[Bug target/95756] _Complex return with constant 0 could be improved

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95756

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
      Known to fail|                            |3.4.6, 5.1.0
          Component|middle-end                  |target
         Resolution|---                         |DUPLICATE

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
What is interesting is for:
```
float  f1()
{
    return 0.0f;
}

```

This starts also out in expand as:
```
;; return 0.0;

(insn 5 4 6 (set (reg:SF 98 [ <retval> ])
        (mem/u/c:SF (symbol_ref/u:DI ("*.LC0") [flags 0x2]) [0  S4 A32]))
"/app/example.cpp":9:12 discrim 1 -1
     (expr_list:REG_EQUAL (const_double:SF 0.0 [0x0.0p+0])
        (nil)))
```

Which in itself funny.

But the way expand combines the expression for complex is a bit interesting:
```
(insn 12 11 13 2 (set (mem/c:SF (plus:DI (reg/f:DI 93 virtual-stack-vars)
                (const_int -8 [0xfffffffffffffff8])) [0  S4 A32])
        (reg:SF 100)) "/app/example.cpp":4:1 -1
     (nil))
(insn 13 12 14 2 (set (mem/c:SF (plus:DI (reg/f:DI 93 virtual-stack-vars)
                (const_int -4 [0xfffffffffffffffc])) [0  S4 A32])
        (reg:SF 101)) "/app/example.cpp":4:1 -1
     (nil))
(insn 14 13 15 2 (set (reg:DI 20 xmm0)
        (mem/c:DI (plus:DI (reg/f:DI 93 virtual-stack-vars)
                (const_int -8 [0xfffffffffffffff8])) [0  S8 A32]))
"/app/example.cpp":4:1 -1
     (nil))
```

Which means this exactly a dup of bug 48609.

*** This bug has been marked as a duplicate of bug 48609 ***