From 86a4b8eac37691788e1447b1ff61b33d774dfa86 Mon Sep 17 00:00:00 2001
From: Purnendu Chakraborty <purnendu.chakraborty@nasa.gov>
Date: Fri, 12 May 2023 19:28:20 -0400
Subject: [PATCH 1/4] Find OpenACC

---
 esma.cmake | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/esma.cmake b/esma.cmake
index 6debfc16..e131691c 100644
--- a/esma.cmake
+++ b/esma.cmake
@@ -33,6 +33,10 @@ include (esma_compiler)
 
 find_package (OpenMP)
 
+### OpenACC ###
+
+find_package (OpenACC)
+
 ### Position independent code ###
 
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)

From 850a51083a8dce0e2700726a48c5e2ab390cea5f Mon Sep 17 00:00:00 2001
From: Purnendu Chakraborty <purnendu.chakraborty@nasa.gov>
Date: Sat, 24 Jun 2023 14:03:53 -0400
Subject: [PATCH 2/4] Added option GPU_PHYSICS with default value OFF

---
 esma.cmake | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/esma.cmake b/esma.cmake
index e131691c..e5b421ad 100644
--- a/esma.cmake
+++ b/esma.cmake
@@ -33,9 +33,12 @@ include (esma_compiler)
 
 find_package (OpenMP)
 
-### OpenACC ###
+### GPU Physics ###
 
-find_package (OpenACC)
+option(GPU_PHYSICS "Build GPU ports of Physics components" OFF)
+if (GPU_PHYSICS)
+  find_package (OpenACC)
+endif ()
 
 ### Position independent code ###
 

From 8f2dbf48fc434af81c3ee8d6c6125217690a0a99 Mon Sep 17 00:00:00 2001
From: Purnendu Chakraborty <purnendu.chakraborty@nasa.gov>
Date: Fri, 30 Jun 2023 12:24:47 -0400
Subject: [PATCH 3/4] Added a set of variables for OpenACC compilation

---
 CHANGELOG.md                     |  4 ++++
 compiler/flags/GNU_Fortran.cmake |  8 ++++++++
 esma.cmake                       | 14 +++++++-------
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 66d68f5c..00a45442 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Added option `GPU_PHYSICS` which defaults to `OFF`. When `ON`, available
+  OpenACC ports of Phsyics routines will be built instead of their original
+  versions.
+
 ### Changed
 
 ## [3.30.0] - 2023-06-23
diff --git a/compiler/flags/GNU_Fortran.cmake b/compiler/flags/GNU_Fortran.cmake
index 9140d491..608d7612 100644
--- a/compiler/flags/GNU_Fortran.cmake
+++ b/compiler/flags/GNU_Fortran.cmake
@@ -110,6 +110,10 @@ set (NO_ALIAS "")
 
 set (NO_RANGE_CHECK "-fno-range-check")
 
+set (OPENACC_COMPILE "-fopenacc")
+set (OPENACC_OFFLOAD_TARGETS "-foffload=nvptx-none")
+set (OPENACC_OFFLOAD_OPTIONS "-lgfortran -lgomp -lm")
+
 cmake_host_system_information(RESULT proc_description QUERY PROCESSOR_DESCRIPTION)
 
 if ( ${CMAKE_HOST_SYSTEM_PROCESSOR} STREQUAL aarch64 )
@@ -202,6 +206,10 @@ endif ()
 #set (GEOS_Fortran_Aggressive_Flags "-O2 -march=native -ffast-math -ftree-vectorize -funroll-loops --param max-unroll-times=4 ${PREFER_AVX128} -mno-fma -mveclibabi=svml")
 #set (GEOS_Fortran_Aggressive_FPE_Flags "${DEBINFO} ${TRACEBACK} ${MISMATCH} ${ALLOW_BOZ}")
 
+# OpenACC flags
+# -------------
+set (GEOS_Fortran_OpenACC_Flags "${OPENACC_COMPILE} ${OPENACC_OFFLOAD_TARGETS}")
+set (GEOS_Fortran_OpenACC_Flags_Offload_Libs "${OPENACC_COMPILE} ${OPENACC_OFFLOAD_OPTIONS} ${OPENACC_OFFLOAD_TARGETS}")
 
 # Common variables for every compiler
 include(Generic_Fortran)
diff --git a/esma.cmake b/esma.cmake
index e5b421ad..0c5e5db7 100644
--- a/esma.cmake
+++ b/esma.cmake
@@ -24,6 +24,13 @@ option(BUILD_SHARED_LIBS "Build the shared library" OFF)
 set (ECBUILD_2_COMPAT_VALUE OFF)
 include (ecbuild_system NO_POLICY_SCOPE)
 
+### GPU Physics ###
+
+option(GPU_PHYSICS "Build GPU ports of Physics components" OFF)
+if (GPU_PHYSICS)
+  find_package (OpenACC)
+endif ()
+
 ### Compiler Support ###
 
 list (APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/compiler")
@@ -33,13 +40,6 @@ include (esma_compiler)
 
 find_package (OpenMP)
 
-### GPU Physics ###
-
-option(GPU_PHYSICS "Build GPU ports of Physics components" OFF)
-if (GPU_PHYSICS)
-  find_package (OpenACC)
-endif ()
-
 ### Position independent code ###
 
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)

From 718762fb16b19128f29228e5e2309a69d3ca9043 Mon Sep 17 00:00:00 2001
From: Purnendu Chakraborty <purnendu.chakraborty@nasa.gov>
Date: Fri, 30 Jun 2023 12:40:34 -0400
Subject: [PATCH 4/4] Added -foffload

---
 compiler/flags/GNU_Fortran.cmake | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/flags/GNU_Fortran.cmake b/compiler/flags/GNU_Fortran.cmake
index 608d7612..7c34c544 100644
--- a/compiler/flags/GNU_Fortran.cmake
+++ b/compiler/flags/GNU_Fortran.cmake
@@ -112,7 +112,7 @@ set (NO_RANGE_CHECK "-fno-range-check")
 
 set (OPENACC_COMPILE "-fopenacc")
 set (OPENACC_OFFLOAD_TARGETS "-foffload=nvptx-none")
-set (OPENACC_OFFLOAD_OPTIONS "-lgfortran -lgomp -lm")
+set (OPENACC_OFFLOAD_OPTIONS "-foffload=-lgfortran -lgomp -lm")
 
 cmake_host_system_information(RESULT proc_description QUERY PROCESSOR_DESCRIPTION)