<div dir="ltr"><div><div><div><div>Hi Jan/Tom, </div>Sorry to resurrect an ancient thread, but I was poking at the piglit CL ULP issue last night, and thought I'd try to get us closer to a solution after dropping the matter for too long. </div>I've modified your test program with what I was thinking of trying, and I wouldn't mind your feedback. </div>I realize that we still have issues with discrepancies between python-generated expected results based on cpu/rounding mode and the , but I'd at least like for us to be able to nail down the C portion before we start redefining all of our expected test results. In the long term, we probably want to hand-select our inputs/outputs instead of trusting python, but I don't necessarily think that we should block fixing our ULP calculations on getting that done. </div><div>For now, I'm still ignoring the half-ULP possibility, and just generating a minimum/maximum allowed value based on running nextafterf(expected, POS/NEG INFINITY) in a loop for ULP iterations. Does that sound like a tenable solution? </div><div> </div>--Aaron </div><div class="gmail_extra"> <div class="gmail_quote">On Sun, Jun 14, 2015 at 4:19 PM, Jan Vesely <<a href="mailto:jan.vesely@rutgers.edu" target="_blank">jan.vesely@rutgers.edu</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On Sat, 2015-06-13 at 21:22 -0500, Aaron Watry wrote: > Meh, this still feels broken. Give me a bit longer. and it is :). I don't think this can work based on abs(expected - real), since ULP depends on the magnitude of the numbers. This information is lost after subtraction. I had an idea some time back to implement this using nextafterf in both directions and checking whether the result falls in that interval. However, there is still a problem. Some of the expected values are already rounded (I'm not sure what rounding mode is used by python by default), but unless it always rounds in one direction, we'll still get slight differences based on whether the actual value was rounded up or down. I have attached a small test program that shows the deficiencies of fabsf based approaches. regards, Jan <div class="HOEnZb"><div class="h5"> > > --Aaron > > On Sat, Jun 13, 2015 at 2:28 PM, Aaron Watry <<a href="mailto:awatry@gmail.com">awatry@gmail.com</a>> wrote: > > > We need to actually check against the float value from the union, > > instead of just doing (diff > ulp), which seems to cast the diff to > > an int before checking against ulp. > > > > Signed-off-by: Aaron Watry <<a href="mailto:awatry@gmail.com">awatry@gmail.com</a>> > > CC: Tom Stellard <<a href="mailto:thomas.stellard@amd.com">thomas.stellard@amd.com</a>> > > CC: Jan Vesely <<a href="mailto:jan.vesely@rutgers.edu">jan.vesely@rutgers.edu</a>> > > --- > > tests/util/piglit-util-cl.c | 28 ++++++++++++++-------------- > > 1 file changed, 14 insertions(+), 14 deletions(-) > > > > diff --git a/tests/util/piglit-util-cl.c b/tests/util/piglit-util-cl.c > > index 47e0c7a..6cdd718 100644 > > --- a/tests/util/piglit-util-cl.c > > +++ b/tests/util/piglit-util-cl.c > > @@ -80,7 +80,7 @@ piglit_cl_probe_floating(float value, float expect, > > uint32_t ulp) > > > > diff = fabsf(value - expect); > > > > - if(diff > ulp || isnan(value)) { > > + if (diff > t.f || isnan(value)) { > > printf("Expecting %f (0x%x) with tolerance %f (%u ulps), > > but got %f (0x%x)\n", > > e.f, e.u, t.f, t.u, v.f, v.u); > > return false; > > @@ -108,7 +108,7 @@ piglit_cl_probe_double(double value, double expect, > > uint64_t ulp) > > > > diff = fabsl(value - expect); > > > > - if(diff > ulp || isnan(value)) { > > + if (diff > t.f || isnan(value)) { > > printf("Expecting %f (0x%lx) with tolerance %f (%lu ulps), > > but got %f (0x%lx)\n", > > e.f, e.u, t.f, t.u, v.f, v.u); > > return false; > > @@ -162,7 +162,7 @@ piglit_cl_get_platform_version(cl_platform_id platform) > > int scanf_count; > > int major; > > int minor; > > - > > + > > /* > > * Returned format: > > * > > OpenCL<space><major_version.minor_version><space><platform-specific > > information> > > @@ -353,7 +353,7 @@ piglit_cl_get_info(void* fn_ptr, void* obj, cl_uint > > param) > > > > if(errNo == CL_SUCCESS) { > > param_ptr = calloc(param_size, sizeof(char)); > > - > > + > > /* retrieve param */ > > if(fn_ptr == clGetPlatformInfo) { > > errNo = clGetPlatformInfo(*(cl_platform_id*)obj, > > param, > > @@ -463,7 +463,7 @@ piglit_cl_get_program_build_info(cl_program program, > > cl_device_id device, > > .program = program, > > .device = device > > }; > > - > > + > > return piglit_cl_get_info(clGetProgramBuildInfo, &args, param); > > } > > > > @@ -479,7 +479,7 @@ piglit_cl_get_kernel_work_group_info(cl_kernel kernel, > > cl_device_id device, > > .kernel = kernel, > > .device = device > > }; > > - > > + > > return piglit_cl_get_info(clGetKernelWorkGroupInfo, &args, param); > > } > > > > @@ -620,7 +620,7 @@ piglit_cl_get_device_ids(cl_platform_id platform_id, > > cl_device_type device_type, > > piglit_cl_get_error_name(errNo)); > > return 0; > > } > > - > > + > > /* get device list */ > > if(device_ids != NULL && num_device_ids > 0) { > > *device_ids = malloc(num_device_ids * > > sizeof(cl_device_id)); > > @@ -761,7 +761,7 @@ > > piglit_cl_build_program_with_source_extended(piglit_cl_context context, > > piglit_cl_get_error_name(errNo)); > > return NULL; > > } > > - > > + > > errNo = clBuildProgram(program, > > context->num_devices, > > context->device_ids, > > @@ -788,7 +788,7 @@ > > piglit_cl_build_program_with_source_extended(piglit_cl_context context, > > char* log = > > piglit_cl_get_program_build_info(program, > > > > context->device_ids[i], > > > > CL_PROGRAM_BUILD_LOG); > > - > > + > > printf("Build log for device %s:\n -------- \n%s\n > > -------- \n", > > device_name, > > log); > > @@ -848,11 +848,11 @@ > > piglit_cl_build_program_with_binary_extended(piglit_cl_context context, > > for(i = 0; i < context->num_devices; i++) { > > char* device_name = > > piglit_cl_get_device_info(context->device_ids[i], > > > > CL_DEVICE_NAME); > > - > > + > > printf("Error for %s: %s\n", > > device_name, > > piglit_cl_get_error_name(binary_status[i])); > > - > > + > > free(device_name); > > } > > > > @@ -860,7 +860,7 @@ > > piglit_cl_build_program_with_binary_extended(piglit_cl_context context, > > return NULL; > > } > > free(binary_status); > > - > > + > > errNo = clBuildProgram(program, > > context->num_devices, > > context->device_ids, > > @@ -884,11 +884,11 @@ > > piglit_cl_build_program_with_binary_extended(piglit_cl_context context, > > char* log = > > piglit_cl_get_program_build_info(program, > > > > context->device_ids[i], > > > > CL_PROGRAM_BUILD_LOG); > > - > > + > > printf("Build log for device %s:\n -------- \n%s\n > > -------- \n", > > device_name, > > log); > > - > > + > > free(device_name); > > free(log); > > } > > -- > > 2.1.4 > > > > </div></div>-- Jan Vesely <<a href="mailto:jan.vesely@rutgers.edu">jan.vesely@rutgers.edu</a>> </blockquote></div> </div>