From 3bb92747ba56cf1ab282a8317eaef066e780e807 Mon Sep 17 00:00:00 2001
From: Tom Deakin <tom.deakin@bristol.ac.uk>
Date: Fri, 31 Jul 2015 16:54:11 +0100
Subject: [PATCH] Check for double support in OpenCL

---
 common.h       | 8 ++++++++
 ocl-stream.cpp | 3 +++
 2 files changed, 11 insertions(+)

diff --git a/common.h b/common.h
index 6b881a5..4e15ed6 100644
--- a/common.h
+++ b/common.h
@@ -93,6 +93,14 @@ struct badmemsize : public std::exception
     }
 };
 
+struct nodouble : public std::exception
+{
+    virtual const char * what () const throw ()
+    {
+        return "Device does not support double precision, please use --float";
+    }
+};
+
 template < typename T >
 void check_solution(void* a_in, void* b_in, void* c_in)
 {
diff --git a/ocl-stream.cpp b/ocl-stream.cpp
index 822db7b..7ebe3be 100644
--- a/ocl-stream.cpp
+++ b/ocl-stream.cpp
@@ -165,6 +165,9 @@ int main(int argc, char *argv[])
         std::string name = getDeviceName(device);
         std::cout << "Using OpenCL device " << name << std::endl;
 
+        // Check device can do double precision if requested
+        if (!useFloat && !device.getInfo<CL_DEVICE_DOUBLE_FP_CONFIG>()) throw nodouble();
+
         // Check buffers fit on the device
         status = "Getting device memory sizes";
         cl_ulong totalmem = device.getInfo<CL_DEVICE_GLOBAL_MEM_SIZE>();