re PR target/55023 (hppa: wrong code generated with tail call optimisation)

	PR target/55023
	* dse.c (scan_insn): Treat sibling call as though it does a wild read.
	* testsuite/gcc.dg/pr55023.c: New file.

From-SVN: r219037

1 files changed, 11 insertions, 0 deletions

diff --git a/gcc/dse.c b/gcc/dse.c
index 2555bd1..3a7f31c 100644
--- a/gcc/dse.c
+++ b/gcc/dse.c
@@ -2483,6 +2483,17 @@ scan_insn (bb_info_t bb_info, rtx_insn *insn)
 
       insn_info->cannot_delete = true;
 
+      /* Arguments for a sibling call that are pushed to memory are passed
+	 using the incoming argument pointer of the current function.  These
+	 may or may not be frame related depending on the target.  Since
+	 argument pointer related stores are not currently tracked, we treat
+	 a sibling call as though it does a wild read.  */
+      if (SIBLING_CALL_P (insn))
+	{
+	  add_wild_read (bb_info);
+	  return;
+	}
+
       /* Const functions cannot do anything bad i.e. read memory,
 	 however, they can read their parameters which may have
 	 been pushed onto the stack.