Add loongarch64 Support (#314)

* Add macros for LOONGARCH hwcaps

* Update hwcaps.h

* LoongArch Support

* Remove unused definitions.

* Add ignored feature in test.

src/impl_loongarch_linux.c

@@ -0,0 +1,89 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "cpu_features_macros.h"
+
+#ifdef CPU_FEATURES_ARCH_LOONGARCH
+#if defined(CPU_FEATURES_OS_LINUX)
+
+#include "cpuinfo_loongarch.h"
+
+////////////////////////////////////////////////////////////////////////////////
+// Definitions for introspection.
+////////////////////////////////////////////////////////////////////////////////
+#define INTROSPECTION_TABLE                            \
+  LINE(LOONGARCH_CPUCFG, CPUCFG, "cfg", HWCAP_LOONGARCH_CPUCFG, 0) \
+  LINE(LOONGARCH_LAM, LAM, "lam", HWCAP_LOONGARCH_LAM, 0) \
+  LINE(LOONGARCH_UAL, UAL, "ual", HWCAP_LOONGARCH_UAL, 0) \
+  LINE(LOONGARCH_FPU, FPU, "fpu", HWCAP_LOONGARCH_FPU, 0) \
+  LINE(LOONGARCH_LSX, LSX, "lsx", HWCAP_LOONGARCH_LSX, 0) \
+  LINE(LOONGARCH_LASX, LASX, "lasx", HWCAP_LOONGARCH_LASX, 0) \
+  LINE(LOONGARCH_CRC32, CRC32, "crc32", HWCAP_LOONGARCH_CRC32, 0) \
+  LINE(LOONGARCH_COMPLEX, COMPLEX, "complex", HWCAP_LOONGARCH_COMPLEX, 0) \
+  LINE(LOONGARCH_CRYPTO, CRYPTO, "crypto", HWCAP_LOONGARCH_CRYPTO, 0) \
+  LINE(LOONGARCH_LVZ, LVZ, "lvz", HWCAP_LOONGARCH_LVZ, 0) \
+  LINE(LOONGARCH_LBT_X86, LBT_X86, "lbt_x86", HWCAP_LOONGARCH_LBT_X86, 0) \
+  LINE(LOONGARCH_LBT_ARM, LBT_ARM, "lbt_arm", HWCAP_LOONGARCH_LBT_ARM, 0) \
+  LINE(LOONGARCH_LBT_MIPS, LBT_MIPS, "lbt_mips", HWCAP_LOONGARCH_LBT_MIPS, 0) \
+  LINE(LOONGARCH_PTW, PTW, "ptw", HWCAP_LOONGARCH_PTW, 0)
+#define INTROSPECTION_PREFIX LoongArch
+#define INTROSPECTION_ENUM_PREFIX LOONGARCH
+#include "define_introspection_and_hwcaps.inl"
+
+////////////////////////////////////////////////////////////////////////////////
+// Implementation.
+////////////////////////////////////////////////////////////////////////////////
+
+#include <stdbool.h>
+#include <stdio.h>
+
+#include "internal/filesystem.h"
+#include "internal/stack_line_reader.h"
+
+static const LoongArchInfo kEmptyLoongArchInfo;
+
+static bool HandleLoongArchLine(const LineResult result, LoongArchInfo* const info) {
+  StringView line = result.line;
+  StringView key, value;
+  if (CpuFeatures_StringView_GetAttributeKeyValue(line, &key, &value)) {
+    if (CpuFeatures_StringView_IsEquals(key, str("Features"))) {
+      for (size_t i = 0; i < LOONGARCH_LAST_; ++i) {
+        kSetters[i](&info->features, CpuFeatures_StringView_HasWord(
+                                         value, kCpuInfoFlags[i], ' '));
+      }
+    }
+  }
+  return !result.eof;
+}
+
+static void FillProcCpuInfoData(LoongArchInfo* const info) {
+  const int fd = CpuFeatures_OpenFile("/proc/cpuinfo");
+  if (fd >= 0) {
+    StackLineReader reader;
+    StackLineReader_Initialize(&reader, fd);
+    for (;;) {
+      if (!HandleLoongArchLine(StackLineReader_NextLine(&reader), info)) break;
+    }
+    CpuFeatures_CloseFile(fd);
+  }
+}
+
+LoongArchInfo GetLoongArchInfo(void) {
+  LoongArchInfo info = kEmptyLoongArchInfo;
+  FillProcCpuInfoData(&info);
+  return info;
+}
+
+#endif  // defined(CPU_FEATURES_OS_LINUX)
+#endif  // CPU_FEATURES_ARCH_LOONGARCH

src/utils/list_cpu_features.c

@@ -39,6 +39,8 @@
 #include "cpuinfo_s390x.h"
 #elif defined(CPU_FEATURES_ARCH_RISCV)
 #include "cpuinfo_riscv.h"
+#elif defined(CPU_FEATURES_ARCH_LOONGARCH)
+#include "cpuinfo_loongarch.h"
 #endif
 
 // Design principles
@@ -215,6 +217,9 @@ DEFINE_ADD_FLAGS(GetS390XFeaturesEnumValue, GetS390XFeaturesEnumName, S390XFeatu
 #elif defined(CPU_FEATURES_ARCH_RISCV)
 DEFINE_ADD_FLAGS(GetRiscvFeaturesEnumValue, GetRiscvFeaturesEnumName, RiscvFeatures,
                  RISCV_LAST_)
+#elif defined(CPU_FEATURES_ARCH_LOONGARCH)
+DEFINE_ADD_FLAGS(GetLoongArchFeaturesEnumValue, GetLoongArchFeaturesEnumName, LoongArchFeatures,
+                 LOONGARCH_LAST_)
 #endif
 
 // Prints a json string with characters escaping.
@@ -432,6 +437,10 @@ static Node* CreateTree(void) {
   AddMapEntry(root, "vendor", CreateString(info.vendor));
   AddMapEntry(root, "microarchitecture", CreateString(info.uarch));
   AddFlags(root, &info.features); 
+#elif defined(CPU_FEATURES_ARCH_LOONGARCH)
+  const LoongArchInfo info = GetLoongArchInfo();
+  AddMapEntry(root, "arch", CreateString("loongarch"));
+  AddFlags(root, &info.features); 
 #endif
   return root;
 }