[i386][Float128][compiler-rt] compiler-rt lack of __subtf3 symbol #121757
Description
The __subtf3 function is automatically generated by the subtraction compiler of the float 128 type. However, the compiler rt library of the i386 architecture does not provide the __subtf3 function. The libgcc provides the __subtf3 function. Why does this difference exist? Can we make up for it or do not allow the compiler to automatically generate the __subtf3 function?
case
#include <iostream>
int main() {
// 创建两个 __float128 类型的变量
__float128 a = 1.23456789012345678901234567890123456789Q; // 精度较高
__float128 b = 0.12345678901234567890123456789012345678Q;
// 执行减法，编译器将自动使用 __subtf3
__float128 result = a - b;
return 0;
}
use compiler-rt error: -rtlib=compiler-rt -m32
use libgcc ok: -m32
https://godbolt.org/z/3YT3PbPEW