Hi Vineet, Vineet Gupta wrote, > The syscall ABI includes the gcc functional calling ABI since a syscall > implies userland caller and kernel callee. > > The current gcc ABI (v3) for ARCv2 ISA required 64-bit data be passed in > even-odd register pairs, (potentially punching reg holes when passing such > values as args). This was partly driven by the fact that the double-word > LDD/STD instructions in ARCv2 expect the register alignment and thus gcc > forcing this avoids extra MOV at the cost of a few unused register (which we > have plenty anyways). > > This however was rejected as part of upstreaming gcc port to HS. So the new > ABI v4 doesn't enforce the even-odd reg restriction. > > Do note that for ARCompact ISA builds v3 and v4 are practically the same in > terms of gcc code generation. > > This change is dormant for now (gcc 4.8.x based tools) and will only kick > in with switch to gcc 6.x based tools. > > Signed-off-by: Vineet Gupta <vgupta at synopsys.com> Thanks, applied and pushed, Waldemar
