Minor improvements in GPT2 tokenizer (#3567)

* Fixing minor bugs in bpe_gpt2_preprocess

* Don't add bos token in test

1 files changed, 4 insertions, 5 deletions

diff --git a/llama.cpp b/llama.cpp
index 4653c802..7ed87223 100644
--- a/llama.cpp
+++ b/llama.cpp
@@ -6342,7 +6342,6 @@ private:
         for (int i = 0; i < (int)text_utf.size(); i++) {
             const std::string & utf_char = text_utf[i];
             bool split_condition = false;
-            // const char* text_pos = raw_text_p + utf_char.seq_offset_bytes;
             int bytes_remain = text_utf.size() - i;
             // forward backward lookups
             const std::string & utf_char_next = (i + 1 < (int)text_utf.size()) ? text_utf[i + 1] : "";
@@ -6368,9 +6367,9 @@ private:
             if (!split_condition && bytes_remain >= 3) {
                 // 're|'ve|'ll
                 if (utf_char == "\'" && (
-                    (utf_char_next == "r" || utf_char_next_next == "e") ||
-                    (utf_char_next == "v" || utf_char_next_next == "e") ||
-                    (utf_char_next == "l" || utf_char_next_next == "l"))
+                    (utf_char_next == "r" && utf_char_next_next == "e") ||
+                    (utf_char_next == "v" && utf_char_next_next == "e") ||
+                    (utf_char_next == "l" && utf_char_next_next == "l"))
                     ) {
                     split_condition = true;
                 }
@@ -6421,7 +6420,7 @@ private:
                 else if (collecting_special && (codepoint_type(utf_char) == CODEPOINT_TYPE_LETTER || codepoint_type(utf_char) == CODEPOINT_TYPE_DIGIT || codepoint_type(utf_char) == CODEPOINT_TYPE_WHITESPACE)) {
                     split_condition = true;
                 }
-                else if (collecting_whitespace_lookahead && codepoint_type(utf_char_next) != CODEPOINT_TYPE_WHITESPACE) {
+                else if (collecting_whitespace_lookahead && (codepoint_type(utf_char_next) == CODEPOINT_TYPE_LETTER || codepoint_type(utf_char_next) == CODEPOINT_TYPE_DIGIT)) {
                     split_condition = true;
                 }
             }