🚀 go-pugleaf

The following program should print "1 2" but instead prints "2 2".

An examination of the assembly code (see below) indicates that main()
uses the same space for return value for both calls to fill(), and the
call to fill(2) happens before fill(1).right is extracted.

Details:
   gcc version 2.7.2, configured as sparc-sun-sunos4.1.4
   Running on a SPARCstation 5, SunOS 4.1.4
   Compiled using "gcc gcc-bug3.c".
   

---- Cut here ----

struct rec {
    int left;
    int right;
};

struct rec fill(int v)
{
    struct rec x;
    x.left = x.right = v;
    return x;
}

main()
{
    printf("%d %d\n", fill(1).right, fill(2).right);
}

---- End program ----

_main:
        !#PROLOGUE# 0
        save %sp,-112,%sp
        !#PROLOGUE# 1
        call ___main,0
        nop
        add %fp,-16,%o0
        st %o0,[%sp+64]		<- Address for the return value is fp-16
        mov 1,%o0
        call _fill,0
        nop
        unimp 8
        add %fp,-16,%o0
        st %o0,[%sp+64]		<- Address for the return value is again fp-16
        mov 2,%o0
        call _fill,0
        nop
        unimp 8
        sethi %hi(LC0),%o1
        or %o1,%lo(LC0),%o0
        ld [%fp-12],%o1		<- Extract right from result of fill(1), but
				   this is actually fill(2) now!!!
        ld [%fp-12],%o2		<- Extract right from result of fill(2)
        call _printf,0
        nop
L2:
        ret
        restore