ARM: Split the condition codes out of the CPSR.

This allows those bits to be renamed while allowing the other fields to
control the behavior of the processor.

8 files changed, 39 insertions, 28 deletions

diff --git a/src/arch/arm/intregs.hh b/src/arch/arm/intregs.hh
index 78ad39ee2..b5f955c4b 100644
--- a/src/arch/arm/intregs.hh
+++ b/src/arch/arm/intregs.hh
@@ -104,6 +104,7 @@ enum IntRegIndex
     INTREG_UREG0,
     INTREG_RHI,
     INTREG_RLO,
+    INTREG_CONDCODES,
 
     NUM_INTREGS,
     NUM_ARCH_INTREGS = INTREG_PC + 1,
diff --git a/src/arch/arm/isa/decoder.isa b/src/arch/arm/isa/decoder.isa
index a999b52e9..ebadeb985 100644
--- a/src/arch/arm/isa/decoder.isa
+++ b/src/arch/arm/isa/decoder.isa
@@ -91,9 +91,9 @@ format DataOp {
                 0x2: sub({{ Rd = resTemp = Rn - op2; }}, sub);
                 0x3: rsb({{ Rd = resTemp = op2 - Rn; }}, rsb);
                 0x4: add({{ Rd = resTemp = Rn + op2; }}, add);
-                0x5: adc({{ Rd = resTemp = Rn + op2 + Cpsr<29:>; }}, add);
-                0x6: sbc({{ Rd = resTemp = Rn - op2 - !Cpsr<29:>; }}, sub);
-                0x7: rsc({{ Rd = resTemp = op2 - Rn - !Cpsr<29:>; }}, rsb);
+                0x5: adc({{ Rd = resTemp = Rn + op2 + CondCodes<29:>; }}, add);
+                0x6: sbc({{ Rd = resTemp = Rn - op2 - !CondCodes<29:>; }}, sub);
+                0x7: rsc({{ Rd = resTemp = op2 - Rn - !CondCodes<29:>; }}, rsb);
                 0x8: tst({{ resTemp = Rn & op2; }});
                 0x9: teq({{ resTemp = Rn ^ op2; }});
                 0xa: cmp({{ resTemp = Rn - op2; }}, sub);
@@ -163,9 +163,15 @@ format DataOp {
                 0x2: subi({{ Rd = resTemp = Rn - rotated_imm; }}, sub);
                 0x3: rsbi({{ Rd = resTemp = rotated_imm - Rn; }}, rsb);
                 0x4: addi({{ Rd = resTemp = Rn + rotated_imm; }}, add);
-                0x5: adci({{ Rd = resTemp = Rn + rotated_imm + Cpsr<29:>; }}, add);
-                0x6: sbci({{ Rd = resTemp = Rn -rotated_imm - !Cpsr<29:>; }}, sub);
-                0x7: rsci({{ Rd = resTemp = rotated_imm - Rn - !Cpsr<29:>;}}, rsb);
+                0x5: adci({{
+                    Rd = resTemp = Rn + rotated_imm + CondCodes<29:>;
+                }}, add);
+                0x6: sbci({{
+                    Rd = resTemp = Rn -rotated_imm - !CondCodes<29:>;
+                }}, sub);
+                0x7: rsci({{
+                    Rd = resTemp = rotated_imm - Rn - !CondCodes<29:>;
+                }}, rsb);
                 0x8: tsti({{ resTemp = Rn & rotated_imm; }});
                 0x9: teqi({{ resTemp = Rn ^ rotated_imm; }});
                 0xa: cmpi({{ resTemp = Rn - rotated_imm; }}, sub);
@@ -437,7 +443,7 @@ format DataOp {
         }
         format PredOp {
             // ARM System Call (SoftWare Interrupt)
-            1: swi({{ if (testPredicate(Cpsr, condCode))
+            1: swi({{ if (testPredicate(CondCodes, condCode))
                       {
                           if (IMMED_23_0)
                               xc->syscall(IMMED_23_0);
diff --git a/src/arch/arm/isa/formats/branch.isa b/src/arch/arm/isa/formats/branch.isa
index 95f4f14e1..5f1b541ff 100644
--- a/src/arch/arm/isa/formats/branch.isa
+++ b/src/arch/arm/isa/formats/branch.isa
@@ -52,7 +52,7 @@ def format Branch(code,*opt_flags) {{
     else:
          inst_flags += ('IsCondControl', )
 
-    icode =  'if (testPredicate(Cpsr, condCode)) {\n'
+    icode =  'if (testPredicate(CondCodes, condCode)) {\n'
     icode += code
     icode += '  NPC = NPC + 4 + disp;\n'
     icode += '} else {\n'
@@ -90,7 +90,7 @@ def format BranchExchange(code,*opt_flags) {{
 
     #Condition code
 
-    icode =  'if (testPredicate(Cpsr, condCode)) {\n'
+    icode =  'if (testPredicate(CondCodes, condCode)) {\n'
     icode += code
     icode += '  NPC = Rm & 0xfffffffe; // Masks off bottom bit\n'
     icode += '} else {\n'
diff --git a/src/arch/arm/isa/formats/fp.isa b/src/arch/arm/isa/formats/fp.isa
index e88531580..e79529615 100644
--- a/src/arch/arm/isa/formats/fp.isa
+++ b/src/arch/arm/isa/formats/fp.isa
@@ -119,8 +119,8 @@ let {{
         _ic = %(fReg1)s >= %(fReg2)s;
         _iv = (isnan(%(fReg1)s) || isnan(%(fReg2)s)) & 1;
 
-        Cpsr = _in << 31 | _iz << 30 | _ic << 29 | _iv << 28 |
-            (Cpsr & 0x0FFFFFFF);
+        CondCodes = _in << 31 | _iz << 30 | _ic << 29 | _iv << 28 |
+            (CondCodes & 0x0FFFFFFF);
         '''
 }};
 
diff --git a/src/arch/arm/isa/formats/pred.isa b/src/arch/arm/isa/formats/pred.isa
index e90788c91..3c97560fd 100644
--- a/src/arch/arm/isa/formats/pred.isa
+++ b/src/arch/arm/isa/formats/pred.isa
@@ -34,7 +34,7 @@
 //
 
 let {{
-    predicateTest = 'testPredicate(Cpsr, condCode)'
+    predicateTest = 'testPredicate(CondCodes, condCode)'
 }};
 
 def template PredOpExecute {{
@@ -90,8 +90,8 @@ let {{
         _iv = %(ivValue)s & 1;
         _ic = %(icValue)s & 1;
 
-        Cpsr =  _in << 31 | _iz << 30 | _ic << 29 | _iv << 28 |
-            (Cpsr & 0x0FFFFFFF);
+        CondCodes =  _in << 31 | _iz << 30 | _ic << 29 | _iv << 28 |
+            (CondCodes & 0x0FFFFFFF);
 
         DPRINTF(Arm, "in = %%d\\n", _in);
         DPRINTF(Arm, "iz = %%d\\n", _iz);
@@ -105,8 +105,8 @@ let {{
     def getCcCode(flagtype):
         icReg = icImm = iv = ''
         if flagtype == "none":
-            icReg = icImm = 'Cpsr<29:>'
-            iv = 'Cpsr<28:>'
+            icReg = icImm = 'CondCodes<29:>'
+            iv = 'CondCodes<28:>'
         elif flagtype == "add":
             icReg = icImm = 'findCarry(32, resTemp, Rn, op2)'
             iv = 'findOverflow(32, resTemp, Rn, op2)'
@@ -117,17 +117,17 @@ let {{
             icReg = icImm = 'findCarry(32, resTemp, op2, ~Rn)'
             iv = 'findOverflow(32, resTemp, op2, ~Rn)'
         else:
-            icReg = 'shift_carry_rs(Rm, Rs, shift, Cpsr<29:>)'
-            icImm = 'shift_carry_imm(Rm, shift_size, shift, Cpsr<29:>)'
-            iv = 'Cpsr<28:>'
+            icReg = 'shift_carry_rs(Rm, Rs, shift, CondCodes<29:>)'
+            icImm = 'shift_carry_imm(Rm, shift_size, shift, CondCodes<29:>)'
+            iv = 'CondCodes<28:>'
         return (calcCcCode % {"icValue" : icReg, "ivValue" : iv},
                 calcCcCode % {"icValue" : icImm, "ivValue" : iv})
 
     def getImmCcCode(flagtype):
         ivValue = icValue = ''
         if flagtype == "none":
-            icValue = 'Cpsr<29:>'
-            ivValue = 'Cpsr<28:>'
+            icValue = 'CondCodes<29:>'
+            ivValue = 'CondCodes<28:>'
         elif flagtype == "add":
             icValue = 'findCarry(32, resTemp, Rn, rotated_imm)'
             ivValue = 'findOverflow(32, resTemp, Rn, rotated_imm)'
@@ -138,18 +138,18 @@ let {{
             icValue = 'findCarry(32, resTemp, rotated_imm, ~Rn)'
             ivValue = 'findOverflow(32, resTemp, rotated_imm, ~Rn)'
         else:
-            icValue = '(rotate ? rotated_carry:Cpsr<29:>)'
-            ivValue = 'Cpsr<28:>'
+            icValue = '(rotate ? rotated_carry:CondCodes<29:>)'
+            ivValue = 'CondCodes<28:>'
         return calcCcCode % vars()
 }};
 
 def format DataOp(code, flagtype = logic) {{
     (regCcCode, immCcCode) = getCcCode(flagtype)
     regCode = '''uint32_t op2 = shift_rm_rs(Rm, Rs,
-                                            shift, Cpsr<29:0>);
+                                            shift, CondCodes<29:0>);
                  op2 = op2;''' + code
     immCode = '''uint32_t op2 = shift_rm_imm(Rm, shift_size,
-                                             shift, Cpsr<29:0>);
+                                             shift, CondCodes<29:0>);
                  op2 = op2;''' + code
     regIop = InstObjParams(name, Name, 'PredIntOp',
                            {"code": regCode,
diff --git a/src/arch/arm/isa/formats/util.isa b/src/arch/arm/isa/formats/util.isa
index b5efec568..d42ffb147 100644
--- a/src/arch/arm/isa/formats/util.isa
+++ b/src/arch/arm/isa/formats/util.isa
@@ -33,8 +33,10 @@ let {{
 # Generic substitutions for Arm instructions
 def ArmGenericCodeSubs(code):
     # Substitute in the shifted portion of operations
-    new_code = re.sub(r'Rm_Imm', 'shift_rm_imm(Rm, shift_size, shift, Cpsr<29:>)', code)
-    new_code = re.sub(r'Rm_Rs', 'shift_rm_rs(Rm, Rs, shift, Cpsr<29:>)', new_code)
+    new_code = re.sub(r'Rm_Imm',
+            'shift_rm_imm(Rm, shift_size, shift, CondCodes<29:>)', code)
+    new_code = re.sub(r'Rm_Rs',
+            'shift_rm_rs(Rm, Rs, shift, CondCodes<29:>)', new_code)
     return new_code
 
 def LoadStoreBase(name, Name, ea_code, memacc_code, mem_flags, inst_flags,
diff --git a/src/arch/arm/isa/operands.isa b/src/arch/arm/isa/operands.isa
index 4ac6790e5..02acc8ed7 100644
--- a/src/arch/arm/isa/operands.isa
+++ b/src/arch/arm/isa/operands.isa
@@ -66,6 +66,7 @@ def operands {{
     'Rhi': ('IntReg', 'uw', 'INTREG_RHI', 'IsInteger', 7),
     'Rlo': ('IntReg', 'uw', 'INTREG_RLO', 'IsInteger', 8),
     'LR': ('IntReg', 'uw', 'INTREG_LR', 'IsInteger', 9),
+    'CondCodes': ('IntReg', 'uw', 'INTREG_CONDCODES', 'IsInteger', 10),
 
     #Register fields for microops
     'Ra' : ('IntReg', 'uw', 'ura', 'IsInteger', 11, maybePCRead, maybePCWrite),
diff --git a/src/arch/arm/nativetrace.cc b/src/arch/arm/nativetrace.cc
index 1ad9e1a19..01f3205eb 100644
--- a/src/arch/arm/nativetrace.cc
+++ b/src/arch/arm/nativetrace.cc
@@ -97,7 +97,8 @@ Trace::ArmNativeTrace::ThreadState::update(ThreadContext *tc)
     changed[STATE_PC] = (newState[STATE_PC] != oldState[STATE_PC]);
 
     //CPSR
-    newState[STATE_CPSR] = tc->readMiscReg(MISCREG_CPSR);
+    newState[STATE_CPSR] = tc->readMiscReg(MISCREG_CPSR) |
+                           tc->readIntReg(INTREG_CONDCODES);
     changed[STATE_CPSR] = (newState[STATE_CPSR] != oldState[STATE_CPSR]);
 }