emit-rtl: document next_nonnote_nondebug_insn_bb () can breach into next BB

gcc/ChangeLog:

	* emit-rtl.cc (next_nonnote_nondebug_insn): Update comments.

Signed-off-by: Vineet Gupta <vineetg@rivosinc.com>

diff --git a/gcc/emit-rtl.cc b/gcc/emit-rtl.cc
index 50e3bfcb777adf99e67d169dbf4c7e8613a7c78a..e64032970d095878e0248e183ab571b0845192b4 100644 (file)
--- a/gcc/emit-rtl.cc
+++ b/gcc/emit-rtl.cc
@@ -3690,7 +3690,11 @@ next_nonnote_nondebug_insn (rtx_insn *insn)
 
 /* Return the next insn after INSN that is not a NOTE nor DEBUG_INSN,
    but stop the search before we enter another basic block.  This
-   routine does not look inside SEQUENCEs.  */
+   routine does not look inside SEQUENCEs.
+   NOTE: This can potentially bleed into next BB. If current insn is
+        last insn of BB, followed by a code_label before the start of
+        the next BB, code_label will be returned. But this is the
+        behavior rest of gcc assumes/relies on e.g. get_last_bb_insn.  */
 
 rtx_insn *
 next_nonnote_nondebug_insn_bb (rtx_insn *insn)