Add safe mode option to disable problematic optimizations.

With safe mode, oclvanitygen works with AMD's CPU OpenCL device.

oclvanitygen.c

@@ -422,8 +422,10 @@ vg_ocl_hash_program(vg_ocl_context_t *vocp, const char *opts,
 	MD5_Update(&ctx, str, strlen(str) + 1);
 	str = vg_ocl_device_getstr(vocp->voc_ocldid, CL_DEVICE_NAME);
 	MD5_Update(&ctx, str, strlen(str) + 1);
-	MD5_Update(&ctx, opts, strlen(opts) + 1);
+	if (opts)
-	MD5_Update(&ctx, program, size);
+		MD5_Update(&ctx, opts, strlen(opts) + 1);
+	if (size)
+		MD5_Update(&ctx, program, size);
 	MD5_Final(hash_out, &ctx);
 }
 
@@ -616,7 +618,8 @@ vg_ocl_context_callback(const char *errinfo,
 }
 
 int
-vg_ocl_init(vg_context_t *vcp, vg_ocl_context_t *vocp, cl_device_id did)
+vg_ocl_init(vg_context_t *vcp, vg_ocl_context_t *vocp, cl_device_id did,
+	    int safe_mode)
 {
 	cl_int ret;
 	const char *vend, *options;
@@ -633,7 +636,7 @@ vg_ocl_init(vg_context_t *vcp, vg_ocl_context_t *vocp, cl_device_id did)
 	if (vcp->vc_verbose > 1)
 		vg_ocl_dump_info(vocp);
 
-	if (!vg_ocl_check_driver(vocp)) {
+	if (!vg_ocl_check_driver(vocp) && (vcp->vc_verbose > 0)) {
 		char yesbuf[16];
 		printf("Type 'yes' to continue: ");
 		fflush(stdout);
@@ -661,9 +664,12 @@ vg_ocl_init(vg_context_t *vcp, vg_ocl_context_t *vocp, cl_device_id did)
 	}
 
 	options = "-DUNROLL_MAX=16";
-
 	vend = vg_ocl_device_getstr(did, CL_DEVICE_VENDOR);
-	if (!strcmp(vend, "Advanced Micro Devices, Inc.") ||
+
+	if (safe_mode) {
+		options = NULL;
+
+	} else if (!strcmp(vend, "Advanced Micro Devices, Inc.") ||
 	    !strcmp(vend, "AMD")) {
 		/* Radeons do better with less flow control */
 		options = "-DUNROLL_MAX=16 -DVERY_EXPENSIVE_BRANCHES";
@@ -1335,8 +1341,8 @@ out:
  */
 
 void *
-vg_opencl_loop(vg_context_t *vcp, cl_device_id did, int worksize,
+vg_opencl_loop(vg_context_t *vcp, cl_device_id did, int safe_mode,
-	       int nrows, int ncols, int invsize)
+	       int worksize, int nrows, int ncols, int invsize)
 {
 	int i;
 	int round, full_worksize;
@@ -1363,7 +1369,7 @@ vg_opencl_loop(vg_context_t *vcp, cl_device_id did, int worksize,
 
 	struct timeval tvstart;
 
-	if (!vg_ocl_init(vcp, &ctx, did))
+	if (!vg_ocl_init(vcp, &ctx, did, safe_mode))
 		return NULL;
 
 	pkey = vxcp->vxc_key;
@@ -1983,11 +1989,12 @@ main(int argc, char **argv)
 	int nrows = 0, ncols = 0;
 	int invsize = 0;
 	int remove_on_match = 1;
+	int safe_mode = 0;
 	vg_context_t *vcp = NULL;
 	cl_device_id did;
 	const char *result_file = NULL;
 
-	while ((opt = getopt(argc, argv, "vqrikNTp:d:w:g:b:h?f:o:s:")) != -1) {
+	while ((opt = getopt(argc, argv, "vqrikNTp:d:w:g:b:Sh?f:o:s:")) != -1) {
 		switch (opt) {
 		case 'v':
 			verbose = 2;
@@ -2049,6 +2056,9 @@ main(int argc, char **argv)
 				return 1;
 			}
 			break;
+		case 'S':
+			safe_mode = 1;
+			break;
 		case 'f':
 			if (fp) {
 				printf("Multiple files specified\n");
@@ -2161,6 +2171,7 @@ main(int argc, char **argv)
 		return 1;
 	}
 
-	vg_opencl_loop(vcp, did, worksize, nrows, ncols, invsize);
+	vg_opencl_loop(vcp, did, safe_mode,
+		       worksize, nrows, ncols, invsize);
 	return 0;
 }