3 files changed, 66 insertions, 28 deletions
diff --git a/src/arch/arm/isa/formats/fp.isa b/src/arch/arm/isa/formats/fp.isa
index 9d40a4a43..3a0cad1c5 100644
--- a/src/arch/arm/isa/formats/fp.isa
+++ b/src/arch/arm/isa/formats/fp.isa
@@ -758,7 +758,15 @@ let {{
                                       bits(machInst, 24)) << 7) |
                             (bits(machInst, 18, 16) << 4) |
                             (bits(machInst, 3, 0) << 0);
-        const uint64_t bigImm = simd_modified_imm(op, cmode, imm);
+
+        // Check for invalid immediate encodings and return an unknown op
+        // if it happens
+        bool immValid = true;
+        const uint64_t bigImm = simd_modified_imm(op, cmode, imm, immValid);
+        if (!immValid) {
+            return new Unknown(machInst);
+        }
+
         if (op) {
             if (bits(cmode, 3) == 0) {
                 if (bits(cmode, 0) == 0) {
diff --git a/src/arch/arm/isa/formats/misc.isa b/src/arch/arm/isa/formats/misc.isa
index c2003fe6d..6a734a582 100644
--- a/src/arch/arm/isa/formats/misc.isa
+++ b/src/arch/arm/isa/formats/misc.isa
@@ -100,7 +100,10 @@ let {{
           case MISCREG_NOP:
             return new NopInst(machInst);
           case NUM_MISCREGS:
-            return new Unknown(machInst);
+            return new FailUnimplemented(
+                    csprintf("miscreg crn:%d opc1:%d crm:%d opc2:%d %s unknown",
+                    crn, opc1, crm, opc2, isRead ? "read" : "write").c_str(),
+                    machInst);
           case MISCREG_DCCISW:
             return new WarnUnimplemented(
                     isRead ? "mrc dccisw" : "mcr dcisw", machInst);
diff --git a/src/arch/arm/isa/insts/neon.isa b/src/arch/arm/isa/insts/neon.isa
index a2948b90a..5aca525a4 100644
--- a/src/arch/arm/isa/insts/neon.isa
+++ b/src/arch/arm/isa/insts/neon.isa
@@ -871,14 +871,21 @@ let {{
         if readDest:
             readDestCode = 'destElem = gtoh(destReg.elements[i]);'
         eWalkCode += '''
-        assert(imm >= 0 && imm < eCount);
-        for (unsigned i = 0; i < eCount; i++) {
-            Element srcElem1 = gtoh(srcReg1.elements[i]);
-            Element srcElem2 = gtoh(srcReg2.elements[imm]);
-            Element destElem;
-            %(readDest)s
-            %(op)s
-            destReg.elements[i] = htog(destElem);
+        if (imm < 0 && imm >= eCount) {
+#if FULL_SYSTEM
+            fault = new UndefinedInstruction;
+#else
+            fault = new UndefinedInstruction(false, mnemonic);
+#endif
+        } else {
+            for (unsigned i = 0; i < eCount; i++) {
+                Element srcElem1 = gtoh(srcReg1.elements[i]);
+                Element srcElem2 = gtoh(srcReg2.elements[imm]);
+                Element destElem;
+                %(readDest)s
+                %(op)s
+                destReg.elements[i] = htog(destElem);
+            }
         }
         ''' % { "op" : op, "readDest" : readDestCode }
         for reg in range(rCount):
@@ -919,14 +926,21 @@ let {{
         if readDest:
             readDestCode = 'destElem = gtoh(destReg.elements[i]);'
         eWalkCode += '''
-        assert(imm >= 0 && imm < eCount);
-        for (unsigned i = 0; i < eCount; i++) {
-            Element srcElem1 = gtoh(srcReg1.elements[i]);
-            Element srcElem2 = gtoh(srcReg2.elements[imm]);
-            BigElement destElem;
-            %(readDest)s
-            %(op)s
-            destReg.elements[i] = htog(destElem);
+        if (imm < 0 && imm >= eCount) {
+#if FULL_SYSTEM
+            fault = new UndefinedInstruction;
+#else
+            fault = new UndefinedInstruction(false, mnemonic);
+#endif
+        } else {
+            for (unsigned i = 0; i < eCount; i++) {
+                Element srcElem1 = gtoh(srcReg1.elements[i]);
+                Element srcElem2 = gtoh(srcReg2.elements[imm]);
+                BigElement destElem;
+                %(readDest)s
+                %(op)s
+                destReg.elements[i] = htog(destElem);
+            }
         }
         ''' % { "op" : op, "readDest" : readDestCode }
         for reg in range(2 * rCount):
@@ -965,14 +979,21 @@ let {{
         if readDest:
             readDestCode = 'destReg = destRegs[i];'
         eWalkCode += '''
-        assert(imm >= 0 && imm < rCount);
-        for (unsigned i = 0; i < rCount; i++) {
-            FloatReg srcReg1 = srcRegs1[i];
-            FloatReg srcReg2 = srcRegs2[imm];
-            FloatReg destReg;
-            %(readDest)s
-            %(op)s
-            destRegs[i] = destReg;
+        if (imm < 0 && imm >= eCount) {
+#if FULL_SYSTEM
+            fault = new UndefinedInstruction;
+#else
+            fault = new UndefinedInstruction(false, mnemonic);
+#endif
+        } else {
+            for (unsigned i = 0; i < rCount; i++) {
+                FloatReg srcReg1 = srcRegs1[i];
+                FloatReg srcReg2 = srcRegs2[imm];
+                FloatReg destReg;
+                %(readDest)s
+                %(op)s
+                destRegs[i] = destReg;
+            }
         }
         ''' % { "op" : op, "readDest" : readDestCode }
         for reg in range(rCount):
@@ -3277,8 +3298,14 @@ let {{
                 destReg.elements[i] = srcReg1.elements[index];
             } else {
                 index -= eCount;
-                assert(index < eCount);
-                destReg.elements[i] = srcReg2.elements[index];
+                if (index >= eCount)
+#if FULL_SYSTEM
+                    fault = new UndefinedInstruction;
+#else
+                    fault = new UndefinedInstruction(false, mnemonic);
+#endif
+                else
+                    destReg.elements[i] = srcReg2.elements[index];
             }
         }
     '''