ira.c (validate_equiv_mem): Remove code to avoid invalidation of readonly memory…

ira.c (validate_equiv_mem): Remove code to avoid invalidation of readonly memory equivalances for...

	* ira.c (validate_equiv_mem): Remove code to avoid invalidation
	of readonly memory equivalances for const/pure calls.

From-SVN: r166309

gcc/ChangeLog

+2010-11-04  Jeff Law  <law@redhat.com>
+
+	* ira.c (validate_equiv_mem): Remove code to avoid invalidation
+	of readonly memory equivalances for const/pure calls.
+
 2010-11-04  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/45733

gcc/ira.c

@@ -1915,8 +1915,12 @@ validate_equiv_mem (rtx start, rtx reg, rtx memref)
       if (find_reg_note (insn, REG_DEAD, reg))
 	return 1;
 
-      if (CALL_P (insn) && ! MEM_READONLY_P (memref)
-	  && ! RTL_CONST_OR_PURE_CALL_P (insn))
+      /* This used to ignore readonly memory and const/pure calls.  The problem
+	 is the equivalent form may reference a pseudo which gets assigned a
+	 call clobbered hard reg.  When we later replace REG with its
+	 equivalent form, the value in the call-clobbered reg has been
+	 changed and all hell breaks loose.  */
+      if (CALL_P (insn))
 	return 0;
 
       note_stores (PATTERN (insn), validate_equiv_mem_from_store, NULL);