[OpenMP][deviceRTLs] Drop `assert` in common parts of `deviceRTLs`

[tianshilei1992]

Summary

The header assert.h needs to be included in order to use assert in the code.
When building NVPTX deviceRTLs on a CUDA free system, it requires headers from
gcc-multilib, which some systems don't have. This patch drops the use of
assert in common parts of deviceRTLs. In light of
openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h, a code block

if (!cond)
  __builtin_trap();

is being used. The builtin will be translated to call void @llvm.trap(), and
the corresponding PTX is trap;.

[JonChesterfield]

Yep, like this.

Ptx documents an intrinsic/builtin/syscall thing for assert that we could use instead of trap. Involves creating a call to __assertfail, takes five arguments one of which is sizeof(char). This is much simpler and serves the same purpose though.

Could you delete the assert impl from amdgpu at the same time?

[tianshilei1992]

Remove useless function in amdgcn

[JonChesterfield]

openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h

20–21

Can drop this include too

[tianshilei1992]

removed #include <assert.h>

[tianshilei1992]

openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h

20–21

Aha, you guys also included it here 😂

openmp/libomptarget/deviceRTLs/amdgcn/src/target_impl.h

 #ifndef OMPTARGET_AMDGCN_TARGET_IMPL_H
 #define OMPTARGET_AMDGCN_TARGET_IMPL_H
 
 #ifndef __AMDGCN__
 #error "amdgcn target_impl.h expects to be compiled under __AMDGCN__"
 #endif
 
 #include "amdgcn_interface.h"
 
-#include <assert.h>
 #include <inttypes.h>
 #include <stddef.h>
 #include <stdint.h>
 
 #define DEVICE __attribute__((device))
 #define INLINE inline DEVICE
 #define NOINLINE __attribute__((noinline)) DEVICE
 #define SHARED(NAME) __attribute__((shared)) NAME
 #define EXTERN_SHARED(NAME) __attribute__((shared)) NAME
enum DATA_SHARING_SIZES {
   // The maximum number of warps in use
   DS_Max_Warp_Number = 16,
 };
 
 enum : __kmpc_impl_lanemask_t {
   __kmpc_impl_all_lanes = ~(__kmpc_impl_lanemask_t)0
 };
 
-// DEVICE versions of part of libc
-INLINE void __assert_fail(const char *, const char *, unsigned int,
-                          const char *) {
-  __builtin_trap();
-}
 EXTERN int printf(const char *, ...);
 
 #endif

openmp/libomptarget/deviceRTLs/common/debug.h

 }
 
 #endif
 #if OMPTARGET_NVPTX_TEST
 
 template <typename... Arguments>
 NOINLINE static void check(bool cond, const char *fmt,
                            Arguments... parameters) {
-  if (!cond)
+  if (!cond) {
     printf(fmt, (int)GetBlockIdInKernel(), (int)GetThreadIdInBlock(),
            (int)GetWarpId(), (int)GetLaneId(), parameters...);
-  assert(cond);
+    __builtin_trap();
+  }
 }
 
-NOINLINE static void check(bool cond) { assert(cond); }
+NOINLINE static void check(bool cond) {
+  if (!cond)
+    __builtin_trap();
+}
 #endif
 
 // set flags that are tested (inclusion properties)
 
 #define LD_ALL (LD_SET_ALL)
 
 #define LD_LOOP (LD_SET_LOOP | LD_SET_LOOPD)
 #define LD_LOOPD (LD_SET_LOOPD)

openmp/libomptarget/deviceRTLs/nvptx/src/target_impl.h

 //===------------ target_impl.h - NVPTX OpenMP GPU options ------- CUDA -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // Definitions of target specific functions
 //
 //===----------------------------------------------------------------------===//
 #ifndef _TARGET_IMPL_H_
 #define _TARGET_IMPL_H_
 
-#include <assert.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
 
 #include "nvptx_interface.h"
 
 #define DEVICE
 #define INLINE inline __attribute__((always_inline)) DEVICE