Commit ae8c46c

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fix: Math.pow constant optimization behaves inconsistently in different versions of node (#2920)

use the pow function compiled by AS bootstrap to optimize the constant propagation of pow

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-10

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+24

-10

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`@@ -32,6 +32,7 @@`
`32`	`32`	`"@types/node": "^18.19.75",`
`33`	`33`	`"@typescript-eslint/eslint-plugin": "^5.62.0",`
`34`	`34`	`"@typescript-eslint/parser": "^5.62.0",`
	`35`	`+ "as-float": "^1.0.1",`
`35`	`36`	`"diff": "^7.0.0",`
`36`	`37`	`"esbuild": "^0.25.0",`
`37`	`38`	`"eslint": "^8.57.1",`

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`@@ -7,3 +7,4 @@ declare function f32_as_i32(value: f32): i32;`
`7`	`7`	`declare function i32_as_f32(value: i32): f32;`
`8`	`8`	`declare function f64_as_i64(value: f64): i64;`
`9`	`9`	`declare function i64_as_f64(value: i64): f64;`
	`10`	`+declare function f64_pow(value: f64, exponent: f64): f64;`

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`@@ -3,6 +3,8 @@`
`3`	`3`	`* @license Apache-2.0`
`4`	`4`	`*/`
`5`	`5`
	`6`	`+import { f64_pow } from "as-float";`
	`7`	`+`
`6`	`8`	`/* eslint-disable no-undef */`
`7`	`9`
`8`	`10`	`const F64 = new Float64Array(1);`
`@@ -29,3 +31,5 @@ globalThis.i64_as_f64 = function i64_as_f64(value) {`
`29`	`31`	`I32[1] = i64_high(value);`
`30`	`32`	`return F64[0];`
`31`	`33`	`};`
	`34`	`+`
	`35`	`+globalThis.f64_pow = f64_pow;`

Lines changed: 4 additions & 10 deletions

Original file line number	Diff line number	Diff line change
`@@ -11,16 +11,10 @@ export function isPowerOf2(x: i32): bool {`
`11`	`11`	`export function accuratePow64(x: f64, y: f64): f64 {`
`12`	`12`	`if (!ASC_TARGET) { // ASC_TARGET == JS`
`13`	`13`	`// Engines like V8, WebKit and SpiderMonkey uses powi fast path if exponent is integer`
`14`		`- // This speculative optimization leads to loose precisions like 10 ** 208 != 1e208`
`15`		`- // or/and 10 ** -5 != 1e-5 anymore. For avoid this behaviour we are forcing exponent`
`16`		`- // to fractional form and compensate this afterwards.`
`17`		`- if (isFinite(y) && Math.abs(y) >= 2 && Math.trunc(y) == y) {`
`18`		`- if (y < 0) {`
`19`		`- return Math.pow(x, y + 0.5) / Math.pow(x, 0.5);`
`20`		`- } else {`
`21`		`- return Math.pow(x, y - 0.5) * Math.pow(x, 0.5);`
`22`		`- }`
`23`		`- }`
	`14`	`+ // This speculative optimization leads to loose precisions like 10 ** -5 != 1e-5 anymore`
	`15`	`+ // and introduces inconsistencies between different engines and versions`
	`16`	`+ // For avoid this behavior we using bootstrap f64_pow function.`
	`17`	`+ return f64_pow(x, y);`
`24`	`18`	`}`
`25`	`19`	`return Math.pow(x, y);`
`26`	`20`	`}`

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