| Issue |
87446
|
| Summary |
[clang] Clang stack frame is too large in specific scenarios.
|
| Labels |
clang
|
| Assignees |
|
| Reporter |
CoTinker
|
test.c
```
#define PERROR(fmt) \
do { \
char dbg_buffer[4096 +1]={0}; \
} while(0);
void foo() {
PERROR("/opt/1");
PERROR("/opt/2");
PERROR("/opt/3");
}
```
clang
```
% clang test.c -o test.s -S -O0
foo: // @foo
stp x29, x30, [sp, #-32]! // 16-byte Folded Spill
str x28, [sp, #16] // 8-byte Folded Spill
mov x29, sp
sub sp, sp, #3, lsl #12 // =12288
...
```
gcc
```
% gcc test.c -o test.s -S -O0
foo:
mov x12, 4128
sub sp, sp, x12
...
```
https://godbolt.org/z/od5Yc1zKr
clang is 12288，while gcc is only 4128. It seems that clang is (PERROR nums * struct size), and gcc is more reasonable.
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