On Mon, Dec 11, 2023 at 7:39 AM Xi Ruoyao <xry...@xry111.site> wrote:
>
> Ping again.
OK, sorry for the delay.
Richard.
> On Fri, 2023-12-01 at 13:44 +0800, Xi Ruoyao wrote:
> > Ping.
> >
> > On Fri, 2023-11-24 at 17:09 +0800, Xi Ruoyao wrote:
> > > With -fno-fp-int-builtin-inexact, trunc is not allowed to raise
> > > FE_INEXACT and it should produce an integral result (if the input is not
> > > NaN or Inf). Thus FE_INEXACT should not be raised.
> > >
> > > But (int)x may raise FE_INEXACT when x is a non-integer, non-NaN, and
> > > non-Inf value. C23 recommends to do so in a footnote.
> > >
> > > Thus we should not simplify (int)trunc(x) to (int)x if
> > > -fno-fp-int-builtin-inexact is in-effect.
> > >
> > > gcc/ChangeLog:
> > >
> > > PR middle-end/107723
> > > * convert.cc (convert_to_integer_1) [case BUILT_IN_TRUNC]: Break
> > > early if !flag_fp_int_builtin_inexact and flag_trapping_math.
> > >
> > > gcc/testsuite/ChangeLog:
> > >
> > > PR middle-end/107723
> > > * gcc.dg/torture/builtin-fp-int-inexact-trunc.c: New test.
> > > ---
> > >
> > > Change from v1: add flag_trapping_math into the condition.
> > >
> > > Bootstrapped and regtested on x86_64-linux-gnu. Ok for trunk?
> > >
> > > gcc/convert.cc | 3 ++-
> > > .../gcc.dg/torture/builtin-fp-int-inexact-trunc.c | 12 ++++++++++++
> > > 2 files changed, 14 insertions(+), 1 deletion(-)
> > > create mode 100644
> > > gcc/testsuite/gcc.dg/torture/builtin-fp-int-inexact-trunc.c
> > >
> > > diff --git a/gcc/convert.cc b/gcc/convert.cc
> > > index 46c8bcb31f8..f214b750188 100644
> > > --- a/gcc/convert.cc
> > > +++ b/gcc/convert.cc
> > > @@ -591,7 +591,8 @@ convert_to_integer_1 (tree type, tree expr, bool
> > > dofold)
> > > CASE_FLT_FN (BUILT_IN_TRUNC):
> > > CASE_FLT_FN_FLOATN_NX (BUILT_IN_TRUNC):
> > > if (call_expr_nargs (s_expr) != 1
> > > - || !SCALAR_FLOAT_TYPE_P (TREE_TYPE (CALL_EXPR_ARG (s_expr, 0))))
> > > + || !SCALAR_FLOAT_TYPE_P (TREE_TYPE (CALL_EXPR_ARG (s_expr, 0)))
> > > + || (!flag_fp_int_builtin_inexact && flag_trapping_math))
> > > break;
> > > return convert_to_integer_1 (type, CALL_EXPR_ARG (s_expr, 0),
> > > dofold);
> > > diff --git a/gcc/testsuite/gcc.dg/torture/builtin-fp-int-inexact-trunc.c
> > > b/gcc/testsuite/gcc.dg/torture/builtin-fp-int-inexact-trunc.c
> > > new file mode 100644
> > > index 00000000000..09731183621
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.dg/torture/builtin-fp-int-inexact-trunc.c
> > > @@ -0,0 +1,12 @@
> > > +/* Test -fno-fp-int-builtin-inexact. */
> > > +/* { dg-do compile } */
> > > +/* { dg-options "-fno-fp-int-builtin-inexact -fdump-tree-original" } */
> > > +
> > > +long
> > > +x (double y)
> > > +{
> > > + return __builtin_trunc (y);
> > > +}
> > > +
> > > +/* Optimization should not discard the __builtin_trunc call. */
> > > +/* { dg-final { scan-tree-dump "__builtin_trunc" "original" } } */
> >
>
> --
> Xi Ruoyao <xry...@xry111.site>
> School of Aerospace Science and Technology, Xidian University
