On Mon, Jul 11, 2016 at 10:07 PM, Michael Meissner <meiss...@linux.vnet.ibm.com> wrote: > These configuration switches will allow the PowerPC GCC developers to switch > defaults in the compiler to debug the code, before making the decision to flip > the default permanently. In the future, when the defaults have been changed, > these configuration options would allow developers to go back to the previous > versions without modifying the code using the --disable-<switch> form. > > The first option is --enable-lra, which changes the compiler so that the > default is to use the LRA register allocator instead of the older RELOAD > allocator. The PowerPC team would like to switch the default, but there is a > critical bug in LRA that must be fixed before we can change the default: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69847 > > The second option is --enable-float128, which changes the compiler so that the > default for VSX systems is to enable the __float128 keyword to allow users > access to the IEEE 128-bit floating point implementation without having to use > the keyword. > > Both of these switches are debug switches, and are not meant to be used by > non-developers. > > The --enable-lra swich causes the following tests to fail: > > * testsuite/gcc.target/powerpc/bool3-p7.c > * testsuite/gcc.target/powerpc/bool3-p8.c > > See bug 71846 (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71846) for more > details. > > The --enable-float128 switch causes libquadmath and libstdc++ to fail because > we do not yet have enough of the support in the compiler to allow these > libraries to build. It is our intention, that we will use the > --enable-float128 option and work on getting the libraries fixed. If I build > just a C compiler and disable building libquadmath, there are no regressions > in > the C tests with __float128 enabled or disabled. > > Can I check these options into the trunk as non-default options?
Instead of adding more configury can we please enable LRA on trunk by default _now_? Otherwise the amount of testing it recieves won't really increase. Richard. > > -- > 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 >
