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Roman Lebedev ca5caf3fc8 [llvm-exegesis] Throughput support in analysis mode 
Summary:
D57000 / [[ https://bugs.llvm.org/show_bug.cgi?id=37698 | PR37698 ]] added support for measuring of the inverse throughput.
But the support for the analysis was not added.
This attempts to fix that. (analysis done o bdver2 / piledriver)

First, small-scale experiment:
```
$ ./bin/llvm-exegesis -num-repetitions=10000 -mode=inverse_throughput -opcode-name=BSF64rr
Check generated assembly with: /usr/bin/objdump -d /tmp/snippet-d0acdd.o
---
mode:            inverse_throughput
key:
  instructions:
    - 'BSF64rr RAX RDX'
  config:          ''
  register_initial_values:
    - 'RDX=0x0'
cpu_name:        bdver2
llvm_triple:     x86_64-unknown-linux-gnu
num_repetitions: 10000
measurements:
  - { key: inverse_throughput, value: 3.0278, per_snippet_value: 3.0278 }
error:           ''
info:            instruction has no tied variables picking Uses different from defs
assembled_snippet: 48BA0000000000000000480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2C3
...
```
If we plug `bsfq	%r12, %r10` into llvm-mca:
https://godbolt.org/z/ZtOyhJ
```
Dispatch Width:    4
uOps Per Cycle:    3.00
IPC:               0.50
Block RThroughput: 2.0
```
So RThroughput mismatch exists.

Now, let's upscale and analyse:
{F8207148}
`$ ./bin/llvm-exegesis -mode=analysis -analysis-epsilon=1.0 -benchmarks-file=/tmp/benchmarks-inverse_throughput.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html`:
{F8207172}
{F8207197}
And if we now look at https://www.agner.org/optimize/instruction_tables.pdf,
`Reciprocal throughput` for `BSF r,r` is listed as `3`.
Yay?

Reviewers: courbet, gchatelet

Reviewed By: courbet

Subscribers: tschuett, RKSimon, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57647

llvm-svn: 353023
2019-02-04 09:12:17 +00:00
benchmarks Pull google/benchmark library to the LLVM tree 2018-08-28 09:42:41 +00:00
bindings Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
cmake Revert "Bump minimum toolchain version" 2019-02-02 06:01:12 +00:00
docs [llvm-exegesis] Don't default to running&dumping all analyses to '-' 2019-02-04 09:12:08 +00:00
examples Fix compilation of examples after 13680223b9d8 / r352827 2019-02-01 03:23:42 +00:00
include [PatternMatch] add special-case uaddo matching for increment-by-one (2nd try) 2019-02-03 16:16:48 +00:00
lib [SCEV] Do not bother creating separate SCEVUnknown for unreachable nodes 2019-02-04 05:04:19 +00:00
projects Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
resources
runtimes Revert "[CMake] Use __libc_start_main rather than fopen when checking for C library" 2019-01-28 19:26:41 +00:00
test [llvm-exegesis] Don't default to running&dumping all analyses to '-' 2019-02-04 09:12:08 +00:00
tools [llvm-exegesis] Throughput support in analysis mode 2019-02-04 09:12:17 +00:00
unittests [opaque pointer types] Pass value type to GetElementPtr creation. 2019-02-01 20:44:47 +00:00
utils [X86] Print %st(0) as %st when its implicit to the instruction. Continue printing it as %st(0) when its encoded in the instruction. 2019-02-04 04:15:10 +00:00
.arcconfig [llvm] Set up .arcconfig to point to Diffusion L repository 2018-01-12 15:37:41 +00:00
.clang-format
.clang-tidy Disable tidy checks with too many hits 2019-02-01 11:20:13 +00:00
.gitattributes [DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label. 2018-05-09 02:40:45 +00:00
.gitignore gitignore: ignore clangd index files. 2019-01-25 14:05:18 +00:00
CMakeLists.txt Revert "Bump minimum toolchain version" 2019-02-02 06:01:12 +00:00
CODE_OWNERS.TXT [llvm-mca] Move llvm-mca library to llvm/lib/MCA. 2018-12-17 08:08:31 +00:00
configure
CREDITS.TXT Remove a period from CREDITS.TXT (testing email change). NFC 2019-01-19 09:07:38 +00:00
LICENSE.TXT Fix typos throughout the license files that somehow I and my reviewers 2019-01-21 09:52:34 +00:00
llvm.spec.in Update structured references to the license to the new license. 2019-01-19 11:30:51 +00:00
LLVMBuild.txt Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
README.txt Test commit. 2018-09-22 01:01:03 +00:00
RELEASE_TESTERS.TXT Update the list of platforms & archs 2018-12-16 14:47:16 +00:00

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