1. The RISC-V code for Procedure Y is shown in the first column of the following table. Procedure X calls Procedure Y and Procedure Y calls Procedure Z to accomplish certain functions. You need to examine the listed RISC-V code and fill in the missing instructions according to the procedure call and register usage convention. At the beginning of Y, a stack frame is created for saving registers, parameters, and local variables. Register x10 is used for passing arguments from X to Y and from Y to Z. Registers x5, x6, x8 and x9 are used and updated in Y. The operations of different parts of the procedure are commented on the right column of the table, where a hint in red for filling in needed RISC-V instructions. Note that all registers are 64-bit.

procedureY:		Label for Procedure Y
addi	sp, sp, -40 sd x5, x0 sd x8, x0 sd x9, x0 sd x5, x0	Create stack space, Save registers (fill in needed RISC-V code)
... ... ld ld add sub add ...	x8, 0(x10) x9, 8(x10) x5, x10, x8 x6, x5, x9 x10, x5, x6	Procedure Y body I // use of x8, x9, x5, x6, x10, note that x5, x6 are temporary registers
jal	procedureZ	(fill in RISC-V code) Call procedure Z (fill in RISC-V code)
add add ... ...	x5, x8, x5 x28, x9, x5	Procedure Y body II
		Restore registers, return stack space (fill in RISC-V code)
jalr x0, 0(ra)		Return to caller