+/// Emit something like ".long Hi+Offset-Lo" where the size in bytes of the
+/// directive is specified by Size and Hi/Lo specify the labels.
+static void emitLabelOffsetDifference(MCStreamer &Streamer, const MCSymbol *Hi,
+ uint64_t Offset, const MCSymbol *Lo,
+ unsigned Size) {
+ MCContext &Context = Streamer.getContext();
+
+ // Emit Hi+Offset - Lo
+ // Get the Hi+Offset expression.
+ const MCExpr *Plus =
+ MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, Context),
+ MCConstantExpr::Create(Offset, Context), Context);
+
+ // Get the Hi+Offset-Lo expression.
+ const MCExpr *Diff = MCBinaryExpr::CreateSub(
+ Plus, MCSymbolRefExpr::Create(Lo, Context), Context);
+
+ // Otherwise, emit with .set (aka assignment).
+ MCSymbol *SetLabel = Context.CreateTempSymbol();
+ Streamer.EmitAssignment(SetLabel, Diff);
+ Streamer.EmitSymbolValue(SetLabel, Size);
+}
+