Pitchumani Sivanupandi <pitchumani.s@xxxxxxxxxxx> writes: > Consider the following test case: > // gcc-4.6.1// option: -O1 > register void *ptr asm("rbx") ; > void testfn1(void* func){ ptr = func; // removed as dead code goto *ptr;} > When compiling with O1 option, 'ptr = func' definition is removed as dead code. But ref[1] says it should not be deleted even if it appears to be dead. > In dead code elimination (gcc/dce.c), the register definition is not checked for "global register variable". > Is gcc's behaviour is correct? > ref1: http://gcc.gnu.org/onlinedocs/gcc/Global-Reg-Vars.html That is definitely a bug. Please file a bug report as described at http://gcc.gnu.org/bugs . Thanks. Ian