code wiki / _hdl_build / _regalloc_lf_repro.nx
_regalloc_lf_repro.nx
buildroot/runtime/_hdl_build/_regalloc_lf_repro.nx
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_regalloc_lf_repro.nx -- candidate TEN-SECOND repro for LM-REGALLOC: the
large-frame / high-register-pressure miscompile where the x86 regalloc
miscalculates an alloca-slot offset so a local write lands on a POINTER
ARG's spill slot, corrupting it (the parse_stmt in-source comment; the
same bug my && short-circuit change surfaced by enlarging the function).
RECIPE: pointer arg `p` read early + many if-expr ALLOCAS + CALLS (force p
to spill) + p re-read/written AFTER the allocas. If the bug fires, p is
corrupted -> p[1]=v1 segfaults or p[1]!=42. GREEN(exit0)=no bug here;
RED(segfault/!=42)=repro = the team's deterministic gate. license_tier: ORIGINAL
dependencies 1 imports · 0 importers
imports: nx_syscalls.nx
imported by: nobody (leaf or entry point)
call flow from main pre-order; caps 40 nodes / depth 6 declared; ↻ = already shown
structs
| none |
consts
| none |
functions
| 11 | func rp(s: *u8) -> i64 { var n: i64=0; while s[n]!=(0 as u8){n=n+1} sys_write(1,s,n); return 0 } |
| 12 | func rn(v: i64) -> i64 { let b: *u8=sys_mmap(28); var m: i64=v; if m<0{m=0-m} let t: *u8=sys_mmap(28); var k: i64=0; if m==0{t[0]=48 as u8;k=1}; while m>0{t[k]=(48+(m%10)) as u8;m=m/10;k=k+1}; var i: i64=0; while i<k{b[i]=t[k-1-i];i=i+1}; sys_write(1,b,k); return 0 } |
| 14 | func work(x: i64) -> i64 { return x * 2 + 1 } called by 1: bug |
| 16 | func bug(p: *i64) -> i64 |
| 43 | func main() -> i64 |