Fix the ridiculous SubtargetFeatures API where it implicitly expects CPU name to

be the first encoded as the first feature. It then uses the CPU name to look up
features / scheduling itineray even though clients know full well the CPU name
being used to query these properties.

The fix is to just have the clients explictly pass the CPU name!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134127 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 21 insertions, 41 deletions

diff --git a/lib/MC/SubtargetFeature.cpp b/lib/MC/SubtargetFeature.cpp
index 3ed122a..a6f6b13 100644
--- a/lib/MC/SubtargetFeature.cpp
+++ b/lib/MC/SubtargetFeature.cpp
@@ -63,6 +63,9 @@ static inline std::string PrependFlag(const std::string &Feature,
 /// Split - Splits a string of comma separated items in to a vector of strings.
 ///
 static void Split(std::vector<std::string> &V, const std::string &S) {
+  if (S.empty())
+    return;
+
   // Start at beginning of string.
   size_t Pos = 0;
   while (true) {
@@ -88,7 +91,7 @@ static std::string Join(const std::vector<std::string> &V) {
   std::string Result;
   // If the vector is not empty 
   if (!V.empty()) {
-    // Start with the CPU feature
+    // Start with the first feature
     Result = V[0];
     // For each successive feature
     for (size_t i = 1; i < V.size(); i++) {
@@ -186,27 +189,6 @@ void SubtargetFeatures::setString(const std::string &Initial) {
   Split(Features, LowercaseString(Initial));
 }
 
-
-/// setCPU - Set the CPU string.  Replaces previous setting.  Setting to ""
-/// clears CPU.
-void SubtargetFeatures::setCPU(const std::string &String) {
-  Features[0] = LowercaseString(String);
-}
-
-
-/// setCPUIfNone - Setting CPU string only if no string is set.
-///
-void SubtargetFeatures::setCPUIfNone(const std::string &String) {
-  if (Features[0].empty()) setCPU(String);
-}
-
-/// getCPU - Returns current CPU.
-///
-const std::string & SubtargetFeatures::getCPU() const {
-  return Features[0];
-}
-
-
 /// SetImpliedBits - For each feature that is (transitively) implied by this
 /// feature, set it.
 ///
@@ -245,12 +227,13 @@ void ClearImpliedBits(uint64_t &Bits, const SubtargetFeatureKV *FeatureEntry,
   }
 }
 
-/// getBits - Get feature bits.
+/// getFeatureBits - Get feature bits a CPU.
 ///
-uint64_t SubtargetFeatures::getBits(const SubtargetFeatureKV *CPUTable,
-                                          size_t CPUTableSize,
-                                    const SubtargetFeatureKV *FeatureTable,
-                                          size_t FeatureTableSize) {
+uint64_t SubtargetFeatures::getFeatureBits(const std::string &CPU,
+                                         const SubtargetFeatureKV *CPUTable,
+                                         size_t CPUTableSize,
+                                         const SubtargetFeatureKV *FeatureTable,
+                                         size_t FeatureTableSize) {
   assert(CPUTable && "missing CPU table");
   assert(FeatureTable && "missing features table");
 #ifndef NDEBUG
@@ -266,12 +249,11 @@ uint64_t SubtargetFeatures::getBits(const SubtargetFeatureKV *CPUTable,
   uint64_t Bits = 0;                    // Resulting bits
 
   // Check if help is needed
-  if (Features[0] == "help")
+  if (CPU == "help")
     Help(CPUTable, CPUTableSize, FeatureTable, FeatureTableSize);
   
   // Find CPU entry
-  const SubtargetFeatureKV *CPUEntry =
-                            Find(Features[0], CPUTable, CPUTableSize);
+  const SubtargetFeatureKV *CPUEntry = Find(CPU, CPUTable, CPUTableSize);
   // If there is a match
   if (CPUEntry) {
     // Set base feature bits
@@ -284,12 +266,12 @@ uint64_t SubtargetFeatures::getBits(const SubtargetFeatureKV *CPUTable,
         SetImpliedBits(Bits, &FE, FeatureTable, FeatureTableSize);
     }
   } else {
-    errs() << "'" << Features[0]
+    errs() << "'" << CPU
            << "' is not a recognized processor for this target"
            << " (ignoring processor)\n";
   }
   // Iterate through each feature
-  for (size_t i = 1; i < Features.size(); i++) {
+  for (size_t i = 0, E = Features.size(); i < E; i++) {
     const std::string &Feature = Features[i];
     
     // Check for help
@@ -323,9 +305,10 @@ uint64_t SubtargetFeatures::getBits(const SubtargetFeatureKV *CPUTable,
   return Bits;
 }
 
-/// Get info pointer
-void *SubtargetFeatures::getInfo(const SubtargetInfoKV *Table,
-                                       size_t TableSize) {
+/// Get scheduling itinerary of a CPU.
+void *SubtargetFeatures::getItinerary(const std::string &CPU,
+                                      const SubtargetInfoKV *Table,
+                                      size_t TableSize) {
   assert(Table && "missing table");
 #ifndef NDEBUG
   for (size_t i = 1; i < TableSize; i++) {
@@ -334,12 +317,12 @@ void *SubtargetFeatures::getInfo(const SubtargetInfoKV *Table,
 #endif
 
   // Find entry
-  const SubtargetInfoKV *Entry = Find(Features[0], Table, TableSize);
+  const SubtargetInfoKV *Entry = Find(CPU, Table, TableSize);
   
   if (Entry) {
     return Entry->Value;
   } else {
-    errs() << "'" << Features[0]
+    errs() << "'" << CPU
            << "' is not a recognized processor for this target"
            << " (ignoring processor)\n";
     return NULL;
@@ -367,10 +350,7 @@ void SubtargetFeatures::dump() const {
 /// subtarget. It would be better if we could encode this information
 /// into the IR. See <rdar://5972456>.
 ///
-void SubtargetFeatures::getDefaultSubtargetFeatures(const std::string &CPU,
-                                                    const Triple& Triple) {
-  setCPU(CPU);
-
+void SubtargetFeatures::getDefaultSubtargetFeatures(const Triple& Triple) {
   if (Triple.getVendor() == Triple::Apple) {
     if (Triple.getArch() == Triple::ppc) {
       // powerpc-apple-*