Add a note about lowering llvm.memset, llvm.memcpy, and llvm.memmove to a

few stores under certain conditions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25777 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt
index 2308761644..ac8f3f1e08 100644
--- a/lib/Target/X86/README.txt
+++ b/lib/Target/X86/README.txt
@@ -168,6 +168,13 @@ Combine: a = sin(x), b = cos(x) into a,b = sincos(x).
 
 //===---------------------------------------------------------------------===//
 
+For all targets, not just X86:
+When llvm.memcpy, llvm.memset, or llvm.memmove are lowered, they should be 
+optimized to a few store instructions if the source is constant and the length
+is smallish (< 8). This will greatly help some tests like Shootout/strcat.c
+
+//===---------------------------------------------------------------------===//
+
 Solve this DAG isel folding deficiency:
 
 int X, Y;