On 07/29/2010 02:35 PM, Segher Boessenkool wrote: >> asm volatile ( >> "\n\t" >> : >> : "r" (pu8In4), "r" (s32PosInt), "r" (s16CoeffOrg), "r" (u32PosFrac), >> "r" (u8Out), "r" (u32Step), "r" (u32TgtWidth) >> : "r2", "r3", "r4", "r5", "r6", "r7", "r8 >> ); > > You have 7 inputs and 7 clobbers. Assuming this is ARM or some other > arch with about 16 regs, this is very much pushing the boundaries of > the possible. > >> reg_org.c:12: error: can't find a register in class 'GENERAL_REGS' >> while reloading 'asm' >> reg_org.c:12: error: 'asm' operand has impossible constraints >> >> I Want to know >> 1-> why compilation is happening with gcc-4.2 toolchian not with gcc-4.3 > > You got lucky with 4.2, and you don't with 4.3 . > >> 2-> what is the difference between gcc-4.2 and gcc4.3 related to asm >> volatile > > Nothing really. The compiler sometimes needs a few registers to do other > things, but you used up all of them. That's right. If you look a bit more you will see that this is the same question as http://gcc.gnu.org/ml/gcc-help/2010-07/msg00046.html which I answered in the same way, but was ignored. Perhaps they'll keep asking until they get an answer they like. Andrew.
