mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-02-13 04:48:20 +00:00
Code Issues Packages Projects Releases Wiki Activity

stage2: implement big int to float conversion

Browse Source
This commit is contained in:
Andrew Kelley 2021-10-20 16:41:08 -07:00
parent 4cb5fed10b
commit c8ded2f9c9
3 changed files with 39 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
src/value.zig
View File

@ -1853,17 +1853,26 @@ pub const Value = extern union {
};
}
pub fn intToFloat(val: Value, allocator: *Allocator, dest_ty: Type, target: Target) !Value {
pub fn intToFloat(val: Value, arena: *Allocator, dest_ty: Type, target: Target) !Value {
switch (val.tag()) {
.undef, .zero, .one => return val,
.the_only_possible_value => return Value.initTag(.zero), // for i0, u0
.int_u64 => {
return intToFloatInner(val.castTag(.int_u64).?.data, allocator, dest_ty, target);
return intToFloatInner(val.castTag(.int_u64).?.data, arena, dest_ty, target);
},
.int_i64 => {
return intToFloatInner(val.castTag(.int_i64).?.data, allocator, dest_ty, target);
return intToFloatInner(val.castTag(.int_i64).?.data, arena, dest_ty, target);
},
.int_big_positive => {
const limbs = val.castTag(.int_big_positive).?.data;
const float = bigIntToFloat(limbs, true);
return floatToValue(float, arena, dest_ty, target);
},
.int_big_negative => {
const limbs = val.castTag(.int_big_negative).?.data;
const float = bigIntToFloat(limbs, false);
return floatToValue(float, arena, dest_ty, target);
},
.int_big_positive, .int_big_negative => @panic("big int to float"),
else => unreachable,
}
}
@ -1878,6 +1887,16 @@ pub const Value = extern union {
}
}
fn floatToValue(float: f128, arena: *Allocator, dest_ty: Type, target: Target) !Value {
switch (dest_ty.floatBits(target)) {
16 => return Value.Tag.float_16.create(arena, @floatCast(f16, float)),
32 => return Value.Tag.float_32.create(arena, @floatCast(f32, float)),
64 => return Value.Tag.float_64.create(arena, @floatCast(f64, float)),
128 => return Value.Tag.float_128.create(arena, float),
else => unreachable,
}
}
/// Supports both floats and ints; handles undefined.
pub fn numberAddWrap(
lhs: Value,

16
test/behavior/eval.zig
View File

@ -390,3 +390,19 @@ test "inline for with same type but different values" {
}
try expect(res == 5);
}
test "f32 at compile time is lossy" {
try expect(@as(f32, 1 << 24) + 1 == 1 << 24);
}
test "f32 at compile time is lossy" {
try expect(@as(f32, 1 << 24) + 1 == 1 << 24);
}
test "f64 at compile time is lossy" {
try expect(@as(f64, 1 << 53) + 1 == 1 << 53);
}
test {
comptime try expect(@as(f128, 1 << 113) == 10384593717069655257060992658440192);
}

12
test/behavior/eval_stage1.zig
View File

@ -114,22 +114,10 @@ test "float literal at compile time not lossy" {
try expect(9007199254740992.0 + 1.0 == 9007199254740993.0);
}
test "f32 at compile time is lossy" {
try expect(@as(f32, 1 << 24) + 1 == 1 << 24);
}
test "f64 at compile time is lossy" {
try expect(@as(f64, 1 << 53) + 1 == 1 << 53);
}
test "f128 at compile time is lossy" {
try expect(@as(f128, 10384593717069655257060992658440192.0) + 1 == 10384593717069655257060992658440192.0);
}
test {
comptime try expect(@as(f128, 1 << 113) == 10384593717069655257060992658440192);
}
pub fn TypeWithCompTimeSlice(comptime field_name: []const u8) type {
_ = field_name;
return struct {