From 0f87ef8edb8009209fb687095486128861e09583 Mon Sep 17 00:00:00 2001
From: Sam Hatfield <samuel.hatfield@ecmwf.int>
Date: Wed, 12 May 2021 18:48:07 +0900
Subject: [PATCH] Update FFTW benchmark

---
 fftw_benchmark/Makefile  | 11 ++++++++---
 fftw_benchmark/README.md | 12 ++++++------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/fftw_benchmark/Makefile b/fftw_benchmark/Makefile
index ad84d3a..48eddd6 100644
--- a/fftw_benchmark/Makefile
+++ b/fftw_benchmark/Makefile
@@ -1,6 +1,5 @@
 #===============================================================================
-# Makefile for Lorenz '63 model used for investigating half-precision support on
-# Fugaku
+# Makefile for FFTW benchmark.
 #
 # ECMWF/RIKEN-CCS
 #===============================================================================
@@ -10,13 +9,19 @@ ifeq ($(FORTCOMP),)
 FORTCOMP := frtpx
 endif
 
+# Set optimisation flag to -Kfast if not already set
 ifeq ($(FORTOPT),)
 FORTOPT := -Kfast
 endif
 
+# Link to libfjcrt when compiling on Fugaku
+ifeq ($(FORTLIB),)
+FORTLIB := -lfjcrt
+endif
+
 # Define main target
 main: main.o
-	$(FORTCOMP) $(FORTOPT) $(FFTWF_LIB) -o $@ $^
+	$(FORTCOMP) $(FORTOPT) $(FFTWF_LIB) $(FORTLIB) -o $@ $^
 
 # Define generic target for Fortran 90
 %.o: %.F90
diff --git a/fftw_benchmark/README.md b/fftw_benchmark/README.md
index d838ed8..0c9f4a0 100644
--- a/fftw_benchmark/README.md
+++ b/fftw_benchmark/README.md
@@ -10,11 +10,11 @@ It is based on [this](https://gist.github.com/appleparan/c048c44668ede7ef28ba63c
 First define the `FFTWF_LIB` environment variable, pointing it to the location
 of the FFTW library directory. For example, on Fugaku I set
 ```
-export FFTWF_LIB=-L/vol0004/apps/oss/spack-v0.16/opt/spack/linux-rhel8-a64fx/\
-    fj-4.3.1/fftw-3.3.8-b6z4s4rfp5ju6m6pa3zr5a2xpbws7zum/lib\
-    -Wl,-rpath,/vol0004/apps/oss/spack-v0.16/opt/spack/linux-rhel8-a64fx/\
-    fj-4.3.1/fftw-3.3.8-b6z4s4rfp5ju6m6pa3zr5a2xpbws7zum/lib -lfftw3f
+export FFTWF_LIB="-L/vol0004/apps/oss/spack-v0.16/opt/spack/linux-rhel8-a64fx/fj-4.3.1/fujitsu-fftw-master-2irjm2a56j7tahcmggbnde2uxf6gjdml/lib -Wl,-rpath,/vol0004/apps/oss/spack-v0.16/opt/spack/linux-rhel8-a64fx/fj-4.3.1/fujitsu-fftw-master-2irjm2a56j7tahcmggbnde2uxf6gjdml/lib -lfftw3f"
 ```
+which uses the `fujitsu-fftw` Spack module.
+
 Also if you don't want to use the Fujitsu compiler you must also set the
-`FORTCOMP` environment variable to your compiler of choice, and set the
-`FORTOPT` environment variable with your optimisation flags.
+`FORTCOMP` environment variable to your compiler of choice, set the
+`FORTOPT` environment variable with your optimisation flags and set the
+`FORTLIB` to the empty string.