diff options
| -rw-r--r-- | lib/Target/SystemZ/README.txt | 14 |
1 files changed, 5 insertions, 9 deletions
diff --git a/lib/Target/SystemZ/README.txt b/lib/Target/SystemZ/README.txt index d5361fb..afa6cf0 100644 --- a/lib/Target/SystemZ/README.txt +++ b/lib/Target/SystemZ/README.txt @@ -58,14 +58,11 @@ condition codes. For example, we could use LCDFR instead of LCDBR. -- -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 REVERSED and STORE REVERSED -- -We could take advantage of the various ... UNDER MASK instructions, -such as ICM and STCM. +We don't use ICM or STCM. -- |