Generalize emitAbsoluteSymbolDiff.
This makes emitAbsoluteSymbolDiff always succeed and moves logic from the asm
printer to it.
The object one now also works on ELF. If two symbols are in the same fragment,
we will never move them apart.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239552 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/MC/MCObjectStreamer.h b/include/llvm/MC/MCObjectStreamer.h
index 462b3b4..131da07 100644
--- a/include/llvm/MC/MCObjectStreamer.h
+++ b/include/llvm/MC/MCObjectStreamer.h
@@ -136,7 +136,7 @@
///
/// \pre Offset of \c Hi is greater than the offset \c Lo.
/// \return true on success.
- bool emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
+ void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
unsigned Size) override;
bool mayHaveInstructions(MCSection &Sec) const override;
diff --git a/include/llvm/MC/MCStreamer.h b/include/llvm/MC/MCStreamer.h
index 628fb76..4dd53df 100644
--- a/include/llvm/MC/MCStreamer.h
+++ b/include/llvm/MC/MCStreamer.h
@@ -636,14 +636,12 @@
unsigned Isa, unsigned Discriminator,
StringRef FileName);
- /// Emit the absolute difference between two symbols if possible.
+ /// Emit the absolute difference between two symbols.
///
/// \pre Offset of \c Hi is greater than the offset \c Lo.
/// \return true on success.
- virtual bool emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
- unsigned Size) {
- return false;
- }
+ virtual void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
+ unsigned Size);
virtual MCSymbol *getDwarfLineTableSymbol(unsigned CUID);
virtual void EmitCFISections(bool EH, bool Debug);
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 04b936a..dd1d9a9 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1590,25 +1590,7 @@
/// .set if it avoids relocations.
void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
unsigned Size) const {
- if (!MAI->doesDwarfUseRelocationsAcrossSections())
- if (OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size))
- return;
-
- // Get the Hi-Lo expression.
- const MCExpr *Diff =
- MCBinaryExpr::createSub(MCSymbolRefExpr::create(Hi, OutContext),
- MCSymbolRefExpr::create(Lo, OutContext),
- OutContext);
-
- if (!MAI->doesSetDirectiveSuppressesReloc()) {
- OutStreamer->EmitValue(Diff, Size);
- return;
- }
-
- // Otherwise, emit with .set (aka assignment).
- MCSymbol *SetLabel = createTempSymbol("set");
- OutStreamer->EmitAssignment(SetLabel, Diff);
- OutStreamer->EmitSymbolValue(SetLabel, Size);
+ OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
}
/// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
diff --git a/lib/MC/MCObjectStreamer.cpp b/lib/MC/MCObjectStreamer.cpp
index 6de02bc..a73c171 100644
--- a/lib/MC/MCObjectStreamer.cpp
+++ b/lib/MC/MCObjectStreamer.cpp
@@ -54,21 +54,18 @@
}
}
-bool MCObjectStreamer::emitAbsoluteSymbolDiff(const MCSymbol *Hi,
+void MCObjectStreamer::emitAbsoluteSymbolDiff(const MCSymbol *Hi,
const MCSymbol *Lo,
unsigned Size) {
- // Must both be assigned to the same (valid) fragment.
- if (!Hi->getFragment() || Hi->getFragment() != Lo->getFragment())
- return false;
-
- // Must be a data fragment.
- if (!isa<MCDataFragment>(Hi->getFragment()))
- return false;
+ // If not assigned to the same (valid) fragment, fallback.
+ if (!Hi->getFragment() || Hi->getFragment() != Lo->getFragment()) {
+ MCStreamer::emitAbsoluteSymbolDiff(Hi, Lo, Size);
+ return;
+ }
assert(Hi->getOffset() >= Lo->getOffset() &&
"Expected Hi to be greater than Lo");
EmitIntValue(Hi->getOffset() - Lo->getOffset(), Size);
- return true;
}
void MCObjectStreamer::reset() {
diff --git a/lib/MC/MCStreamer.cpp b/lib/MC/MCStreamer.cpp
index 011969a..349de97 100644
--- a/lib/MC/MCStreamer.cpp
+++ b/lib/MC/MCStreamer.cpp
@@ -638,6 +638,25 @@
visitUsedExpr(*Inst.getOperand(i).getExpr());
}
+void MCStreamer::emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
+ unsigned Size) {
+ // Get the Hi-Lo expression.
+ const MCExpr *Diff =
+ MCBinaryExpr::createSub(MCSymbolRefExpr::create(Hi, Context),
+ MCSymbolRefExpr::create(Lo, Context), Context);
+
+ const MCAsmInfo *MAI = Context.getAsmInfo();
+ if (!MAI->doesSetDirectiveSuppressesReloc()) {
+ EmitValue(Diff, Size);
+ return;
+ }
+
+ // Otherwise, emit with .set (aka assignment).
+ MCSymbol *SetLabel = Context.createTempSymbol("set", true);
+ EmitAssignment(SetLabel, Diff);
+ EmitSymbolValue(SetLabel, Size);
+}
+
void MCStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {}
void MCStreamer::EmitThumbFunc(MCSymbol *Func) {}
void MCStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
