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stage1: Off-by-one error in int to float conversion

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The base is 2^64 and not 2^64-1.

Closes #6683
This commit is contained in:
LemonBoy 2020-10-15 10:16:20 +02:00 committed by Veikka Tuominen
parent 7b150dd05e
commit ab585c680b
2 changed files with 20 additions and 0 deletions
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4
src/stage1/bigfloat.cpp
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@ -46,6 +46,10 @@ void bigfloat_init_bigint(BigFloat *dest, const BigInt *op) {
float128_t base;
ui64_to_f128M(UINT64_MAX, &base);
float128_t one_f128;
ui32_to_f128M(1, &one_f128);
f128M_add(&base, &one_f128, &base);
const uint64_t *digits = bigint_ptr(op);
for (size_t i = op->digit_count - 1;;) {

16
test/stage1/behavior/cast.zig
View File

@ -375,6 +375,22 @@ test "comptime_int @intToFloat" {
expect(@TypeOf(result) == f32);
expect(result == 1234.0);
}
{
const result = @intToFloat(f64, 1234);
expect(@TypeOf(result) == f64);
expect(result == 1234.0);
}
{
const result = @intToFloat(f128, 1234);
expect(@TypeOf(result) == f128);
expect(result == 1234.0);
}
// big comptime_int (> 64 bits) to f128 conversion
{
const result = @intToFloat(f128, 0x1_0000_0000_0000_0000);
expect(@TypeOf(result) == f128);
expect(result == 0x1_0000_0000_0000_0000.0);
}
}
test "@intCast i32 to u7" {