llvm/test/tools/llvm-exegesis/lit.local.cfg

   1 import subprocess
   2 import re
   3 import lit.util
   4
   5
   6 def can_execute_generated_snippets(arch):
   7     is_host_arch = arch in config.root.host_triple
   8     # 'native' feature is defined as "host arch == default triple arch"
   9     is_native_codegen = "native" in config.available_features
  10     return is_host_arch and is_native_codegen
  11
  12
  13 def can_use_perf_counters(mode, extra_options=[]):
  14     # We need libpfm to be installed and allow reading perf counters. We can
  15     # only know that at runtime, so we try to measure an empty code snippet
  16     # and bail out on error.
  17     llvm_exegesis_exe = lit.util.which("llvm-exegesis", config.llvm_tools_dir)
  18     if llvm_exegesis_exe is None:
  19         print("could not find llvm-exegesis")
  20         return False
  21     try:
  22         return_code = subprocess.call(
  23             [llvm_exegesis_exe, "-mode", mode, "-snippets-file", "/dev/null"]
  24             + extra_options,
  25             stdout=subprocess.DEVNULL,
  26             stderr=subprocess.DEVNULL,
  27         )
  28         return return_code == 0
  29     except OSError:
  30         print("could not exec llvm-exegesis")
  31         return False
  32
  33
  34 for arch in ["aarch64", "mips", "powerpc", "x86_64"]:
  35     if can_execute_generated_snippets(arch):
  36         config.available_features.add("exegesis-can-execute-%s" % arch)
  37
  38 if can_use_perf_counters("latency"):
  39     config.available_features.add("exegesis-can-measure-latency")
  40
  41 if can_use_perf_counters("uops"):
  42     config.available_features.add("exegesis-can-measure-uops")
  43
  44 if can_execute_generated_snippets("x86_64"):
  45     # Check for support of LBR format with cycles.
  46     if can_use_perf_counters(
  47         "latency", ["-x86-lbr-sample-period", "123", "-repetition-mode", "loop"]
  48     ):
  49         config.available_features.add("exegesis-can-measure-latency-lbr")
  50