search for: findoptimalmemoplow

...the odd thing is that the 16 bit move is performed by picking bytes separately from the source struct, then combining them into 16 bit values by means of shifts, swap, and or, then moved as words to the destination. I don’t know why simple 16 bit load and stores are used instead. Will try to track findOptimalMemOpLowering with the debugger to see if I see some light. So thanks for pointing that out to me. John Tel: 620 28 45 13 > On 13 May 2019, at 09:33, Tim Northover <t.p.northover at gmail.com> wrote: > > Hi Joan, > > On Mon, 13 May 2019 at 07:53, Joan Lluch <joan.lluch at iclou...

Hi John, On Tue, 14 May 2019 at 17:51, Joan Lluch <joan.lluch at icloud.com> wrote: > This problem is also shared by the MSP430 target, and it’s very easy to reproduce by just compiling the code that I posted before. That's some good detective work; it definitely explains what you're seeing. Since MSP430 is affected it would probably be pretty easy to upstream an alignment-aware

Hi Tim, Thanks for your reply. That’s what I was afraid of. I will try on the cfe-list as you suggest though. The reason I want structs to be aligned/padded to 2 bytes is because my architecture only has 16 bit operations. I can read (sign and zero extended) and write (truncated) 8 bit data from/to memory, but all intermediate operations in registers are performed in 16 bit registers. This

Hi Joan, On Mon, 13 May 2019 at 18:01, Joan Lluch <joan.lluch at icloud.com> wrote: > After looking at it a bit further, I think this is a Clang thing. Clang issues “align 2” if the struct has at least one int (2 bytes), but also if the entire struct size is multiple of 2. For example a struct with 4 char members. In these cases the LLVM backend correctly creates word sized load/stores

Hi, For my 32-bit architecture backend, I run into trouble because strcpy is converted into i64 store instructions, on which instruction selection fails. No i64 store is declared anywhere in my .td files or architecture backend, so I would assume that they are automatically converted into 2 i32 stores, but apparently, that is not the case. Do I need to add anything to my backend to have this