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authorAndrea Di Biagio <Andrea_DiBiagio@sn.scee.net>2018-03-26 12:04:53 +0000
committerAndrea Di Biagio <Andrea_DiBiagio@sn.scee.net>2018-03-26 12:04:53 +0000
commitd1569290efa3b6b647faec6f0a8e3cc40be40b6b (patch)
tree8bf3157692696754df1f30a879db90ecb6f6e9ae /llvm/docs/CommandGuide/llvm-mca.rst
parent5af3fb2b94bf21c0be40da03302e7169bc7d61a3 (diff)
downloadbcm5719-llvm-d1569290efa3b6b647faec6f0a8e3cc40be40b6b.tar.gz
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[llvm-mca] Add flag -instruction-tables to print the theoretical resource pressure distribution for instructions (PR36874)
The goal of this patch is to address most of PR36874. To fully fix PR36874 we need to split the "InstructionInfo" view from the "SummaryView". That would make easy to check the latency and rthroughput as well. The patch reuses all the logic from ResourcePressureView to print out the "instruction tables". We have an entry for every instruction in the input sequence. Each entry reports the theoretical resource pressure distribution. Resource pressure is uniformly distributed across all the processor resource units of a group. At the moment, the backend pipeline is not configurable, so the only way to fix this is by creating a different driver that simply sends instruction events to the resource pressure view. That means, we don't use the Backend interface. Instead, it is simpler to just have a different code-path for when flag -instruction-tables is specified. Once Clement addresses bug 36663, then we can port the "instruction tables" logic into a stage of our configurable pipeline. Updated the BtVer2 test cases (thanks Simon for the help). Now we pass flag -instruction-tables to each modified test. Differential Revision: https://reviews.llvm.org/D44839 llvm-svn: 328487
Diffstat (limited to 'llvm/docs/CommandGuide/llvm-mca.rst')
-rw-r--r--llvm/docs/CommandGuide/llvm-mca.rst8
1 files changed, 8 insertions, 0 deletions
diff --git a/llvm/docs/CommandGuide/llvm-mca.rst b/llvm/docs/CommandGuide/llvm-mca.rst
index e3ec28e3a8d..082cd3574b2 100644
--- a/llvm/docs/CommandGuide/llvm-mca.rst
+++ b/llvm/docs/CommandGuide/llvm-mca.rst
@@ -124,6 +124,14 @@ option specifies "``-``", then the output will also be sent to standard output.
Limit the number of cycles in the timeline view. By default, the number of
cycles is set to 80.
+.. option:: -instruction-tables
+
+ Prints resource pressure information based on the static information
+ available from the processor model. This differs from the resource pressure
+ view because it doesn't require that the code is simulated. It instead prints
+ the theoretical uniform distribution of resource pressure for every
+ instruction in sequence.
+
EXIT STATUS
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