+/// \brief Transform a not absolute MCExpr containing a reference to a GOT
+/// equivalent global, by a target specific GOT pc relative access to the
+/// final symbol.
+static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
+ const Constant *BaseCst,
+ uint64_t Offset) {
+ // The global @foo below illustrates a global that uses a got equivalent.
+ //
+ // @bar = global i32 42
+ // @gotequiv = private unnamed_addr constant i32* @bar
+ // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
+ // i64 ptrtoint (i32* @foo to i64))
+ // to i32)
+ //
+ // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
+ // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
+ // form:
+ //
+ // foo = cstexpr, where
+ // cstexpr := <gotequiv> - "." + <cst>
+ // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
+ //
+ // After canonicalization by evaluateAsRelocatable `ME` turns into:
+ //
+ // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
+ // gotpcrelcst := <offset from @foo base> + <cst>
+ //
+ MCValue MV;
+ if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
+ return;
+
+ const MCSymbol *GOTEquivSym = &MV.getSymA()->getSymbol();
+ if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
+ return;
+
+ const GlobalValue *BaseGV = dyn_cast<GlobalValue>(BaseCst);
+ if (!BaseGV)
+ return;
+
+ const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
+ if (BaseSym != &MV.getSymB()->getSymbol())
+ return;
+
+ // Make sure to match:
+ //
+ // gotpcrelcst := <offset from @foo base> + <cst>
+ //
+ // If gotpcrelcst is positive it means that we can safely fold the pc rel
+ // displacement into the GOTPCREL. We can also can have an extra offset <cst>
+ // if the target knows how to encode it.
+ //
+ int64_t GOTPCRelCst = Offset + MV.getConstant();
+ if (GOTPCRelCst < 0)
+ return;
+ if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
+ return;
+
+ // Emit the GOT PC relative to replace the got equivalent global, i.e.:
+ //
+ // bar:
+ // .long 42
+ // gotequiv:
+ // .quad bar
+ // foo:
+ // .long gotequiv - "." + <cst>
+ //
+ // is replaced by the target specific equivalent to:
+ //
+ // bar:
+ // .long 42
+ // foo:
+ // .long bar@GOTPCREL+<gotpcrelcst>
+ //
+ AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
+ const GlobalVariable *GV = Result.first;
+ int NumUses = (int)Result.second;
+ const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
+ const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
+ *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
+ FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
+
+ // Update GOT equivalent usage information
+ --NumUses;
+ if (NumUses >= 0)
+ AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
+}
+
+static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP,
+ const Constant *BaseCV, uint64_t Offset) {
+ const DataLayout *DL = AP.TM.getDataLayout();