Merge pull request #3966 from Citadel-Station-13/upstream-merge-32650

[MIRROR] Speeds up saycode by almost doubling get_hearers_in_view() performance

code/__HELPERS/game.dm

@@ -214,17 +214,28 @@
 /proc/get_hearers_in_view(R, atom/source)
 	// Returns a list of hearers in view(R) from source (ignoring luminosity). Used in saycode.
 	var/turf/T = get_turf(source)
-	var/list/hear = list()
+	. = list()
 
 	if(!T)
-		return hear
+		return
 
-	var/list/range = get_hear(R, T)
-	for(var/atom/movable/A in range)
-		hear |= recursive_hear_check(A)
-
-	return hear
+	var/list/processing_list = list()
+	if (R == 0) // if the range is zero, we know exactly where to look for, we can skip view
+		processing_list += T.contents // We can shave off one iteration by assuming turfs cannot hear
+	else  // A variation of get_hear inlined here to take advantage of the compiler's fastpath for obj/mob in view
+		var/lum = T.luminosity
+		T.luminosity = 6 // This is the maximum luminosity
+		processing_list = viewers(R, T)
+		for(var/obj/O in view(R, T))
+			processing_list += O
+		T.luminosity = lum
 
+	while(processing_list.len) // recursive_hear_check inlined here
+		var/atom/A = processing_list[1]
+		if(A.flags_1 & HEAR_1)
+			. += A
+		processing_list.Cut(1, 2)
+		processing_list += A.contents
 
 /proc/get_mobs_in_radio_ranges(list/obj/item/device/radio/radios)