On Tue, Feb 14, 2017 at 03:26:09PM +0100, Sebastian Huber wrote: > >>>I propose to mark powerpc*-*-*spe* as obsolete in GCC 7. This includes > >>>the spe.h installed header file, all the __builtin_spe* intrinsics, the > >>>-mfloat-gprs= command-line option, and the support for the SPE ABIs. > >>> > >>>No one has properly tested these targets in a long time (the latest > >>>testresults I could find are from July 2015, >1000 failures), and the > >>>SPE support makes a lot of code much more complex. > >>> > >>>Any objections to this obsoletion? GCC 7 will then be the last release > >>>with support for SPE (it will need --enable-obsolete to build these > >>>targets), and we will delete the SPE support during GCC 8 development. > >>the SPE unit is still used in the embedded PowerPC processors from > >>Freescale/NXP/Qualcomm, for example QorIQ P1020. These products are not > >>obsolete or even not recommended for new designs. These chips have a > >>long product life-cycle.
Yes. SPE is part of some e500 and some e200 CPUs I think (but only some, in both cases). > >It is also used in many PPC based microcontrollers, which are used in > >the automotive industry and other places where you need highly reliable > >and robust but powerful microcontrollers. However, gcc support for > >these has traditionally been poor - there is little support for the > >variety of cores and configurations available from Freescale/NXP. I > >believe there is a chicken-and-egg situation here - few people use gcc > >with these devices because there is poorer device support compared to > >Freescale CodeWarrior or Green Hills, and there is little incentive for > >gcc developers (such as the CodeSourcery or IBM PPC folks) to support > >devices in gcc if no one uses that combination. > > Yes, we use GCC also one these chips, however, due to the lack of VLE > support the situation is even worse. Looks like support for the non-IBM > PowerPC is dead in GCC. I can understand this pretty well. It's not true though; we still support all those cores, just not the VLE extension (we never have), and I propose GCC 7 will drop the SPE extension as well -- not all other support we have for those cores. They will have to use soft float, alas. We also still support all non-IBM non-FSL cores. > With the Qualcomm takeover of Freescale/NXP I guess the PowerPC has no > future in this area and they will move to ARM for the processor cores. That is my understanding as well, yes. > >>Its a pity that Freescale/NXP/Qualcomm stopped to support GCC > >>development and IBM is burdened to take care of this. I can understand > >>your reasoning, however, its not true that there are no users of the SPE > >>unit. (I never said there are no users, I'm well aware). The burden is not just IBM's, also all other GCC developers and users. > >I think what would be needed would be for Freescale/NXP/Qualcomm to put > >some money and effort in here, with the aim of making gcc their standard > >compiler for these targets (as they have done for ARM, replacing the old > >CodeWarrior compiler). > > > >Failing that, it is of course better to have no SPE support than broken > >SPE support, especially if it makes development harder for other devices. > > Yes, in case Qualcomm shows no interest to support their PowerPC stuff > in GCC its quite understandable to remove the support for it eventually. > IBM already did a great job in keeping it up and running for a long time. That is the unfortunate reality. Segher