* caller-save.c (insert_one_insn): If inserting before a call_insn

	then the registers containing the arguments of the call are
	live_throughout in the new insn.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@130733 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 32 insertions, 0 deletions

diff --git a/gcc/caller-save.c b/gcc/caller-save.c
index 26ac50eadd1..7976fd5fd75 100644
--- a/gcc/caller-save.c
+++ b/gcc/caller-save.c
@@ -850,6 +850,38 @@ insert_one_insn (struct insn_chain *chain, int before_p, int code, rtx pat)
 		SET_REGNO_REG_SET (&new->live_throughout, regno + i);
 	    }
 	}
+
+      /* If CHAIN->INSN is a call, then the registers which contain
+	 the arguments to the function are live in the new insn.  */
+      if (CALL_P (chain->insn))
+	{
+	  for (link = CALL_INSN_FUNCTION_USAGE (chain->insn);
+	       link != NULL_RTX;
+	       link = XEXP (link, 1))
+	    {
+	      rtx arg = XEXP (link, 0);
+
+	      if (GET_CODE (arg) == USE)
+		{
+		  rtx reg = XEXP (arg, 0);
+
+		  if (REG_P (reg))
+		    {
+		      int i, regno = REGNO (reg);
+
+		      /* Registers in CALL_INSN_FUNCTION_USAGE are always
+			 hard registers.  */
+		      gcc_assert (regno < FIRST_PSEUDO_REGISTER);
+
+		      for (i = hard_regno_nregs[regno][GET_MODE (reg)] - 1;
+			   i >= 0; i--)
+			SET_REGNO_REG_SET (&new->live_throughout, regno + i);
+		    }
+		}
+	    }
+	  
+	}
+
       CLEAR_REG_SET (&new->dead_or_set);
       if (chain->insn == BB_HEAD (BASIC_BLOCK (chain->block)))
 	BB_HEAD (BASIC_BLOCK (chain->block)) = new->insn;