On Mon, Oct 26, 2015 at 10:50 AM, Richard Sandiford
<rdsandif...@googlemail.com> wrote:
> Tested on x86_64-linux-gnu, aarch64-linux-gnu and arm-linux-gnueabi.
> OK to install?
Ok.
Thanks,
Richard.
> Thanks,
> Richard
>
>
> gcc/
> * builtins.c (fold_builtin_exponent): Delete.
> (fold_builtin_2): Handle constant expN arguments here.
> * match.pd: Fold expN(logN(x)) -> x.
>
> diff --git a/gcc/builtins.c b/gcc/builtins.c
> index 3d39d43..e5a00ee 100644
> --- a/gcc/builtins.c
> +++ b/gcc/builtins.c
> @@ -7516,47 +7516,6 @@ fold_const_builtin_pow (tree arg0, tree arg1, tree
> type)
> return NULL_TREE;
> }
>
> -/* A subroutine of fold_builtin to fold the various exponent
> - functions. Return NULL_TREE if no simplification can be made.
> - FUNC is the corresponding MPFR exponent function. */
> -
> -static tree
> -fold_builtin_exponent (location_t loc, tree fndecl, tree arg,
> - int (*func)(mpfr_ptr, mpfr_srcptr, mp_rnd_t))
> -{
> - if (validate_arg (arg, REAL_TYPE))
> - {
> - tree type = TREE_TYPE (TREE_TYPE (fndecl));
> - tree res;
> -
> - /* Calculate the result when the argument is a constant. */
> - if ((res = do_mpfr_arg1 (arg, type, func, NULL, NULL, 0)))
> - return res;
> -
> - /* Optimize expN(logN(x)) = x. */
> - if (flag_unsafe_math_optimizations)
> - {
> - const enum built_in_function fcode = builtin_mathfn_code (arg);
> -
> - if ((func == mpfr_exp
> - && (fcode == BUILT_IN_LOG
> - || fcode == BUILT_IN_LOGF
> - || fcode == BUILT_IN_LOGL))
> - || (func == mpfr_exp2
> - && (fcode == BUILT_IN_LOG2
> - || fcode == BUILT_IN_LOG2F
> - || fcode == BUILT_IN_LOG2L))
> - || (func == mpfr_exp10
> - && (fcode == BUILT_IN_LOG10
> - || fcode == BUILT_IN_LOG10F
> - || fcode == BUILT_IN_LOG10L)))
> - return fold_convert_loc (loc, type, CALL_EXPR_ARG (arg, 0));
> - }
> - }
> -
> - return NULL_TREE;
> -}
> -
> /* Fold function call to builtin memchr. ARG1, ARG2 and LEN are the
> arguments to the call, and TYPE is its return type.
> Return NULL_TREE if no simplification can be made. */
> @@ -9004,14 +8963,20 @@ fold_builtin_1 (location_t loc, tree fndecl, tree
> arg0)
> break;
>
> CASE_FLT_FN (BUILT_IN_EXP):
> - return fold_builtin_exponent (loc, fndecl, arg0, mpfr_exp);
> + if (validate_arg (arg0, REAL_TYPE))
> + return do_mpfr_arg1 (arg0, type, mpfr_exp, NULL, NULL, 0);
> + break;
>
> CASE_FLT_FN (BUILT_IN_EXP2):
> - return fold_builtin_exponent (loc, fndecl, arg0, mpfr_exp2);
> + if (validate_arg (arg0, REAL_TYPE))
> + return do_mpfr_arg1 (arg0, type, mpfr_exp2, NULL, NULL, 0);
> + break;
>
> CASE_FLT_FN (BUILT_IN_EXP10):
> CASE_FLT_FN (BUILT_IN_POW10):
> - return fold_builtin_exponent (loc, fndecl, arg0, mpfr_exp10);
> + if (validate_arg (arg0, REAL_TYPE))
> + return do_mpfr_arg1 (arg0, type, mpfr_exp10, NULL, NULL, 0);
> + break;
>
> CASE_FLT_FN (BUILT_IN_EXPM1):
> if (validate_arg (arg0, REAL_TYPE))
> diff --git a/gcc/match.pd b/gcc/match.pd
> index a8adffb..303889b 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -2408,12 +2408,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (rdiv @0 (exps:s @1))
> (mult @0 (exps (negate @1)))))
>
> - /* Special case, optimize logN(expN(x)) = x. */
> (for logs (LOG LOG2 LOG10 LOG10)
> exps (EXP EXP2 EXP10 POW10)
> + /* logN(expN(x)) -> x. */
> (simplify
> (logs (exps @0))
> - @0))
> + @0)
> + /* expN(logN(x)) -> x. */
> + (simplify
> + (exps (logs @0))
> + @0))
>
> /* Optimize logN(func()) for various exponential functions. We
> want to determine the value "x" and the power "exponent" in
>
