The name carries the types
__mulsf3 reads as a sentence:
mul — the operation.sf — single float, the type it works in. df would be double.3 — how many values the operation touches, counting the result. Binary operators are 3; unary __negsf2 is 2.
So a single bl __mulsf3 tells you the operator is *, both operands are 32-bit floats in r0 and r1, and the product comes back in r0 as a 32-bit float. That is the entire type signature of the operation, written on the branch.
Here is a multiply where both operands are the same value:
0 push {lr}
2 mov r1, r0
4 bl __mulsf3-4
8 pop {r1}
10 bx r1
The helper always wants two arguments, so squaring costs an extra mov to give it a second copy. There is no way to tell __mulsf3 that both operands are the same value; it reads r0 and r1 either way.
That mov r1, r0 is worth remembering as a shape. When you see an argument duplicated into the second operand register just before a helper call, the source used one value twice.
In your target the operands are fetched before the call rather than handed straight in. Read the two ldr offsets and work out what they are counting.
Your task
Write func_08288960 to reproduce the target assembly.