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wasm: implement @addWithOverflow for 64bit ints

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Luuk de Gram 2023-05-01 19:39:40 +02:00
parent 8236a26c60
commit 992de8e617
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GPG Key ID: A8CFE58E4DC7D664
1 changed files with 37 additions and 4 deletions
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41
src/arch/wasm/CodeGen.zig
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@ -5553,7 +5553,7 @@ fn airMulWithOverflow(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
return func.fail("TODO: Implement overflow arithmetic for integer bitsize: {d}", .{int_info.bits});
};
if (wasm_bits > 32) {
if (wasm_bits > 64) {
return func.fail("TODO: Implement `@mulWithOverflow` for integer bitsize: {d}", .{int_info.bits});
}
@ -5586,7 +5586,7 @@ fn airMulWithOverflow(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk down_cast;
}
} else if (int_info.signedness == .signed) blk: {
} else if (int_info.signedness == .signed and wasm_bits == 32) blk: {
const lhs_abs = try func.signAbsValue(lhs, lhs_ty);
const rhs_abs = try func.signAbsValue(rhs, lhs_ty);
const bin_op = try (try func.binOp(lhs_abs, rhs_abs, lhs_ty, .mul)).toLocal(func, lhs_ty);
@ -5594,7 +5594,7 @@ fn airMulWithOverflow(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
_ = try func.cmp(mul_abs, bin_op, lhs_ty, .neq);
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk try func.wrapOperand(bin_op, lhs_ty);
} else blk: {
} else if (wasm_bits == 32) blk: {
var bin_op = try (try func.binOp(lhs, rhs, lhs_ty, .mul)).toLocal(func, lhs_ty);
defer bin_op.free(func);
const shift_imm = if (wasm_bits == 32)
@ -5605,7 +5605,40 @@ fn airMulWithOverflow(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
_ = try func.cmp(shr, zero, lhs_ty, .neq);
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk try func.wrapOperand(bin_op, lhs_ty);
};
} else if (int_info.bits == 64 and int_info.signedness == .unsigned) blk: {
const new_ty = Type.initTag(.u128);
var lhs_upcast = try (try func.intcast(lhs, lhs_ty, new_ty)).toLocal(func, lhs_ty);
defer lhs_upcast.free(func);
var rhs_upcast = try (try func.intcast(rhs, lhs_ty, new_ty)).toLocal(func, lhs_ty);
defer rhs_upcast.free(func);
const bin_op = try func.binOp(lhs_upcast, rhs_upcast, new_ty, .mul);
const lsb = try func.load(bin_op, lhs_ty, 8);
_ = try func.cmp(lsb, zero, lhs_ty, .neq);
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk try func.load(bin_op, lhs_ty, 0);
} else if (int_info.bits == 64 and int_info.signedness == .signed) blk: {
const shift_val: WValue = .{ .imm64 = 63 };
var lhs_shifted = try (try func.binOp(lhs, shift_val, lhs_ty, .shr)).toLocal(func, lhs_ty);
defer lhs_shifted.free(func);
var rhs_shifted = try (try func.binOp(rhs, shift_val, lhs_ty, .shr)).toLocal(func, lhs_ty);
defer rhs_shifted.free(func);
const bin_op = try func.callIntrinsic(
"__multi3",
&[_]Type{Type.i64} ** 4,
Type.initTag(.i128),
&.{ lhs, lhs_shifted, rhs, rhs_shifted },
);
const res = try func.allocLocal(lhs_ty);
const msb = try func.load(bin_op, lhs_ty, 0);
try func.addLabel(.local_tee, res.local.value);
const msb_shifted = try func.binOp(msb, shift_val, lhs_ty, .shr);
const lsb = try func.load(bin_op, lhs_ty, 8);
_ = try func.cmp(lsb, msb_shifted, lhs_ty, .neq);
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk res;
} else return func.fail("TODO: @mulWithOverflow for integers between 32 and 64 bits", .{});
var bin_op_local = try bin_op.toLocal(func, lhs_ty);
defer bin_op_local.free(func);