From 2f480b10e2a638e1e52f7c90479925b258f720c8 Mon Sep 17 00:00:00 2001 From: Robert Griesemer Date: Tue, 27 Apr 2010 14:06:53 -0700 Subject: [PATCH] pidigits: ~10% performance win by using adds instead of shifts user time for pidigits -s -n=10000: 6.466s w/ adds 7.138s w/ shifts R=rsc CC=golang-dev https://golang.org/cl/1021041 --- test/bench/pidigits.go | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/test/bench/pidigits.go b/test/bench/pidigits.go index a05515028a..3e455dc838 100644 --- a/test/bench/pidigits.go +++ b/test/bench/pidigits.go @@ -63,7 +63,7 @@ func extract_digit() int64 { } // Compute (numer * 3 + accum) / denom - tmp1.Lsh(numer, 1) + tmp1.Add(numer, numer) // tmp1.Lsh(numer, 1) tmp1.Add(tmp1, numer) tmp1.Add(tmp1, accum) tmp1.DivMod(tmp1, denom, tmp2) @@ -84,7 +84,7 @@ func next_term(k int64) { y2.New(k*2 + 1) bigk.New(k) - tmp1.Lsh(numer, 1) + tmp1.Add(numer, numer) // tmp1.Lsh(numer, 1) accum.Add(accum, tmp1) accum.Mul(accum, y2) numer.Mul(numer, bigk)