diff --git a/src/frontend/A64/decoder/a64.inc b/src/frontend/A64/decoder/a64.inc index c540209f..2ba49e70 100644 --- a/src/frontend/A64/decoder/a64.inc +++ b/src/frontend/A64/decoder/a64.inc @@ -285,7 +285,7 @@ INST(RORV, "RORV", "z0011 //INST(PACGA, "PACGA", "10011010110mmmmm001100nnnnnddddd") // Data Processing - Register - 1 source -//INST(RBIT_int, "RBIT", "z101101011000000000000nnnnnddddd") +INST(RBIT_int, "RBIT", "z101101011000000000000nnnnnddddd") INST(REV16_int, "REV16", "z101101011000000000001nnnnnddddd") INST(REV, "REV", "z10110101100000000001onnnnnddddd") INST(CLZ_int, "CLZ", "z101101011000000000100nnnnnddddd") diff --git a/src/frontend/A64/translate/impl/data_processing_register.cpp b/src/frontend/A64/translate/impl/data_processing_register.cpp index e3afcb61..b7a20a9c 100644 --- a/src/frontend/A64/translate/impl/data_processing_register.cpp +++ b/src/frontend/A64/translate/impl/data_processing_register.cpp @@ -29,6 +29,47 @@ bool TranslatorVisitor::CLS_int(bool sf, Reg Rn, Reg Rd) { return true; } +bool TranslatorVisitor::RBIT_int(bool sf, Reg Rn, Reg Rd) { + const auto rbit32 = [this](const IR::U32& operand) { + // x = (x & 0x55555555) << 1 | ((x >> 1) & 0x55555555); + const IR::U32 first_lsl = ir.LogicalShiftLeft(ir.And(operand, ir.Imm32(0x55555555)), ir.Imm8(1)); + const IR::U32 first_lsr = ir.And(ir.LogicalShiftRight(operand, ir.Imm8(1)), ir.Imm32(0x55555555)); + const IR::U32 first = ir.Or(first_lsl, first_lsr); + + // x = (x & 0x33333333) << 2 | ((x >> 2) & 0x33333333); + const IR::U32 second_lsl = ir.LogicalShiftLeft(ir.And(first, ir.Imm32(0x33333333)), ir.Imm8(2)); + const IR::U32 second_lsr = ir.And(ir.LogicalShiftRight(first, ir.Imm8(2)), ir.Imm32(0x33333333)); + const IR::U32 second = ir.Or(second_lsl, second_lsr); + + // x = (x & 0x0F0F0F0F) << 4 | ((x >> 4) & 0x0F0F0F0F); + const IR::U32 third_lsl = ir.LogicalShiftLeft(ir.And(second, ir.Imm32(0x0F0F0F0F)), ir.Imm8(4)); + const IR::U32 third_lsr = ir.And(ir.LogicalShiftRight(second, ir.Imm8(4)), ir.Imm32(0x0F0F0F0F)); + const IR::U32 third = ir.Or(third_lsl, third_lsr); + + // x = (x << 24) | ((x & 0xFF00) << 8) | ((x >> 8) & 0xFF00) | (x >> 24); + const IR::U32 fourth_lsl = ir.Or(ir.LogicalShiftLeft(third, ir.Imm8(24)), + ir.LogicalShiftLeft(ir.And(third, ir.Imm32(0xFF00)), ir.Imm8(8))); + const IR::U32 fourth_lsr = ir.Or(ir.And(ir.LogicalShiftRight(third, ir.Imm8(8)), ir.Imm32(0xFF00)), + ir.LogicalShiftRight(third, ir.Imm8(24))); + return ir.Or(fourth_lsl, fourth_lsr); + }; + + const size_t datasize = sf ? 64 : 32; + const IR::U32U64 operand = X(datasize, Rn); + + if (sf) { + const IR::U32 lsw = rbit32(ir.LeastSignificantWord(operand)); + const IR::U32 msw = rbit32(ir.MostSignificantWord(operand).result); + const IR::U64 result = ir.Pack2x32To1x64(msw, lsw); + + X(datasize, Rd, result); + } else { + X(datasize, Rd, rbit32(operand)); + } + + return true; +} + bool TranslatorVisitor::REV(bool sf, bool opc_0, Reg Rn, Reg Rd) { const size_t datasize = sf ? 64 : 32;