The following removes a premature optimization/canonicalization from
fold-const.c which is now done by reassoc. This avoids doing this
when sincos is not run (at -Og). The reassoc pass now does this
transform (and in a more generic way by using powi).
I suspect there are a few missed simplifications regarding to
mixing powi and pow, so for the branches guarding the folding
with !optimize_debug is more appropriate.
Still on trunk we're now getting additional mult/add reassoc
features and should revisit pow[i] handling there.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2016-04-28 Richard Biener <rguent...@suse.de>
PR middle-end/70777
* fold-const.c (fold_binary_loc): Remove x*x to pow(x,2.0)
canonicalization.
Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c (revision 235510)
+++ gcc/fold-const.c (working copy)
@@ -10033,24 +10033,6 @@ fold_binary_loc (location_t loc,
&& TREE_CODE (arg1) == CONJ_EXPR
&& operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
return fold_mult_zconjz (loc, type, arg0);
-
- if (flag_unsafe_math_optimizations)
- {
-
- /* Canonicalize x*x as pow(x,2.0), which is expanded as x*x. */
- if (!in_gimple_form
- && optimize
- && operand_equal_p (arg0, arg1, 0))
- {
- tree powfn = mathfn_built_in (type, BUILT_IN_POW);
-
- if (powfn)
- {
- tree arg = build_real (type, dconst2);
- return build_call_expr_loc (loc, powfn, 2, arg0, arg);
- }
- }
- }
}
goto associate;
