__devicelib_assert_fail implementation

This is a DPCPP device library extension described in
https://github.com/triSYCL/sycl/blob/sycl/unified/master/sycl/doc/design/Assert.md
DPCPP assert(expr) macro ends up in call to __devicelib_assert_fail.
Per design, the implementation needs to:
   1. Write "1" to flag field in the assert buffer header. The buffer header is defined below.
   2. Print the assert message to assert buffer. This is done in a similar fashion as "printf".
      __builtin_IB_printf_to_buffer builtin function is used for this purpose - it basically wraps
      the printf functionality to a buffer provided as an argument.
   3. Trigger a software exception by setting appropriate Control Register bits.
      This is done by __builtin_IB_software_exception builtin.
   4. We need to ensure that all stores in this function are uncached.
      This is handled by NontemporalLoadsAndStoresInAssert pass.

Author: PawelJurek

IGC/BiFModule/Implementation/IBiF_Impl.cl

@@ -110,3 +110,8 @@ SPDX-License-Identifier: MIT
 // Tile ID Extension Opcodes
 //*****************************************************************************/
 #include "tileid.cl"
+
+//*****************************************************************************/
+// Assert implementation
+//*****************************************************************************/
+#include "assert.cl"

IGC/BiFModule/Implementation/assert.cl

@@ -0,0 +1,41 @@
+/*========================== begin_copyright_notice ============================
+
+Copyright (C) 2023 Intel Corporation
+
+SPDX-License-Identifier: MIT
+
+============================= end_copyright_notice ===========================*/
+
+// __devicelib_assert_fail implementation.
+// This is a DPCPP device library extension described in
+// https://github.com/triSYCL/sycl/blob/sycl/unified/master/sycl/doc/design/Assert.md
+// DPCPP assert(expr) macro ends up in call to __devicelib_assert_fail.
+// Per design, the implementation needs to:
+//    1. Write "1" to flag field in the assert buffer header. The buffer header is defined below.
+//    2. Print the assert message to assert buffer. This is done in a similar fashion as "printf".
+//       __builtin_IB_printf_to_buffer builtin function is used for this purpose - it basically wraps
+//       the printf functionality to a buffer provided as an argument.
+//    3. Trigger a software exception by setting appropriate Control Register bits.
+//       This is done by __builtin_IB_software_exception builtin.
+//    4. We need to ensure that all stores in this function are uncached.
+//       This is handled by NontemporalLoadsAndStoresInAssert pass.
+
+#include "IBiF_Header.cl"
+
+__global volatile uchar* __builtin_IB_get_assert_buffer();
+void __builtin_IB_software_exception();
+int __builtin_IB_printf_to_buffer(global char* buf, global char* currentOffset, int bufSize, ...);
+
+typedef struct {
+    int size;
+    int flag;
+    int begin;
+} AssertBufferHeader;
+
+void __devicelib_assert_fail(char *expr, char *file, int line, char *func, long gid0, long gid1, long gid2, long lid0, long lid1, long lid2) {
+    AssertBufferHeader* header = (AssertBufferHeader*) __builtin_IB_get_assert_buffer();
+    header->flag = 1;
+    global char* buf = (global char*) header;
+    __builtin_IB_printf_to_buffer(buf, buf + 8, header->size, "%s:%d: %s: global id: [%lu,%lu,%lu], local id: [%lu,%lu,%lu] Assertion `%s` failed", file, line, func, gid0, gid1, gid2, lid0, lid1, lid2, expr);
+    __builtin_IB_software_exception();
+}