Subzero: Remove a couple clumsy uses of snprintf.

src/IceTimerTree.cpp

 //===- subzero/src/IceTimerTree.cpp - Pass timer defs ---------------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
 /// \brief Defines the TimerTree class, which tracks flat and cumulative
 /// execution time collection of call chains.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "IceTimerTree.h"
 
 #include "IceDefs.h"
 
 #ifdef __clang__
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wunused-parameter"
 #endif // __clang__
 
+#include "llvm/Support/Format.h"
 #include "llvm/Support/Timer.h"
 
 #ifdef __clang__
 #pragma clang diagnostic pop
 #endif // __clang__
 
 namespace Ice {
 
 TimerStack::TimerStack(const std::string &Name)
     : Name(Name), FirstTimestamp(timestamp()), LastTimestamp(FirstTimestamp) {
@@ skipping 189 matching lines @@
 
 namespace {
 
 using DumpMapType = std::multimap<double, std::string>;
 
 // Dump the Map items in reverse order of their time contribution.
 void dumpHelper(Ostream &Str, const DumpMapType &Map, double TotalTime) {
   if (!BuildDefs::timers())
     return;
   for (auto &I : reverse_range(Map)) {
-    char buf[80];
-    snprintf(buf, llvm::array_lengthof(buf), "  %10.6f (%4.1f%%): ", I.first,
-             I.first * 100 / TotalTime);
-    Str << buf << I.second << "\n";
+    Str << llvm::format("  %10.6f (%4.1f%%): ", I.first,
+                        I.first * 100 / TotalTime) << I.second << "\n";
   }
 }
 
 // Write a printf() format string into Buf[], in the format "[%5lu] ", where
 // "5" is actually the number of digits in MaxVal. E.g.,
 //   MaxVal=0     ==> "[%1lu] "
 //   MaxVal=5     ==> "[%1lu] "
 //   MaxVal=9876  ==> "[%4lu] "
 void makePrintfFormatString(char *Buf, size_t BufLen, size_t MaxVal) {
   if (!BuildDefs::timers())
@@ skipping 59 matching lines @@
   dumpHelper(Str, FlatMap, TotalTime);
   Str << "Number of timer updates: " << StateChangeCount << "\n";
 }
 
 double TimerStack::timestamp() {
   // TODO: Implement in terms of std::chrono for C++11.
   return llvm::TimeRecord::getCurrentTime(false).getWallTime();
 }
 
 } // end of namespace Ice