| Issue |
61640
|
| Summary |
Wrong code for inline assembly with `-masm=intel` on x86_64
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
lhmouse
|
Godbolt: https://gcc.godbolt.org/z/bn15EWhsq
```c++
using my_function = int (int, int);
extern my_function* my_fptr;
int
ptc_indirect_call(int a, int b)
{
return my_fptr(a, b);
}
int
asm_indirect_call(int a, int b)
{
__asm__ ("jmp qword ptr [my_fptr@GOTPCREL]");
__builtin_unreachable();
}
```
```asm
ptc_indirect_call(int, int): # @ptc_indirect_call(int, int)
mov rax, qword ptr [rip + my_fptr@GOTPCREL]
mov rax, qword ptr [rax]
jmp rax # TAILCALL
asm_indirect_call(int, int): # @asm_indirect_call(int, int)
jmp my_fptr@GOTPCREL
```
The inline asm statement gets compiled as a direct call and will jump to nonexecutable data.
(the at&t syntax however doesn't suffer from this issue.)
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