Sqrt in assembler is worth 3-4X for nbody

R=rsc
DELTA=10  (10 added, 0 deleted, 0 changed)
OCL=34987
CL=34987

diff --git a/test/bench/timing.log b/test/bench/timing.log
index 32a0b9a5ba3e0467c91c8318160b99343bcf68db..edd40e2507967eae573aece12c218a45cc07fb98 100644 (file)
--- a/test/bench/timing.log
+++ b/test/bench/timing.log
@@ -388,3 +388,13 @@ threadring 50000000
 
 chameneos 6000000
        gc chameneosredux       26.62u 0.00s 26.63r     # +13%
+
+Sep 24, 2009
+
+# Sqrt now in assembler for 6g.
+nbody -n 50000000
+       # remember, at least for 6g, alignment of loops may be important
+       gcc -O2 nbody.c 21.24u 0.00s 21.25r
+       gccgo -O2 nbody.go      121.03u 0.00s 121.04r
+       gc nbody        30.26u 0.00s 30.27r     # -65% ***
+       gc_B nbody      30.20u 0.02s 30.22r     # -72% ***