Posts / Tag
#abi
2 posts
RISC-VAssembly and the ABI: Registers, Calling Convention, Stack Frames, ELF
Part 6 of the RISC-V series. I follow the psABI calling convention and stack frame through real C functions. The work() frame was 80 bytes, and arguments from the 9th onward went on the stack. I checked argument locations per ABI and relocations, and linker relaxation shrank .text from 800 bytes to 712 bytes.
RISC-VRV64I: W Instructions, Sign-Extension Rules, and What Differs from 32-Bit
Part 5 of the RISC-V series. I checked RV64I's W instructions and sign-extension rules on QEMU. 0x7fffffff+1 became 0xffffffff80000000 with addw, and 64-bit constants took an average of 7.887 instructions with li. I also look at why utoa10 from part 1 grew.