On Mon, Jun 19, 2023 at 12:33 PM Toru Kisuki via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > Hi, > > > With -O3 -fsignaling-nans -fno-signed-zeros, compiler should not simplify 'x > + 0.0' to 'x'. >
OK if you bootstrapped / tested this change. Thanks, Richard. > GCC Bugzilla : Bug 110305 > > > gcc/ChangeLog: > > 2023-06-19 Toru Kisuki <tkis...@tachyum.com> > > * simplify-rtx.cc (simplify_context::simplify_binary_operation_1): > > --- > gcc/simplify-rtx.cc | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc > index e152918b0f1..cc96b36ad4e 100644 > --- a/gcc/simplify-rtx.cc > +++ b/gcc/simplify-rtx.cc > @@ -2698,7 +2698,8 @@ simplify_context::simplify_binary_operation_1 (rtx_code > code, > when x is NaN, infinite, or finite and nonzero. They aren't > when x is -0 and the rounding mode is not towards -infinity, > since (-0) + 0 is then 0. */ > - if (!HONOR_SIGNED_ZEROS (mode) && trueop1 == CONST0_RTX (mode)) > + if (!HONOR_SIGNED_ZEROS (mode) && !HONOR_SNANS (mode) > + && trueop1 == CONST0_RTX (mode)) > return op0; > > /* ((-a) + b) -> (b - a) and similarly for (a + (-b)). These > -- > 2.38.1 >
