diff mbox series

[v8,02/12] Fix pro_and_epilogue for sibcalls at -O0

Message ID 20240622185557.1589179-3-ak@linux.intel.com
State New
Headers show
Series [v8,01/12] Improve must tail in RTL backend | expand

Commit Message

Andi Kleen June 22, 2024, 6:54 p.m. UTC 
Some of the cfg fixups in pro_and_epilogue for sibcalls were dependent on "optimize".
Make them check cfun->tail_call_marked instead to handle the -O0 musttail
case. This fixes the musttail test cases on arm targets.

	PR115255

gcc/ChangeLog:

	* function.cc (thread_prologue_and_epilogue_insns): Check
	  cfun->tail_call_marked for sibcalls too.
	(rest_of_handle_thread_prologue_and_epilogue): Dito.
---
 gcc/function.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Richard Biener July 5, 2024, 10:41 a.m. UTC | #1 
On Sat, Jun 22, 2024 at 8:57 PM Andi Kleen <ak@linux.intel.com> wrote:
>
> Some of the cfg fixups in pro_and_epilogue for sibcalls were dependent on "optimize".
> Make them check cfun->tail_call_marked instead to handle the -O0 musttail
> case. This fixes the musttail test cases on arm targets.
>
>         PR115255
>
> gcc/ChangeLog:
>
>         * function.cc (thread_prologue_and_epilogue_insns): Check
>           cfun->tail_call_marked for sibcalls too.
>         (rest_of_handle_thread_prologue_and_epilogue): Dito.
> ---
>  gcc/function.cc | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/function.cc b/gcc/function.cc
> index 4edd4da12474..7c9b181423d4 100644
> --- a/gcc/function.cc
> +++ b/gcc/function.cc
> @@ -6261,6 +6261,7 @@ thread_prologue_and_epilogue_insns (void)
>    /* Threading the prologue and epilogue changes the artificial refs in the
>       entry and exit blocks, and may invalidate DF info for tail calls.  */
>    if (optimize
> +      || cfun->tail_call_marked

Can you add comments in both places as to this being because of [[musttail]]
which marks tail-calls even with -fno-optimize-sibling-calls?

OK with those change.

>        || flag_optimize_sibling_calls
>        || flag_ipa_icf_functions
>        || in_lto_p)
> @@ -6557,7 +6558,7 @@ rest_of_handle_thread_prologue_and_epilogue (function *fun)
>  {
>    /* prepare_shrink_wrap is sensitive to the block structure of the control
>       flow graph, so clean it up first.  */
> -  if (optimize)
> +  if (cfun->tail_call_marked || optimize)
>      cleanup_cfg (0);
>
>    /* On some machines, the prologue and epilogue code, or parts thereof,
> --
> 2.45.2
>
diff mbox series

Patch

diff --git a/gcc/function.cc b/gcc/function.cc
index 4edd4da12474..7c9b181423d4 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -6261,6 +6261,7 @@  thread_prologue_and_epilogue_insns (void)
   /* Threading the prologue and epilogue changes the artificial refs in the
      entry and exit blocks, and may invalidate DF info for tail calls.  */
   if (optimize
+      || cfun->tail_call_marked
       || flag_optimize_sibling_calls
       || flag_ipa_icf_functions
       || in_lto_p)
@@ -6557,7 +6558,7 @@  rest_of_handle_thread_prologue_and_epilogue (function *fun)
 {
   /* prepare_shrink_wrap is sensitive to the block structure of the control
      flow graph, so clean it up first.  */
-  if (optimize)
+  if (cfun->tail_call_marked || optimize)
     cleanup_cfg (0);
 
   /* On some machines, the prologue and epilogue code, or parts thereof,