authorgravatar for 57540512+rdimas-ut@users.noreply.github.comRuben Dimas <57540512+rdimas-ut@users.noreply.github.com> 2023-09-12 02:19:21-04:00
committergravatar for marc@tiehu.isMarc Tiehuis <marc@tiehu.is> 2023-09-12 22:22:07+12:00
loga8a4f1755e440bc6ff8c27fad0da91ed83f20841
tree5a8d07ab1b5a3038b7707860b374430f15455a12
parent7827265ea81c72e44da9b7d9b91e68d557e4db6d

std.math.asinh: fixed -0.0 evaluating to 0.0

1 files changed, 10 insertions(+), 19 deletions(-)

lib/std/math/asinh.zig+10-19
...@@ -28,30 +28,25 @@ pub fn asinh(x: anytype) @TypeOf(x) {...@@ -28,30 +28,25 @@ pub fn asinh(x: anytype) @TypeOf(x) {
28fn asinh32(x: f32) f32 {28fn asinh32(x: f32) f32 {
29 const u = @as(u32, @bitCast(x));29 const u = @as(u32, @bitCast(x));
30 const i = u & 0x7FFFFFFF;30 const i = u & 0x7FFFFFFF;
31 const s = i >> 31;31 const s = u >> 31;
3232
33 var rx = @as(f32, @bitCast(i)); // |x|33 var rx = @as(f32, @bitCast(i)); // |x|
3434
35 // TODO: Shouldn't need this explicit check.
36 if (math.isNegativeInf(x)) {
37 return x;
38 }
39
40 // |x| >= 0x1p12 or inf or nan35 // |x| >= 0x1p12 or inf or nan
41 if (i >= 0x3F800000 + (12 << 23)) {36 if (i >= 0x3F800000 + (12 << 23)) {
42 rx = @log(rx) + 0.69314718055994530941723212145817656;37 rx = @log(rx) + 0.69314718055994530941723212145817656;
43 }38 }
44 // |x| >= 239 // |x| >= 2
45 else if (i >= 0x3F800000 + (1 << 23)) {40 else if (i >= 0x3F800000 + (1 << 23)) {
46 rx = @log(2 * x + 1 / (@sqrt(x * x + 1) + x));41 rx = @log(2 * rx + 1 / (@sqrt(rx * rx + 1) + rx));
47 }42 }
48 // |x| >= 0x1p-12, up to 1.6ulp error43 // |x| >= 0x1p-12, up to 1.6ulp error
49 else if (i >= 0x3F800000 - (12 << 23)) {44 else if (i >= 0x3F800000 - (12 << 23)) {
50 rx = math.log1p(x + x * x / (@sqrt(x * x + 1) + 1));45 rx = math.log1p(rx + rx * rx / (@sqrt(rx * rx + 1) + 1));
51 }46 }
52 // |x| < 0x1p-12, inexact if x != 047 // |x| < 0x1p-12, inexact if x != 0
53 else {48 else {
54 math.doNotOptimizeAway(x + 0x1.0p120);49 math.doNotOptimizeAway(rx + 0x1.0p120);
55 }50 }
5651
57 return if (s != 0) -rx else rx;52 return if (s != 0) -rx else rx;
...@@ -60,29 +55,25 @@ fn asinh32(x: f32) f32 {...@@ -60,29 +55,25 @@ fn asinh32(x: f32) f32 {
60fn asinh64(x: f64) f64 {55fn asinh64(x: f64) f64 {
61 const u = @as(u64, @bitCast(x));56 const u = @as(u64, @bitCast(x));
62 const e = (u >> 52) & 0x7FF;57 const e = (u >> 52) & 0x7FF;
63 const s = e >> 63;58 const s = u >> 63;
6459
65 var rx = @as(f64, @bitCast(u & (maxInt(u64) >> 1))); // |x|60 var rx = @as(f64, @bitCast(u & (maxInt(u64) >> 1))); // |x|
6661
67 if (math.isNegativeInf(x)) {
68 return x;
69 }
70
71 // |x| >= 0x1p26 or inf or nan62 // |x| >= 0x1p26 or inf or nan
72 if (e >= 0x3FF + 26) {63 if (e >= 0x3FF + 26) {
73 rx = @log(rx) + 0.693147180559945309417232121458176568;64 rx = @log(rx) + 0.693147180559945309417232121458176568;
74 }65 }
75 // |x| >= 266 // |x| >= 2
76 else if (e >= 0x3FF + 1) {67 else if (e >= 0x3FF + 1) {
77 rx = @log(2 * x + 1 / (@sqrt(x * x + 1) + x));68 rx = @log(2 * rx + 1 / (@sqrt(rx * rx + 1) + rx));
78 }69 }
79 // |x| >= 0x1p-12, up to 1.6ulp error70 // |x| >= 0x1p-12, up to 1.6ulp error
80 else if (e >= 0x3FF - 26) {71 else if (e >= 0x3FF - 26) {
81 rx = math.log1p(x + x * x / (@sqrt(x * x + 1) + 1));72 rx = math.log1p(rx + rx * rx / (@sqrt(rx * rx + 1) + 1));
82 }73 }
83 // |x| < 0x1p-12, inexact if x != 074 // |x| < 0x1p-12, inexact if x != 0
84 else {75 else {
85 math.doNotOptimizeAway(x + 0x1.0p120);76 math.doNotOptimizeAway(rx + 0x1.0p120);
86 }77 }
8778
88 return if (s != 0) -rx else rx;79 return if (s != 0) -rx else rx;
...@@ -121,7 +112,7 @@ test "math.asinh64" {...@@ -121,7 +112,7 @@ test "math.asinh64" {
121112
122test "math.asinh32.special" {113test "math.asinh32.special" {
123 try expect(asinh32(0.0) == 0.0);114 try expect(asinh32(0.0) == 0.0);
124 try expect(asinh32(-0.0) == -0.0);115 try expect(@as(u32, @bitCast(asinh32(-0.0))) == @as(u32, 2147483648));
125 try expect(math.isPositiveInf(asinh32(math.inf(f32))));116 try expect(math.isPositiveInf(asinh32(math.inf(f32))));
126 try expect(math.isNegativeInf(asinh32(-math.inf(f32))));117 try expect(math.isNegativeInf(asinh32(-math.inf(f32))));
127 try expect(math.isNan(asinh32(math.nan(f32))));118 try expect(math.isNan(asinh32(math.nan(f32))));
...@@ -129,7 +120,7 @@ test "math.asinh32.special" {...@@ -129,7 +120,7 @@ test "math.asinh32.special" {
129120
130test "math.asinh64.special" {121test "math.asinh64.special" {
131 try expect(asinh64(0.0) == 0.0);122 try expect(asinh64(0.0) == 0.0);
132 try expect(asinh64(-0.0) == -0.0);123 try expect(@as(u64, @bitCast(asinh64(-0.0))) == @as(u64, 9223372036854775808));
133 try expect(math.isPositiveInf(asinh64(math.inf(f64))));124 try expect(math.isPositiveInf(asinh64(math.inf(f64))));
134 try expect(math.isNegativeInf(asinh64(-math.inf(f64))));125 try expect(math.isNegativeInf(asinh64(-math.inf(f64))));
135 try expect(math.isNan(asinh64(math.nan(f64))));126 try expect(math.isNan(asinh64(math.nan(f64))));