Fixed the LLVM ARM v7 assembler and instruction printer for 8-bit immediate offset addressing. The assembler and instruction printer were not properly handeling the #-0 immediate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156608 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 9 insertions, 3 deletions

diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 7822501..8865979 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -914,7 +914,9 @@ public:
     // Immediate offset in range [-255, 255].
     if (!Memory.OffsetImm) return true;
     int64_t Val = Memory.OffsetImm->getValue();
-    return Val > -256 && Val < 256;
+    // The #-0 offset is encoded as INT32_MIN, and we have to check 
+    // for this too.
+    return (Val > -256 && Val < 256) || Val == INT32_MIN;
   }
   bool isAM3Offset() const {
     if (Kind != k_Immediate && Kind != k_PostIndexRegister)
diff --git a/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp b/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
index 34a76b2..be7e098 100644
--- a/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
+++ b/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
@@ -426,9 +426,13 @@ void ARMInstPrinter::printAM3PreOrOffsetIndexOp(const MCInst *MI, unsigned Op,
     return;
   }
 
-  if (unsigned ImmOffs = ARM_AM::getAM3Offset(MO3.getImm()))
+  //If the op is sub we have to print the immediate even if it is 0 
+  unsigned ImmOffs = ARM_AM::getAM3Offset(MO3.getImm());
+  ARM_AM::AddrOpc op = ARM_AM::getAM3Op(MO3.getImm());
+ 
+  if (ImmOffs || (op == ARM_AM::sub))
     O << ", #"
-      << ARM_AM::getAddrOpcStr(ARM_AM::getAM3Op(MO3.getImm()))
+      << ARM_AM::getAddrOpcStr(op)
       << ImmOffs;
   O << ']';
 }