> The following hunk of code results in UB on the recently added testcase, > because if cmp_mode is SImode or DImode, then 1 << 32 or 1 << 64 is > undefined. Fixed by using GET_MODE_MASK, plus UINTVAL because size is > really unsigned (code later on uses unsignedp=1 too).
Doesn't the current check make sure that the RTL constant is valid for the mode though (since RTL constants are sign-extended for their mode)? See emit_block_move_via_movmem for an equivalent check with GET_MODE_MASK >> 1. -- Eric Botcazou
