// Emit the rest of the function body.
EmitFunctionBody();
+ // If we need V4T thumb mode Register Indirect Jump pads, emit them.
+ // These are created per function, rather than per TU, since it's
+ // relatively easy to exceed the thumb branch range within a TU.
+ if (! ThumbIndirectPads.empty()) {
+ OutStreamer.EmitAssemblerFlag(MCAF_Code16);
+ EmitAlignment(1);
+ for (unsigned i = 0, e = ThumbIndirectPads.size(); i < e; i++) {
+ OutStreamer.EmitLabel(ThumbIndirectPads[i].second);
+ EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tBX)
+ .addReg(ThumbIndirectPads[i].first)
+ // Add predicate operands.
+ .addImm(ARMCC::AL)
+ .addReg(0));
+ }
+ ThumbIndirectPads.clear();
+ }
+
// We didn't modify anything.
return false;
}
// absence of its emission implies zero).
}
+ // TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath is the
+ // equivalent of GCC's -ffinite-math-only flag.
if (TM.Options.NoInfsFPMath && TM.Options.NoNaNsFPMath)
ATS.emitAttribute(ARMBuildAttrs::ABI_FP_number_model,
ARMBuildAttrs::Allowed);
return;
}
case ARM::tBX_CALL: {
- EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tMOVr)
- .addReg(ARM::LR)
- .addReg(ARM::PC)
- // Add predicate operands.
- .addImm(ARMCC::AL)
- .addReg(0));
+ if (Subtarget->hasV5TOps())
+ llvm_unreachable("Expected BLX to be selected for v5t+");
+
+ // On ARM v4t, when doing a call from thumb mode, we need to ensure
+ // that the saved lr has its LSB set correctly (the arch doesn't
+ // have blx).
+ // So here we generate a bl to a small jump pad that does bx rN.
+ // The jump pads are emitted after the function body.
+
+ unsigned TReg = MI->getOperand(0).getReg();
+ MCSymbol *TRegSym = nullptr;
+ for (unsigned i = 0, e = ThumbIndirectPads.size(); i < e; i++) {
+ if (ThumbIndirectPads[i].first == TReg) {
+ TRegSym = ThumbIndirectPads[i].second;
+ break;
+ }
+ }
- EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tBX)
- .addReg(MI->getOperand(0).getReg())
- // Add predicate operands.
- .addImm(ARMCC::AL)
- .addReg(0));
+ if (!TRegSym) {
+ TRegSym = OutContext.CreateTempSymbol();
+ ThumbIndirectPads.push_back(std::make_pair(TReg, TRegSym));
+ }
+
+ // Create a link-saving branch to the Reg Indirect Jump Pad.
+ EmitToStreamer(OutStreamer, MCInstBuilder(ARM::tBL)
+ // Predicate comes first here.
+ .addImm(ARMCC::AL).addReg(0)
+ .addExpr(MCSymbolRefExpr::Create(TRegSym, OutContext)));
return;
}
case ARM::BMOVPCRX_CALL: {