Commit 61ebfe6603c8fef26008683f96b62dab2c502429 | zig

5 files changed, 121 insertions(+), 2 deletions(-)

std/special/compiler_rt/floatunditf.zig created+28

...	@@ -0,0 +1,28 @@
1	const builtin = @import("builtin");
2	const is_test = builtin.is_test;
3	const std = @import("../../index.zig");
4
5	pub extern fn __floatunditf(a: u128) f128 {
6	@setRuntimeSafety(is_test);
7
8	if (a == 0) {
9	return 0;
10	}
11
12	const mantissa_bits = std.math.floatMantissaBits(f128);
13	const exponent_bits = std.math.floatExponentBits(f128);
14	const exponent_bias = (1 << (exponent_bits - 1)) - 1;
15	const implicit_bit = 1 << mantissa_bits;
16
17	const exp = (u128.bit_count - 1) - @clz(a);
18	const shift = mantissa_bits - @intCast(u7, exp);
19
20	var result: u128 = (a << shift) ^ implicit_bit;
21	result += (@intCast(u128, exp) + exponent_bias) << mantissa_bits;
22
23	return @bitCast(f128, result);
24	}
25
26	test "import floatunditf" {
27	_ = @import("floatunditf_test.zig");
28	}

std/special/compiler_rt/floatunditf_test.zig created+33

...	@@ -0,0 +1,33 @@
1	const __floatunditf = @import("floatunditf.zig").__floatunditf;
2	const assert = @import("std").debug.assert;
3
4	fn test__floatunditf(a: u128, expected_hi: u64, expected_lo: u64) void {
5	const x = __floatunditf(a);
6
7	const x_repr = @bitCast(u128, x);
8	const x_hi = @intCast(u64, x_repr >> 64);
9	const x_lo = @truncate(u64, x_repr);
10
11	if (x_hi == expected_hi and x_lo == expected_lo) {
12	return;
13	}
14	// nan repr
15	else if (expected_hi == 0x7fff800000000000 and expected_lo == 0x0) {
16	if ((x_hi & 0x7fff000000000000) == 0x7fff000000000000 and ((x_hi & 0xffffffffffff) > 0 or x_lo > 0)) {
17	return;
18	}
19	}
20
21	@panic("__floatunditf test failure");
22	}
23
24	test "floatunditf" {
25	test__floatunditf(0xffffffffffffffff, 0x403effffffffffff, 0xfffe000000000000);
26	test__floatunditf(0xfffffffffffffffe, 0x403effffffffffff, 0xfffc000000000000);
27	test__floatunditf(0x8000000000000000, 0x403e000000000000, 0x0);
28	test__floatunditf(0x7fffffffffffffff, 0x403dffffffffffff, 0xfffc000000000000);
29	test__floatunditf(0x123456789abcdef1, 0x403b23456789abcd, 0xef10000000000000);
30	test__floatunditf(0x2, 0x4000000000000000, 0x0);
31	test__floatunditf(0x1, 0x3fff000000000000, 0x0);
32	test__floatunditf(0x0, 0x0, 0x0);
33	}

std/special/compiler_rt/floatunsitf.zig created+29

...	@@ -0,0 +1,29 @@
1	const builtin = @import("builtin");
2	const is_test = builtin.is_test;
3	const std = @import("../../index.zig");
4
5	pub extern fn __floatunsitf(a: u64) f128 {
6	@setRuntimeSafety(is_test);
7
8	if (a == 0) {
9	return 0;
10	}
11
12	const mantissa_bits = std.math.floatMantissaBits(f128);
13	const exponent_bits = std.math.floatExponentBits(f128);
14	const exponent_bias = (1 << (exponent_bits - 1)) - 1;
15	const implicit_bit = 1 << mantissa_bits;
16
17	const exp = (u64.bit_count - 1) - @clz(a);
18	const shift = mantissa_bits - @intCast(u7, exp);
19
20	// TODO: @bitCast alignment error
21	var result align(16) = (@intCast(u128, a) << shift) ^ implicit_bit;
22	result += (@intCast(u128, exp) + exponent_bias) << mantissa_bits;
23
24	return @bitCast(f128, result);
25	}
26
27	test "import floatunsitf" {
28	_ = @import("floatunsitf_test.zig");
29	}

std/special/compiler_rt/floatunsitf_test.zig created+29

...	@@ -0,0 +1,29 @@
1	const __floatunsitf = @import("floatunsitf.zig").__floatunsitf;
2	const assert = @import("std").debug.assert;
3
4	fn test__floatunsitf(a: u64, expected_hi: u64, expected_lo: u64) void {
5	const x = __floatunsitf(a);
6
7	const x_repr = @bitCast(u128, x);
8	const x_hi = @intCast(u64, x_repr >> 64);
9	const x_lo = @truncate(u64, x_repr);
10
11	if (x_hi == expected_hi and x_lo == expected_lo) {
12	return;
13	}
14	// nan repr
15	else if (expected_hi == 0x7fff800000000000 and expected_lo == 0x0) {
16	if ((x_hi & 0x7fff000000000000) == 0x7fff000000000000 and ((x_hi & 0xffffffffffff) > 0 or x_lo > 0)) {
17	return;
18	}
19	}
20
21	@panic("__floatunsitf test failure");
22	}
23
24	test "floatunsitf" {
25	test__floatunsitf(0x7fffffff, 0x401dfffffffc0000, 0x0);
26	test__floatunsitf(0, 0x0, 0x0);
27	test__floatunsitf(0xffffffff, 0x401efffffffe0000, 0x0);
28	test__floatunsitf(0x12345678, 0x401b234567800000, 0x0);
29	}

std/special/compiler_rt/truncXfYf2.zig+2-2

...	@@ -85,8 +85,8 @@ inline fn truncXfYf2(comptime dst_t: type, comptime src_t: type, a: src_t) dst_t	...	@@ -85,8 +85,8 @@ inline fn truncXfYf2(comptime dst_t: type, comptime src_t: type, a: src_t) dst_t
85	// a underflows on conversion to the destination type or is an exact	85	// a underflows on conversion to the destination type or is an exact
86	// zero. The result may be a denormal or zero. Extract the exponent	86	// zero. The result may be a denormal or zero. Extract the exponent
87	// to get the shift amount for the denormalization.	87	// to get the shift amount for the denormalization.
88	const aExp = aAbs >> srcSigBits;	88	const aExp = @intCast(u32, aAbs >> srcSigBits);
89	const shift = srcExpBias - dstExpBias - aExp + 1;	89	const shift = @intCast(u32, srcExpBias - dstExpBias - aExp + 1);
90		90
91	const significand: src_rep_t = (aRep & srcSignificandMask) \| srcMinNormal;	91	const significand: src_rep_t = (aRep & srcSignificandMask) \| srcMinNormal;
92		92