On 10 January 2012 19:49, Artur Skawina <art.08...@gmail.com> wrote: >> I have porting the runtime/phobos asms to gcc asm on my to-do list, will >> try to get to that within two weeks. What would be the preferred way - >> version() guards? if yes - what version? Or would you prefer replacing >> the asms, if the changes are not going to be merged upstream anyway? > > So i decided to start with this today. As i have a case where turning on > logging increases a programs run time from seconds to hours, while it > spends most of the time in the GC, thought gcbits would be a good place > to start. > > But after adding gdc asm support to GCBits.testClear() the only thing that > changed was this: > > XXXXXXXX <uint gc.gcbits.GCBits.testClear(uint)>: > push %eRX > mov %eRX,%eRX > mov XX(%eRX),%eRX > - push %eRX > - mov %eRX,%eRX > - shr $0x5,%eRX > - lea XX(,%eRX,4),%eRX > - mov XX(%eRX),%eRX > - add (%eRX),%eRX > - mov $0x1,%eRX > - shl %Rl,%eRX > - mov %eRX,%eRX > mov (%eRX),%eRX > - not %eRX > - and %eRX,%eRX > - and %eRX,%eRX > - mov %eRX,(%eRX) > - pop %eRX > + mov XX(%eRX),%eRX > + btr %eRX,XX(%eRX) > + sbb %eRX,%eRX > pop %eRX > ret > > OK, the function turned into ~ three instructions, good, but why didn't it > then get inlined into any of the callers? Trying to force things with an > attribute turned up this: >
four instructions. :~) > ../../../libphobos/gc/gcx.d: In member function 'gc.gcx.Gcx.fullcollect': > BUILD32/gdc/dev/gcc-4.6.1/libphobos/gc/gcbits.d:119:0: sorry, unimplemented: > inlining failed in call to 'testClear': function body not available > ../../../libphobos/gc/gcx.d:2647:0: sorry, unimplemented: called from here > BUILD32/gdc/dev/gcc-4.6.1/libphobos/gc/gcbits.d:119:0: sorry, unimplemented: > inlining failed in call to 'testClear': function body not available > ../../../libphobos/gc/gcx.d:2729:0: sorry, unimplemented: called from here > make[3]: *** [gc/gcx.o] Error 1 > > Any way to make this work? Much of the asm gains will be lost when the code > isn't inlined. > > artur > How is the function written? -- Iain Buclaw *(p < e ? p++ : p) = (c & 0x0f) + '0';
