Question

我有以下32位霓虹灯代码，它只是提取图像：

extractY8ImageARM(unsigned char *from, unsigned char *to, int left, int top, int width, int height, int stride)
from: pointer to the original image
to: pointer to the destination extracted image
left, top: position where to extract in the original image
width, height: size of the extracted image
stride: width of the original image

这是汇编代码：

.text
.arch armv7-a
.fpu neon
.type extractY8ImageARM, STT_FUNC
.global extractY8ImageARM

extractY8ImageARM:
from    .req r0
to  .req r1
left    .req r2
top .req r3
width   .req r4
height  .req r5
stride  .req r6
tmp .req r7

    push {r0-r7, lr}

//Let's get back the arguments
    ldr width, [sp, #(9 * 4)]
    ldr height, [sp, #(10 * 4)]
    ldr stride, [sp, #(11 * 4)]

//Update the from pointer. Advance left + stride * top
    add from, from, left
    mul tmp, top, stride
    add from, from, tmp

.loopV:
//We will copy width
    mov tmp, width

.loopH:
//Read and store data
    pld [from]
    vld1.u8 { d0, d1, d2, d3 }, [from]!

    pld [to]
    vst1.u8 { d0, d1, d2, d3 }, [to]!

    subs tmp, tmp, #32
    bgt .loopH

//We advance the from pointer for the next line
    add from, from, stride
    sub from, from, width

    subs height, height, #1
    bgt .loopV


    pop {r0-r7, pc}

.unreq from
.unreq to
.unreq left
.unreq top
.unreq width
.unreq height
.unreq stride
.unreq tmp

我需要将它移植到64位霓虹灯。任何人都可以帮我翻译吗？我已经阅读了这篇白皮书http://malideveloper.arm.com/downloads/Porting%20to%20ARM%2064-bit.pdf，所以我或多或少地了解了这些差异。

我的代码很简单，如何在64位氖组件文件中传递参数和加载/存储数据就是一个很好的例子。我宁愿避免内在。

Answer 1

整个代码如下所示：

.text
.arch armv8-a
.type extractY8ImageARM, STT_FUNC
.global extractY8ImageARM

extractY8ImageARM:
from    .req x0
to  .req x1
left    .req x2
top .req x3
width   .req x4
height  .req x5
stride  .req x6
tmp .req x9

    add from, from, left
    mul tmp, top, stride
    add from, from, tmp

.loopV:
    mov tmp, width

.loopH:
    ld1 {v0.16b, v1.16b, v2.16b, v3.16b}, [from], #64

    st1 {v0.16b, v1.16b, v2.16b, v3.16b}, [to], #64

    subs tmp, tmp, #64
    bgt .loopH

    add from, from, stride
    sub from, from, width

    subs height, height, #1
    bgt .loopV

    ret


.unreq from
.unreq to
.unreq left
.unreq top
.unreq width
.unreq height
.unreq stride
.unreq tmp

将ARM 32位氖转换为ARM 64位氖

1 个答案: