stage2 AArch64: Implement binOp for add, sub

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joachimschmidt557 2022-02-09 23:19:28 +01:00
parent 8bfc4b2f9c
commit edb2a75982
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3 changed files with 249 additions and 11 deletions

View File

@ -511,10 +511,10 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
switch (air_tags[inst]) {
// zig fmt: off
.add, .ptr_add => try self.airAdd(inst),
.add, .ptr_add => try self.airBinOp(inst),
.addwrap => try self.airAddWrap(inst),
.add_sat => try self.airAddSat(inst),
.sub, .ptr_sub => try self.airSub(inst),
.sub, .ptr_sub => try self.airBinOp(inst),
.subwrap => try self.airSubWrap(inst),
.sub_sat => try self.airSubSat(inst),
.mul => try self.airMul(inst),
@ -950,9 +950,249 @@ fn airSlice(self: *Self, inst: Air.Inst.Index) !void {
return self.finishAir(inst, result, .{ bin_op.lhs, bin_op.rhs, .none });
}
fn airAdd(self: *Self, inst: Air.Inst.Index) !void {
/// Don't call this function directly. Use binOp instead.
///
/// Calling this function signals an intention to generate a Mir
/// instruction of the form
///
/// op dest, lhs, rhs
///
/// Asserts that generating an instruction of that form is possible.
fn binOpRegister(
self: *Self,
tag: Air.Inst.Tag,
maybe_inst: ?Air.Inst.Index,
lhs: MCValue,
rhs: MCValue,
lhs_ty: Type,
rhs_ty: Type,
) !MCValue {
const lhs_is_register = lhs == .register;
const rhs_is_register = rhs == .register;
if (lhs_is_register) self.register_manager.freezeRegs(&.{lhs.register});
if (rhs_is_register) self.register_manager.freezeRegs(&.{rhs.register});
const lhs_reg = if (lhs_is_register) lhs.register else blk: {
const track_inst: ?Air.Inst.Index = if (maybe_inst) |inst| inst: {
const bin_op = self.air.instructions.items(.data)[inst].bin_op;
break :inst Air.refToIndex(bin_op.lhs).?;
} else null;
const reg = try self.register_manager.allocReg(track_inst);
self.register_manager.freezeRegs(&.{reg});
break :blk reg;
};
defer self.register_manager.unfreezeRegs(&.{lhs_reg});
const rhs_reg = if (rhs_is_register) rhs.register else blk: {
const track_inst: ?Air.Inst.Index = if (maybe_inst) |inst| inst: {
const bin_op = self.air.instructions.items(.data)[inst].bin_op;
break :inst Air.refToIndex(bin_op.rhs).?;
} else null;
const reg = try self.register_manager.allocReg(track_inst);
self.register_manager.freezeRegs(&.{reg});
break :blk reg;
};
defer self.register_manager.unfreezeRegs(&.{rhs_reg});
const dest_reg = if (maybe_inst) |inst| blk: {
const bin_op = self.air.instructions.items(.data)[inst].bin_op;
if (lhs_is_register and self.reuseOperand(inst, bin_op.lhs, 0, lhs)) {
break :blk lhs_reg;
} else if (rhs_is_register and self.reuseOperand(inst, bin_op.rhs, 1, rhs)) {
break :blk rhs_reg;
} else {
break :blk try self.register_manager.allocReg(inst);
}
} else try self.register_manager.allocReg(null);
if (!lhs_is_register) try self.genSetReg(lhs_ty, lhs_reg, lhs);
if (!rhs_is_register) try self.genSetReg(rhs_ty, rhs_reg, rhs);
const mir_tag: Mir.Inst.Tag = switch (tag) {
.add => .add_shifted_register,
.sub => .sub_shifted_register,
else => unreachable,
};
const mir_data: Mir.Inst.Data = switch (tag) {
.add,
.sub,
=> .{ .rrr_imm6_shift = .{
.rd = dest_reg,
.rn = lhs_reg,
.rm = rhs_reg,
.imm6 = 0,
.shift = .lsl,
} },
else => unreachable,
};
_ = try self.addInst(.{
.tag = mir_tag,
.data = mir_data,
});
return MCValue{ .register = dest_reg };
}
/// Don't call this function directly. Use binOp instead.
///
/// Calling this function signals an intention to generate a Mir
/// instruction of the form
///
/// op dest, lhs, #rhs_imm
///
/// Set lhs_and_rhs_swapped to true iff inst.bin_op.lhs corresponds to
/// rhs and vice versa. This parameter is only used when maybe_inst !=
/// null.
///
/// Asserts that generating an instruction of that form is possible.
fn binOpImmediate(
self: *Self,
tag: Air.Inst.Tag,
maybe_inst: ?Air.Inst.Index,
lhs: MCValue,
rhs: MCValue,
lhs_ty: Type,
lhs_and_rhs_swapped: bool,
) !MCValue {
const lhs_is_register = lhs == .register;
if (lhs_is_register) self.register_manager.freezeRegs(&.{lhs.register});
const lhs_reg = if (lhs_is_register) lhs.register else blk: {
const track_inst: ?Air.Inst.Index = if (maybe_inst) |inst| inst: {
const bin_op = self.air.instructions.items(.data)[inst].bin_op;
break :inst Air.refToIndex(
if (lhs_and_rhs_swapped) bin_op.rhs else bin_op.lhs,
).?;
} else null;
const reg = try self.register_manager.allocReg(track_inst);
self.register_manager.freezeRegs(&.{reg});
break :blk reg;
};
defer self.register_manager.unfreezeRegs(&.{lhs_reg});
const dest_reg = if (maybe_inst) |inst| blk: {
const bin_op = self.air.instructions.items(.data)[inst].bin_op;
if (lhs_is_register and self.reuseOperand(
inst,
if (lhs_and_rhs_swapped) bin_op.rhs else bin_op.lhs,
if (lhs_and_rhs_swapped) 1 else 0,
lhs,
)) {
break :blk lhs_reg;
} else {
break :blk try self.register_manager.allocReg(inst);
}
} else try self.register_manager.allocReg(null);
if (!lhs_is_register) try self.genSetReg(lhs_ty, lhs_reg, lhs);
const mir_tag: Mir.Inst.Tag = switch (tag) {
.add => .add_immediate,
.sub => .sub_immediate,
else => unreachable,
};
const mir_data: Mir.Inst.Data = switch (tag) {
.add,
.sub,
=> .{ .rr_imm12_sh = .{
.rd = dest_reg,
.rn = lhs_reg,
.imm12 = @intCast(u12, rhs.immediate),
} },
else => unreachable,
};
_ = try self.addInst(.{
.tag = mir_tag,
.data = mir_data,
});
return MCValue{ .register = dest_reg };
}
/// For all your binary operation needs, this function will generate
/// the corresponding Mir instruction(s). Returns the location of the
/// result.
///
/// If the binary operation itself happens to be an Air instruction,
/// pass the corresponding index in the inst parameter. That helps
/// this function do stuff like reusing operands.
///
/// This function does not do any lowering to Mir itself, but instead
/// looks at the lhs and rhs and determines which kind of lowering
/// would be best suitable and then delegates the lowering to other
/// functions.
fn binOp(
self: *Self,
tag: Air.Inst.Tag,
maybe_inst: ?Air.Inst.Index,
lhs: MCValue,
rhs: MCValue,
lhs_ty: Type,
rhs_ty: Type,
) !MCValue {
switch (tag) {
.add,
.sub,
=> {
switch (lhs_ty.zigTypeTag()) {
.Float => return self.fail("TODO binary operations on floats", .{}),
.Vector => return self.fail("TODO binary operations on vectors", .{}),
.Int => {
assert(lhs_ty.eql(rhs_ty));
const int_info = lhs_ty.intInfo(self.target.*);
if (int_info.bits <= 64) {
// Only say yes if the operation is
// commutative, i.e. we can swap both of the
// operands
const lhs_immediate_ok = switch (tag) {
.add => lhs == .immediate and lhs.immediate <= std.math.maxInt(u12),
.sub => false,
else => unreachable,
};
const rhs_immediate_ok = switch (tag) {
.add,
.sub,
=> rhs == .immediate and rhs.immediate <= std.math.maxInt(u12),
else => unreachable,
};
if (rhs_immediate_ok) {
return try self.binOpImmediate(tag, maybe_inst, lhs, rhs, lhs_ty, false);
} else if (lhs_immediate_ok) {
// swap lhs and rhs
return try self.binOpImmediate(tag, maybe_inst, rhs, lhs, rhs_ty, true);
} else {
return try self.binOpRegister(tag, maybe_inst, lhs, rhs, lhs_ty, rhs_ty);
}
} else {
return self.fail("TODO binary operations on int with bits > 64", .{});
}
},
else => unreachable,
}
},
.ptr_add,
.ptr_sub,
=> return self.fail("TODO ptr_add, ptr_sub", .{}),
else => unreachable,
}
}
fn airBinOp(self: *Self, inst: Air.Inst.Index) !void {
const tag = self.air.instructions.items(.tag)[inst];
const bin_op = self.air.instructions.items(.data)[inst].bin_op;
const result: MCValue = if (self.liveness.isUnused(inst)) .dead else return self.fail("TODO implement add for {}", .{self.target.cpu.arch});
const lhs = try self.resolveInst(bin_op.lhs);
const rhs = try self.resolveInst(bin_op.rhs);
const lhs_ty = self.air.typeOf(bin_op.lhs);
const rhs_ty = self.air.typeOf(bin_op.rhs);
const result: MCValue = if (self.liveness.isUnused(inst)) .dead else try self.binOp(tag, inst, lhs, rhs, lhs_ty, rhs_ty);
return self.finishAir(inst, result, .{ bin_op.lhs, bin_op.rhs, .none });
}
@ -968,12 +1208,6 @@ fn airAddSat(self: *Self, inst: Air.Inst.Index) !void {
return self.finishAir(inst, result, .{ bin_op.lhs, bin_op.rhs, .none });
}
fn airSub(self: *Self, inst: Air.Inst.Index) !void {
const bin_op = self.air.instructions.items(.data)[inst].bin_op;
const result: MCValue = if (self.liveness.isUnused(inst)) .dead else return self.fail("TODO implement sub for {}", .{self.target.cpu.arch});
return self.finishAir(inst, result, .{ bin_op.lhs, bin_op.rhs, .none });
}
fn airSubWrap(self: *Self, inst: Air.Inst.Index) !void {
const bin_op = self.air.instructions.items(.data)[inst].bin_op;
const result: MCValue = if (self.liveness.isUnused(inst)) .dead else return self.fail("TODO implement subwrap for {}", .{self.target.cpu.arch});

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@ -93,6 +93,7 @@ pub fn emitMir(
.add_shifted_register => try emit.mirAddSubtractShiftedRegister(inst),
.cmp_shifted_register => try emit.mirAddSubtractShiftedRegister(inst),
.sub_shifted_register => try emit.mirAddSubtractShiftedRegister(inst),
.cset => try emit.mirConditionalSelect(inst),
@ -584,8 +585,9 @@ fn mirAddSubtractShiftedRegister(emit: *Emit, inst: Mir.Inst.Index) !void {
const imm6 = rrr_imm6_shift.imm6;
switch (tag) {
.cmp_shifted_register => try emit.writeInstruction(Instruction.subsShiftedRegister(rd, rn, rm, shift, imm6)),
.add_shifted_register => try emit.writeInstruction(Instruction.addShiftedRegister(rd, rn, rm, shift, imm6)),
.cmp_shifted_register => try emit.writeInstruction(Instruction.subsShiftedRegister(rd, rn, rm, shift, imm6)),
.sub_shifted_register => try emit.writeInstruction(Instruction.subShiftedRegister(rd, rn, rm, shift, imm6)),
else => unreachable,
}
}

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@ -116,6 +116,8 @@ pub const Inst = struct {
strh_register,
/// Subtract (immediate)
sub_immediate,
/// Subtract (shifted register)
sub_shifted_register,
/// Supervisor Call
svc,
};