naga raj <gnuuser.raj@xxxxxxxxx> writes: > I need to emit a swap instruction from a embedded target which is > using Gcc-4.1.2. > > I am trying to emit a instruction which will perform following operation > > R0=0x12345678; > > swap R1,R0 > > Then after this R1 should contain R1= 0x00007856; Not 0x78563421? > As there is no bswap rtl expression in Gcc-4.1.2 I have tried various > alternatives like: > > 1. Used rotate rtl expression > > 2. ashift,ashiftrt and or to generate the above instruction > > > but compiler is not generating(emitting) swap instruction. Current gcc has a bswap RTL pattern which swaps bytes in a word. It was added in gcc 4.3. That's the thing to use if your instruction actually swaps bytes in a word. For versions of gcc before that you will have to use an intrinsic function. Ian
