Implement basic aarch64 struct arg passing ABI

- Missing: vaargs, >2 member HFAs

- Reworked the way stack allocation references are lowered. Now RSTACK
  persists throughout all passes until emit. This allows deferring stack
  frame layouting until the end in a less messy way than before, which
  was emiting frame-pointer relative addresses @ isel time and patching them up
  later in emit to account for actual stack frame layout.

1 files changed, 1 insertions, 3 deletions

diff --git a/src/ir_regalloc.c b/src/ir_regalloc.c
index 31f03c2..26b90a6 100644
--- a/src/ir_regalloc.c
+++ b/src/ir_regalloc.c
@@ -111,9 +111,7 @@ typedef struct RegAlloc {
        stktop;
 } RegAlloc;
 
-#define stkslotref(fn, off)                             \
-      mkaddr((IRAddr){.base = mkref(RREG, mctarg->bpr), \
-                      .disp = -(fn)->stksiz - 8 - (off)})
+#define stkslotref(fn, off) mkref(RSTACK, (fn)->stksiz + (off))
 
 /* Parallel moves algorithm from QBE
  * <https://c9x.me/git/qbe.git/tree/rega.c?id=e493a7f23352f51acc0a1e12284ab19d7894488a#n201> */