Inline assembly - PowerPC - return value override

Ido100 — Sun, 21 Jan 2024 09:31:29 GMT

Hello community!

I want to create some inline assembly examples for PowerPC architecture.
During the implementation I encountered several challenges.

For Example:

Function that sum two local variables and return the sum value.

While debugging the code I found out the code save the correct sum value in r0 register, but before it return value, I saw the r3 override with 0 value.

int my_asm_add_local(void) { int sum = 0; int a = 4, b = 2; asm volatile("se_add %1, %2\n\t" "se_stw %1, 0(%0)\n\t" : "=r" (sum) : "r" (a), "r" (b) ); return sum; }

code from debugger

int my_asm_add_local(void) 182106F0 my_asm_a.:e_stwu r1,-0x10(r1) ; r1,-16(r1) 0080 se_mflr r0 D501 se_stw r0,0x14(r1) ; a,20(r1) { int sum = 0; int a = 4, b = 2; 4840 se_li r0,0x4 ; a,4 4823 se_li r3,0x2 ; r3,2 asm volatile("se_add %1, %2\n\t" 0430 se_add r0,r3 ; a,b D003 se_stw r0,0x0(r3) ; a,0(r3) "se_stw %1, 0(%0)\n\t" : "=r" (sum) : "r" (a), "r" (b) ); return sum; 4803 se_li r3,0x0 ; b,0 } C501 se_lwz r0,0x14(r1) ; a,20(r1) 0090 se_mtlr r0 20F1 se_addi r1,0x10 ; r1,16 0004 se_blr 4444 se_or r4,r4

I would appreciate any help.

In addition, if anyone knows a good source information with examples of inline assembly for PowerPC, it is could be help.

Re: Inline assembly - PowerPC - return value override

yipingwang — Mon, 29 Jan 2024 09:15:13 GMT

Please disassemble the library code provided in CodeWarrior project to generate assembly code.

Other NXP ProductsのトピックRe: Inline assembly - PowerPC - return value override

Inline assembly - PowerPC - return value override

Re: Inline assembly - PowerPC - return value override