[TableGen] Replace StringRef::slice with substr. NFC

Author: MaskRay

llvm/utils/TableGen/AsmMatcherEmitter.cpp

@@ -1001,7 +1001,7 @@ void MatchableInfo::tokenizeAsmString(const AsmMatcherInfo &Info,
     char Char = String[i];
     if (Variant.BreakCharacters.contains(Char)) {
       if (InTok) {
-        addAsmOperand(String.slice(Prev, i), false);
+        addAsmOperand(String.substr(Prev, i - Prev), false);
         Prev = i;
         IsIsolatedToken = false;
       }
@@ -1010,7 +1010,7 @@ void MatchableInfo::tokenizeAsmString(const AsmMatcherInfo &Info,
     }
     if (Variant.TokenizingCharacters.contains(Char)) {
       if (InTok) {
-        addAsmOperand(String.slice(Prev, i), IsIsolatedToken);
+        addAsmOperand(String.substr(Prev, i - Prev), IsIsolatedToken);
         InTok = false;
         IsIsolatedToken = false;
       }
@@ -1021,7 +1021,7 @@ void MatchableInfo::tokenizeAsmString(const AsmMatcherInfo &Info,
     }
     if (Variant.SeparatorCharacters.contains(Char)) {
       if (InTok) {
-        addAsmOperand(String.slice(Prev, i), IsIsolatedToken);
+        addAsmOperand(String.substr(Prev, i - Prev), IsIsolatedToken);
         InTok = false;
       }
       Prev = i + 1;
@@ -1032,7 +1032,7 @@ void MatchableInfo::tokenizeAsmString(const AsmMatcherInfo &Info,
     switch (Char) {
     case '\\':
       if (InTok) {
-        addAsmOperand(String.slice(Prev, i), false);
+        addAsmOperand(String.substr(Prev, i - Prev), false);
         InTok = false;
         IsIsolatedToken = false;
       }
@@ -1045,7 +1045,7 @@ void MatchableInfo::tokenizeAsmString(const AsmMatcherInfo &Info,
 
     case '$': {
       if (InTok) {
-        addAsmOperand(String.slice(Prev, i), IsIsolatedToken);
+        addAsmOperand(String.substr(Prev, i - Prev), IsIsolatedToken);
         InTok = false;
         IsIsolatedToken = false;
       }
@@ -1059,7 +1059,7 @@ void MatchableInfo::tokenizeAsmString(const AsmMatcherInfo &Info,
       size_t EndPos = String.find('}', i);
       assert(EndPos != StringRef::npos &&
              "Missing brace in operand reference!");
-      addAsmOperand(String.slice(i, EndPos + 1), IsIsolatedToken);
+      addAsmOperand(String.substr(i, EndPos + 1 - i), IsIsolatedToken);
       Prev = EndPos + 1;
       i = EndPos;
       IsIsolatedToken = false;

llvm/utils/TableGen/Common/CodeGenInstruction.cpp

@@ -566,7 +566,8 @@ std::string CodeGenInstruction::FlattenAsmStringVariants(StringRef Cur,
     }
 
     // Select the Nth variant (or empty).
-    StringRef Selection = Cur.slice(VariantsStart, VariantsEnd);
+    StringRef Selection =
+        Cur.substr(VariantsStart, VariantsEnd - VariantsStart);
     for (unsigned i = 0; i != Variant; ++i)
       Selection = Selection.split('|').second;
     Res += Selection.split('|').first;