On Fri, Mar 06, 2015 at 01:05:31PM +0100, Richard Biener wrote: > On Thu, Mar 5, 2015 at 9:06 PM, Michael Meissner > <meiss...@linux.vnet.ibm.com> wrote: > > This patch fixes PR 65240, which was a latent bug that was introduced when I > > added the -mupper-regs support to the PowerPC compiler. In the PowerPC > > compiler, if you use -ffast-math, the compiler allows floating point > > constants > > in move RTLs until register allocation time, in order to allow the > > optimizations that replace division by a constant with multiplication by the > > reciprocal. > > Don't we perform this optimization on the GIMPLE/tree level already? > > Richard.
I've suspected that the code is a hold over from the days when the multiply by the reciprocal was done in RTL. I didn't want to change the logic right now, but it something that should be investigated when GCC 6.0 opens up. -- Michael Meissner, IBM IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA email: meiss...@linux.vnet.ibm.com, phone: +1 (978) 899-4797
