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On 6/17/09, Jeff Law <law@redhat.com> wrote:It'll completely disable the RTL loop optimizers. Granted this is less important today than before, but it's still bad. And more importantly, the register allocators and reload should be fixed to DTRT rather than hacking around them.
Richard Guenther wrote:
On Wed, Jun 17, 2009 at 4:01 PM, H.J. Lu<hongjiu.lu@intel.com> wrote:Agreed. In fact, it can have horrific performance impacts.
Hi,
Some SSE4 instructions have implicit XMM0 operand. This patch helps RA deal with them by forcing operand into XMM0 during expand. OK for trunk and 4.4?
I don't think it's a particularly good idea to put things in hardregs that early.
Why? Most optimizazions that can be done for this insn can only be
done on GIMPLE, right? And the insn must have that specific register.
So unless I am missing something, I don't see why this patch would do
any harm.
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