50 lines
1.7 KiB
INI
50 lines
1.7 KiB
INI
import subprocess
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import re
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import lit.util
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def can_execute_generated_snippets(arch):
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is_host_arch = arch in config.root.host_triple
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# 'native' feature is defined as "host arch == default triple arch"
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is_native_codegen = "native" in config.available_features
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return is_host_arch and is_native_codegen
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def can_use_perf_counters(mode, extra_options=[]):
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# We need libpfm to be installed and allow reading perf counters. We can
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# only know that at runtime, so we try to measure an empty code snippet
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# and bail out on error.
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llvm_exegesis_exe = lit.util.which("llvm-exegesis", config.llvm_tools_dir)
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if llvm_exegesis_exe is None:
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print("could not find llvm-exegesis")
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return False
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try:
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return_code = subprocess.call(
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[llvm_exegesis_exe, "-mode", mode, "-snippets-file", "/dev/null"]
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+ extra_options,
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stdout=subprocess.DEVNULL,
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stderr=subprocess.DEVNULL,
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)
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return return_code == 0
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except OSError:
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print("could not exec llvm-exegesis")
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return False
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for arch in ["aarch64", "mips", "powerpc", "x86_64"]:
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if can_execute_generated_snippets(arch):
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config.available_features.add("exegesis-can-execute-%s" % arch)
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if can_use_perf_counters("latency"):
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config.available_features.add("exegesis-can-measure-latency")
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if can_use_perf_counters("uops"):
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config.available_features.add("exegesis-can-measure-uops")
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if can_execute_generated_snippets("x86_64"):
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# Check for support of LBR format with cycles.
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if can_use_perf_counters(
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"latency", ["-x86-lbr-sample-period", "123", "-repetition-mode", "loop"]
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):
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config.available_features.add("exegesis-can-measure-latency-lbr")
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