ARM: Decode to specialized conditional/unconditional versions of instructions.

This is to avoid condition code based dependences from effectively serializing
instructions when the instruction doesn't actually use them.

9 files changed, 38 insertions, 30 deletions

diff --git a/src/arch/arm/insts/pred_inst.hh b/src/arch/arm/insts/pred_inst.hh
index b5095dcef..2cb383ad3 100644
--- a/src/arch/arm/insts/pred_inst.hh
+++ b/src/arch/arm/insts/pred_inst.hh
@@ -176,7 +176,9 @@ class PredOp : public ArmStaticInst
     /// Constructor
     PredOp(const char *mnem, ExtMachInst _machInst, OpClass __opClass) :
            ArmStaticInst(mnem, _machInst, __opClass),
-           condCode((ConditionCode)(unsigned)machInst.condCode)
+           condCode(machInst.itstateMask ?
+                   (ConditionCode)(uint8_t)machInst.itstateCond :
+                   (ConditionCode)(unsigned)machInst.condCode)
     {
     }
 };
diff --git a/src/arch/arm/isa/formats/pred.isa b/src/arch/arm/isa/formats/pred.isa
index 897edc2dc..18df8491c 100644
--- a/src/arch/arm/isa/formats/pred.isa
+++ b/src/arch/arm/isa/formats/pred.isa
@@ -150,10 +150,10 @@ def format DataOp(code, flagtype = logic) {{
                             "predicate_test": predicateTest})
     regCcIop = InstObjParams(name, Name + "Cc", 'PredIntOp',
                              {"code": regCode + regCcCode,
-                              "predicate_test": predicateTest})
+                              "predicate_test": condPredicateTest})
     immCcIop = InstObjParams(name, Name + "ImmCc", 'PredIntOp',
                              {"code": immCode + immCcCode,
-                              "predicate_test": predicateTest})
+                              "predicate_test": condPredicateTest})
     header_output = BasicDeclare.subst(regIop) + \
                     BasicDeclare.subst(immIop) + \
                     BasicDeclare.subst(regCcIop) + \
@@ -176,7 +176,7 @@ def format DataImmOp(code, flagtype = logic) {{
                          "predicate_test": predicateTest})
     ccIop = InstObjParams(name, Name + "Cc", 'PredImmOp',
                           {"code": code + getImmCcCode(flagtype),
-                           "predicate_test": predicateTest})
+                           "predicate_test": condPredicateTest})
     header_output = BasicDeclare.subst(iop) + \
                     BasicDeclare.subst(ccIop)
     decoder_output = BasicConstructor.subst(iop) + \
diff --git a/src/arch/arm/isa/insts/data.isa b/src/arch/arm/isa/insts/data.isa
index 09019d0f4..5cb9e545b 100644
--- a/src/arch/arm/isa/insts/data.isa
+++ b/src/arch/arm/isa/insts/data.isa
@@ -129,7 +129,7 @@ let {{
         immIopCc = InstObjParams(mnem + "s", mnem.capitalize() + suffix + "Cc",
                                  "DataImmOp",
                                  {"code" : immCode + immCcCode,
-                                  "predicate_test": predicateTest})
+                                  "predicate_test": condPredicateTest})
 
         def subst(iop):
             global header_output, decoder_output, exec_output
@@ -166,7 +166,7 @@ let {{
         regIopCc = InstObjParams(mnem + "s", mnem.capitalize() + suffix + "Cc",
                                  "DataRegOp",
                                  {"code" : regCode + regCcCode,
-                                  "predicate_test": predicateTest})
+                                  "predicate_test": condPredicateTest})
 
         def subst(iop):
             global header_output, decoder_output, exec_output
@@ -206,7 +206,7 @@ let {{
                                     mnem.capitalize() + suffix + "Cc",
                                     "DataRegRegOp",
                                     {"code" : regRegCode + regRegCcCode,
-                                     "predicate_test": predicateTest})
+                                     "predicate_test": condPredicateTest})
 
         def subst(iop):
             global header_output, decoder_output, exec_output
diff --git a/src/arch/arm/isa/insts/macromem.isa b/src/arch/arm/isa/insts/macromem.isa
index 2b42dfac8..ca2c7c6ab 100644
--- a/src/arch/arm/isa/insts/macromem.isa
+++ b/src/arch/arm/isa/insts/macromem.isa
@@ -77,7 +77,7 @@ let {{
                                       {'memacc_code': microLdrRetUopCode,
                                        'ea_code':
                                           'EA = Rb + (up ? imm : -imm);',
-                                       'predicate_test': predicateTest},
+                                       'predicate_test': condPredicateTest},
                                       ['IsMicroop'])
 
     microStrUopCode = "Mem = cSwap(Ra.uw, ((CPSR)Cpsr).e);"
diff --git a/src/arch/arm/isa/insts/mem.isa b/src/arch/arm/isa/insts/mem.isa
index 51805c28e..f5631a3b7 100644
--- a/src/arch/arm/isa/insts/mem.isa
+++ b/src/arch/arm/isa/insts/mem.isa
@@ -97,21 +97,27 @@ let {{
                 + initiateAccTemplate.subst(iop)
                 + completeAccTemplate.subst(iop))
 
+    def pickPredicate(blobs):
+        for val in blobs.values():
+            if re.search('(?<!Opt)CondCodes', val):
+                return condPredicateTest
+        return predicateTest
+
     def loadStoreBase(name, Name, imm, eaCode, accCode, postAccCode,
                       memFlags, instFlags, double, strex, base = 'Memory',
                       execTemplateBase = ''):
         codeBlobs = { "ea_code": eaCode,
                       "memacc_code": accCode,
-                      "postacc_code": postAccCode,
-                      "predicate_test": predicateTest }
+                      "postacc_code": postAccCode }
+        codeBlobs["predicate_test"] = pickPredicate(codeBlobs)
         return loadStoreBaseWork(name, Name, imm, False, False, False,
                                  codeBlobs, memFlags, instFlags, double,
                                  strex, base, execTemplateBase)
 
     def RfeBase(name, Name, eaCode, accCode, memFlags, instFlags):
         codeBlobs = { "ea_code": eaCode,
-                      "memacc_code": accCode,
-                      "predicate_test": predicateTest }
+                      "memacc_code": accCode }
+        codeBlobs["predicate_test"] = pickPredicate(codeBlobs)
         return loadStoreBaseWork(name, Name, False, False, True, False,
                                  codeBlobs, memFlags, instFlags, False, False,
                                  'RfeOp', 'Load')
@@ -119,8 +125,8 @@ let {{
     def SrsBase(name, Name, eaCode, accCode, memFlags, instFlags):
         codeBlobs = { "ea_code": eaCode,
                       "memacc_code": accCode,
-                      "postacc_code": "",
-                      "predicate_test": predicateTest }
+                      "postacc_code": "" }
+        codeBlobs["predicate_test"] = pickPredicate(codeBlobs)
         return loadStoreBaseWork(name, Name, False, False, False, True,
                                  codeBlobs, memFlags, instFlags, False, False,
                                  'SrsOp', 'Store')
@@ -129,8 +135,8 @@ let {{
                  instFlags):
         codeBlobs = { "ea_code": eaCode,
                       "preacc_code": preAccCode,
-                      "postacc_code": postAccCode,
-                      "predicate_test": predicateTest }
+                      "postacc_code": postAccCode }
+        codeBlobs["predicate_test"] = pickPredicate(codeBlobs)
         return loadStoreBaseWork(name, Name, False, True, False, False,
                                  codeBlobs, memFlags, instFlags, False, False,
                                  'Swap', 'Swap')
diff --git a/src/arch/arm/isa/insts/misc.isa b/src/arch/arm/isa/insts/misc.isa
index 6b81853f1..15c319df9 100644
--- a/src/arch/arm/isa/insts/misc.isa
+++ b/src/arch/arm/isa/insts/misc.isa
@@ -63,7 +63,7 @@ let {{
     mrsCpsrCode = "Dest = (Cpsr | CondCodes) & 0xF8FF03DF"
     mrsCpsrIop = InstObjParams("mrs", "MrsCpsr", "MrsOp",
                                { "code": mrsCpsrCode,
-                                 "predicate_test": predicateTest }, [])
+                                 "predicate_test": condPredicateTest }, [])
     header_output += MrsDeclare.subst(mrsCpsrIop)
     decoder_output += MrsConstructor.subst(mrsCpsrIop)
     exec_output += PredOpExecute.subst(mrsCpsrIop)
@@ -85,7 +85,7 @@ let {{
     '''
     msrCpsrRegIop = InstObjParams("msr", "MsrCpsrReg", "MsrRegOp",
                                   { "code": msrCpsrRegCode,
-                                    "predicate_test": predicateTest }, [])
+                                    "predicate_test": condPredicateTest }, [])
     header_output += MsrRegDeclare.subst(msrCpsrRegIop)
     decoder_output += MsrRegConstructor.subst(msrCpsrRegIop)
     exec_output += PredOpExecute.subst(msrCpsrRegIop)
@@ -107,7 +107,7 @@ let {{
     '''
     msrCpsrImmIop = InstObjParams("msr", "MsrCpsrImm", "MsrImmOp",
                                   { "code": msrCpsrImmCode,
-                                    "predicate_test": predicateTest }, [])
+                                    "predicate_test": condPredicateTest }, [])
     header_output += MsrImmDeclare.subst(msrCpsrImmIop)
     decoder_output += MsrImmConstructor.subst(msrCpsrImmIop)
     exec_output += PredOpExecute.subst(msrCpsrImmIop)
@@ -197,7 +197,7 @@ let {{
     '''
     ssatIop = InstObjParams("ssat", "Ssat", "RegImmRegShiftOp",
                             { "code": ssatCode,
-                              "predicate_test": predicateTest }, [])
+                              "predicate_test": condPredicateTest }, [])
     header_output += RegImmRegShiftOpDeclare.subst(ssatIop)
     decoder_output += RegImmRegShiftOpConstructor.subst(ssatIop)
     exec_output += PredOpExecute.subst(ssatIop)
@@ -213,7 +213,7 @@ let {{
     '''
     usatIop = InstObjParams("usat", "Usat", "RegImmRegShiftOp",
                             { "code": usatCode,
-                              "predicate_test": predicateTest }, [])
+                              "predicate_test": condPredicateTest }, [])
     header_output += RegImmRegShiftOpDeclare.subst(usatIop)
     decoder_output += RegImmRegShiftOpConstructor.subst(usatIop)
     exec_output += PredOpExecute.subst(usatIop)
@@ -234,7 +234,7 @@ let {{
     '''
     ssat16Iop = InstObjParams("ssat16", "Ssat16", "RegImmRegOp",
                               { "code": ssat16Code,
-                                "predicate_test": predicateTest }, [])
+                                "predicate_test": condPredicateTest }, [])
     header_output += RegImmRegOpDeclare.subst(ssat16Iop)
     decoder_output += RegImmRegOpConstructor.subst(ssat16Iop)
     exec_output += PredOpExecute.subst(ssat16Iop)
@@ -255,7 +255,7 @@ let {{
     '''
     usat16Iop = InstObjParams("usat16", "Usat16", "RegImmRegOp",
                               { "code": usat16Code,
-                                "predicate_test": predicateTest }, [])
+                                "predicate_test": condPredicateTest }, [])
     header_output += RegImmRegOpDeclare.subst(usat16Iop)
     decoder_output += RegImmRegOpConstructor.subst(usat16Iop)
     exec_output += PredOpExecute.subst(usat16Iop)
@@ -415,7 +415,7 @@ let {{
     '''
     selIop = InstObjParams("sel", "Sel", "RegRegRegOp",
                            { "code": selCode,
-                             "predicate_test": predicateTest }, [])
+                             "predicate_test": condPredicateTest }, [])
     header_output += RegRegRegOpDeclare.subst(selIop)
     decoder_output += RegRegRegOpConstructor.subst(selIop)
     exec_output += PredOpExecute.subst(selIop)
diff --git a/src/arch/arm/isa/insts/mult.isa b/src/arch/arm/isa/insts/mult.isa
index 13c9df07b..ffe59117b 100644
--- a/src/arch/arm/isa/insts/mult.isa
+++ b/src/arch/arm/isa/insts/mult.isa
@@ -92,7 +92,7 @@ let {{
         if doCc:
             iopCc = InstObjParams(mnem + "s", Name + "Cc", base,
                                   {"code" : code + ccCode,
-                                   "predicate_test": predicateTest})
+                                   "predicate_test": condPredicateTest})
 
         if regs == 3:
             declare = Mult3Declare
diff --git a/src/arch/arm/isa/operands.isa b/src/arch/arm/isa/operands.isa
index 0c52703e1..a086bb03c 100644
--- a/src/arch/arm/isa/operands.isa
+++ b/src/arch/arm/isa/operands.isa
@@ -154,6 +154,9 @@ def operands {{
 
     'LR': ('IntReg', 'uw', 'INTREG_LR', 'IsInteger', 2),
     'CondCodes': ('IntReg', 'uw', 'INTREG_CONDCODES', None, 2),
+    'OptCondCodes': ('IntReg', 'uw',
+            '''(condCode == COND_AL || condCode == COND_UC) ?
+               INTREG_ZERO : INTREG_CONDCODES''', None, 2),
 
     #Register fields for microops
     'Ra' : ('IntReg', 'uw', 'ura', 'IsInteger', 2, maybePCRead, maybePCWrite),
diff --git a/src/arch/arm/isa/templates/pred.isa b/src/arch/arm/isa/templates/pred.isa
index c8f30ddf0..7a5b92760 100644
--- a/src/arch/arm/isa/templates/pred.isa
+++ b/src/arch/arm/isa/templates/pred.isa
@@ -46,11 +46,8 @@
 //
 
 let {{
-    predicateTest = '''
-        testPredicate(CondCodes, machInst.itstateMask ?
-            (ConditionCode)(uint8_t)machInst.itstateCond :
-            condCode)
-    '''
+    predicateTest = 'testPredicate(OptCondCodes, condCode)'
+    condPredicateTest = 'testPredicate(CondCodes, condCode)'
 }};
 
 def template DataImmDeclare {{