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A64: Implement RBIT

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Lioncash 2018-01-23 19:13:47 -05:00 committed by MerryMage
parent 9b0a21915f
commit 6f9216d544
2 changed files with 42 additions and 1 deletions
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2
src/frontend/A64/decoder/a64.inc
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@ -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")

41
src/frontend/A64/translate/impl/data_processing_register.cpp
View file

@ -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;