kc3-lang/libjpeg-turbo

2023-07-28T11:46:10

x86-64 SIMD: Use std stack frame/prologue/epilogue This allows debuggers and profilers to reliably capture backtraces from within the x86-64 SIMD functions. In places where rbp was previously used to access temporary variables (after stack alignment), we now use r15 and save/restore it accordingly. The total amount of work is approximately the same, because the previous code pushed the pre-alignment stack pointer to the aligned stack. The new prologue and epilogue actually have fewer instructions. Also note that the {un}collect_args macros now use rbp instead of rax to access arguments passed on the stack, so we save a few instructions there as well. Based on: https://github.com/alk/libjpeg-turbo/commit/debcc7c3b436467aea8d02c66a514c5099d0ad37 Closes #707 Closes #708