--- /dev/null
+Common register allocation / spilling problem:
+
+ mul lr, r4, lr
+ str lr, [sp, #+52]
+ ldr lr, [r1, #+32]
+ sxth r3, r3
+ ldr r4, [sp, #+52]
+ mla r4, r3, lr, r4
+
+can be:
+
+ mul lr, r4, lr
+ mov r4, lr
+ str lr, [sp, #+52]
+ ldr lr, [r1, #+32]
+ sxth r3, r3
+ mla r4, r3, lr, r4
+
+and then "merge" mul and mov:
+
+ mul r4, r4, lr
+ str lr, [sp, #+52]
+ ldr lr, [r1, #+32]
+ sxth r3, r3
+ mla r4, r3, lr, r4
+
+It also increase the likelyhood the store may become dead.