Proof-of-concept cl_ext_device_side_abort impl. for CPU devices

CMakeLists.txt

@@ -1100,7 +1100,7 @@ endif()
 # These are mandatory for OpenCL 1.1 (except for 3D writes but those are CPU-independent)
 set(HOST_DEVICE_EXTENSIONS "cl_khr_byte_addressable_store cl_khr_global_int32_base_atomics \
   cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics \
-  cl_khr_local_int32_extended_atomics cl_khr_3d_image_writes")
+  cl_khr_local_int32_extended_atomics cl_khr_3d_image_writes cl_ext_device_side_abort")
 
 set(HOST_DEVICE_FEATURES_30 "__opencl_c_3d_image_writes  __opencl_c_images \
   __opencl_c_atomic_order_acq_rel __opencl_c_atomic_order_seq_cst \

include/_kernel.h

@@ -235,3 +235,12 @@
 #include "pocl_image_types.h"
 
 #pragma OPENCL EXTENSION all : disable
+
+/****************************************************************************/
+/* PoCL-implemented extensions */
+
+#ifdef cl_ext_device_side_abort
+
+void abort_platform ();
+
+#endif

lib/CL/devices/basic/basic.c

@@ -194,6 +194,9 @@ pocl_basic_init (unsigned j, cl_device_id device, const char* parameters)
   device->version_of_latest_passed_cts = HOST_DEVICE_LATEST_CTS_PASS;
   device->extensions = HOST_DEVICE_EXTENSIONS;
 
+  static const char *dev_aux_funcs[] = { "__pocl_flush_printf_buffer", NULL };
+  device->device_aux_functions = dev_aux_funcs;
+
 #if (HOST_DEVICE_CL_VERSION_MAJOR >= 3)
   device->features = HOST_DEVICE_FEATURES_30;
 

lib/CL/devices/pthread/pthread.c

@@ -148,6 +148,8 @@ pocl_pthread_init (unsigned j, cl_device_id device, const char* parameters)
 
   device->version_of_latest_passed_cts = HOST_DEVICE_LATEST_CTS_PASS;
   device->extensions = HOST_DEVICE_EXTENSIONS;
+  static const char *dev_aux_funcs[] = { "__pocl_flush_printf_buffer", NULL };
+  device->device_aux_functions = dev_aux_funcs;
 
 #if (HOST_DEVICE_CL_VERSION_MAJOR >= 3)
   device->features = HOST_DEVICE_FEATURES_30;

lib/kernel/abort_platform.c

@@ -0,0 +1,31 @@
+/* cl_ext_device_side_abort for CPU/host devices.
+
+   Copyright (c) 2022 Pekka Jääskeläinen / Parmance
+
+   Permission is hereby granted, free of charge, to any person obtaining a copy
+   of this software and associated documentation files (the "Software"), to
+   deal in the Software without restriction, including without limitation the
+   rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+   sell copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+   IN THE SOFTWARE.
+*/
+
+#include <stdlib.h>
+
+void
+abort_platform ()
+{
+  __pocl_flush_printf ();
+  abort ();
+}

lib/kernel/host/CMakeLists.txt

@@ -1,7 +1,7 @@
 #=============================================================================
 #   CMake build system files
 #
-#   Copyright (c) 2014 pocl developers
+#   Copyright (c) 2014-2022 pocl developers
 #
 #   Permission is hereby granted, free of charge, to any person obtaining a copy
 #   of this software and associated documentation files (the "Software"), to deal
@@ -294,6 +294,8 @@ else()
 endif()
 endif()
 
+list(APPEND KERNEL_SOURCES abort_platform.c)
+
 set(HOST_DEVICE_CL_VERSION_3DIGIT "${HOST_DEVICE_CL_VERSION_MAJOR}${HOST_DEVICE_CL_VERSION_MINOR}0")
 set(HOST_DEVICE_CL_VERSION_STD  "${HOST_DEVICE_CL_VERSION_MAJOR}.${HOST_DEVICE_CL_VERSION_MINOR}")
 

lib/kernel/printf.c

@@ -27,6 +27,7 @@
 #include "printf_base.h"
 
 #include <stdarg.h>
+#include <unistd.h>
 
 #define OCL_C_AS
 
@@ -711,6 +712,17 @@ extern char *_printf_buffer;
 extern uint32_t *_printf_buffer_position;
 extern uint32_t _printf_buffer_capacity;
 
+void
+__pocl_flush_printf_buffer (char *restrict buffer, uint32_t *buffer_index,
+                            uint32_t buffer_capacity)
+{
+  if (*buffer_index > 0 && buffer_capacity > 0)
+    {
+      write (STDOUT_FILENO, buffer, *buffer_index);
+      *buffer_index = 0;
+    }
+}
+
 /* This is a placeholder printf function that will be replaced by calls
  * to __pocl_printf(), after an LLVM pass handles the hidden arguments.
  * both __pocl_printf and __pocl_printf_format_simple must be referenced
@@ -734,6 +746,7 @@ printf (const PRINTF_FMT_STR_AS char *restrict fmt, ...)
                  _printf_buffer_capacity, NULL);
 
   *_printf_buffer_position = p.printf_buffer_index;
+
   return r;
 }
 

lib/llvmopencl/Workgroup.cc

@@ -463,6 +463,8 @@ static bool callsPrintf(Function *F) {
         return true;
       if (callee->getName().equals("__pocl_printf"))
         return true;
+      if (callee->getName().equals("__pocl_flush_printf"))
+        return true;
       if (callsPrintf(callee))
         return true;
     }
@@ -516,10 +518,12 @@ static Function *cloneFunctionWithPrintfArgs(Value *pb, Value *pbp, Value *pbc,
   return NewF;
 }
 
-// Recursively replace _cl_printf calls with _pocl_printf calls, while
-// propagating the required pocl_context->printf_buffer arguments.
+// Recursively replace _cl_printf calls with _pocl_printf calls,
+// and __pocl_flush_printf with __pocl_flush_printf_buffer calls
+// while propagating the required pocl_context->printf_buffer arguments.
 static void replacePrintfCalls(Value *pb, Value *pbp, Value *pbc, bool isKernel,
-                               Function *poclPrintf, Module &M, Function *L,
+                               Function *poclPrintf, Function *poclFlushPrintf,
+                               Module &M, Function *L,
                                FunctionMapping &printfCache) {
 
   // If none of the kernels use printf(), it will not be linked into the
@@ -558,7 +562,8 @@ static void replacePrintfCalls(Value *pb, Value *pbp, Value *pbc, bool isKernel,
       if (oldF == nullptr)
         continue;
 
-      if (oldF->getName().equals("printf")) {
+      if (oldF->getName().equals("printf") ||
+          oldF->getName().equals("__pocl_flush_printf")) {
         ops.clear();
         ops.push_back(pb);
         ops.push_back(pbp);
@@ -582,8 +587,10 @@ static void replacePrintfCalls(Value *pb, Value *pbp, Value *pbc, bool isKernel,
           ops.push_back(Operand);
         }
 
-        CallInst *NewCI = CallInst::Create(poclPrintf, ops);
-        NewCI->setCallingConv(poclPrintf->getCallingConv());
+        Function *F =
+            oldF->getName().equals("printf") ? poclPrintf : poclFlushPrintf;
+        CallInst *NewCI = CallInst::Create(F, ops);
+        NewCI->setCallingConv(F->getCallingConv());
 #ifdef LLVM_OLDER_THAN_11_0
         CallSite CS(CallInstr);
         NewCI->setTailCall(CS.isTailCall());
@@ -635,8 +642,8 @@ static void replacePrintfCalls(Value *pb, Value *pbp, Value *pbc, bool isKernel,
       needsPrintf = callsPrintf(oldF);
       if (needsPrintf) {
         newF = cloneFunctionWithPrintfArgs(pb, pbp, pbc, oldF, &M);
-        replacePrintfCalls(nullptr, nullptr, nullptr, false, poclPrintf, M,
-                           newF, printfCache);
+        replacePrintfCalls(nullptr, nullptr, nullptr, false, poclPrintf,
+                           poclFlushPrintf, M, newF, printfCache);
 
         printfCache.insert(
             std::pair<llvm::Function *, llvm::Function *>(oldF, newF));
@@ -796,7 +803,12 @@ Workgroup::createWrapper(Function *F, FunctionMapping &printfCache) {
 
   if (DeviceSidePrintf) {
     Function *poclPrintf = M->getFunction("__pocl_printf");
-    replacePrintfCalls(pb, pbp, pbc, true, poclPrintf, *M, L, printfCache);
+    Function *poclFlushPrintf = M->getFunction("__pocl_flush_printf_buffer");
+    if (poclFlushPrintf == nullptr) {
+      M->dump();
+    }
+    replacePrintfCalls(pb, pbp, pbc, true, poclPrintf, poclFlushPrintf, *M, L,
+                       printfCache);
   }
 
   L->setSubprogram(F->getSubprogram());

tests/kernel/test_abort_platform.cl

@@ -0,0 +1,18 @@
+void
+subfunction ()
+{
+  printf ("Aborting from subfunction!\n");
+#ifdef cl_ext_device_side_abort
+  abort_platform ();
+#else
+
+#error cl_ext_device_side_abort not supported by the device!
+
+#endif
+}
+
+kernel void
+test_abort_platform ()
+{
+  subfunction ();
+}