[CodeGen] Print performance counter information in CSV.

This ensures that tools can parse performance information which Polly
generates easily.

- Sample output:
```name=out.csv
scop function, entry block name, exit block name, total time
warmup, %entry.split, %polly.merge_new_and_old, 1960
f, %entry.split, %polly.merge_new_and_old, 1238
g, %entry.split, %polly.merge_new_and_old, 1218
```

- Example code to parse output:
```lang=python, name=example-parse.py
import asciitable
import sys

table = asciitable.read('out.csv', delimiter=',')
asciitable.write(table, sys.stdout, delimiter=',')
```

llvm-svn: 304533

1 files changed, 13 insertions, 3 deletions

diff --git a/polly/lib/CodeGen/PerfMonitor.cpp b/polly/lib/CodeGen/PerfMonitor.cpp
index 9fbd07b2649..5423d5a4fa6 100644
--- a/polly/lib/CodeGen/PerfMonitor.cpp
+++ b/polly/lib/CodeGen/PerfMonitor.cpp
@@ -152,6 +152,15 @@ Function *PerfMonitor::insertFinalReporting() {
   RuntimeDebugBuilder::createCPUPrinter(Builder, "Total: ", CyclesTotal, "\n");
   RuntimeDebugBuilder::createCPUPrinter(Builder, "Scops: ", CyclesInScops,
                                         "\n");
+
+  // Print the preamble for per-scop information.
+  RuntimeDebugBuilder::createCPUPrinter(Builder, "\n");
+  RuntimeDebugBuilder::createCPUPrinter(Builder, "Per SCoP information\n");
+  RuntimeDebugBuilder::createCPUPrinter(Builder, "--------------------\n");
+
+  RuntimeDebugBuilder::createCPUPrinter(
+      Builder, "scop function, "
+               "entry block name, exit block name, total time\n");
   ReturnFromFinal = Builder.CreateRetVoid();
   return ExitFn;
 }
@@ -173,9 +182,10 @@ void PerfMonitor::AppendScopReporting() {
   std::string EntryName, ExitName;
   std::tie(EntryName, ExitName) = S.getEntryExitStr();
 
-  RuntimeDebugBuilder::createCPUPrinter(
-      Builder, "Scop(", S.getFunction().getName(), " |from: ", EntryName,
-      " |to: ", ExitName, "): ", CyclesInCurrentScop, "\n");
+  // print in CSV for easy parsing with other tools.
+  RuntimeDebugBuilder::createCPUPrinter(Builder, S.getFunction().getName(),
+                                        ", ", EntryName, ", ", ExitName, ", ",
+                                        CyclesInCurrentScop, "\n");
 
   ReturnFromFinal = Builder.CreateRetVoid();
 }