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authorChris Lattner <sabre@nondot.org>2006-02-03 21:25:23 +0000
committerChris Lattner <sabre@nondot.org>2006-02-03 21:25:23 +0000
commitf92bafa2cad6c9c6bdc6fb6ec5fe2d20ca2c9e89 (patch)
tree3ea95b304a32c367ee29f752c0d63740681cd3bf
parent7632e2beb4f0eacc49d580cbf23c89f24ad07ce9 (diff)
add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25942 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/Target/README.txt4
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/Target/README.txt b/lib/Target/README.txt
index 2a0d8e121c..32a2e7ccbd 100644
--- 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)".
+//===---------------------------------------------------------------------===//