On 08/31/2016 02:38 PM, Tom Lane wrote:
Heikki Linnakangas <hlinn...@iki.fi> writes:
Now that we are OK with static inline functions, we can save some cycles
from floating-point functions, by turning Float4GetDatum,
Float8GetDatum, and DatumGetFloat8 into static inlines.
Looks good to me.
Ok, will push.
I wonder whether there is a compiler-dependent way of avoiding the union
trick ... or maybe gcc is already smart enough that it doesn't matter?
It seems to compile into a single instruction, so it can't get any
better from a performance point of view.
float8pl:
.LFB79:
.loc 1 871 0
.cfi_startproc
.LVL297:
.LBB959:
.LBB960:
.loc 2 733 0
movsd 40(%rdi), %xmm2
.LBE960:
.LBE959:
.LBB961:
.LBB962:
movsd 32(%rdi), %xmm1
...
A union is probably what language pedantics would prefer anyway, and
anything else would be more of a trick.
- Heikki
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