Add a memset loop that LoopIdiomRecognize doesn't recognize.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124082 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/README.txt b/lib/Target/README.txt
index 67aec852fa049c8876f0df369cb39f9e6e975698..ea9bc8d84c8c0fc67592b5087e06b39ce64b27b6 100644 (file)
--- a/lib/Target/README.txt
+++ b/lib/Target/README.txt
@@ -289,6 +289,14 @@ unsigned int popcount(unsigned int input) {
 
 This sort of thing should be added to the loop idiom pass.
 
+This loop isn't converted to a memset:
+
+void f(char *dest, int n) {
+  for (int i = 0; i < n; ++i) {
+    dest[n] = 0;
+  }
+}
+
 //===---------------------------------------------------------------------===//
 
 These should turn into single 16-bit (unaligned?) loads on little/big endian