| """ |
| Platform-agnostic helper to query for CPU features. |
| """ |
| |
| import re |
| |
| |
| class CPUFeature: |
| def __init__(self, linux_cpu_info_flag: str = None, darwin_sysctl_key: str = None): |
| self.cpu_info_flag = linux_cpu_info_flag |
| self.sysctl_key = darwin_sysctl_key |
| |
| def __str__(self): |
| for arch_class in ALL_ARCHS: |
| for feat_var in dir(arch_class): |
| if self == getattr(arch_class, feat_var): |
| return f"{arch_class.__name__}.{feat_var}" |
| raise AssertionError("unreachable") |
| |
| def is_supported(self, triple, cmd_runner): |
| if re.match(".*-.*-linux", triple): |
| err_msg, res = self._is_supported_linux(cmd_runner) |
| elif re.match(".*-apple-.*", triple): |
| err_msg, res = self._is_supported_darwin(cmd_runner) |
| else: |
| err_msg, res = None, False |
| |
| if err_msg: |
| print(f"CPU feature check failed: {err_msg}") |
| |
| return res |
| |
| def _is_supported_linux(self, cmd_runner): |
| if not self.cpu_info_flag: |
| return f"Unspecified cpuinfo flag for {self}", False |
| |
| cmd = "cat /proc/cpuinfo" |
| err, retcode, output = cmd_runner(cmd) |
| if err.Fail() or retcode != 0: |
| return output, False |
| |
| # Assume that every processor presents the same features. |
| # Look for the first "Features: ...." line. Features are space separated. |
| if m := re.search(r"Features\s*: (.*)\n", output): |
| features = m.group(1).split() |
| return None, (self.cpu_info_flag in features) |
| |
| return 'No "Features:" line found in /proc/cpuinfo', False |
| |
| def _is_supported_darwin(self, cmd_runner): |
| if not self.sysctl_key: |
| return f"Unspecified sysctl key for {self}", False |
| |
| cmd = f"sysctl -n {self.sysctl_key}" |
| err, retcode, output = cmd_runner(cmd) |
| if err.Fail() or retcode != 0: |
| return output, False |
| |
| return None, (output.strip() == "1") |
| |
| |
| class AArch64: |
| FPMR = CPUFeature("fpmr") |
| GCS = CPUFeature("gcs") |
| MTE = CPUFeature("mte", "hw.optional.arm.FEAT_MTE4") |
| MTE_STORE_ONLY = CPUFeature("mtestoreonly") |
| PTR_AUTH = CPUFeature("paca", "hw.optional.arm.FEAT_PAuth2") |
| SME = CPUFeature("sme", "hw.optional.arm.FEAT_SME") |
| SME_FA64 = CPUFeature("smefa64") |
| SME2 = CPUFeature("sme2", "hw.optional.arm.FEAT_SME2") |
| SVE = CPUFeature("sve") |
| |
| |
| class Loong: |
| LASX = CPUFeature("lasx") |
| LSX = CPUFeature("lsx") |
| |
| |
| ALL_ARCHS = [AArch64, Loong] |
