add a note.

llvm-svn: 131863
diff --git a/llvm/lib/Target/README.txt b/llvm/lib/Target/README.txt
index 0105ae4..260cb5c 100644
--- a/llvm/lib/Target/README.txt
+++ b/llvm/lib/Target/README.txt
@@ -2346,3 +2346,13 @@
 because one call is passing an i32 and the other is passing an i64.
 
 //===---------------------------------------------------------------------===//
+
+I see this sort of pattern in 176.gcc in a few places (e.g. the start of
+store_bit_field).  The rem should be replaced with a multiply and subtract:
+
+  %3 = sdiv i32 %A, %B
+  %4 = srem i32 %A, %B
+
+Similarly for udiv/urem.
+
+//===---------------------------------------------------------------------===//