ARM: Move util functions out of the isa desc.

2 files changed, 271 insertions, 16 deletions

diff --git a/src/arch/arm/insts/static_inst.cc b/src/arch/arm/insts/static_inst.cc
index ae53199fa..64bc9751f 100644
--- a/src/arch/arm/insts/static_inst.cc
+++ b/src/arch/arm/insts/static_inst.cc
@@ -31,7 +31,228 @@
 
 namespace ArmISA
 {
-void ArmStaticInst::printReg(std::ostream &os, int reg) const
+static int32_t arm_NEG(int32_t val) { return (val >> 31); }
+static int32_t arm_POS(int32_t val) { return ((~val) >> 31); }
+
+// Shift Rm by an immediate value
+int32_t
+ArmStaticInst::shift_rm_imm(uint32_t base, uint32_t shamt,
+                            uint32_t type, uint32_t cfval) const
+{
+    enum ArmShiftType shiftType;
+    shiftType = (enum ArmShiftType) type;
+
+    switch (shiftType)
+    {
+        case LSL:
+            return (base << shamt);
+        case LSR:
+            if (shamt == 0)
+                return (0);
+            else
+                return (base >> shamt);
+        case ASR:
+            if (shamt == 0)
+                return ((uint32_t) ((int32_t) base >> 31L));
+            else
+                return ((uint32_t) (((int32_t) base) >> shamt));
+        case ROR:
+            //shamt = shamt & 0x1f;
+            if (shamt == 0)
+                return (cfval << 31) | (base >> 1); // RRX
+            else
+                return (base << (32 - shamt)) | (base >> shamt);
+        default:
+            fprintf(stderr, "Unhandled shift type\n");
+            exit(1);
+            break;
+    }
+    return 0;
+}
+
+// Shift Rm by Rs
+int32_t
+ArmStaticInst::shift_rm_rs(uint32_t base, uint32_t shamt,
+                           uint32_t type, uint32_t cfval) const
+{
+    enum ArmShiftType shiftType;
+    shiftType = (enum ArmShiftType) type;
+
+    switch (shiftType)
+    {
+        case LSL:
+            if (shamt == 0)
+                return (base);
+            else if (shamt >= 32)
+                return (0);
+            else
+                return (base << shamt);
+        case LSR:
+            if (shamt == 0)
+                return (base);
+            else if (shamt >= 32)
+                return (0);
+            else
+                return (base >> shamt);
+        case ASR:
+            if (shamt == 0)
+                return base;
+            else if (shamt >= 32)
+                return ((uint32_t) ((int32_t) base >> 31L));
+            else
+                return ((uint32_t) (((int32_t) base) >> (int) shamt));
+        case ROR:
+            shamt = shamt & 0x1f;
+            if (shamt == 0)
+                return (base);
+            else
+                return ((base << (32 - shamt)) | (base >> shamt));
+        default:
+            fprintf(stderr, "Unhandled shift type\n");
+            exit(1);
+            break;
+    }
+    return 0;
+}
+
+
+// Generate C for a shift by immediate
+int32_t
+ArmStaticInst::shift_carry_imm(uint32_t base, uint32_t shamt,
+                               uint32_t type, uint32_t cfval) const
+{
+    enum ArmShiftType shiftType;
+    shiftType = (enum ArmShiftType) type;
+
+    switch (shiftType)
+    {
+        case LSL:
+            return (base >> (32 - shamt)) & 1;
+        case LSR:
+            if (shamt == 0)
+                return (base >> 31) & 1;
+            else
+                return (base >> (shamt - 1)) & 1;
+        case ASR:
+            if (shamt == 0)
+                return (base >> 31L);
+            else
+                return ((uint32_t) (((int32_t) base) >> (shamt - 1))) & 1;
+        case ROR:
+            shamt = shamt & 0x1f;
+            if (shamt == 0)
+                return (base & 1); // RRX
+            else
+                return (base >> (shamt - 1)) & 1;
+        default:
+            fprintf(stderr, "Unhandled shift type\n");
+            exit(1);
+            break;
+
+    }
+    return 0;
+}
+
+
+// Generate C for a shift by Rs
+int32_t
+ArmStaticInst::shift_carry_rs(uint32_t base, uint32_t shamt,
+                              uint32_t type, uint32_t cfval) const
+{
+    enum ArmShiftType shiftType;
+    shiftType = (enum ArmShiftType) type;
+
+    switch (shiftType)
+    {
+        case LSL:
+            if (shamt == 0)
+                return (!!cfval);
+            else if (shamt == 32)
+                return (base & 1);
+            else if (shamt > 32)
+                return (0);
+            else
+                return ((base >> (32 - shamt)) & 1);
+        case LSR:
+            if (shamt == 0)
+                return (!!cfval);
+            else if (shamt == 32)
+                return (base >> 31);
+            else if (shamt > 32)
+                return (0);
+            else
+                return ((base >> (shamt - 1)) & 1);
+        case ASR:
+            if (shamt == 0)
+                return (!!cfval);
+            else if (shamt >= 32)
+                return (base >> 31L);
+            else
+                return (((uint32_t) (((int32_t) base) >> (shamt - 1))) & 1);
+        case ROR:
+            if (shamt == 0)
+                return (!!cfval);
+            shamt = shamt & 0x1f;
+            if (shamt == 0)
+                return (base >> 31); // RRX
+            else
+                return ((base >> (shamt - 1)) & 1);
+        default:
+            fprintf(stderr, "Unhandled shift type\n");
+            exit(1);
+            break;
+
+    }
+    return 0;
+}
+
+
+// Generate the appropriate carry bit for an addition operation
+int32_t
+ArmStaticInst::arm_add_carry(int32_t result, int32_t lhs, int32_t rhs) const
+{
+    if ((lhs | rhs) >> 30)
+        return ((arm_NEG(lhs) && arm_NEG(rhs)) ||
+                (arm_NEG(lhs) && arm_POS(result)) ||
+                (arm_NEG(rhs) && arm_POS(result)));
+
+    return 0;
+}
+
+// Generate the appropriate carry bit for a subtraction operation
+int32_t
+ArmStaticInst::arm_sub_carry(int32_t result, int32_t lhs, int32_t rhs) const
+{
+    if ((lhs >= rhs) || ((rhs | lhs) >> 31))
+        return ((arm_NEG(lhs) && arm_POS(rhs)) ||
+                (arm_NEG(lhs) && arm_POS(result)) ||
+                (arm_POS(rhs) && arm_POS(result)));
+
+    return 0;
+}
+
+int32_t
+ArmStaticInst::arm_add_overflow(int32_t result, int32_t lhs, int32_t rhs) const
+{
+    if ((lhs | rhs) >> 30)
+        return ((arm_NEG(lhs) && arm_NEG(rhs) && arm_POS(result)) ||
+                (arm_POS(lhs) && arm_POS(rhs) && arm_NEG(result)));
+
+    return 0;
+}
+
+int32_t
+ArmStaticInst::arm_sub_overflow(int32_t result, int32_t lhs, int32_t rhs) const
+{
+    if ((lhs >= rhs) || ((rhs | lhs) >> 31))
+        return ((arm_NEG(lhs) && arm_POS(rhs) && arm_POS(result)) ||
+                (arm_POS(lhs) && arm_NEG(rhs) && arm_NEG(result)));
+
+    return 0;
+}
+
+void
+ArmStaticInst::printReg(std::ostream &os, int reg) const
 {
     if (reg < FP_Base_DepTag) {
         ccprintf(os, "r%d", reg);
@@ -41,8 +262,9 @@ void ArmStaticInst::printReg(std::ostream &os, int reg) const
     }
 }
 
-std::string ArmStaticInst::generateDisassembly(Addr pc,
-        const SymbolTable *symtab) const
+std::string
+ArmStaticInst::generateDisassembly(Addr pc,
+                                   const SymbolTable *symtab) const
 {
     std::stringstream ss;
 
diff --git a/src/arch/arm/insts/static_inst.hh b/src/arch/arm/insts/static_inst.hh
index 5c88657b8..9ee166ecb 100644
--- a/src/arch/arm/insts/static_inst.hh
+++ b/src/arch/arm/insts/static_inst.hh
@@ -34,22 +34,55 @@
 
 namespace ArmISA
 {
-    class ArmStaticInst : public StaticInst
-    {
-      protected:
+class ArmStaticInst : public StaticInst
+{
+  protected:
+    // Shift Rm by an immediate value
+    int32_t
+    shift_rm_imm(uint32_t base, uint32_t shamt,
+                 uint32_t type, uint32_t cfval) const;
+
+    // Shift Rm by Rs
+    int32_t
+    shift_rm_rs(uint32_t base, uint32_t shamt,
+                uint32_t type, uint32_t cfval) const;
+
+    // Generate C for a shift by immediate
+    int32_t
+    shift_carry_imm(uint32_t base, uint32_t shamt,
+                    uint32_t type, uint32_t cfval) const;
+
+    // Generate C for a shift by Rs
+    int32_t
+    shift_carry_rs(uint32_t base, uint32_t shamt,
+                   uint32_t type, uint32_t cfval) const;
 
-        // Constructor
-        ArmStaticInst(const char *mnem, MachInst _machInst, OpClass __opClass)
-            : StaticInst(mnem, _machInst, __opClass)
-        {
-        }
+    // Generate the appropriate carry bit for an addition operation
+    int32_t
+    arm_add_carry(int32_t result, int32_t lhs, int32_t rhs) const;
+
+    // Generate the appropriate carry bit for a subtraction operation
+    int32_t
+    arm_sub_carry(int32_t result, int32_t lhs, int32_t rhs) const;
+
+    int32_t
+    arm_add_overflow(int32_t result, int32_t lhs, int32_t rhs) const;
+
+    int32_t
+    arm_sub_overflow(int32_t result, int32_t lhs, int32_t rhs) const;
+
+    // Constructor
+    ArmStaticInst(const char *mnem, MachInst _machInst, OpClass __opClass)
+        : StaticInst(mnem, _machInst, __opClass)
+    {
+    }
 
-        /// Print a register name for disassembly given the unique
-        /// dependence tag number (FP or int).
-        void printReg(std::ostream &os, int reg) const;
+    /// Print a register name for disassembly given the unique
+    /// dependence tag number (FP or int).
+    void printReg(std::ostream &os, int reg) const;
 
-        std::string generateDisassembly(Addr pc, const SymbolTable *symtab) const;
-    };
+    std::string generateDisassembly(Addr pc, const SymbolTable *symtab) const;
+};
 }
 
 #endif //__ARCH_ARM_INSTS_STATICINST_HH__