invalid-LDR_PRE-arm.txt was already passing, but for the wrong reasons. We were failing to specify enough fixed bits of LDR_PRE/LDRB_PRE, resulting in decoding conflicts. Separate them into immediate vs. register versions, allowing us to specify the necessary fixed bits. This in turn results in the test being decoded properly, and being rejected as UNPREDICTABLE rather than a hard failure.

llvm-svn: 138653

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index f0d74f3345d..a1054250c4c 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -127,6 +127,8 @@ class ARMAsmParser : public MCTargetAsmParser {
   // Asm Match Converter Methods
   bool cvtLdWriteBackRegAddrMode2(MCInst &Inst, unsigned Opcode,
                                   const SmallVectorImpl<MCParsedAsmOperand*> &);
+  bool cvtLdWriteBackRegAddrModeImm12(MCInst &Inst, unsigned Opcode,
+                                  const SmallVectorImpl<MCParsedAsmOperand*> &);
   bool cvtStWriteBackRegAddrModeImm12(MCInst &Inst, unsigned Opcode,
                                   const SmallVectorImpl<MCParsedAsmOperand*> &);
   bool cvtStWriteBackRegAddrMode2(MCInst &Inst, unsigned Opcode,
@@ -2233,6 +2235,23 @@ cvtLdWriteBackRegAddrMode2(MCInst &Inst, unsigned Opcode,
   return true;
 }
 
+/// cvtLdWriteBackRegAddrModeImm12 - Convert parsed operands to MCInst.
+/// Needed here because the Asm Gen Matcher can't handle properly tied operands
+/// when they refer multiple MIOperands inside a single one.
+bool ARMAsmParser::
+cvtLdWriteBackRegAddrModeImm12(MCInst &Inst, unsigned Opcode,
+                         const SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
+  ((ARMOperand*)Operands[2])->addRegOperands(Inst, 1);
+
+  // Create a writeback register dummy placeholder.
+  Inst.addOperand(MCOperand::CreateImm(0));
+
+  ((ARMOperand*)Operands[3])->addMemImm12OffsetOperands(Inst, 2);
+  ((ARMOperand*)Operands[1])->addCondCodeOperands(Inst, 2);
+  return true;
+}
+
+
 /// cvtStWriteBackRegAddrModeImm12 - Convert parsed operands to MCInst.
 /// Needed here because the Asm Gen Matcher can't handle properly tied operands
 /// when they refer multiple MIOperands inside a single one.