2 files changed, 17 insertions, 9 deletions
diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
index 1cb97ce61fc..e3cfae84ee0 100644
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -273,13 +273,10 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
 
   Value = Target.getConstant();
 
-  bool IsThumb = false;
   if (const MCSymbolRefExpr *A = Target.getSymA()) {
     const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
     if (Sym.isDefined())
       Value += Layout.getSymbolOffset(&getSymbolData(Sym));
-    if (isThumbFunc(&Sym))
-      IsThumb = true;
   }
   if (const MCSymbolRefExpr *B = Target.getSymB()) {
     const MCSymbol &Sym = B->getSymbol().AliasedSymbol();
@@ -302,12 +299,8 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
     Value -= Offset;
   }
 
-  // ARM fixups based from a thumb function address need to have the low
-  // bit set. The actual value is always at least 16-bit aligned, so the
-  // low bit is normally clear and available for use as an ISA flag for
-  // interworking.
-  if (IsThumb)
-    Value |= 1;
+  // Let the backend adjust the fixup value if necessary.
+  Backend.processFixupValue(*this, Layout, Fixup, DF, Target, Value);
 
   return IsResolved;
 }
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
index 7b3f966ea82..88fea5745d8 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -22,6 +22,7 @@
 #include "llvm/MC/MCSectionMachO.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/MCValue.h"
 #include "llvm/Object/MachOFormat.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -101,6 +102,20 @@ public:
     return Infos[Kind - FirstTargetFixupKind];
   }
 
+  /// processFixupValue - Target hook to process the literal value of a fixup
+  /// if necessary.
+  void processFixupValue(const MCAssembler &Asm, const MCAsmLayout &Layout,
+                         const MCFixup &Fixup, const MCFragment *DF,
+                         MCValue &Target, uint64_t &Value) {
+    // Some fixups to thumb function symbols need the low bit (thumb bit)
+    // twiddled.
+    if (const MCSymbolRefExpr *A = Target.getSymA()) {
+      const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
+      if (Asm.isThumbFunc(&Sym))
+        Value |= 1;
+    }
+  }
+
   bool MayNeedRelaxation(const MCInst &Inst) const;
 
   bool fixupNeedsRelaxation(const MCFixup &Fixup,