https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118864
ak at gcc dot gnu.org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |ak at gcc dot gnu.org
--- Comment #3 from ak at gcc dot gnu.org ---
For cross jumping it would be in old_insns_match_p I think
FWIW I tried to write a patch there for noreturn, but it didn't fix
the original issue in PR118198, likely due to some other code
transformations
diff --git a/gcc/cfgcleanup.cc b/gcc/cfgcleanup.cc
index d28d2323191..b784d5eca7a 100644
--- a/gcc/cfgcleanup.cc
+++ b/gcc/cfgcleanup.cc
@@ -53,6 +53,7 @@ along with GCC; see the file COPYING3. If not see
#include "dbgcnt.h"
#include "rtl-iter.h"
#include "regs.h"
+#include "calls.h"
#include "function-abi.h"
#define FORWARDER_BLOCK_P(BB) ((BB)->flags & BB_FORWARDER_BLOCK)
@@ -1207,6 +1208,11 @@ old_insns_match_p (int mode ATTRIBUTE_UNUSED, rtx_insn
*i1, rtx_insn *i2)
|| SIBLING_CALL_P (i1) != SIBLING_CALL_P (i2))
return dir_none;
+ /* Avoid merging noreturn to improve backtraces. */
+ if (rtx call = get_call_rtx_from (i1);
+ call && find_reg_note (call, REG_NORETURN, NULL))
+ return dir_none;
+
/* For address sanitizer, never crossjump __asan_report_* builtins,
otherwise errors might be reported on incorrect lines. */
if (flag_sanitize & SANITIZE_ADDRESS)
diff --git a/gcc/tree-ssa-tail-merge.cc b/gcc/tree-ssa-tail-merge.cc
index d897970079c..fc23672930d 100644
--- a/gcc/tree-ssa-tail-merge.cc
+++ b/gcc/tree-ssa-tail-merge.cc
@@ -1312,6 +1312,10 @@ merge_stmts_p (gimple *stmt1, gimple *stmt2)
if (lookup_stmt_eh_lp_fn (cfun, stmt1) != lookup_stmt_eh_lp_fn (cfun,
stmt2))
return false;
+ /* Don't merge noreturn to give accurate backtraces. */
+ if (is_gimple_call (stmt1) && (gimple_call_flags (stmt1) & ECF_NORETURN))
+ return false;
+
if (is_gimple_call (stmt1)
&& gimple_call_internal_p (stmt1))
switch (gimple_call_internal_fn (stmt1))
