Convert StringMap to using StringRef for its APIs.

 - Yay for '-'s and simplifications!

 - I kept StringMap::GetOrCreateValue for compatibility purposes, this can
   eventually go away. Likewise the StringMapEntry Create functions still follow
   the old style.

 - NIFC.

llvm-svn: 76888

1 files changed, 10 insertions, 16 deletions

diff --git a/llvm/lib/Support/StringMap.cpp b/llvm/lib/Support/StringMap.cpp
index 0c61732a61b..040308bbfd4 100644
--- a/llvm/lib/Support/StringMap.cpp
+++ b/llvm/lib/Support/StringMap.cpp
@@ -65,14 +65,13 @@ static unsigned HashString(const char *Start, const char *End) {
 /// specified bucket will be non-null.  Otherwise, it will be null.  In either
 /// case, the FullHashValue field of the bucket will be set to the hash value
 /// of the string.
-unsigned StringMapImpl::LookupBucketFor(const char *NameStart,
-                                        const char *NameEnd) {
+unsigned StringMapImpl::LookupBucketFor(const StringRef &Name) {
   unsigned HTSize = NumBuckets;
   if (HTSize == 0) {  // Hash table unallocated so far?
     init(16);
     HTSize = NumBuckets;
   }
-  unsigned FullHashValue = HashString(NameStart, NameEnd);
+  unsigned FullHashValue = HashString(Name.begin(), Name.end());
   unsigned BucketNo = FullHashValue & (HTSize-1);
   
   unsigned ProbeAmt = 1;
@@ -102,12 +101,10 @@ unsigned StringMapImpl::LookupBucketFor(const char *NameStart,
       // being non-null and for the full hash value) not at the items.  This
       // is important for cache locality.
       
-      // Do the comparison like this because NameStart isn't necessarily
+      // Do the comparison like this because Name isn't necessarily
       // null-terminated!
       char *ItemStr = (char*)BucketItem+ItemSize;
-      unsigned ItemStrLen = BucketItem->getKeyLength();
-      if (unsigned(NameEnd-NameStart) == ItemStrLen &&
-          memcmp(ItemStr, NameStart, ItemStrLen) == 0) {
+      if (Name == StringRef(ItemStr, BucketItem->getKeyLength())) {
         // We found a match!
         return BucketNo;
       }
@@ -126,10 +123,10 @@ unsigned StringMapImpl::LookupBucketFor(const char *NameStart,
 /// FindKey - Look up the bucket that contains the specified key. If it exists
 /// in the map, return the bucket number of the key.  Otherwise return -1.
 /// This does not modify the map.
-int StringMapImpl::FindKey(const char *KeyStart, const char *KeyEnd) const {
+int StringMapImpl::FindKey(const StringRef &Key) const {
   unsigned HTSize = NumBuckets;
   if (HTSize == 0) return -1;  // Really empty table?
-  unsigned FullHashValue = HashString(KeyStart, KeyEnd);
+  unsigned FullHashValue = HashString(Key.begin(), Key.end());
   unsigned BucketNo = FullHashValue & (HTSize-1);
   
   unsigned ProbeAmt = 1;
@@ -151,9 +148,7 @@ int StringMapImpl::FindKey(const char *KeyStart, const char *KeyEnd) const {
       // Do the comparison like this because NameStart isn't necessarily
       // null-terminated!
       char *ItemStr = (char*)BucketItem+ItemSize;
-      unsigned ItemStrLen = BucketItem->getKeyLength();
-      if (unsigned(KeyEnd-KeyStart) == ItemStrLen &&
-          memcmp(ItemStr, KeyStart, ItemStrLen) == 0) {
+      if (Key == StringRef(ItemStr, BucketItem->getKeyLength())) {
         // We found a match!
         return BucketNo;
       }
@@ -172,16 +167,15 @@ int StringMapImpl::FindKey(const char *KeyStart, const char *KeyEnd) const {
 /// delete it.  This aborts if the value isn't in the table.
 void StringMapImpl::RemoveKey(StringMapEntryBase *V) {
   const char *VStr = (char*)V + ItemSize;
-  StringMapEntryBase *V2 = RemoveKey(VStr, VStr+V->getKeyLength());
+  StringMapEntryBase *V2 = RemoveKey(StringRef(VStr, V->getKeyLength()));
   V2 = V2;
   assert(V == V2 && "Didn't find key?");
 }
 
 /// RemoveKey - Remove the StringMapEntry for the specified key from the
 /// table, returning it.  If the key is not in the table, this returns null.
-StringMapEntryBase *StringMapImpl::RemoveKey(const char *KeyStart,
-                                             const char *KeyEnd) {
-  int Bucket = FindKey(KeyStart, KeyEnd);
+StringMapEntryBase *StringMapImpl::RemoveKey(const StringRef &Key) {
+  int Bucket = FindKey(Key);
   if (Bucket == -1) return 0;
   
   StringMapEntryBase *Result = TheTable[Bucket].Item;