On Mon, Oct 26, 2015 at 10:41 AM, Richard Sandiford
<rdsandif...@googlemail.com> wrote:
> An upcoming patch adds a match.pd rule that folds pow(pow(x,y),z)
> to pow(x,y*z). This fold can reuse the existing pow gimple statement
> and simply replace the operands with x and y*z. However, the y*z
> itself requires a separate gimple statement and the code wasn't
> prepared to handle that.
>
> Tested on x86_64-linux-gnu, aarch64-linux-gnu and arm-linux-gnueabi.
> OK to install?
Hmm, I put the assert there because of the !inplace case but I see the
is_tree_code case alredy behaves the same.
I think the intent of fold_stmt_inplace (and thus the 'inplace' case)
was that no additional stmts are inserted (and obviously the
stmt itself being not replaced, so gsi_stmt () is the same before and
after).
So I think both the is_gimple_assign && is_tree_code and the
case you are amending need a
if (inplace && !gimple_seq_empty_p (*seq))
return false;
Thanks,
Richard.
> Thanks,
> Richard
>
>
> gcc/
> * gimple-fold.c (replace_stmt_with_simplification): Allow calls
> to have nonempty sequences.
>
> diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
> index 1869c09..4b9b782 100644
> --- a/gcc/gimple-fold.c
> +++ b/gcc/gimple-fold.c
> @@ -3365,7 +3365,14 @@ replace_stmt_with_simplification (gimple_stmt_iterator
> *gsi,
> }
> if (i < 3)
> gcc_assert (ops[i] == NULL_TREE);
> - gcc_assert (gimple_seq_empty_p (*seq));
> + if (dump_file && (dump_flags & TDF_DETAILS))
> + {
> + fprintf (dump_file, "gimple_simplified to ");
> + if (!gimple_seq_empty_p (*seq))
> + print_gimple_seq (dump_file, *seq, 0, TDF_SLIM);
> + print_gimple_stmt (dump_file, gsi_stmt (*gsi), 0, TDF_SLIM);
> + }
> + gsi_insert_seq_before (gsi, *seq, GSI_SAME_STMT);
> return true;
> }
> else if (!inplace)
>
