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stage1: Allow wrapping negation on unsigned ints at comptime

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Closes #7951
Closes #8574
This commit is contained in:
LemonBoy
2021-04-23 19:15:52 +02:00
parent 41efdc73b9
commit cc8e49283d
4 changed files with 20 additions and 10 deletions
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4
src/stage1/bigint.cpp
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@@ -1446,10 +1446,10 @@ void bigint_negate(BigInt *dest, const BigInt *op) {
bigint_normalize(dest);
}
void bigint_negate_wrap(BigInt *dest, const BigInt *op, size_t bit_count) {
void bigint_negate_wrap(BigInt *dest, const BigInt *op, size_t bit_count, bool is_signed) {
BigInt zero;
bigint_init_unsigned(&zero, 0);
bigint_sub_wrap(dest, &zero, op, bit_count, true);
bigint_sub_wrap(dest, &zero, op, bit_count, is_signed);
}
void bigint_not(BigInt *dest, const BigInt *op, size_t bit_count, bool is_signed) {

2
src/stage1/bigint.hpp
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@@ -75,7 +75,7 @@ void bigint_shl_trunc(BigInt *dest, const BigInt *op1, const BigInt *op2, size_t
void bigint_shr(BigInt *dest, const BigInt *op1, const BigInt *op2);
void bigint_negate(BigInt *dest, const BigInt *op);
void bigint_negate_wrap(BigInt *dest, const BigInt *op, size_t bit_count);
void bigint_negate_wrap(BigInt *dest, const BigInt *op, size_t bit_count, bool is_signed);
void bigint_not(BigInt *dest, const BigInt *op, size_t bit_count, bool is_signed);
void bigint_truncate(BigInt *dest, const BigInt *op, size_t bit_count, bool is_signed);

6
src/stage1/ir.cpp
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@@ -21660,8 +21660,8 @@ static ErrorMsg *ir_eval_negation_scalar(IrAnalyze *ira, IrInst* source_instr, Z
{
bool is_float = (scalar_type->id == ZigTypeIdFloat || scalar_type->id == ZigTypeIdComptimeFloat);
bool ok_type = ((scalar_type->id == ZigTypeIdInt && scalar_type->data.integral.is_signed) ||
scalar_type->id == ZigTypeIdComptimeInt || (is_float && !is_wrap_op));
bool ok_type = scalar_type->id == ZigTypeIdInt || scalar_type->id == ZigTypeIdComptimeInt ||
(is_float && !is_wrap_op);
if (!ok_type) {
const char *fmt = is_wrap_op ? "invalid wrapping negation type: '%s'" : "invalid negation type: '%s'";
@@ -21672,7 +21672,7 @@ static ErrorMsg *ir_eval_negation_scalar(IrAnalyze *ira, IrInst* source_instr, Z
float_negate(scalar_out_val, operand_val);
} else if (is_wrap_op) {
bigint_negate_wrap(&scalar_out_val->data.x_bigint, &operand_val->data.x_bigint,
scalar_type->data.integral.bit_count);
scalar_type->data.integral.bit_count, scalar_type->data.integral.is_signed);
} else {
bigint_negate(&scalar_out_val->data.x_bigint, &operand_val->data.x_bigint);
}

18
test/stage1/behavior/math.zig
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@@ -229,16 +229,26 @@ fn testSignedWrappingEval(x: i32) void {
expect(max_val == maxInt(i32));
}
test "negation wrapping" {
testNegationWrappingEval(minInt(i16));
comptime testNegationWrappingEval(minInt(i16));
test "signed negation wrapping" {
testSignedNegationWrappingEval(minInt(i16));
comptime testSignedNegationWrappingEval(minInt(i16));
}
fn testNegationWrappingEval(x: i16) void {
fn testSignedNegationWrappingEval(x: i16) void {
expect(x == -32768);
const neg = -%x;
expect(neg == -32768);
}
test "unsigned negation wrapping" {
testUnsignedNegationWrappingEval(1);
comptime testUnsignedNegationWrappingEval(1);
}
fn testUnsignedNegationWrappingEval(x: u16) void {
expect(x == 1);
const neg = -%x;
expect(neg == maxInt(u16));
}
test "unsigned 64-bit division" {
test_u64_div();
comptime test_u64_div();