On Fri, May 27, 2022 at 3:57 PM Andrew MacLeod via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On 5/27/22 15:33, Andi Kleen wrote:
> > Andrew MacLeod via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> >> diff --git a/gcc/gimple-range-side-effect.cc
> >> b/gcc/gimple-range-side-effect.cc
> >> index 2c8c77dc569..548e4bea313 100644
> >> --- a/gcc/gimple-range-side-effect.cc
> >> +++ b/gcc/gimple-range-side-effect.cc
> >> @@ -116,6 +116,23 @@ stmt_side_effects::stmt_side_effects (gimple *s)
> >> walk_stmt_load_store_ops (s, (void *)this, non_null_loadstore,
> >> non_null_loadstore);
> >>
> >> + if (is_a<gassign *> (s))
> >> + {
> >> + switch (gimple_assign_rhs_code (s))
> >> + {
> >> + case TRUNC_DIV_EXPR:
> >> + case CEIL_DIV_EXPR:
> >> + case FLOOR_DIV_EXPR:
> >> + case ROUND_DIV_EXPR:
> >> + case EXACT_DIV_EXPR:
> >> + // Divide means operand 2 is not zero after this stmt.
> >> + if (gimple_range_ssa_p (gimple_assign_rhs2 (s)))
> >> + add_nonzero (gimple_assign_rhs2 (s));
> > Sorry I'm late, but how does this ensure the value is a integer?
> > I believe for floating point the assumption is not correct because
> > division by zero doesn't necessarily fault.
> >
> > -Andi
> >
> gimple_range_ssa_p() only returns non-zero when the value is an ssa_name
> whose type is supported by the range calculators... currently only
> integrals values. When we support floating points we will have to add
> additional logic.
>
Maybe add a comment to that effect, then? As a reminder...
> Andrew
>
