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| author | Clement Courbet <courbet@google.com> | 2019-10-08 14:30:24 +0000 |
|---|---|---|
| committer | Clement Courbet <courbet@google.com> | 2019-10-08 14:30:24 +0000 |
| commit | 2cd0f2895946de546d066f67c88ff365d3210017 (patch) | |
| tree | 1dde8cff5615fac6906b453afef96f2fb7fbc685 /llvm/docs/CommandGuide | |
| parent | cf3ab6d96c3e9477b05bbbe8b525151320e96d71 (diff) | |
| download | bcm5719-llvm-2cd0f2895946de546d066f67c88ff365d3210017.tar.gz bcm5719-llvm-2cd0f2895946de546d066f67c88ff365d3210017.zip | |
[llvm-exegesis] Add options to SnippetGenerator.
Summary:
This adds a `-max-configs-per-opcode` option to limit the number of
configs per opcode.
Reviewers: gchatelet
Subscribers: tschuett, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68642
llvm-svn: 374054
Diffstat (limited to 'llvm/docs/CommandGuide')
| -rw-r--r-- | llvm/docs/CommandGuide/llvm-exegesis.rst | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/llvm/docs/CommandGuide/llvm-exegesis.rst b/llvm/docs/CommandGuide/llvm-exegesis.rst index 4ac1c766354..81e92e7736d 100644 --- a/llvm/docs/CommandGuide/llvm-exegesis.rst +++ b/llvm/docs/CommandGuide/llvm-exegesis.rst @@ -195,11 +195,23 @@ OPTIONS to specify at least one of the `-analysis-clusters-output-file=` and `-analysis-inconsistencies-output-file=`. -.. option:: -num-repetitions=<Number of repetition> +.. option:: -num-repetitions=<Number of repetitions> Specify the number of repetitions of the asm snippet. Higher values lead to more accurate measurements but lengthen the benchmark. +.. option:: -max-configs-per-opcode=<value> + + Specify the maximum configurations that can be generated for each opcode. + By default this is `1`, meaning that we assume that a single measurement is + enough to characterize an opcode. This might not be true of all instructions: + for example, the performance characteristics of the LEA instruction on X86 + depends on the value of assigned registers and immediates. Setting a value of + `-max-configs-per-opcode` larger than `1` allows `llvm-exegesis` to explore + more configurations to discover if some register or immediate assignments + lead to different performance characteristics. + + .. option:: -benchmarks-file=</path/to/file> File to read (`analysis` mode) or write (`latency`/`uops`/`inverse_throughput` |
