On Mon, Apr 02, 2018 at 05:30:54PM -0700, Jacob Keller wrote: > On Mon, Apr 2, 2018 at 7:05 AM, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > +/* PCIe speed to Mb/s reduced by encoding overhead */ > > +#define PCIE_SPEED2MBS_ENC(speed) \ > > + ((speed) == PCIE_SPEED_16_0GT ? (16000*(128/130)) : \ > > + (speed) == PCIE_SPEED_8_0GT ? (8000*(128/130)) : \ > > + (speed) == PCIE_SPEED_5_0GT ? (5000*(8/10)) : \ > > + (speed) == PCIE_SPEED_2_5GT ? (2500*(8/10)) : \ > > + 0) > > + > > Should this be "(speed * x ) / y" instead? wouldn't they calculate > 128/130 and truncate that to zero before multiplying by the speed? Or > are compilers smart enough to do this the other way to avoid the > losses? Yep, thanks for saving me yet more embarrassment.
