Question

下面的代码使用SSE将数组arr1与arr2相乘，并将结果放到arr3。数组有count个元素。 arr1，arr2和arr3的类型为float*。问题是编译器不支持Intel语法。这段代码在AT＆amp; T语法中看起来如何？

编译器是GCC 4.4.7。

__asm__ volatile (
    ".intel_syntax noprefix \n\t"
    "loop:                  \n\t"
    "movups xmm0, [eax+edx] \n\t"
    "movups xmm1, [ebx+edx] \n\t"
    "mulps xmm0, xmm1       \n\t"
    "movups [ecx+edx], xmm0 \n\t"
    "sub edx, 16            \n\t"
    "jnz loop               \n\t"
    :
    : "a"(arr1), "b"(arr2), "c"(arr3), "d"(count)
    : "xmm0", "xmm1"
);

Answer 1

__asm__ volatile (
    "loop:                          \n\t"
    "subq $0x10, %%rdx              \n\t"
    "movups (%%rax,%%rdx), %%xmm0   \n\t"
    "movups (%%rbx,%%rdx), %%xmm1   \n\t"
    "mulps %%xmm1, %%xmm0           \n\t"
    "movups %%xmm0, (%%rcx,%%rdx)   \n\t"
    "jnz loop                       \n\t"
    :
    : "a"(arr1), "b"(arr2), "c"(arr3), "d"(count)
    : "xmm0", "xmm1"
);

arr1，arr2和arr3是8字节指针，计数是8字节整数，因此寄存器为r_x

将内联汇编从英特尔转换为AT＆amp; T语法

1 个答案: