN (TRUNC, ECF_CONST, btrunc, unary) /* Binary math functions. */ diff --git a/gcc/optabs.def b/gcc/optabs.def index 5a67f5eed5e..eb9e22acd8f 100644 --- a/gcc/optabs.def +++ b/gcc/optabs.def @@ -267,6 +267,7 @@ OPTAB_D (fnms_optab, "fnms$a4") OPTAB_D (rint_optab, "rint$a2") OPTAB_D (round_optab, "round$a2") +OPTAB_D (roundeven_optab, "roundeven$a2") OPTAB_D (floor_optab, "floor$a2") OPTAB_D (ceil_optab, "ceil$a2") OPTAB_D (btrunc_optab, "btrunc$a2") diff --git a/gcc/real.c b/gcc/real.c index f822ae82d61..9c57f50e8fc 100644 --- a/gcc/real.c +++ b/gcc/real.c @@ -5004,10 +5006,39 @@ void +/* 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); + fprintf (stderr, "\nhere\n"); + fprintf (stderr, "\n i = %ld\n", i); + if(i % 2) + do_add (r, &t, &dconstm1, 0); + else + *r = t; } /* Set the sign of R to the sign of X. */ 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 *);