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A64: Implement URSHR (scalar) and URSRA (scalar)

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Now that the utility function is all set up from implementing SRSRA, the
unsigned variants can now be trivially implemented by modifying the
utility function to perform a logical shift right instead of an
arithmetical shift right for the unsigned case.
This commit is contained in:
Lioncash 2018-05-11 10:42:31 -04:00 committed by MerryMage
parent 1e70a589b0
commit 7bce8d8757
2 changed files with 31 additions and 6 deletions
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4
src/frontend/A64/decoder/a64.inc
View file

@ -480,8 +480,8 @@ INST(SHL_1, "SHL", "01011
//INST(FCVTZS_fix_1, "FCVTZS (vector, fixed-point)", "010111110IIIIiii111111nnnnnddddd")
INST(USHR_1, "USHR", "011111110IIIIiii000001nnnnnddddd")
INST(USRA_1, "USRA", "011111110IIIIiii000101nnnnnddddd")
//INST(URSHR_1, "URSHR", "011111110IIIIiii001001nnnnnddddd")
//INST(URSRA_1, "URSRA", "011111110IIIIiii001101nnnnnddddd")
INST(URSHR_1, "URSHR", "011111110IIIIiii001001nnnnnddddd")
INST(URSRA_1, "URSRA", "011111110IIIIiii001101nnnnnddddd")
INST(SRI_1, "SRI", "011111110IIIIiii010001nnnnnddddd")
INST(SLI_1, "SLI", "011111110IIIIiii010101nnnnnddddd")
//INST(SQSHLU_1, "SQSHLU", "011111110IIIIiii011001nnnnnddddd")

33
src/frontend/A64/translate/impl/simd_scalar_shift_by_immediate.cpp
View file

@ -40,14 +40,21 @@ static void ShiftRight(TranslatorVisitor& v, Imm<4> immh, Imm<3> immb, Vec Vn, V
}
static void RoundingShiftRight(TranslatorVisitor& v, Imm<4> immh, Imm<3> immb, Vec Vn, Vec Vd,
ShiftExtraBehavior behavior) {
ShiftExtraBehavior behavior, Signedness signedness) {
const size_t esize = 64;
const u8 shift_amount = static_cast<u8>((esize * 2) - concatenate(immh, immb).ZeroExtend());
const IR::U64 operand = v.V_scalar(esize, Vn);
const IR::U64 round_bit = v.ir.LogicalShiftRight(v.ir.LogicalShiftLeft(operand, v.ir.Imm8(64 - shift_amount)), v.ir.Imm8(63));
const IR::U64 result = [&] {
IR::U64 tmp = v.ir.Add(v.ir.ArithmeticShiftRight(operand, v.ir.Imm8(shift_amount)), round_bit);
const IR::U64 shifted = [&]() -> IR::U64 {
if (signedness == Signedness::Signed) {
return v.ir.ArithmeticShiftRight(operand, v.ir.Imm8(shift_amount));
}
return v.ir.LogicalShiftRight(operand, v.ir.Imm8(shift_amount));
}();
IR::U64 tmp = v.ir.Add(shifted, round_bit);
if (behavior == ShiftExtraBehavior::Accumulate) {
tmp = v.ir.Add(tmp, v.V_scalar(esize, Vd));
@ -122,7 +129,7 @@ bool TranslatorVisitor::SRSHR_1(Imm<4> immh, Imm<3> immb, Vec Vn, Vec Vd) {
return ReservedValue();
}
RoundingShiftRight(*this, immh, immb, Vn, Vd, ShiftExtraBehavior::None);
RoundingShiftRight(*this, immh, immb, Vn, Vd, ShiftExtraBehavior::None, Signedness::Signed);
return true;
}
@ -131,7 +138,7 @@ bool TranslatorVisitor::SRSRA_1(Imm<4> immh, Imm<3> immb, Vec Vn, Vec Vd) {
return ReservedValue();
}
RoundingShiftRight(*this, immh, immb, Vn, Vd, ShiftExtraBehavior::Accumulate);
RoundingShiftRight(*this, immh, immb, Vn, Vd, ShiftExtraBehavior::Accumulate, Signedness::Signed);
return true;
}
@ -168,6 +175,24 @@ bool TranslatorVisitor::SHL_1(Imm<4> immh, Imm<3> immb, Vec Vn, Vec Vd) {
return true;
}
bool TranslatorVisitor::URSHR_1(Imm<4> immh, Imm<3> immb, Vec Vn, Vec Vd) {
if (!immh.Bit<3>()) {
return ReservedValue();
}
RoundingShiftRight(*this, immh, immb, Vn, Vd, ShiftExtraBehavior::None, Signedness::Unsigned);
return true;
}
bool TranslatorVisitor::URSRA_1(Imm<4> immh, Imm<3> immb, Vec Vn, Vec Vd) {
if (!immh.Bit<3>()) {
return ReservedValue();
}
RoundingShiftRight(*this, immh, immb, Vn, Vd, ShiftExtraBehavior::Accumulate, Signedness::Unsigned);
return true;
}
bool TranslatorVisitor::USHR_1(Imm<4> immh, Imm<3> immb, Vec Vn, Vec Vd) {
if (!immh.Bit<3>()) {
return ReservedValue();