Fix #13035, a bug around Thumb instruction LDRD/STRD with negative #0 offset index issue.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161162 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 29 insertions, 16 deletions

diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 89f7ec227e..c3610c81a6 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -1040,7 +1040,8 @@ public:
     // Immediate offset a multiple of 4 in range [-1020, 1020].
     if (!Memory.OffsetImm) return true;
     int64_t Val = Memory.OffsetImm->getValue();
-    return Val >= -1020 && Val <= 1020 && (Val & 3) == 0;
+    // Special case, #-0 is INT32_MIN.
+    return (Val >= -1020 && Val <= 1020 && (Val & 3) == 0) || Val == INT32_MIN;
   }
   bool isMemImm0_1020s4Offset() const {
     if (!isMemory() || Memory.OffsetRegNum != 0 || Memory.Alignment != 0)
diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 6f36dcc1ef..e47bf66e3a 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -3151,9 +3151,14 @@ static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
 
 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
                            uint64_t Address, const void *Decoder) {
-  int imm = Val & 0xFF;
-  if (!(Val & 0x100)) imm *= -1;
-  Inst.addOperand(MCOperand::CreateImm(imm << 2));
+  if (Val == 0)
+    Inst.addOperand(MCOperand::CreateImm(INT32_MIN));
+  else {
+    int imm = Val & 0xFF;
+
+    if (!(Val & 0x100)) imm *= -1;
+    Inst.addOperand(MCOperand::CreateImm(imm << 2));
+  }
 
   return MCDisassembler::Success;
 }
diff --git a/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp b/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
index ad99c14cee..8b9109ec98 100644
--- a/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
+++ b/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
@@ -972,12 +972,17 @@ void ARMInstPrinter::printT2AddrModeImm8s4Operand(const MCInst *MI,
 
   O << "[" << getRegisterName(MO1.getReg());
 
-  int32_t OffImm = (int32_t)MO2.getImm() / 4;
+  int32_t OffImm = (int32_t)MO2.getImm();
+
+  assert(((OffImm & 0x3) == 0) && "Not a valid immediate!");
+
   // Don't print +0.
-  if (OffImm < 0)
-    O << ", #-" << -OffImm * 4;
+  if (OffImm == INT32_MIN)
+    O << ", #-0";
+  else if (OffImm < 0)
+    O << ", #-" << -OffImm;
   else if (OffImm > 0)
-    O << ", #" << OffImm * 4;
+    O << ", #" << OffImm;
   O << "]";
 }
 
@@ -1009,15 +1014,17 @@ void ARMInstPrinter::printT2AddrModeImm8s4OffsetOperand(const MCInst *MI,
                                                         unsigned OpNum,
                                                         raw_ostream &O) {
   const MCOperand &MO1 = MI->getOperand(OpNum);
-  int32_t OffImm = (int32_t)MO1.getImm() / 4;
+  int32_t OffImm = (int32_t)MO1.getImm();
+
+  assert(((OffImm & 0x3) == 0) && "Not a valid immediate!");
+
   // Don't print +0.
-  if (OffImm != 0) {
-    O << ", ";
-    if (OffImm < 0)
-      O << "#-" << -OffImm * 4;
-    else if (OffImm > 0)
-      O << "#" << OffImm * 4;
-  }
+  if (OffImm == INT32_MIN)
+    O << ", #-0";
+  else if (OffImm < 0)
+    O << ", #-" << -OffImm;
+  else if (OffImm > 0)
+    O << ", #" << OffImm;
 }
 
 void ARMInstPrinter::printT2AddrModeSoRegOperand(const MCInst *MI,