src: avoid casting std::trunc(... / ...) to size_t

tniessen · RafaelGSS · commit 18b720805f93 · 2022-09-07T09:20:52.000-03:00
Given that the divisor is not zero, the result of dividing unsigned integers is an unsigned integer that is always rounded down, i.e., there is no need to call std::trunc(). Doing so unnecessarily yields a floating-point number, requiring the result to be cast to an unsigned integer again. PR-URL: #44467 Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl> Reviewed-By: Filip Skokan <panva.ip@gmail.com> Reviewed-By: Anna Henningsen <anna@addaleax.net>
diff --git a/src/crypto/crypto_keygen.cc b/src/crypto/crypto_keygen.cc
@@ -65,8 +65,7 @@ Maybe<bool> SecretKeyGenTraits::AdditionalConfig(
     SecretKeyGenConfig* params) {
   Environment* env = Environment::GetCurrent(args);
   CHECK(args[*offset]->IsUint32());
-  params->length = static_cast<size_t>(
-      std::trunc(args[*offset].As<Uint32>()->Value() / CHAR_BIT));
+  params->length = args[*offset].As<Uint32>()->Value() / CHAR_BIT;
   if (params->length > INT_MAX) {
     THROW_ERR_OUT_OF_RANGE(env,
                            "length must be less than or equal to %u bits",
