[PATCH] Optimize square root squared (PR21126)

[hfinkel at anl.gov]

LGTM.

================
Comment at: test/Transforms/InstCombine/fmul.ll:130
@@ +129,3 @@
+declare double @llvm.sqrt.f64(double)
+attributes #0 = { "unsafe-fp-math"="true" }
+
----------------
We don't need the "unsafe-fp-math"="true" because you're just checking the 'fast' on the fmul, right? If you don't need it, please remove it.

http://reviews.llvm.org/D5584