PR middle-end/27802

	* reg-stack.c (subst_stack_regs): Handle noreturn function calls
	that (would) return their results in stack registers.

	* gcc.dg/pr27802-1.c: New test case.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@114721 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 10 insertions, 0 deletions

diff --git a/gcc/reg-stack.c b/gcc/reg-stack.c
index 83f4ebb081e..fc742bdce60 100644
--- a/gcc/reg-stack.c
+++ b/gcc/reg-stack.c
@@ -2282,6 +2282,16 @@ subst_stack_regs (rtx insn, stack regstack)
   if (NOTE_P (insn) || INSN_DELETED_P (insn))
     return control_flow_insn_deleted;
 
+  /* If this a noreturn call, we can't insert pop insns after it.
+     Instead, reset the stack state to empty.  */
+  if (CALL_P (insn)
+      && find_reg_note (insn, REG_NORETURN, NULL))
+    {
+      regstack->top = -1;
+      CLEAR_HARD_REG_SET (regstack->reg_set);
+      return control_flow_insn_deleted;
+    }
+
   /* If there is a REG_UNUSED note on a stack register on this insn,
      the indicated reg must be popped.  The REG_UNUSED note is removed,
      since the form of the newly emitted pop insn references the reg,