[llvm-commits] CVS: llvm/lib/Target/README.txt

[Chris Lattner]

Changes in directory llvm/lib/Target:

README.txt updated: 1.33 -> 1.34
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Log message:

Add a note


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Diffs of the changes:  (+19 -0)

 README.txt |   19 +++++++++++++++++++
 1 files changed, 19 insertions(+)


Index: llvm/lib/Target/README.txt
diff -u llvm/lib/Target/README.txt:1.33 llvm/lib/Target/README.txt:1.34
--- llvm/lib/Target/README.txt:1.33	Sat May 20 22:57:07 2006
+++ llvm/lib/Target/README.txt	Tue May 30 16:29:15 2006
@@ -251,3 +251,22 @@
         ret void
 }
 
+//===---------------------------------------------------------------------===//
+
+dag/inst combine "clz(x)>>5 -> x==0" for 32-bit x.
+
+Compile:
+
+int bar(int x)
+{
+  int t = __builtin_clz(x);
+  return -(t>>5);
+}
+
+to:
+
+_bar:   addic r3,r3,-1
+        subfe r3,r3,r3
+        blr
+
+