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ir: Fix shift code for u0 operands

master
LemonBoy 2020-03-10 23:04:49 +01:00
parent 300fceac6e
commit 4ab13a359d
2 changed files with 50 additions and 15 deletions
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46
src/ir.cpp
View File

@ -16635,34 +16635,47 @@ static IrInstGen *ir_analyze_bit_shift(IrAnalyze *ira, IrInstSrcBinOp *bin_op_in
IrInstGen *casted_op2;
IrBinOp op_id = bin_op_instruction->op_id;
if (op1->value->type->id == ZigTypeIdComptimeInt) {
// comptime_int has no finite bit width
casted_op2 = op2;
if (op_id == IrBinOpBitShiftLeftLossy) {
op_id = IrBinOpBitShiftLeftExact;
}
if (casted_op2->value->data.x_bigint.is_negative) {
if (!instr_is_comptime(op2)) {
ir_add_error(ira, &bin_op_instruction->base.base,
buf_sprintf("LHS of shift must be an integer type, or RHS must be compile-time known"));
return ira->codegen->invalid_inst_gen;
}
ZigValue *op2_val = ir_resolve_const(ira, casted_op2, UndefBad);
if (op2_val == nullptr)
return ira->codegen->invalid_inst_gen;
if (op2_val->data.x_bigint.is_negative) {
Buf *val_buf = buf_alloc();
bigint_append_buf(val_buf, &casted_op2->value->data.x_bigint, 10);
ir_add_error(ira, &casted_op2->base, buf_sprintf("shift by negative value %s", buf_ptr(val_buf)));
bigint_append_buf(val_buf, &op2_val->data.x_bigint, 10);
ir_add_error(ira, &casted_op2->base,
buf_sprintf("shift by negative value %s", buf_ptr(val_buf)));
return ira->codegen->invalid_inst_gen;
}
} else {
assert(op1->value->type->data.integral.bit_count > 0);
const unsigned bit_count = op1->value->type->data.integral.bit_count;
ZigType *shift_amt_type = get_smallest_unsigned_int_type(ira->codegen,
op1->value->type->data.integral.bit_count - 1);
bit_count > 0 ? bit_count - 1 : 0);
casted_op2 = ir_implicit_cast(ira, op2, shift_amt_type);
if (type_is_invalid(casted_op2->value->type))
return ira->codegen->invalid_inst_gen;
if (instr_is_comptime(casted_op2)) {
// This check is only valid iff op1 has at least one bit
if (bit_count > 0 && instr_is_comptime(casted_op2)) {
ZigValue *op2_val = ir_resolve_const(ira, casted_op2, UndefBad);
if (op2_val == nullptr)
return ira->codegen->invalid_inst_gen;
BigInt bit_count_value = {0};
bigint_init_unsigned(&bit_count_value, op1->value->type->data.integral.bit_count);
bigint_init_unsigned(&bit_count_value, bit_count);
if (bigint_cmp(&op2_val->data.x_bigint, &bit_count_value) != CmpLT) {
ErrorMsg* msg = ir_add_error(ira,
@ -16670,14 +16683,23 @@ static IrInstGen *ir_analyze_bit_shift(IrAnalyze *ira, IrInstSrcBinOp *bin_op_in
buf_sprintf("RHS of shift is too large for LHS type"));
add_error_note(ira->codegen, msg, op1->base.source_node,
buf_sprintf("type %s has only %u bits",
buf_ptr(&op1->value->type->name),
op1->value->type->data.integral.bit_count));
buf_ptr(&op1->value->type->name), bit_count));
return ira->codegen->invalid_inst_gen;
}
}
}
// Fast path for zero RHS
if (instr_is_comptime(casted_op2)) {
ZigValue *op2_val = ir_resolve_const(ira, casted_op2, UndefBad);
if (op2_val == nullptr)
return ira->codegen->invalid_inst_gen;
if (bigint_cmp_zero(&op2_val->data.x_bigint) == CmpEQ)
return ir_analyze_cast(ira, &bin_op_instruction->base.base, op1->value->type, op1);
}
if (instr_is_comptime(op1) && instr_is_comptime(casted_op2)) {
ZigValue *op1_val = ir_resolve_const(ira, op1, UndefBad);
if (op1_val == nullptr)
@ -16688,12 +16710,6 @@ static IrInstGen *ir_analyze_bit_shift(IrAnalyze *ira, IrInstSrcBinOp *bin_op_in
return ira->codegen->invalid_inst_gen;
return ir_analyze_math_op(ira, &bin_op_instruction->base.base, op1->value->type, op1_val, op_id, op2_val);
} else if (op1->value->type->id == ZigTypeIdComptimeInt) {
ir_add_error(ira, &bin_op_instruction->base.base,
buf_sprintf("LHS of shift must be an integer type, or RHS must be compile-time known"));
return ira->codegen->invalid_inst_gen;
} else if (instr_is_comptime(casted_op2) && bigint_cmp_zero(&casted_op2->value->data.x_bigint) == CmpEQ) {
return ir_build_cast(ira, &bin_op_instruction->base.base, op1->value->type, op1, CastOpNoop);
}
return ir_build_bin_op_gen(ira, &bin_op_instruction->base.base, op1->value->type,

19
test/stage1/behavior/math.zig
View File

@ -453,6 +453,25 @@ fn testShrExact(x: u8) void {
expect(shifted == 0b00101101);
}
test "shift left/right on u0 operand" {
const S = struct {
fn doTheTest() void {
var x: u0 = 0;
var y: u0 = 0;
expectEqual(@as(u0, 0), x << 0);
expectEqual(@as(u0, 0), x >> 0);
expectEqual(@as(u0, 0), x << y);
expectEqual(@as(u0, 0), x >> y);
expectEqual(@as(u0, 0), @shlExact(x, 0));
expectEqual(@as(u0, 0), @shrExact(x, 0));
expectEqual(@as(u0, 0), @shlExact(x, y));
expectEqual(@as(u0, 0), @shrExact(x, y));
}
};
S.doTheTest();
comptime S.doTheTest();
}
test "comptime_int addition" {
comptime {
expect(35361831660712422535336160538497375248 + 101752735581729509668353361206450473702 == 137114567242441932203689521744947848950);