> /* Immediate shift counts are truncated by the output routines (or was it > the assembler?). Shift counts in a register are truncated by SH. Note > that the native compiler puts too large (> 32) immediate shift counts > into a register and shifts by the register, letting the SH decide what > to do instead of doing that itself. */ > /* ??? The library routines in lib1funcs.asm truncate the shift count. > However, the SH3 has hardware shifts that do not truncate exactly as gcc > expects - the sign bit is significant - so it appears that we need to > leave this zero for correct SH3 code. */
So you have that in the RTL stream we should canonicalize "a << 32" to "a", but "a << (b & 31)" is not the same as "a << b"? Also, how is the sign bit is significant? Does it determine whether the value is left- or right-shifted? Finally, is SH2A the same as SH3? Thanks! Paolo
