cpu: add a condition-code register class

Add a third register class for condition codes,
in parallel with the integer and FP classes.
No ISAs use the CC class at this point though.

4 files changed, 16 insertions, 1 deletions

diff --git a/src/arch/x86/insts/static_inst.cc b/src/arch/x86/insts/static_inst.cc
index 046a11fb6..39091289f 100644
--- a/src/arch/x86/insts/static_inst.cc
+++ b/src/arch/x86/insts/static_inst.cc
@@ -221,6 +221,10 @@ namespace X86ISA
             break;
           }
 
+          case CCRegClass:
+            ccprintf(os, "%%cc%d", rel_reg);
+            break;
+
           case MiscRegClass:
             switch (rel_reg) {
               default:
diff --git a/src/arch/x86/isa.hh b/src/arch/x86/isa.hh
index 3ccc2f0ad..5f36fd7ad 100644
--- a/src/arch/x86/isa.hh
+++ b/src/arch/x86/isa.hh
@@ -85,6 +85,12 @@ namespace X86ISA
             return reg;
         }
 
+        int
+        flattenCCIndex(int reg)
+        {
+            return reg;
+        }
+
         void serialize(std::ostream &os);
         void unserialize(Checkpoint *cp, const std::string &section);
         void startup(ThreadContext *tc);
diff --git a/src/arch/x86/registers.hh b/src/arch/x86/registers.hh
index bb9f5f7b1..d62992dcd 100644
--- a/src/arch/x86/registers.hh
+++ b/src/arch/x86/registers.hh
@@ -57,6 +57,7 @@ const int NumIntArchRegs = NUM_INTREGS;
 const int NumIntRegs =
     NumIntArchRegs + NumMicroIntRegs +
     NumPseudoIntRegs + NumImplicitIntRegs;
+const int NumCCRegs = 0;
 
 // Each 128 bit xmm register is broken into two effective 64 bit registers.
 // Add 8 for the indices that are mapped over the fp stack
@@ -69,7 +70,8 @@ enum DependenceTags {
     // register index which has the IntFoldBit (1 << 6) set.  To be safe
     // we just start at (1 << 7) == 128.
     FP_Reg_Base = 128,
-    Misc_Reg_Base = FP_Reg_Base + NumFloatRegs,
+    CC_Reg_Base = FP_Reg_Base + NumFloatRegs,
+    Misc_Reg_Base = CC_Reg_Base + NumCCRegs, // NumCCRegs == 0
     Max_Reg_Index = Misc_Reg_Base + NumMiscRegs
 };
 
@@ -87,6 +89,7 @@ const int FramePointerReg = INTREG_RBP;
 const int SyscallPseudoReturnReg = INTREG_RDX;
 
 typedef uint64_t IntReg;
+typedef uint64_t CCReg;
 //XXX Should this be a 128 bit structure for XMM memory ops?
 typedef uint64_t LargestRead;
 typedef uint64_t MiscReg;
diff --git a/src/arch/x86/utility.cc b/src/arch/x86/utility.cc
index b50b99dfa..df7d3935d 100644
--- a/src/arch/x86/utility.cc
+++ b/src/arch/x86/utility.cc
@@ -244,6 +244,8 @@ copyRegs(ThreadContext *src, ThreadContext *dest)
     //copy float regs
     for (int i = 0; i < NumFloatRegs; ++i)
          dest->setFloatRegBits(i, src->readFloatRegBits(i));
+    // Will need to add condition-code regs when implemented
+    assert(NumCCRegs == 0);
     copyMiscRegs(src, dest);
     dest->pcState(src->pcState());
 }