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| author | Richard Sandiford <rsandifo@linux.vnet.ibm.com> | 2013-09-10 12:22:45 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@linux.vnet.ibm.com> | 2013-09-10 12:22:45 +0000 |
| commit | 4c708e586eecb039811fdd54a8846002324936b2 (patch) | |
| tree | 88d1e56fe286ebf8c63b3fd44531726f168adea6 | |
| parent | 299fdd814f4c2850d44387d24c440980c5377d3e (diff) | |
| download | external_llvm-4c708e586eecb039811fdd54a8846002324936b2.zip external_llvm-4c708e586eecb039811fdd54a8846002324936b2.tar.gz external_llvm-4c708e586eecb039811fdd54a8846002324936b2.tar.bz2 | |
[SystemZ] Update README.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190404 91177308-0d34-0410-b5e6-96231b3b80d8
| -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. -- |