Question

继续对浮点堆栈进行操作：

fld     qword [perResult]       ;load st0 with perimeter
fsub    qword [firstSide]       ;take st0 and minus firstSide, st0= perimeter - firstSide
fmul    qword [perResult]       ;take st0 and multiply by perimeter, st0 = difference of first equation * perimeter
fstp    qword [res1]            ;take the result off of st0 and place them into variable equation1

;setting up to take perimeter minus second side
fld     qword [perResult]       ;load up perimeter into st0
fsub    qword [secondSide]      ;take st0 and minus secondSide, st0 = perimeter - secondSide
fstp    qword [eq2]

出于某种原因，如果我将方程式注释掉以获得eq2，我将在上一个等式中获得正确的输出以获得res1，

但如果我将方程式2取消注释，我将获得0作为输出

对于下一个等式也是如此，由于某种原因，如果前一个函数之后有一个函数，它会将其归零。

以前有人遇到过这个问题吗？

这是打印功能

mov rdi, areaMsg    
call    print_string
xor r14,r14
movsd   xmm0,  [eq2]    ;move sumResult into xmm0 for printing
mov qword rax, 1
mov r14, [eq2]  ;move result into r14 register for printing float
call    print_float
call    print_nl
jmp Decision

Answer 1

我发现上面的代码没有问题。我在Windows XP下编译并运行它：

bits 16
org 0x100

fld     qword [perResult]       ;load st0 with perimeter
fsub    qword [firstSide]       ;take st0 and minus firstSide, st0= perimeter - firstSide
fmul    qword [perResult]       ;take st0 and multiply by perimeter, st0 = difference of first equation * perimeter
fstp    qword [res1]            ;take the result off of st0 and place them into variable equation1

;setting up to take perimeter minus second side
fld     qword [perResult]       ;load up perimeter into st0
fsub    qword [secondSide]      ;take st0 and minus secondSide, st0 = perimeter - secondSide
fstp    qword [eq2]

ret

align 8

perResult       dq 11.0
firstSide       dq 1.0
res1            dq 0.0 ; (perResult - firstSide) * perResult = (11-1)*11 = 110
secondSide      dq 2.0
eq2             dq 0.0 ; perResult - secondSide = 11-2 = 9

它正确计算了110和9（在调试器中检查）。

如果出现问题，则代码中没有显示。

nasm浮点错误

1 个答案: