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Simplify Math.signbit. Don't ignore sign bit for NaNs #1467

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Merged
merged 2 commits into from
Sep 25, 2020
Merged

Simplify Math.signbit. Don't ignore sign bit for NaNs #1467

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bd441a6
simplify Math.signbit. Don't ignore sign bit for NaNs
MaxGraey Sep 18, 2020
d7a2e85
change portable as well
MaxGraey Sep 18, 2020
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7 changes: 2 additions & 5 deletions std/assembly/math.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -1435,9 +1435,7 @@ export namespace NativeMath {
// @ts-ignore: decorator
@inline
export function signbit(x: f64): bool {
// In ECMAScript all NaN values are indistinguishable from each other
// so we need handle NaN and negative NaN in similar way
return <bool>(<i32>(reinterpret<u64>(x) >>> 63) & i32(x == x));
return <bool>(reinterpret<u64>(x) >>> 63);
}

export function sin(x: f64): f64 { // see: musl/src/math/sin.c
Expand Down Expand Up @@ -2714,8 +2712,7 @@ export namespace NativeMathf {
// @ts-ignore: decorator
@inline
export function signbit(x: f32): bool {
// @ts-ignore: type
return <bool>((reinterpret<u32>(x) >>> 31) & (x == x));
return <bool>(reinterpret<u32>(x) >>> 31);
}

export function sin(x: f32): f32 { // see: musl/src/math/sinf.c
Expand Down
2 changes: 1 addition & 1 deletion std/portable/index.js
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Original file line number Diff line number Diff line change
Expand Up @@ -325,7 +325,7 @@ Object.defineProperties(globalScope["JSMath"], {
sincos_cos: { value: 0.0, writable: true },
signbit: {
value: function signbit(x) {
F64[0] = x; return Boolean((U64[1] >>> 31) & (x == x));
F64[0] = x; return Boolean(U64[1] >>> 31);
}
},
sincos: {
Expand Down
22 changes: 4 additions & 18 deletions tests/compiler/std/math.optimized.wat
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Original file line number Diff line number Diff line change
Expand Up @@ -187,22 +187,16 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $0
local.get $0
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
local.get $1
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $1
local.get $1
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.eq
Expand Down Expand Up @@ -382,20 +376,12 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $0
local.get $0
f32.eq
i32.and
i32.const 0
i32.ne
local.get $1
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $1
local.get $1
f32.eq
i32.and
i32.const 0
i32.ne
i32.eq
Expand Down
6 changes: 3 additions & 3 deletions tests/compiler/std/math.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -3129,7 +3129,7 @@ assert(NativeMath.signbit(-0.0) == true);
assert(NativeMath.signbit(1.0) == false);
assert(NativeMath.signbit(-1.0) == true);
assert(NativeMath.signbit(+NaN) == false);
assert(NativeMath.signbit(-NaN) == false);
assert(NativeMath.signbit(-NaN) == true);
assert(NativeMath.signbit(+Infinity) == false);
assert(NativeMath.signbit(-Infinity) == true);

Expand All @@ -3142,7 +3142,7 @@ assert(NativeMathf.signbit(-0.0) == true);
assert(NativeMathf.signbit(1.0) == false);
assert(NativeMathf.signbit(-1.0) == true);
assert(NativeMathf.signbit(+NaN) == false);
assert(NativeMathf.signbit(-NaN) == false);
assert(NativeMathf.signbit(-NaN) == true);
assert(NativeMathf.signbit(+Infinity) == false);
assert(NativeMathf.signbit(-Infinity) == true);

Expand Down Expand Up @@ -4121,4 +4121,4 @@ assert(1 ** 0.5 == 1.0);
assert(0 ** 0.5 == 0.0);
assert(0 ** -1.0 == Infinity);
assert(0.0 ** 0 == 1.0);
assert(1.0 ** 1 == 1.0);
assert(1.0 ** 1 == 1.0);
114 changes: 22 additions & 92 deletions tests/compiler/std/math.untouched.wat
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Original file line number Diff line number Diff line change
Expand Up @@ -269,11 +269,8 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $3
local.get $3
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
local.get $1
Expand All @@ -282,11 +279,8 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $3
local.get $3
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.eq
Expand Down Expand Up @@ -503,10 +497,6 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $3
local.get $3
f32.eq
i32.and
i32.const 0
i32.ne
local.get $1
Expand All @@ -515,10 +505,6 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $3
local.get $3
f32.eq
i32.and
i32.const 0
i32.ne
i32.eq
Expand Down Expand Up @@ -48467,11 +48453,8 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $0
local.get $0
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.const 0
Expand All @@ -48483,11 +48466,8 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $0
local.get $0
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.const 1
Expand All @@ -48499,11 +48479,8 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $0
local.get $0
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.const 0
Expand All @@ -48515,11 +48492,8 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $0
local.get $0
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.const 1
Expand All @@ -48531,11 +48505,8 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $0
local.get $0
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.const 0
Expand All @@ -48548,14 +48519,11 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $0
local.get $0
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.const 0
i32.const 1
i32.eq
drop
f64.const inf
Expand All @@ -48564,11 +48532,8 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $0
local.get $0
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.const 0
Expand All @@ -48581,11 +48546,8 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $0
local.get $0
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.const 1
Expand All @@ -48597,10 +48559,6 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $4
local.get $4
f32.eq
i32.and
i32.const 0
i32.ne
i32.const 0
Expand All @@ -48612,10 +48570,6 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $4
local.get $4
f32.eq
i32.and
i32.const 0
i32.ne
i32.const 1
Expand All @@ -48627,10 +48581,6 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $4
local.get $4
f32.eq
i32.and
i32.const 0
i32.ne
i32.const 0
Expand All @@ -48642,10 +48592,6 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $4
local.get $4
f32.eq
i32.and
i32.const 0
i32.ne
i32.const 1
Expand All @@ -48657,10 +48603,6 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $4
local.get $4
f32.eq
i32.and
i32.const 0
i32.ne
i32.const 0
Expand All @@ -48673,13 +48615,9 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $4
local.get $4
f32.eq
i32.and
i32.const 0
i32.ne
i32.const 0
i32.const 1
i32.eq
drop
f32.const inf
Expand All @@ -48688,10 +48626,6 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $4
local.get $4
f32.eq
i32.and
i32.const 0
i32.ne
i32.const 0
Expand All @@ -48704,10 +48638,6 @@
i32.reinterpret_f32
i32.const 31
i32.shr_u
local.get $4
local.get $4
f32.eq
i32.and
i32.const 0
i32.ne
i32.const 1
Expand Down
8 changes: 1 addition & 7 deletions tests/compiler/std/string.optimized.wat
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Original file line number Diff line number Diff line change
Expand Up @@ -9249,16 +9249,10 @@
i32.const 3008
i32.const 0
call $~lib/string/parseInt
local.tee $3
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $3
local.get $3
f64.eq
i32.and
i32.eqz
i64.eqz
if
i32.const 0
i32.const 1088
Expand Down
7 changes: 2 additions & 5 deletions tests/compiler/std/string.untouched.wat
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Original file line number Diff line number Diff line change
Expand Up @@ -13147,11 +13147,8 @@
i64.reinterpret_f64
i64.const 63
i64.shr_u
i32.wrap_i64
local.get $32
local.get $32
f64.eq
i32.and
i64.const 0
i64.ne
i32.const 0
i32.ne
i32.eqz
Expand Down