[llvm] r190404 - [SystemZ] Update README.

[Richard Sandiford]

Author: rsandifo
Date: Tue Sep 10 07:22:45 2013
New Revision: 190404

URL: http://llvm.org/viewvc/llvm-project?rev=190404&view=rev
Log:
[SystemZ] Update README.

Modified:
    llvm/trunk/lib/Target/SystemZ/README.txt

Modified: llvm/trunk/lib/Target/SystemZ/README.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/SystemZ/README.txt?rev=190404&r1=190403&r2=190404&view=diff
==============================================================================
--- llvm/trunk/lib/Target/SystemZ/README.txt (original)
+++ llvm/trunk/lib/Target/SystemZ/README.txt Tue Sep 10 07:22:45 2013
@@ -58,14 +58,11 @@ condition codes.  For example, we could
 
 --
 
-We don't optimize block memory operations, except using single MVCs
-for memcpy and single CLCs for memcmp.
+We only use MVC, XC and CLC for constant-length block operations.
+We could extend them to variable-length operations too,
+using EXECUTE RELATIVE LONG.
 
-It's definitely worth using things like NC, XC and OC with
-constant lengths.  MVCIN may be worthwhile too.
-
-We should probably implement general memcpy using MVC with EXECUTE.
-Likewise memcmp and CLC.  MVCLE and CLCLE could be useful too.
+MVCIN, MVCLE and CLCLE may be worthwhile too.
 
 --
 
@@ -93,8 +90,7 @@ We don't use the halfword forms of LOAD
 
 --
 
-We could take advantage of the various ... UNDER MASK instructions,
-such as ICM and STCM.
+We don't use ICM or STCM.
 
 --