[Bug ipa/90401] Missed propagation of by-ref constant argument to callee function

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90401

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
                 CC|                            |jamborm at gcc dot gnu.org
            Version|unknown                     |10.0

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Huh.  IPA-CP dump difference:

@@ -26,6 +26,8 @@
          Unknown VR
     callsite  int caller(int, int&)/2 -> int callee(int&)/1 : 
        param 0: UNKNOWN
+         Aggregate passed by reference:
+           offset: 0, cst: 1
          value: 0x0, mask: 0xfffffffffffffffc
          VR  ~[0, 0]
   Jump functions of caller  int callee(int&)/1:

I guess somehow IPA-CP walks stmts for defs instead of virtual operands?