perf: Speedup DecCoin.Sort() when coins is of length 1 (backport cosm…

…os#18888) (cosmos#18889)

Co-authored-by: Dong Lieu <93205232+DongLieu@users.noreply.github.com>
Co-authored-by: marbar3778 <marbar3778@yahoo.com>

CHANGELOG.md

@@ -43,6 +43,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/gov) [#18707](https://github.com/cosmos/cosmos-sdk/pull/18707) Improve genesis validation.
 * (x/auth/tx) [#18772](https://github.com/cosmos/cosmos-sdk/pull/18772) Remove misleading gas wanted from tx simulation failure log.
 * (client/tx) [#18852](https://github.com/cosmos/cosmos-sdk/pull/18852) Add `WithFromName` to tx factory.
+* (types) [#18888](https://github.com/cosmos/cosmos-sdk/pull/18888) Speedup DecCoin.Sort() if len(coins) <= 1
 * (types) [#18875](https://github.com/cosmos/cosmos-sdk/pull/18875) Speedup coins.Sort() if len(coins) <= 1
 
 ### Bug Fixes

types/dec_coin.go

@@ -609,7 +609,12 @@ func (coins DecCoins) Swap(i, j int) { coins[i], coins[j] = coins[j], coins[i] }
 
 // Sort is a helper function to sort the set of decimal coins in-place.
 func (coins DecCoins) Sort() DecCoins {
-	sort.Sort(coins)
+	// sort.Sort(coins) does a costly runtime copy as part of `runtime.convTSlice`
+	// So we avoid this heap allocation if len(coins) <= 1. In the future, we should hopefully find
+	// a strategy to always avoid this.
+	if len(coins) > 1 {
+		sort.Sort(coins)
+	}
 	return coins
 }