+#if defined(__linux__) && (defined(__arm__) || defined(__aarch64__))
+bool sys::getHostCPUFeatures(StringMap<bool> &Features) {
+ std::string Err;
+ DataStreamer *DS = getDataFileStreamer("/proc/cpuinfo", &Err);
+ if (!DS) {
+ DEBUG(dbgs() << "Unable to open /proc/cpuinfo: " << Err << "\n");
+ return false;
+ }
+
+ // Read 1024 bytes from /proc/cpuinfo, which should contain the Features line
+ // in all cases.
+ char buffer[1024];
+ size_t CPUInfoSize = DS->GetBytes((unsigned char*) buffer, sizeof(buffer));
+ delete DS;
+
+ StringRef Str(buffer, CPUInfoSize);
+
+ SmallVector<StringRef, 32> Lines;
+ Str.split(Lines, "\n");
+
+ SmallVector<StringRef, 32> CPUFeatures;
+
+ // Look for the CPU features.
+ for (unsigned I = 0, E = Lines.size(); I != E; ++I)
+ if (Lines[I].startswith("Features")) {
+ Lines[I].split(CPUFeatures, " ");
+ break;
+ }
+
+#if defined(__aarch64__)
+ // Keep track of which crypto features we have seen
+ enum {
+ CAP_AES = 0x1,
+ CAP_PMULL = 0x2,
+ CAP_SHA1 = 0x4,
+ CAP_SHA2 = 0x8
+ };
+ uint32_t crypto = 0;
+#endif
+
+ for (unsigned I = 0, E = CPUFeatures.size(); I != E; ++I) {
+ StringRef LLVMFeatureStr = StringSwitch<StringRef>(CPUFeatures[I])
+#if defined(__aarch64__)
+ .Case("asimd", "neon")
+ .Case("fp", "fp-armv8")
+ .Case("crc32", "crc")
+#else
+ .Case("half", "fp16")
+ .Case("neon", "neon")
+ .Case("vfpv3", "vfp3")
+ .Case("vfpv3d16", "d16")
+ .Case("vfpv4", "vfp4")
+ .Case("idiva", "hwdiv-arm")
+ .Case("idivt", "hwdiv")
+#endif
+ .Default("");
+
+#if defined(__aarch64__)
+ // We need to check crypto separately since we need all of the crypto
+ // extensions to enable the subtarget feature
+ if (CPUFeatures[I] == "aes")
+ crypto |= CAP_AES;
+ else if (CPUFeatures[I] == "pmull")
+ crypto |= CAP_PMULL;
+ else if (CPUFeatures[I] == "sha1")
+ crypto |= CAP_SHA1;
+ else if (CPUFeatures[I] == "sha2")
+ crypto |= CAP_SHA2;
+#endif
+
+ if (LLVMFeatureStr != "")
+ Features.GetOrCreateValue(LLVMFeatureStr).setValue(true);
+ }
+
+#if defined(__aarch64__)
+ // If we have all crypto bits we can add the feature
+ if (crypto == (CAP_AES | CAP_PMULL | CAP_SHA1 | CAP_SHA2))
+ Features.GetOrCreateValue("crypto").setValue(true);
+#endif
+
+ return true;
+}
+#else