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Diffstat (limited to 'llvm/docs/CommandGuide')
| -rw-r--r-- | llvm/docs/CommandGuide/llvm-mca.rst | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/llvm/docs/CommandGuide/llvm-mca.rst b/llvm/docs/CommandGuide/llvm-mca.rst index b6efd4ec2dc..d669b37013d 100644 --- a/llvm/docs/CommandGuide/llvm-mca.rst +++ b/llvm/docs/CommandGuide/llvm-mca.rst @@ -25,6 +25,24 @@ Given an assembly code sequence, llvm-mca estimates the IPC (Instructions Per Cycle), as well as hardware resource pressure. The analysis and reporting style were inspired by the IACA tool from Intel. +:program:`llvm-mca` allows the usage of special code comments to mark regions of +the assembly code to be analyzed. A comment starting with substring +``LLVM-MCA-BEGIN`` marks the beginning of a code region. A comment starting with +substring ``LLVM-MCA-END`` marks the end of a code region. For example: + +.. code-block:: none + + # LLVM-MCA-BEGIN My Code Region + ... + # LLVM-MCA-END + +Multiple regions can be specified provided that they do not overlap. A code +region can have an optional description. If no user defined region is specified, +then :program:`llvm-mca` assumes a default region which contains every +instruction in the input file. Every region is analyzed in isolation, and the +final performance report is the union of all the reports generated for every +code region. + OPTIONS ------- |
