Avoid un unnecessary bounds check

tbkka · tbkka · commit fa0aa7506bab · 2025-12-08T07:39:09.000Z
diff --git a/stdlib/public/core/FloatingPointFromString.swift b/stdlib/public/core/FloatingPointFromString.swift
@@ -919,7 +919,7 @@ fileprivate func fastParse64(
       }
     }
     nonZeroDigitCount &+= i &- firstSignificantDigitAfterDecimalPointOffset
-    base10Exponent &-= Int32(i &- firstDigitAfterDecimalPointOffset)
+    base10Exponent &-= Int32(truncatingIfNeeded: i &- firstDigitAfterDecimalPointOffset)
 
     if i == firstDigitOffset &+ 1 {
       return .failure // No digits, only a '.'

Original file line number	Diff line number	Diff line change
`@@ -919,7 +919,7 @@ fileprivate func fastParse64(`
`919`	`919`	`}`
`920`	`920`	`}`
`921`	`921`	`nonZeroDigitCount &+= i &- firstSignificantDigitAfterDecimalPointOffset`
`922`		`- base10Exponent &-= Int32(i &- firstDigitAfterDecimalPointOffset)`
	`922`	`+ base10Exponent &-= Int32(truncatingIfNeeded: i &- firstDigitAfterDecimalPointOffset)`
`923`	`923`
`924`	`924`	`if i == firstDigitOffset &+ 1 {`
`925`	`925`	`return .failure // No digits, only a '.'`