[MC] Optimize loops in MC (#98114)

https://llvm.org/docs/CodingStandards.html tells us that we should avoid
evaluating `.end()` each time if possible.

Author: chestnykh

llvm/lib/MC/MCParser/AsmParser.cpp

@@ -6120,8 +6120,8 @@ bool AsmParser::parseMSInlineAsm(
   const char *AsmStart = ASMString.begin();
   const char *AsmEnd = ASMString.end();
   array_pod_sort(AsmStrRewrites.begin(), AsmStrRewrites.end(), rewritesSort);
-  for (auto it = AsmStrRewrites.begin(); it != AsmStrRewrites.end(); ++it) {
-    const AsmRewrite &AR = *it;
+  for (auto I = AsmStrRewrites.begin(), E = AsmStrRewrites.end(); I != E; ++I) {
+    const AsmRewrite &AR = *I;
     // Check if this has already been covered by another rewrite...
     if (AR.Done)
       continue;
@@ -6164,7 +6164,7 @@ bool AsmParser::parseMSInlineAsm(
         SMLoc OffsetLoc = SMLoc::getFromPointer(AR.IntelExp.OffsetName.data());
         size_t OffsetLen = OffsetName.size();
         auto rewrite_it = std::find_if(
-            it, AsmStrRewrites.end(), [&](const AsmRewrite &FusingAR) {
+            I, AsmStrRewrites.end(), [&](const AsmRewrite &FusingAR) {
               return FusingAR.Loc == OffsetLoc && FusingAR.Len == OffsetLen &&
                      (FusingAR.Kind == AOK_Input ||
                       FusingAR.Kind == AOK_CallInput);

llvm/lib/MC/MCParser/MasmParser.cpp

@@ -7474,8 +7474,8 @@ bool MasmParser::parseMSInlineAsm(
   const char *AsmStart = ASMString.begin();
   const char *AsmEnd = ASMString.end();
   array_pod_sort(AsmStrRewrites.begin(), AsmStrRewrites.end(), rewritesSort);
-  for (auto it = AsmStrRewrites.begin(); it != AsmStrRewrites.end(); ++it) {
-    const AsmRewrite &AR = *it;
+  for (auto I = AsmStrRewrites.begin(), E = AsmStrRewrites.end(); I != E; ++I) {
+    const AsmRewrite &AR = *I;
     // Check if this has already been covered by another rewrite...
     if (AR.Done)
       continue;
@@ -7518,7 +7518,7 @@ bool MasmParser::parseMSInlineAsm(
         SMLoc OffsetLoc = SMLoc::getFromPointer(AR.IntelExp.OffsetName.data());
         size_t OffsetLen = OffsetName.size();
         auto rewrite_it = std::find_if(
-            it, AsmStrRewrites.end(), [&](const AsmRewrite &FusingAR) {
+            I, AsmStrRewrites.end(), [&](const AsmRewrite &FusingAR) {
               return FusingAR.Loc == OffsetLoc && FusingAR.Len == OffsetLen &&
                      (FusingAR.Kind == AOK_Input ||
                       FusingAR.Kind == AOK_CallInput);

llvm/lib/MC/XCOFFObjectWriter.cpp

@@ -1385,23 +1385,21 @@ void XCOFFObjectWriter::addExceptionEntry(
 unsigned XCOFFObjectWriter::getExceptionSectionSize() {
   unsigned EntryNum = 0;
 
-  for (auto it = ExceptionSection.ExceptionTable.begin();
-       it != ExceptionSection.ExceptionTable.end(); ++it)
+  for (const auto &TableEntry : ExceptionSection.ExceptionTable)
     // The size() gets +1 to account for the initial entry containing the
     // symbol table index.
-    EntryNum += it->second.Entries.size() + 1;
+    EntryNum += TableEntry.second.Entries.size() + 1;
 
   return EntryNum * (is64Bit() ? XCOFF::ExceptionSectionEntrySize64
                                : XCOFF::ExceptionSectionEntrySize32);
 }
 
 unsigned XCOFFObjectWriter::getExceptionOffset(const MCSymbol *Symbol) {
   unsigned EntryNum = 0;
-  for (auto it = ExceptionSection.ExceptionTable.begin();
-       it != ExceptionSection.ExceptionTable.end(); ++it) {
-    if (Symbol == it->second.FunctionSymbol)
+  for (const auto &TableEntry : ExceptionSection.ExceptionTable) {
+    if (Symbol == TableEntry.second.FunctionSymbol)
       break;
-    EntryNum += it->second.Entries.size() + 1;
+    EntryNum += TableEntry.second.Entries.size() + 1;
   }
   return EntryNum * (is64Bit() ? XCOFF::ExceptionSectionEntrySize64
                                : XCOFF::ExceptionSectionEntrySize32);
@@ -1667,17 +1665,16 @@ void XCOFFObjectWriter::writeSectionForDwarfSectionEntry(
 void XCOFFObjectWriter::writeSectionForExceptionSectionEntry(
     const MCAssembler &Asm, ExceptionSectionEntry &ExceptionEntry,
     uint64_t &CurrentAddressLocation) {
-  for (auto it = ExceptionEntry.ExceptionTable.begin();
-       it != ExceptionEntry.ExceptionTable.end(); it++) {
+  for (const auto &TableEntry : ExceptionEntry.ExceptionTable) {
     // For every symbol that has exception entries, you must start the entries
     // with an initial symbol table index entry
-    W.write<uint32_t>(SymbolIndexMap[it->second.FunctionSymbol]);
+    W.write<uint32_t>(SymbolIndexMap[TableEntry.second.FunctionSymbol]);
     if (is64Bit()) {
       // 4-byte padding on 64-bit.
       W.OS.write_zeros(4);
     }
     W.OS.write_zeros(2);
-    for (auto &TrapEntry : it->second.Entries) {
+    for (auto &TrapEntry : TableEntry.second.Entries) {
       writeWord(TrapEntry.TrapAddress);
       W.write<uint8_t>(TrapEntry.Lang);
       W.write<uint8_t>(TrapEntry.Reason);