offload/DeviceRTL/src/LibC.cpp

   1 //===------- LibC.cpp - Simple implementation of libc functions --- C++ ---===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "LibC.h"
  10
  11 #pragma omp begin declare target device_type(nohost)
  12
  13 namespace impl {
  14 int32_t omp_vprintf(const char *Format, void *Arguments, uint32_t);
  15 }
  16
  17 #pragma omp begin declare variant match(                                       \
  18         device = {arch(nvptx, nvptx64)},                                       \
  19             implementation = {extension(match_any)})
  20 extern "C" int32_t vprintf(const char *, void *);
  21 namespace impl {
  22 int32_t omp_vprintf(const char *Format, void *Arguments, uint32_t) {
  23   return vprintf(Format, Arguments);
  24 }
  25 } // namespace impl
  26 #pragma omp end declare variant
  27
  28 #pragma omp begin declare variant match(device = {arch(amdgcn)})
  29
  30 #ifdef OMPTARGET_HAS_LIBC
  31 // TODO: Remove this handling once we have varargs support.
  32 extern "C" struct FILE *stdout;
  33 extern "C" int32_t rpc_fprintf(FILE *, const char *, void *, uint64_t);
  34
  35 namespace impl {
  36 int32_t omp_vprintf(const char *Format, void *Arguments, uint32_t Size) {
  37   return rpc_fprintf(stdout, Format, Arguments, Size);
  38 }
  39 } // namespace impl
  40 #else
  41 // We do not have a vprintf implementation for AMD GPU so we use a stub.
  42 namespace impl {
  43 int32_t omp_vprintf(const char *Format, void *Arguments, uint32_t) {
  44   return -1;
  45 }
  46 } // namespace impl
  47 #endif
  48 #pragma omp end declare variant
  49
  50 extern "C" {
  51
  52 [[gnu::weak]] int memcmp(const void *lhs, const void *rhs, size_t count) {
  53   auto *L = reinterpret_cast<const unsigned char *>(lhs);
  54   auto *R = reinterpret_cast<const unsigned char *>(rhs);
  55
  56   for (size_t I = 0; I < count; ++I)
  57     if (L[I] != R[I])
  58       return (int)L[I] - (int)R[I];
  59
  60   return 0;
  61 }
  62
  63 [[gnu::weak]] void memset(void *dst, int C, size_t count) {
  64   auto *dstc = reinterpret_cast<char *>(dst);
  65   for (size_t I = 0; I < count; ++I)
  66     dstc[I] = C;
  67 }
  68
  69 /// printf() calls are rewritten by CGGPUBuiltin to __llvm_omp_vprintf
  70 int32_t __llvm_omp_vprintf(const char *Format, void *Arguments, uint32_t Size) {
  71   return impl::omp_vprintf(Format, Arguments, Size);
  72 }
  73 }
  74
  75 #pragma omp end declare target