[NFC] Optimize vector usage in lld

[gAlfonso-bit]

Summary

By using emplace_back, as well as converting some loops to for-each, we can do more efficient vectorization.

Make copy constructor for TemporaryFile noexcept.

[gAlfonso-bit]

Fix formatting

[int3]

lld/COFF/Writer.cpp

521 ↗

(On Diff #481332)

codebase convention is to use explicit type instead of auto as long as it's not too ugly

lld/ELF/InputFiles.cpp

1709 ↗

(On Diff #481332)

c seems like a better name for a char

also there's no need to take this by reference

lld/ELF/MapFile.cpp

248 ↗

(On Diff #481332)

let's keep this, seems like it was intentionally done to help readability

[int3]

clearing queue

[gAlfonso-bit]

Addressed! @MaskRay

[int3]

Thanks!

lld/COFF/DriverUtils.cpp

350 ↗

(On Diff #492237)

maybe add a remark about this noexcept to the commit message

[andrewng]

lld/ELF/InputFiles.cpp

1711 ↗

(On Diff #492237)

Just saw this in passing, I think c needs to be a reference as the intention is to change the character in s.

[gAlfonso-bit]

Done!

[gAlfonso-bit]

@int3 I do not have permission to merge this. Could you?

[int3]

Done :)

[int3]

Just noticed I'd messed up the author attribution in the commit. Sorry ):

llvm/lib/MC/MCExpr.cpp

case Binary: {
     MCValue LHSValue, RHSValue;
 
     if (!ABE->getLHS()->evaluateAsRelocatableImpl(LHSValue, Asm, Layout, Fixup,
                                                   Addrs, InSet) ||
         !ABE->getRHS()->evaluateAsRelocatableImpl(RHSValue, Asm, Layout, Fixup,
                                                   Addrs, InSet)) {
       // Check if both are Target Expressions, see if we can compare them.
       if (const MCTargetExpr *L = dyn_cast<MCTargetExpr>(ABE->getLHS()))
-        if (const MCTargetExpr *R = cast<MCTargetExpr>(ABE->getRHS())) {
+        if (const MCTargetExpr *R = dyn_cast<MCTargetExpr>(ABE->getRHS())) {
           switch (ABE->getOpcode()) {
           case MCBinaryExpr::EQ:
             Res = MCValue::get((L->isEqualTo(R)) ? -1 : 0);
             return true;
           case MCBinaryExpr::NE:
             Res = MCValue::get((R->isEqualTo(R)) ? 0 : -1);
             return true;
           default: break;

llvm/lib/Object/ELFObjectFile.cpp

 Expected<std::vector<BBAddrMap>> ELFObjectFileBase::readBBAddrMap(
     std::optional<unsigned> TextSectionIndex) const {
   if (const auto *Obj = dyn_cast<ELF32LEObjectFile>(this))
     return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex);
   if (const auto *Obj = dyn_cast<ELF64LEObjectFile>(this))
     return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex);
   if (const auto *Obj = dyn_cast<ELF32BEObjectFile>(this))
     return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex);
-  if (const auto *Obj = cast<ELF64BEObjectFile>(this))
-    return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex);
-  else
-    llvm_unreachable("Unsupported binary format");
+  const auto *Obj = cast<ELF64BEObjectFile>(this);
 }