Implements include/exclude register lists for translation.

src/IceClFlags.cpp

Index: src/IceClFlags.cpp
diff --git a/src/IceClFlags.cpp b/src/IceClFlags.cpp
index ed5a71df47ddf0ec3ed8886d5e20a5c4e330d256..aad30b6e4ae1483ecc1b72d77b84aec5e03aa734 100644
--- a/src/IceClFlags.cpp
+++ b/src/IceClFlags.cpp
@@ -287,6 +287,17 @@ cl::opt<int> NopProbabilityAsPercentage(
     "nop-insertion-percentage",
     cl::desc("Nop insertion probability as percentage"), cl::init(10));
 
+/// Restricts registers in corresponding register classes to specified list.
+cl::list<std::string> UseRestrictedRegisters(
+    "use-registers",

[Jim Stichnoth, 2016/01/10 16:51:25]

Can you add the cl::CommaSeparated option here, which should eliminate the need
for custom comma parsing?  See the --verbose option below for reference.

[Karl, 2016/01/12 23:44:04]

Done.

+    cl::desc(
+        "Only use specified registers for corresponding register classes"));
+
+/// List of excluded registers.
+cl::list<std::string>
+    ExcludedRegisters("exclude-registers",

[Jim Stichnoth, 2016/01/10 16:51:25]

I would give these two option names a common prefix, like -reg-include and
-reg-exclude, so that they show up together in the -help output.

[Karl, 2016/01/12 23:44:04]

Switched to '-reg-use' and '-reg-exclude'.

+                      cl::desc("Don't use specified registers"));
+
 /// Verbose options (can be comma-separated).
 cl::list<Ice::VerboseItem> VerboseList(
     "verbose", cl::CommaSeparated,
@@ -421,6 +432,31 @@ cl::opt<bool> BitcodeAsText(
     cl::desc(
         "Accept textual form of PNaCl bitcode records (i.e. not .ll assembly)"),
     cl::init(false));
+
+void splitOnChars(const std::string &Text, const char *Chars,
+                  std::vector<std::string> &Tokens) {
+  size_t Start = 0;
+  bool KeepSplitting = true;
+  while (KeepSplitting) {
+    size_t End = Text.find_first_of(Chars, Start);
+    if (End == std::string::npos) {
+      KeepSplitting = false;
+      End = Text.size();
+    }
+    std::string RegName = Text.substr(Start, End - Start);
+    Tokens.push_back(RegName);
+    Start = End + 1;
+  }
+}
+
+void extractCommaSeparated(cl::list<std::string> &NameList,
+                           std::vector<std::string> &Names) {
+  Names.clear();
+  for (const std::string &Name : NameList) {
+    splitOnChars(Name, ",", Names);
+  }
+}
+
 } // end of anonymous namespace
 
 namespace Ice {
@@ -481,6 +517,9 @@ void ClFlags::resetClFlags(ClFlags &OutFlags) {
   // size_t and 64-bit fields.
   OutFlags.NumTranslationThreads = 0;
   OutFlags.RandomSeed = 0;
+  // Sets.
+  OutFlags.clearExcludedRegisters();
+  OutFlags.clearUseRestrictedRegisters();
 }
 
 void ClFlags::getParsedClFlags(ClFlags &OutFlags) {
@@ -507,6 +546,10 @@ void ClFlags::getParsedClFlags(ClFlags &OutFlags) {
   OutFlags.setDisableTranslation(::DisableTranslation);
   OutFlags.setDumpStats(::DumpStats);
   OutFlags.setEnableBlockProfile(::EnableBlockProfile);
+  std::vector<std::string> RegNames;
+  extractCommaSeparated(::ExcludedRegisters, RegNames);
+  for (const auto &Name : RegNames)
+    OutFlags.insertExcludedRegister(Name);
   OutFlags.setForceMemIntrinOpt(::ForceMemIntrinOpt);
   OutFlags.setFunctionSections(::FunctionSections);
   OutFlags.setNumTranslationThreads(::NumThreads);
@@ -536,6 +579,9 @@ void ClFlags::getParsedClFlags(ClFlags &OutFlags) {
   OutFlags.setTimingFocusOn(::TimingFocusOn);
   OutFlags.setTranslateOnly(::TranslateOnly);
   OutFlags.setUseNonsfi(::UseNonsfi);
+  extractCommaSeparated(::UseRestrictedRegisters, RegNames);
+  for (const auto &Name : RegNames)
+    OutFlags.insertUseRestrictedRegister(Name);
   OutFlags.setUseSandboxing(::UseSandboxing);
   OutFlags.setVerboseFocusOn(::VerboseFocusOn);
   OutFlags.setOutFileType(::OutFileType);