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[Bug rtl-optimization/82153] missed optimization: double rounding
- From: "arjan at linux dot intel.com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sat, 09 Sep 2017 23:06:05 +0000
- Subject: [Bug rtl-optimization/82153] missed optimization: double rounding
- Auto-submitted: auto-generated
- References: <bug-82153-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82153
--- Comment #4 from Arjan van de Ven <arjan at linux dot intel.com> ---
btw gcc has no issue with just generating cvttsd2si
int roundme2(double A)
{
return A * 4.3;
}
generates
20: f2 0f 59 05 00 00 00 mulsd 0x0(%rip),%xmm0 # 28
<roundme2+0x8>
27: 00
28: f2 0f 2c c0 cvttsd2si %xmm0,%eax
2c: c3 retq
so maybe the real missed optimization is a trunc() followed by
assign-to-integer as a general thing