On 2020-11-13 09:41, Richard Biener wrote:
> On Thu, Mar 12, 2020 at 1:41 AM J.W. Jagersma via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
>> diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c
>> index 2a409dcaffe..58b16aa763a 100644
>> --- a/gcc/tree-eh.c
>> +++ b/gcc/tree-eh.c
>> @@ -2077,6 +2077,8 @@ lower_eh_constructs_2 (struct leh_state *state,
>> gimple_stmt_iterator *gsi)
>> DECL_GIMPLE_REG_P (tmp) = 1;
>> gsi_insert_after (gsi, s, GSI_SAME_STMT);
>> }
>> +
>> +record_throwing_stmt:
>> /* Look for things that can throw exceptions, and record them. */
>> if (state->cur_region && stmt_could_throw_p (cfun, stmt))
>> {
>> @@ -2085,6 +2087,36 @@ lower_eh_constructs_2 (struct leh_state *state,
>> gimple_stmt_iterator *gsi)
>> }
>> break;
>>
>> + case GIMPLE_ASM:
>> + {
>> + /* As above with GIMPLE_ASSIGN. Change each register output operand
>> + to a temporary and insert a new stmt to assign this to the
>> original
>> + operand. */
>> + gasm *asm_stmt = as_a <gasm *> (stmt);
>> + if (stmt_could_throw_p (cfun, stmt)
>> + && gimple_asm_noutputs (asm_stmt) > 0
>> + && gimple_stmt_may_fallthru (stmt))
>> + {
>> + for (unsigned i = 0; i < gimple_asm_noutputs (asm_stmt); ++i)
>> + {
>> + tree op = gimple_asm_output_op (asm_stmt, i);
>> + tree opval = TREE_VALUE (op);
>> + if (tree_could_throw_p (opval)
>> + || !is_gimple_reg_type (TREE_TYPE (opval))
>> + || !is_gimple_reg (get_base_address (opval)))
>> + continue;
>> +
>> + tree tmp = create_tmp_reg (TREE_TYPE (opval));
>> + gimple *s = gimple_build_assign (opval, tmp);
>> + gimple_set_location (s, gimple_location (stmt));
>> + gimple_set_block (s, gimple_block (stmt));
>> + TREE_VALUE (op) = tmp;
>> + gsi_insert_after (gsi, s, GSI_SAME_STMT);
>> + }
>> + }
>> + }
>> + goto record_throwing_stmt;
>
> Can you avoid the ugly goto by simply duplicating the common code please?
>
> Otherwise OK.
>
> As you say volatile asms are already considered throwing in some pieces of
> code so this is a step towards fulfilling that promise.
>
> Thanks,
> Richard.
>
Hi Richard,
Thanks for your feedback. I'll have to check again if I made any other
changes since this. If not, and if there are no further objections, I will
resubmit this patch soon with this goto removed.
