tdf#98515: Bail out early if kernel would have ridiculously many parameters

The Right Thing to do would be to compare the accumulated kernel
parameter size against the CL_DEVICE_MAX_PARAMETER_SIZE of the device,
but let's just do this sanity check for now. Bail out if the kernel
would have more than 50 parameters.

Calculating the accumulated kernel parameter size would be more
complicated and I don't want to touch this code more than
necessary. The kernel compilation will fail anyway if the size of
parameters exceeds the limit and this sanity check is just to make us
bail out a bit earlier.

In tdf#98515 the slowness seems to indeed be caused by the OpenCL code
generation , and there the number of parameters was 999, so this
sanity check does fix the slow loading issue (I checked).

Change-Id: Iead6dfb94ec8e7b2968ffed9423f0f9522a10ce9
(cherry picked from commit a48aefcae40663b63005d49a04fc7b89a473d613)
Reviewed-on: https://gerrit.libreoffice.org/26701
Reviewed-by: Tor Lillqvist <tml@collabora.com>
Tested-by: Tor Lillqvist <tml@collabora.com>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/sc/source/core/opencl/formulagroupcl.cxx b/sc/source/core/opencl/formulagroupcl.cxx
index c3167e3c948f..fbd4b0a6b209 100644
--- a/sc/source/core/opencl/formulagroupcl.cxx
+++ b/sc/source/core/opencl/formulagroupcl.cxx
@@ -2628,6 +2628,19 @@ DynamicKernelSoPArguments::DynamicKernelSoPArguments(const ScCalcConfig& config,
                     const formula::DoubleVectorRefToken* pDVR =
                         static_cast<const formula::DoubleVectorRefToken*>(pChild);
 
+                    // FIXME: The Right Thing to do would be to compare the accumulated kernel
+                    // parameter size against the CL_DEVICE_MAX_PARAMETER_SIZE of the device, but
+                    // let's just do this sanity check for now. The kernel compilation will
+                    // hopefully fail anyway if the size of parameters exceeds the limit and this
+                    // sanity check is just to make us bail out a bit earlier.
+
+                    // The number 50 comes from the fact that the minimum size of
+                    // CL_DEVICE_MAX_PARAMETER_SIZE is 256, which for 32-bit code probably means 64
+                    // of them. Round down a bit.
+
+                    if (pDVR->GetArrays().size() > 50)
+                        throw UnhandledToken(("Kernel would have ridiculously many parameters (" + std::to_string(2 + pDVR->GetArrays().size()) + ")").c_str(), __FILE__, __LINE__);
+
                     for (size_t j = 0; j < pDVR->GetArrays().size(); ++j)
                     {
                         SAL_INFO("sc.opencl", "i=" << i << " j=" << j <<