New case to handle someday

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24075 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/README.txt b/lib/Target/PowerPC/README.txt
index abd91575e9e08db258ff6eadf5c4249210007ae1..972e5bbd6e17037b0f1f67eaa2f87dec61bb82e5 100644 (file)
--- a/lib/Target/PowerPC/README.txt
+++ b/lib/Target/PowerPC/README.txt
@@ -217,5 +217,22 @@ _test:
         stw r2, 0(r3)
         blr
 
+===-------------------------------------------------------------------------===
+
+Compile
+int foo(int a) { return a * -2 + 63; }
+
+to
+
+_foo:
+        slwi r0,r3,1
+        subfic r3,r0,63
+        blr
+
+instead of:
 
+_foo:
+        mulli r2,r3,-2
+        addi r3,r2,63
+        blr