On 2/27/24 6:40 AM, Segher Boessenkool wrote: > On Tue, Feb 27, 2024 at 02:02:38AM +0530, jeevitha wrote: >> There is no immediate value splatting instruction in Power. Currently, those >> values need to be stored in a register or memory. To address this issue, I >> have updated the predicate for the second operand in vsx_splat to >> splat_input_operand and corrected the assignment of op1 to operands[1]. >> These changes ensure that operand1 is stored in a register. > > input_operand allows a lot of things that splat_input_operand does not, > not just immediate operands. NAK. > > (For example, *all* memory is okay for input_operand, always). > > I'm not saying we do not want to restrict these things, but a commit > that doesn't discuss this at all is not okay. Sorry.
So it seems you're not NAKing the use of splat_input_operand, but just that it needs more explanation in the git log entry, correct? Yes, input_operand accepts a lot more things than splat_input_operand does, but the multiple define_insns this define_expand feeds, uses gpc_reg_operand, memory_operand and splat_input_operand for their operands[1] operand (splat_input_operand accepts reg and mem too), so it seems to match better what the patterns will be accepting and I always thought that using predicates that more accurately reflect what the define_insns expect/accept lead to better code gen. Mike, was it just an oversight to not use splat_input_operand for the vsx_splat_<mode> expander or was input_operand a conscious decision? If input_operand was used purposely, then we can just fall back to the s/op1/operands[1]/ change which we already know fixes the bug. Peter
