Re: Make regcprop to eliminate noop moves better

[Bernd Schmidt]

On 09/22/2016 01:48 PM, Jan Hubicka wrote:

        * postreload.c (reload_cse_simplify): Also accept USE in noop move
        patterns.

diff --git a/gcc/postreload.c b/gcc/postreload.c
index 61c1ce8..4f3a526 100644
--- a/gcc/postreload.c
+++ b/gcc/postreload.c
@@ -153,7 +153,8 @@ reload_cse_simplify (rtx_insn *insn, rtx testreg)
                  value = SET_DEST (part);
                }
            }
-         else if (GET_CODE (part) != CLOBBER)
+         else if (GET_CODE (part) != CLOBBER
+                  && GET_CODE (part) != USE)
            break;
        }

Hmm. This is probably ok, but what's the USE for in your pattern?


Bernd