2006/08/11(金)MIPSの場合
というわけで，MIPSで平方根を求めるプログラム．fmulとfdivが，それぞれ乗算，除算に相当しています．
.globl main .globl fmul .globl fdiv .globl fsqr main: li $v0,5 syscall add $a0,$zero,$v0 # a0 : jousuu jal fsqr # $v0 = fsqr($a0) nop add $a0, $zero, $v0 li $v0, 1 syscall nop li $v0, 0 syscall # exit nop fsqr: addi $sp, $sp, -24 sw $ra, 20($sp) sw $s0, 16($sp) sw $s1, 12($sp) sw $s2, 8($sp) sw $s3, 4($sp) sw $s4, 0($sp) # init addi $s0, $zero, 1 # x sll $s0, $s0, 16 add $s1, $zero, $a0 # y # addi $s2, $zero, 2 addi $s3, $zero, 20 # i addi $s4, $zero, 2 # sll $s4, $s4, 16 _fsqr: add $a0, $zero, $s0 # $s2 = x / 2 add $a1, $zero, $s4 jal fdiv add $s2, $zero, $v0 # add $a0, $zero, $s0 # $v1 = x * 2 # add $a1, $zero, $s4 jal fmul add $a1, $zero, $v0 add $a0, $zero, $s1 # $s5 = y / $v1 = y / (x * 2) jal fdiv add $s0, $s2, $v0 addi $s3, $s3, -1 bne $s3, $zero, _fsqr add $v0, $zero, $s0 lw $s4, 0($sp) lw $s3, 4($sp) lw $s2, 8($sp) lw $s1, 12($sp) lw $s0, 16($sp) lw $ra, 20($sp) addi $sp, $sp, 20 jr $ra fmul: # init add $t1, $zero, $a0 add $t2, $zero, $a1 addi $t3, $zero, 1 addi $t4, $zero, 1 sll $t4, $t4, 16 add $v0, $zero, $zero add $v1, $zero, $zero addi $t0, $zero, 16 _fmul1: and $t5, $t2, $t3 beq $t5, $zero, _fmul2 add $v0, $v0, $a0 _fmul2: and $t5, $t2, $t4 beq $t5, $zero, _fmul3 add $v1, $v1, $t1 _fmul3: srl $t2, $t2, 1 srl $v0, $v0, 1 sll $t1, $t1, 1 addi $t0, $t0, -1 bne $t0, $zero, _fmul1 add $v0, $v0, $v1 jr $ra fdiv: # init add $v0, $zero, $zero add $v1, $zero, $zero addi $t0, $zero, 48 addi $t1, $zero, 1 sll $t1, $t1, 31 beq $zero, $zero, _fdiv2 _fdiv1: srl $t1, $t1, 1 sll $v0, $v0, 1 sll $v1, $v1, 1 _fdiv2: and $t2, $t1, $a0 beq $t2, $zero, _fdiv3 addi $v1, $v1, 1 _fdiv3: slt $t2, $v1, $a1 bne $t2, $zero, _fdiv4 sub $v1, $v1, $a1 addi $v0, $v0, 1 _fdiv4: addi $t0, $t0, -1 bne $t0, $zero, _fdiv1 jr $ra