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 | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/gcc/function.cc b/gcc/function.cc
index 4edd4da12474..f949c38b916c 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,
@@ -6579,7 +6580,7 @@ rest_of_handle_thread_prologue_and_epilogue (function
*fun)
/* Shrink-wrapping can result in unreachable edges in the epilogue,
see PR57320. */
- cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
+ cleanup_cfg ((cfun->tail_call_marked || optimize) ? CLEANUP_EXPENSIVE : 0);
/* The stack usage info is finalized during prologue expansion. */
if (flag_stack_usage_info || flag_callgraph_info)
--
2.44.0
