fix(stdlib): Properly handle extremely large integer bases in `Number…

….(**)` (#1950)
grain-lang · Jan 25, 2024 · 84c076f · 84c076f
1 parent 7cdcf95
commit 84c076f
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Showing 2 changed files with 11 additions and 11 deletions.
diff --git a/compiler/test/stdlib/number.test.gr b/compiler/test/stdlib/number.test.gr
@@ -204,6 +204,7 @@ assert 10223372036854775809 ** 10 ==
   12472159440978016923768615307032788210916694000775261660538874886865415760948494778813645195039710006678013364969179502650466497057008288260604039903029954443675868581729857084924132550246401
 assert 1 ** 9223372036854775809 == 1
 assert 2.0 ** 9223372036854775809 == Infinity
+assert 2.0 ** 99223372036854775809 == Infinity
 assert pow(1/2, 2) == 1/4
 assert pow(1/2, 3) == 1/8
 assert Number.isRational(pow(1/2, 2))

diff --git a/stdlib/runtime/numbers.gr b/stdlib/runtime/numbers.gr
@@ -2859,19 +2859,20 @@ provide let (**) = (base, power) => {
   } else {
     // Based on https://git.musl-libc.org/cgit/musl/tree/src/math/pow.c
     from WasmF64 use { (==), (!=), (<=), (/), (*), (+) }
-    // Constants
-    let infinity = 1.0W / 0.0W
-    let nan = 0.0W / 0.0W
     let x = coerceNumberToWasmF64(base)
     let y = coerceNumberToWasmF64(power)
     // Fast paths
     if (WasmF64.abs(y) <= 2.0W) {
       if (y == 2.0W) {
         return WasmI32.toGrain(newFloat64(x * x)): Number
       } else if (y == 0.5W) {
-        let output =
-          if (x != infinity) WasmF64.abs(WasmF64.sqrt(x)) else infinity
-        return WasmI32.toGrain(newFloat64(output)): Number
+        if (x != InfinityW) {
+          return WasmI32.toGrain(
+            newFloat64(WasmF64.abs(WasmF64.sqrt(x)))
+          ): Number
+        } else {
+          return Infinity
+        }
       } else if (y == -1.0W) {
         return WasmI32.toGrain(newFloat64(1.0W / x)): Number
       } else if (y == 1.0W) {
@@ -3002,9 +3003,7 @@ provide let (**) = (base, power) => {
     let mut s = 1.0W
     if (hx < 0n) {
       if (yisint == 0n) {
-        from WasmF64 use { (-) }
-        let d = x - x
-        return WasmI32.toGrain(newFloat64(d / d)): Number
+        return NaN
       } else if (yisint == 1n) s = -1.0W
     }
     let mut t1 = 0.0W
@@ -3022,10 +3021,10 @@ provide let (**) = (base, power) => {
       if (iy > 0x43F00000n) {
         if (ix <= 0x3FEFFFFFn) {
           let output = if (hy < 0n) huge * huge else tiny * tiny
-          return WasmI32.toGrain(newFloat64(z)): Number
+          return WasmI32.toGrain(newFloat64(output)): Number
         } else if (ix >= 0x3FF00000n) {
           let output = if (hy > 0n) huge * huge else tiny * tiny
-          return WasmI32.toGrain(newFloat64(z)): Number
+          return WasmI32.toGrain(newFloat64(output)): Number
         }
       }
       if (ix < 0x3FEFFFFFn) {