Pull in r222587 from upstream llvm trunk (by Jörg Sonnenberger):

  Fix transformation of add with pc argument to adr for non-immediate
  arguments.

This fixes an "Unimplemented" error when assembling certain ARM add
instructions with pc-relative arguments.

Reported by:	sbruno
PR:		196412, 196423

1 files changed, 25 insertions, 5 deletions

diff --git a/contrib/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/contrib/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index be3b9d4..faff9a7 100644
--- a/contrib/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/contrib/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -314,7 +314,7 @@ class ARMAsmParser : public MCTargetAsmParser {
   void cvtThumbBranches(MCInst &Inst, const OperandVector &);
 
   bool validateInstruction(MCInst &Inst, const OperandVector &Ops);
-  bool processInstruction(MCInst &Inst, const OperandVector &Ops);
+  bool processInstruction(MCInst &Inst, const OperandVector &Ops, MCStreamer &Out);
   bool shouldOmitCCOutOperand(StringRef Mnemonic, OperandVector &Operands);
   bool shouldOmitPredicateOperand(StringRef Mnemonic, OperandVector &Operands);
 
@@ -6175,7 +6175,8 @@ static unsigned getRealVLDOpcode(unsigned Opc, unsigned &Spacing) {
 }
 
 bool ARMAsmParser::processInstruction(MCInst &Inst,
-                                      const OperandVector &Operands) {
+                                      const OperandVector &Operands,
+                                      MCStreamer &Out) {
   switch (Inst.getOpcode()) {
   // Alias for alternate form of 'ldr{,b}t Rt, [Rn], #imm' instruction.
   case ARM::LDRT_POST:
@@ -6216,12 +6217,31 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
   // Alias for alternate form of 'ADR Rd, #imm' instruction.
   case ARM::ADDri: {
     if (Inst.getOperand(1).getReg() != ARM::PC ||
-        Inst.getOperand(5).getReg() != 0)
+        Inst.getOperand(5).getReg() != 0 ||
+        !(Inst.getOperand(2).isExpr() || Inst.getOperand(2).isImm()))
       return false;
     MCInst TmpInst;
     TmpInst.setOpcode(ARM::ADR);
     TmpInst.addOperand(Inst.getOperand(0));
-    TmpInst.addOperand(Inst.getOperand(2));
+    if (Inst.getOperand(2).isImm()) {
+      TmpInst.addOperand(Inst.getOperand(2));
+    } else {
+      // Turn PC-relative expression into absolute expression.
+      // Reading PC provides the start of the current instruction + 8 and
+      // the transform to adr is biased by that.
+      MCSymbol *Dot = getContext().CreateTempSymbol();
+      Out.EmitLabel(Dot);
+      const MCExpr *OpExpr = Inst.getOperand(2).getExpr();
+      const MCExpr *InstPC = MCSymbolRefExpr::Create(Dot,
+                                                     MCSymbolRefExpr::VK_None,
+                                                     getContext());
+      const MCExpr *Const8 = MCConstantExpr::Create(8, getContext());
+      const MCExpr *ReadPC = MCBinaryExpr::CreateAdd(InstPC, Const8,
+                                                     getContext());
+      const MCExpr *FixupAddr = MCBinaryExpr::CreateAdd(ReadPC, OpExpr,
+                                                        getContext());
+      TmpInst.addOperand(MCOperand::CreateExpr(FixupAddr));
+    }
     TmpInst.addOperand(Inst.getOperand(3));
     TmpInst.addOperand(Inst.getOperand(4));
     Inst = TmpInst;
@@ -8061,7 +8081,7 @@ bool ARMAsmParser::MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
       // encoding is selected. Loop on it while changes happen so the
       // individual transformations can chain off each other. E.g.,
       // tPOP(r8)->t2LDMIA_UPD(sp,r8)->t2STR_POST(sp,r8)
-      while (processInstruction(Inst, Operands))
+      while (processInstruction(Inst, Operands, Out))
         ;
 
       // Only after the instruction is fully processed, we can validate it