maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
233,385 Commits 23 Branches 0 Tags 2.2 GiB
Commit Graph

61 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen 68c2cd059e Avoid looking at stale data in verifyAnalysis(). 
llvm-svn: 161004
 2012-07-30 23:15:12 +00:00
Jakob Stoklund Olesen c14cf57ba9 Allow traces to enter nested loops. 
This lets traces include the final iteration of a nested loop above the
center block, and the first iteration of a nested loop below the center
block.

We still don't allow traces to contain backedges, and traces are
truncated where they would leave a loop, as seen from the center block.

llvm-svn: 161003
 2012-07-30 23:15:10 +00:00
Jakob Stoklund Olesen f308c128ea Assert that all trace candidate blocks have been visited by the PO. 
When computing a trace, all the candidates for pred/succ must have been
visited. Filter out back-edges first, though. The PO traversal ignores
them.

Thanks to Andy for spotting this in review.

llvm-svn: 160995
 2012-07-30 21:10:27 +00:00
Jakob Stoklund Olesen a12a7d5f74 Hook into PassManager's analysis verification. 
By overriding Pass::verifyAnalysis(), the pass contents will be verified
by the pass manager.

llvm-svn: 160994
 2012-07-30 20:57:50 +00:00
Jakob Stoklund Olesen 7361846f32 Add MachineInstr::isTransient(). 
This is a cleaned up version of the isFree() function in
MachineTraceMetrics.cpp.

Transient instructions are very unlikely to produce any code in the
final output. Either because they get eliminated by RegisterCoalescing,
or because they are pseudo-instructions like labels and debug values.

llvm-svn: 160977
 2012-07-30 18:34:14 +00:00
Jakob Stoklund Olesen 3df6c46fdd Add MachineTraceMetrics::verify(). 
This function verifies the consistency of cached data in the
MachineTraceMetrics analysis.

llvm-svn: 160976
 2012-07-30 18:34:11 +00:00
Jakob Stoklund Olesen eb488fe165 Verify that the CFG hasn't changed during invalidate(). 
The MachineTraceMetrics analysis must be invalidated before modifying
the CFG. This will catch some of the violations of that rule.

llvm-svn: 160969
 2012-07-30 17:36:49 +00:00
Jakob Stoklund Olesen 0563369755 Add more debug output to MachineTraceMetrics. 
llvm-svn: 160905
 2012-07-27 23:58:38 +00:00
Jakob Stoklund Olesen 1152202cc2 Keep track of the head and tail of the trace through each block. 
This makes it possible to quickly detect blocks that are outside the
trace.

llvm-svn: 160904
 2012-07-27 23:58:36 +00:00
Jakob Stoklund Olesen 35400b1dda Use an otherwise unused variable. 
llvm-svn: 160798
 2012-07-26 19:42:56 +00:00
Jakob Stoklund Olesen f9029fef2a Start scaffolding for a MachineTraceMetrics analysis pass. 
This is still a work in progress.

Out-of-order CPUs usually execute instructions from multiple basic
blocks simultaneously, so it is necessary to look at longer traces when
estimating the performance effects of code transformations.

The MachineTraceMetrics analysis will pick a typical trace through a
given basic block and provide performance metrics for the trace. Metrics
will include:

- Instruction count through the trace.
- Issue count per functional unit.
- Critical path length, and per-instruction 'slack'.

These metrics can be used to determine the performance limiting factor
when executing the trace, and how it will be affected by a code
transformation.

Initially, this will be used by the early if-conversion pass.

llvm-svn: 160796
 2012-07-26 18:38:11 +00:00