[Bug rtl-optimization/44194] struct returned by value generates useless stores

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2010-05-19 10:22 -------
At leas the stores to s have alias info:

(insn 12 10 14 2 t.c:7 (set (mem/s/c:DI (plus:DI (reg/f:DI 20 frame)
                (const_int -16 [0xfffffffffffffff0])) [2 s+0 S8 A128])
        (reg:DI 60)) 89 {*movdi_1_rex64} (nil))

(insn 14 12 17 2 t.c:7 (set (mem/s/c:DI (plus:DI (reg/f:DI 20 frame)
                (const_int -8 [0xfffffffffffffff8])) [2 s+8 S8 A64])
        (reg:DI 61)) 89 {*movdi_1_rex64} (nil))

so RTL DSE could check whether the stack slot is aliased at all.

The other memory temporary should be avoided at expansion time already.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44194