PR optimization/6233

	* rtlanal.c (pure_call_p): New function.
	* rtl.h (pure_call_p): Declare.
	* loop.c (prescan_loop): Use it to set has_nonconst_call.
	* gcse.c (store_killed_in_insn): Use pure_call_p here too.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@52110 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 25 insertions, 0 deletions

diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index 9348fd01d11..07cb6d8d6a7 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -2011,6 +2011,31 @@ find_regno_fusage (insn, code, regno)
 
   return 0;
 }
+
+/* Return true if INSN is a call to a pure function.  */
+
+int
+pure_call_p (insn)
+     rtx insn;
+{
+  rtx link;
+
+  if (GET_CODE (insn) != CALL_INSN || ! CONST_OR_PURE_CALL_P (insn))
+    return 0;
+
+  /* Look for the note that differentiates const and pure functions.  */
+  for (link = CALL_INSN_FUNCTION_USAGE (insn); link; link = XEXP (link, 1))
+    {
+      rtx u, m;
+
+      if (GET_CODE (u = XEXP (link, 0)) == USE
+	  && GET_CODE (m = XEXP (u, 0)) == MEM && GET_MODE (m) == BLKmode
+	  && GET_CODE (XEXP (m, 0)) == SCRATCH)
+	return 1;
+    }
+
+  return 0;
+}
 
 /* Remove register note NOTE from the REG_NOTES of INSN.  */