misc: Appease gcc 5.1

Three minor issues are resolved:

1. Apparently gcc 5.1 does not like negation of booleans followed by
   bitwise AND.

2. Somehow the compiler also gets confused and warns about
   NoopMachInst being unused (removing it causes compilation errors
   though). Most likely a compiler bug.

3. There seems to be a number of instances where loop unrolling causes
   false positives for the array-bounds check. For now, switch to
   std::array. Potentially we could disable the warning for newer gcc
   versions, but switching to std::array is probably a good move in
   any case.

src/arch/x86/insts/microop.cc

@@ -55,7 +55,7 @@ namespace X86ISA
           case ConditionTests::EZF:
             return ccflags.ezf;
           case ConditionTests::SZnZF:
-            return !(!ccflags.ezf & ccflags.zf);
+            return !(!ccflags.ezf && ccflags.zf);
           case ConditionTests::MSTRZ:
             panic("This condition is not implemented!");
           case ConditionTests::STRZ:
@@ -63,7 +63,7 @@ namespace X86ISA
           case ConditionTests::MSTRC:
             panic("This condition is not implemented!");
           case ConditionTests::STRZnEZF:
-            return !ccflags.ezf & ccflags.zf;
+            return !ccflags.ezf && ccflags.zf;
                 //And no interrupts or debug traps are waiting
           case ConditionTests::OF:
             return ccflags.of;
@@ -88,7 +88,7 @@ namespace X86ISA
           case ConditionTests::NotEZF:
             return !ccflags.ezf;
           case ConditionTests::NotSZnZF:
-            return !ccflags.ezf & ccflags.zf;
+            return !ccflags.ezf && ccflags.zf;
           case ConditionTests::NotMSTRZ:
             panic("This condition is not implemented!");
           case ConditionTests::NotSTRZ:
@@ -96,7 +96,7 @@ namespace X86ISA
           case ConditionTests::NotMSTRC:
             panic("This condition is not implemented!");
           case ConditionTests::STRnZnEZF:
-            return !ccflags.ezf & !ccflags.zf;
+            return !ccflags.ezf && !ccflags.zf;
                 //And no interrupts or debug traps are waiting
           case ConditionTests::NotOF:
             return !ccflags.of;

src/arch/x86/isa_traits.hh

@@ -68,7 +68,7 @@ namespace X86ISA
     const bool CurThreadInfoImplemented = false;
     const int CurThreadInfoReg = -1;
 
-    const ExtMachInst NoopMachInst = {
+    const ExtMachInst NoopMachInst M5_VAR_USED = {
         0x0,                            // No legacy prefixes.
         0x0,                            // No rex prefix.
         { OneByteOpcode, 0x90 },          // One opcode byte, 0x90.

src/cpu/base_dyn_inst.hh

@@ -46,6 +46,7 @@
 #ifndef __CPU_BASE_DYN_INST_HH__
 #define __CPU_BASE_DYN_INST_HH__
 
+#include <array>
 #include <bitset>
 #include <list>
 #include <string>
@@ -258,22 +259,22 @@ class BaseDynInst : public ExecContext, public RefCounted
     /** Flattened register index of the destination registers of this
      *  instruction.
      */
-    TheISA::RegIndex _flatDestRegIdx[TheISA::MaxInstDestRegs];
+    std::array<TheISA::RegIndex, TheISA::MaxInstDestRegs> _flatDestRegIdx;
 
     /** Physical register index of the destination registers of this
      *  instruction.
      */
-    PhysRegIndex _destRegIdx[TheISA::MaxInstDestRegs];
+    std::array<PhysRegIndex, TheISA::MaxInstDestRegs> _destRegIdx;
 
     /** Physical register index of the source registers of this
      *  instruction.
      */
-    PhysRegIndex _srcRegIdx[TheISA::MaxInstSrcRegs];
+    std::array<PhysRegIndex, TheISA::MaxInstSrcRegs> _srcRegIdx;
 
     /** Physical register index of the previous producers of the
      *  architected destinations.
      */
-    PhysRegIndex _prevDestRegIdx[TheISA::MaxInstDestRegs];
+    std::array<PhysRegIndex, TheISA::MaxInstDestRegs> _prevDestRegIdx;
 
 
   public:

src/cpu/o3/dyn_inst.hh

@@ -44,6 +44,8 @@
 #ifndef __CPU_O3_DYN_INST_HH__
 #define __CPU_O3_DYN_INST_HH__
 
+#include <array>
+
 #include "arch/isa_traits.hh"
 #include "config/the_isa.hh"
 #include "cpu/o3/cpu.hh"
@@ -108,13 +110,13 @@ class BaseO3DynInst : public BaseDynInst<Impl>
 
   protected:
     /** Values to be written to the destination misc. registers. */
-    MiscReg _destMiscRegVal[TheISA::MaxMiscDestRegs];
+    std::array<MiscReg, TheISA::MaxMiscDestRegs> _destMiscRegVal;
 
     /** Indexes of the destination misc. registers. They are needed to defer
      * the write accesses to the misc. registers until the commit stage, when
      * the instruction is out of its speculative state.
      */
-    short _destMiscRegIdx[TheISA::MaxMiscDestRegs];
+    std::array<short, TheISA::MaxMiscDestRegs> _destMiscRegIdx;
 
     /** Number of destination misc. registers. */
     uint8_t _numDestMiscRegs;