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From: "pangbw at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/106818] code is genereated differently with or
 without 'extern'
Date: Fri, 02 Sep 2022 22:29:21 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106818

--- Comment #5 from baoshan <pangbw at gmail dot com> ---
Per Andrew's request:

For GCC built for RISC-V,
With the following code:
struct sss_t {
    int i;
    int j;
} sss;
extern char array[sizeof(struct sss_t )];
void foo()
{
    struct sss_t *p =3D (struct sss_t *)array;
    p->i =3D 10;
}

The following asm is generated:
foo():
        lui     a5,%hi(array)
        li      a4,10
        sb      a4,%lo(array)(a5)
        sb      zero,%lo(array+1)(a5)
        sb      zero,%lo(array+2)(a5)
        sb      zero,%lo(array+3)(a5)
        ret
sss:
        .zero   8

While if remove the 'extern' from the C code, the following asm is generate=
d:

foo():
        lui     a5,%hi(array)
        li      a4,10
        sw      a4,%lo(array)(a5)
        ret
array:
        .zero   8
sss:
        .zero   8=