diff options
Diffstat (limited to 'src/arch/arm/insts/static_inst.cc')
-rw-r--r-- | src/arch/arm/insts/static_inst.cc | 228 |
1 files changed, 225 insertions, 3 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; |