[llvm] [Offload] Port llvm-offload-device-info to new offload API (PR #155626)

[Kevin Sala Penades via llvm-commits]

================
@@ -1,32 +1,273 @@
-//===- llvm-offload-device-info.cpp - Device info as seen by LLVM/Offload -===//
+//===- llvm-offload-device-info.cpp - Print liboffload properties ---------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
-// This is a command line utility that, by using LLVM/Offload, and the device
-// plugins, list devices information as seen by the runtime.
+// This is a command line utility that, by using the new liboffload API, prints
+// all devices and properties
 //
 //===----------------------------------------------------------------------===//
 
-#include "omptarget.h"
-#include <cstdio>
+#include <OffloadAPI.h>
+#include <iostream>
+#include <vector>
 
-int main(int argc, char **argv) {
-  __tgt_bin_desc EmptyDesc = {0, nullptr, nullptr, nullptr};
-  __tgt_register_lib(&EmptyDesc);
-  __tgt_init_all_rtls();
+#define OFFLOAD_ERR(X)                                                         \
+  if (auto Err = X) {                                                          \
+    return Err;                                                                \
+  }
+
+enum class PrintKind {
+  NORMAL,
+  FP_FLAGS,
+};
+
+template <typename T, PrintKind PK = PrintKind::NORMAL>
+void doWrite(std::ostream &S, T &&Val) {
+  S << Val;
+}
+
+template <>
+void doWrite<ol_platform_backend_t>(std::ostream &S,
+                                    ol_platform_backend_t &&Val) {
+  switch (Val) {
+  case OL_PLATFORM_BACKEND_UNKNOWN:
+    S << "UNKNOWN";
+    break;
+  case OL_PLATFORM_BACKEND_CUDA:
+    S << "CUDA";
+    break;
+  case OL_PLATFORM_BACKEND_AMDGPU:
+    S << "AMDGPU";
+    break;
+  case OL_PLATFORM_BACKEND_HOST:
+    S << "HOST";
+    break;
+  default:
+    S << "<< INVALID >>";
+    break;
+  }
+}
+template <>
+void doWrite<ol_device_type_t>(std::ostream &S, ol_device_type_t &&Val) {
+  switch (Val) {
+  case OL_DEVICE_TYPE_GPU:
+    S << "GPU";
+    break;
+  case OL_DEVICE_TYPE_CPU:
+    S << "CPU";
+    break;
+  case OL_DEVICE_TYPE_HOST:
+    S << "HOST";
+    break;
+  default:
+    S << "<< INVALID >>";
+    break;
+  }
+}
+template <>
+void doWrite<ol_dimensions_t>(std::ostream &S, ol_dimensions_t &&Val) {
+  S << "{x: " << Val.x << ", y: " << Val.y << ", z: " << Val.z << "}";
+}
+template <>
+void doWrite<ol_device_fp_capability_flags_t, PrintKind::FP_FLAGS>(
+    std::ostream &S, ol_device_fp_capability_flags_t &&Val) {
+  S << Val << " {";
+
+  if (Val & OL_DEVICE_FP_CAPABILITY_FLAG_CORRECTLY_ROUNDED_DIVIDE_SQRT) {
+    S << " CORRECTLY_ROUNDED_DIVIDE_SQRT";
+  }
+  if (Val & OL_DEVICE_FP_CAPABILITY_FLAG_ROUND_TO_NEAREST) {
+    S << " ROUND_TO_NEAREST";
+  }
+  if (Val & OL_DEVICE_FP_CAPABILITY_FLAG_ROUND_TO_ZERO) {
+    S << " ROUND_TO_ZERO";
+  }
+  if (Val & OL_DEVICE_FP_CAPABILITY_FLAG_ROUND_TO_INF) {
+    S << " ROUND_TO_INF";
+  }
+  if (Val & OL_DEVICE_FP_CAPABILITY_FLAG_INF_NAN) {
+    S << " INF_NAN";
+  }
+  if (Val & OL_DEVICE_FP_CAPABILITY_FLAG_DENORM) {
+    S << " DENORM";
+  }
+  if (Val & OL_DEVICE_FP_CAPABILITY_FLAG_FMA) {
+    S << " FMA";
+  }
+  if (Val & OL_DEVICE_FP_CAPABILITY_FLAG_SOFT_FLOAT) {
+    S << " SOFT_FLOAT";
+  }
+
+  S << " }";
+}
 
-  printf("Found %d devices:\n", omp_get_num_devices());
-  for (int Dev = 0; Dev < omp_get_num_devices(); Dev++) {
-    printf("  Device %d:\n", Dev);
-    if (!__tgt_print_device_info(Dev))
----------------
kevinsala wrote:

That makes sense. However, the current API seems limited with what we were printing in `llvm-offload-device-info`. We're losing significant information in this PR.

https://github.com/llvm/llvm-project/pull/155626