Check for unsigned rollover

mborland · mborland · commit 3bc93a9ecf75 · 2025-02-10T13:27:27.000-05:00
diff --git a/include/boost/decimal/decimal32_fast.hpp b/include/boost/decimal/decimal32_fast.hpp
@@ -382,7 +382,7 @@ constexpr decimal32_fast::decimal32_fast(T1 coeff, T2 exp, bool sign) noexcept
     auto biased_exp {static_cast<exponent_type>(exp + detail::bias)};
 
     // Decimal32 exponent holds 8 bits
-    if (biased_exp > detail::max_biased_exp_v<decimal32_fast>)
+    if (biased_exp > detail::max_biased_exp_v<decimal32_fast> || exp > detail::max_biased_exp_v<decimal32_fast>)
     {
         significand_ = detail::d32_fast_inf;
     }
diff --git a/include/boost/decimal/decimal64_fast.hpp b/include/boost/decimal/decimal64_fast.hpp
@@ -390,9 +390,9 @@ constexpr decimal64_fast::decimal64_fast(T1 coeff, T2 exp, bool sign) noexcept
         exp = 0;
     }
 
-    const auto biased_exp {static_cast<std::uint_fast32_t>(exp + detail::bias_v<decimal64>)};
+    const auto biased_exp {static_cast<exponent_type>(exp + detail::bias_v<decimal64>)};
 
-    if (biased_exp > detail::max_biased_exp_v<decimal64>)
+    if (biased_exp > detail::max_biased_exp_v<decimal64> || exp > detail::max_biased_exp_v<decimal64>)
     {
         significand_ = detail::d64_fast_inf;
     }

Original file line number	Diff line number	Diff line change
`@@ -382,7 +382,7 @@ constexpr decimal32_fast::decimal32_fast(T1 coeff, T2 exp, bool sign) noexcept`
`382`	`382`	`auto biased_exp {static_cast<exponent_type>(exp + detail::bias)};`
`383`	`383`
`384`	`384`	`// Decimal32 exponent holds 8 bits`
`385`		`- if (biased_exp > detail::max_biased_exp_v<decimal32_fast>)`
	`385`	`+ if (biased_exp > detail::max_biased_exp_v<decimal32_fast> \|\| exp > detail::max_biased_exp_v<decimal32_fast>)`
`386`	`386`	`{`
`387`	`387`	`significand_ = detail::d32_fast_inf;`
`388`	`388`	`}`
Original file line number	Diff line number	Diff line change
`@@ -390,9 +390,9 @@ constexpr decimal64_fast::decimal64_fast(T1 coeff, T2 exp, bool sign) noexcept`
`390`	`390`	`exp = 0;`
`391`	`391`	`}`
`392`	`392`
`393`		`- const auto biased_exp {static_cast<std::uint_fast32_t>(exp + detail::bias_v<decimal64>)};`
	`393`	`+ const auto biased_exp {static_cast<exponent_type>(exp + detail::bias_v<decimal64>)};`
`394`	`394`
`395`		`- if (biased_exp > detail::max_biased_exp_v<decimal64>)`
	`395`	`+ if (biased_exp > detail::max_biased_exp_v<decimal64> \|\| exp > detail::max_biased_exp_v<decimal64>)`
`396`	`396`	`{`
`397`	`397`	`significand_ = detail::d64_fast_inf;`
`398`	`398`	`}`