1 //===--- GPU helper functions for printf using RPC ------------------------===//
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 "hdr/types/FILE.h"
10 #include "src/__support/GPU/utils.h"
11 #include "src/__support/RPC/rpc_client.h"
12 #include "src/__support/arg_list.h"
13 #include "src/__support/macros/config.h"
14 #include "src/stdio/gpu/file.h"
15 #include "src/string/string_utils.h"
16
17 namespace LIBC_NAMESPACE_DECL {
18
19 template <uint32_t opcode>
vfprintf_impl(::FILE * __restrict file,const char * __restrict format,size_t format_size,va_list vlist)20 LIBC_INLINE int vfprintf_impl(::FILE *__restrict file,
21 const char *__restrict format, size_t format_size,
22 va_list vlist) {
23 uint64_t mask = gpu::get_lane_mask();
24 rpc::Client::Port port = rpc::client.open<opcode>();
25
26 if constexpr (opcode == RPC_PRINTF_TO_STREAM ||
27 opcode == RPC_PRINTF_TO_STREAM_PACKED) {
28 port.send([&](rpc::Buffer *buffer, uint32_t) {
29 buffer->data[0] = reinterpret_cast<uintptr_t>(file);
30 });
31 }
32
33 size_t args_size = 0;
34 port.send_n(format, format_size);
35 port.recv([&](rpc::Buffer *buffer, uint32_t) {
36 args_size = static_cast<size_t>(buffer->data[0]);
37 });
38 port.send_n(vlist, args_size);
39
40 uint32_t ret = 0;
41 for (;;) {
42 const char *str = nullptr;
43 port.recv([&](rpc::Buffer *buffer, uint32_t) {
44 ret = static_cast<uint32_t>(buffer->data[0]);
45 str = reinterpret_cast<const char *>(buffer->data[1]);
46 });
47 // If any lanes have a string argument it needs to be copied back.
48 if (!gpu::ballot(mask, str))
49 break;
50
51 uint64_t size = str ? internal::string_length(str) + 1 : 0;
52 port.send_n(str, size);
53 }
54
55 port.close();
56 return ret;
57 }
58
vfprintf_internal(::FILE * __restrict stream,const char * __restrict format,size_t format_size,va_list vlist)59 LIBC_INLINE int vfprintf_internal(::FILE *__restrict stream,
60 const char *__restrict format,
61 size_t format_size, va_list vlist) {
62 // The AMDPGU backend uses a packed struct for its varargs. We pass it as a
63 // separate opcode so the server knows how much to advance the pointers.
64 #if defined(LIBC_TARGET_ARCH_IS_AMDGPU)
65 if (stream == stdout)
66 return vfprintf_impl<RPC_PRINTF_TO_STDOUT_PACKED>(stream, format,
67 format_size, vlist);
68 else if (stream == stderr)
69 return vfprintf_impl<RPC_PRINTF_TO_STDERR_PACKED>(stream, format,
70 format_size, vlist);
71 else
72 return vfprintf_impl<RPC_PRINTF_TO_STREAM_PACKED>(stream, format,
73 format_size, vlist);
74 #else
75 if (stream == stdout)
76 return vfprintf_impl<RPC_PRINTF_TO_STDOUT>(stream, format, format_size,
77 vlist);
78 else if (stream == stderr)
79 return vfprintf_impl<RPC_PRINTF_TO_STDERR>(stream, format, format_size,
80 vlist);
81 else
82 return vfprintf_impl<RPC_PRINTF_TO_STREAM>(stream, format, format_size,
83 vlist);
84 #endif
85 }
86
87 } // namespace LIBC_NAMESPACE_DECL
88