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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25942 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/README.txt b/lib/Target/README.txt
index 2a0d8e121cacdd95c6abf1c80812372de56f55e7..32a2e7ccbd57f6a088c66bb284ef3932fb42a20e 100644 (file)
--- a/lib/Target/README.txt
+++ b/lib/Target/README.txt
@@ -64,4 +64,8 @@ Number 1 is the preferred solution.
 
 //===---------------------------------------------------------------------===//
 
+For dag combiner and instcombine:
+Fold: "A / (B << N)" where B is a power of 2, to "A >> (N + log2(B))".
+Fold: "A % (B << N)" where B is a power of 2, to "A & ((B << N) - 1)".
 
+//===---------------------------------------------------------------------===//