On Mon, Oct 5, 2015 at 5:17 PM, Richard Sandiford
<richard.sandif...@arm.com> wrote:
> This patch moves the sqrt and cbrt simplification rules to match.pd.
> builtins.c now only does the constant folding.
>
> Bootstrapped & regression-tested on x86_64-linux-gnu. OK to install?
Ok (once prerequesites are approved).
People may notice that on GENERIC we no longer simplify these - this is because
genmatch doesn't output a toplevel entry for simplifying calls (well,
I was lazy,
would need to have hooked into builtins.c folding somewhere but IMHO GENERIC
call folding should go).
Thanks,
Richard.
> Thanks,
> Richard
>
>
> gcc/
> * builtins.c (fold_builtin_sqrt, fold_builtin_cbrt): Delete.
> (fold_builtin_1): Update accordingly. Handle constant arguments here.
> * match.pd: Add rules previously handled by fold_builtin_sqrt
> and fold_builtin_cbrt.
>
> gcc/testsuite/
> * gcc.dg/builtins-47.c: Test the optimized dump instead.
>
> diff --git a/gcc/builtins.c b/gcc/builtins.c
> index 85ba6dd..3df60e8 100644
> --- a/gcc/builtins.c
> +++ b/gcc/builtins.c
> @@ -158,8 +158,6 @@ static bool integer_valued_real_p (tree);
> static tree fold_trunc_transparent_mathfn (location_t, tree, tree);
> static rtx expand_builtin_fabs (tree, rtx, rtx);
> static rtx expand_builtin_signbit (tree, rtx);
> -static tree fold_builtin_sqrt (location_t, tree, tree);
> -static tree fold_builtin_cbrt (location_t, tree, tree);
> static tree fold_builtin_pow (location_t, tree, tree, tree, tree);
> static tree fold_builtin_powi (location_t, tree, tree, tree, tree);
> static tree fold_builtin_cos (location_t, tree, tree, tree);
> @@ -7706,145 +7704,6 @@ fold_builtin_cproj (location_t loc, tree arg, tree
> type)
> return NULL_TREE;
> }
>
> -/* Fold a builtin function call to sqrt, sqrtf, or sqrtl with argument ARG.
> - Return NULL_TREE if no simplification can be made. */
> -
> -static tree
> -fold_builtin_sqrt (location_t loc, tree arg, tree type)
> -{
> -
> - enum built_in_function fcode;
> - tree res;
> -
> - if (!validate_arg (arg, REAL_TYPE))
> - return NULL_TREE;
> -
> - /* Calculate the result when the argument is a constant. */
> - if ((res = do_mpfr_arg1 (arg, type, mpfr_sqrt, &dconst<0> (), NULL, true)))
> - return res;
> -
> - /* Optimize sqrt(expN(x)) = expN(x*0.5). */
> - fcode = builtin_mathfn_code (arg);
> - if (flag_unsafe_math_optimizations && BUILTIN_EXPONENT_P (fcode))
> - {
> - tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg), 0);
> - arg = fold_build2_loc (loc, MULT_EXPR, type,
> - CALL_EXPR_ARG (arg, 0),
> - build_real (type, dconst<1, 2> ()));
> - return build_call_expr_loc (loc, expfn, 1, arg);
> - }
> -
> - /* Optimize sqrt(Nroot(x)) -> pow(x,1/(2*N)). */
> - if (flag_unsafe_math_optimizations && BUILTIN_ROOT_P (fcode))
> - {
> - tree powfn = mathfn_built_in (type, BUILT_IN_POW);
> -
> - if (powfn)
> - {
> - tree arg0 = CALL_EXPR_ARG (arg, 0);
> - tree arg1 = (BUILTIN_SQRT_P (fcode)
> - ? build_real (type, dconst<1, 4> ())
> - : build_real_truncate (type, dconst<1, 6> ()));
> - return build_call_expr_loc (loc, powfn, 2, arg0, arg1);
> - }
> - }
> -
> - /* Optimize sqrt(pow(x,y)) = pow(|x|,y*0.5). */
> - if (flag_unsafe_math_optimizations
> - && (fcode == BUILT_IN_POW
> - || fcode == BUILT_IN_POWF
> - || fcode == BUILT_IN_POWL))
> - {
> - tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg), 0);
> - tree arg0 = CALL_EXPR_ARG (arg, 0);
> - tree arg1 = CALL_EXPR_ARG (arg, 1);
> - tree narg1;
> - if (!tree_expr_nonnegative_p (arg0))
> - arg0 = build1 (ABS_EXPR, type, arg0);
> - narg1 = fold_build2_loc (loc, MULT_EXPR, type, arg1,
> - build_real (type, dconst<1, 2> ()));
> - return build_call_expr_loc (loc, powfn, 2, arg0, narg1);
> - }
> -
> - return NULL_TREE;
> -}
> -
> -/* Fold a builtin function call to cbrt, cbrtf, or cbrtl with argument ARG.
> - Return NULL_TREE if no simplification can be made. */
> -
> -static tree
> -fold_builtin_cbrt (location_t loc, tree arg, tree type)
> -{
> - const enum built_in_function fcode = builtin_mathfn_code (arg);
> - tree res;
> -
> - if (!validate_arg (arg, REAL_TYPE))
> - return NULL_TREE;
> -
> - /* Calculate the result when the argument is a constant. */
> - if ((res = do_mpfr_arg1 (arg, type, mpfr_cbrt, NULL, NULL, 0)))
> - return res;
> -
> - if (flag_unsafe_math_optimizations)
> - {
> - /* Optimize cbrt(expN(x)) -> expN(x/3). */
> - if (BUILTIN_EXPONENT_P (fcode))
> - {
> - tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg), 0);
> - arg = fold_build2_loc (loc, MULT_EXPR, type,
> - CALL_EXPR_ARG (arg, 0),
> - build_real_truncate (type, dconst<1, 3> ()));
> - return build_call_expr_loc (loc, expfn, 1, arg);
> - }
> -
> - /* Optimize cbrt(sqrt(x)) -> pow(x,1/6). */
> - if (BUILTIN_SQRT_P (fcode))
> - {
> - tree powfn = mathfn_built_in (type, BUILT_IN_POW);
> -
> - if (powfn)
> - {
> - tree arg0 = CALL_EXPR_ARG (arg, 0);
> - tree tree_root = build_real_truncate (type, dconst<1, 6> ());
> - return build_call_expr_loc (loc, powfn, 2, arg0, tree_root);
> - }
> - }
> -
> - /* Optimize cbrt(cbrt(x)) -> pow(x,1/9) iff x is nonnegative. */
> - if (BUILTIN_CBRT_P (fcode))
> - {
> - tree arg0 = CALL_EXPR_ARG (arg, 0);
> - if (tree_expr_nonnegative_p (arg0))
> - {
> - tree powfn = mathfn_built_in (type, BUILT_IN_POW);
> -
> - if (powfn)
> - {
> - tree tree_root = build_real_truncate (type, dconst<1, 9>
> ());
> - return build_call_expr_loc (loc, powfn, 2, arg0, tree_root);
> - }
> - }
> - }
> -
> - /* Optimize cbrt(pow(x,y)) -> pow(x,y/3) iff x is nonnegative. */
> - if (fcode == BUILT_IN_POW
> - || fcode == BUILT_IN_POWF
> - || fcode == BUILT_IN_POWL)
> - {
> - tree arg00 = CALL_EXPR_ARG (arg, 0);
> - tree arg01 = CALL_EXPR_ARG (arg, 1);
> - if (tree_expr_nonnegative_p (arg00))
> - {
> - tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg), 0);
> - tree c = build_real_truncate (type, dconst<1, 3> ());
> - tree narg01 = fold_build2_loc (loc, MULT_EXPR, type, arg01, c);
> - return build_call_expr_loc (loc, powfn, 2, arg00, narg01);
> - }
> - }
> - }
> - return NULL_TREE;
> -}
> -
> /* Fold function call to builtin cos, cosf, or cosl with argument ARG.
> TYPE is the type of the return value. Return NULL_TREE if no
> simplification can be made. */
> @@ -9943,10 +9802,14 @@ fold_builtin_1 (location_t loc, tree fndecl, tree
> arg0)
> return fold_builtin_carg (loc, arg0, type);
>
> CASE_FLT_FN (BUILT_IN_SQRT):
> - return fold_builtin_sqrt (loc, arg0, type);
> + if (validate_arg (arg0, REAL_TYPE))
> + return do_mpfr_arg1 (arg0, type, mpfr_sqrt, &dconst<0> (), NULL,
> true);
> + break;
>
> CASE_FLT_FN (BUILT_IN_CBRT):
> - return fold_builtin_cbrt (loc, arg0, type);
> + if (validate_arg (arg0, REAL_TYPE))
> + return do_mpfr_arg1 (arg0, type, mpfr_cbrt, NULL, NULL, 0);
> + break;
>
> CASE_FLT_FN (BUILT_IN_ASIN):
> if (validate_arg (arg0, REAL_TYPE))
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 5ab8c06..db8b731 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -2315,3 +2315,44 @@ along with GCC; see the file COPYING3. If not see
> (with { tree utype = unsigned_type_for (TREE_TYPE (@0)); }
> (convert (bit_and (op (convert:utype @0) (convert:utype @1))
> (convert:utype @4))))))))
> +
> +(if (flag_unsafe_math_optimizations)
> + (for sqrts (SQRT)
> + cbrts (CBRT)
> + exps (EXP EXP2 EXP10 POW10)
> + /* sqrt(expN(x)) -> expN(x*0.5). */
> + (simplify
> + (sqrts (exps @0))
> + (exps (mult @0 { build_real (type, dconst<1, 2> ()); })))
> + /* cbrt(expN(x)) -> expN(x/3). */
> + (simplify
> + (cbrts (exps @0))
> + (exps (mult @0 { build_real_truncate (type, dconst<1, 3> ()); }))))
> +
> + (for sqrts (SQRT)
> + cbrts (CBRT)
> + pows (POW)
> + /* sqrt(sqrt(x)) -> pow(x,1/4). */
> + (simplify
> + (sqrts (sqrts @0))
> + (pows @0 { build_real (type, dconst<1, 4> ()); }))
> + /* cbrt(sqrt(x)) -> pow(x,1/6). */
> + (simplify
> + (sqrts (cbrts @0))
> + (pows @0 { build_real_truncate (type, dconst<1, 6> ()); }))
> + /* sqrt(cbrt(x)) -> pow(x,1/6). */
> + (simplify
> + (cbrts (sqrts @0))
> + (pows @0 { build_real_truncate (type, dconst<1, 6> ()); }))
> + /* cbrt(cbrt(x)) -> pow(x,1/9), iff x is nonnegative. */
> + (simplify
> + (cbrts (cbrts nonnegative_p@0))
> + (pows @0 { build_real_truncate (type, dconst<1, 9> ()); }))
> + /* sqrt(pow(x,y)) -> pow(|x|,y*0.5). */
> + (simplify
> + (sqrts (pows @0 @1))
> + (pows (abs @0) (mult @1 { build_real (type, dconst<1, 2> ()); })))
> + /* cbrt(pow(x,y)) -> pow(x,y/3), iff x is nonnegative. */
> + (simplify
> + (cbrts (pows nonnegative_p@0 @1))
> + (pows @0 (mult @1 { build_real_truncate (type, dconst<1, 3> ()); })))))
> diff --git a/gcc/testsuite/gcc.dg/builtins-47.c
> b/gcc/testsuite/gcc.dg/builtins-47.c
> index 024d7ee..fbe9d21 100644
> --- a/gcc/testsuite/gcc.dg/builtins-47.c
> +++ b/gcc/testsuite/gcc.dg/builtins-47.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O -ffast-math -fdump-tree-gimple" } */
> +/* { dg-options "-O -ffast-math -fdump-tree-optimized" } */
>
> extern double sqrt (double);
> extern double pow (double, double);
> @@ -15,5 +15,5 @@ int main ()
> return 0;
> }
>
> -/* { dg-final { scan-tree-dump-times "sqrt" 0 "gimple" } } */
> -/* { dg-final { scan-tree-dump-times "pow" 0 "gimple" } } */
> +/* { dg-final { scan-tree-dump-times "sqrt" 0 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "pow" 0 "optimized" } } */
>
