On Fri, Jul 6, 2012 at 9:27 AM, Feng LI <nemoking...@gmail.com> wrote: > Hi folks, > > I have a backend hook (x86_64) for builtin function expansion, so > I have this: > > expand_simple_binop (DImode, ASHIFT, op0, > GEN_INT (32),op0,1,OPTAB_DIRECT); > > to generate op0 = op0<<32 (op0 is the first argument of this builtin > function, with type SIZE_T) > > The thing goes well in the assemble code, where I got: > movq 104(%rbx), %rax > salq $32, %rax > addq 80(%rbx), %rax > > as expected. > > But at execution time, it gives me a strange behavior, > So I disassemble the code, > > 401135: 48 8b 43 68 mov 0x68(%rbx),%rax > 401140: 48 c1 e0 20 shl $0x20,%rax > 401144: 48 03 43 50 add 0x50(%rbx),%rax > > and it turns out salq are changed to shl which leads to the > strange behavior. shl only allows shift less or equal than 31. >
I was reminded that SHL == SAL. Your problem lies elsewhere. H.J.
