[Bug target/49065] Write of non-aligned volatile float generates extra read instructions on PowerPC

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=49065

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |msebor at gcc dot gnu.org

--- Comment #2 from Martin Sebor <msebor at gcc dot gnu.org> ---
I recall seeing problems due to this as well.  FWIW, with a recent enough
compiler (GCC 4.7 and beyond), the __builtin_assume_aligned intrinsic can be
used to work around it.

void __attribute__ ((weak)) volatile_bad(volatile struct msg *p) {
    p = __builtin_assume_aligned (p, _Alignof (float));
    p->data = 0.0;
}