/* * 830_cast_base_index — indexing a DIRECT-CAST base `(e:*[N]T)[i]` must * stride by the cast element type's size, not the 8B default (task * #19old, .ai/rob-19old-spec.md). wwstage-only fix; cstage was already * correct. * * The bug: cgindex (selfhost/cmd/wcc/cgenexpr.ww) derived the element * stride/load-width `esz` only for N_DOT / N_UN-deref / N_INDEX base * node-kinds (read off the stamped index-result tinfo n.type_). An * N_CAST base matched NO arm, so esz stayed at the 8B default — for a * narrow element (u32/u16/u8) the stride and load width were both * wrong and the read returned 0/garbage. cstage reads it uniformly via * idx_eff(base->type)->sub->size (cmd/w6c/cgen.c N_INDEX); the fix adds * `|| base.kind == nkind.N_CAST` to the stamped-tinfo esz arm, which * fixes stride + load width + signedness together (all read from dt). * * row | shape | stride | want * ---------+-------------------------------+--------+------ * u32_idx | [4]u32, ((&a):*[4]u32)[i] | 4 | 30 * u16_idx | [4]u16, ((&a):*[4]u16)[i] | 2 | 30 * u8_idx | [4]u8, ((&a):*[4]u8)[i] | 1 | 40 * u64_ctl | [4]u64, ((&a):*[4]u64)[i] | 8 | 20 (control) * * The whitelist of base node-kinds was whack-a-mole (#19old residuals): * N_CALL, N_SLICE and N_TYPEASSERT bases ALSO fell to the 8B default. The * fix routes every non-ident, non-N_INDEX base through the stamped-n.type_ * arm (mirrors cstage's uniform idx_eff, no node-kind gate). These rows * pin the residual base kinds: * * call_idx | mk(&a)[i] (N_CALL *[4]u32) | 4 | 30 * slc_idx | a[0:4][i] (N_SLICE []u16) | 2 | 30 * asrt_idx | (v as *[4]u16)[i] (N_TYPEASSERT) | 2 | 30 * * The <8B rows are the mutation-sane rows: pre-fix wwstage strides by 8 * and reads 0/garbage. u64_ctl pins no-regress for the already-correct * 8B-stride case. A byte-id row pins cstage==wwstage `.s` for the * cast-base index source (the convergence the fix delivers). */ #include #include #include #include #include static int runwait(const char *cmd) { int rc = system(cmd); if (rc == -1) return -1; if (WIFEXITED(rc)) return WEXITSTATUS(rc); return -1; } struct row { const char *label; const char *src; int want; }; static const struct row rows[] = { /* u32_idx — stride 4 / MOVL. THE bug: pre-fix wwstage strides by * 8 and reads 0. */ { "u32_idx", "package main;\n" "export fn main() i32 = {\n" "\tlet a: [4]u32 = [10u32, 20u32, 30u32, 40u32];\n" "\tlet i: int = 2;\n" "\treturn ((&a): *[4]u32)[i]: i32;\n" "};\n", 30 }, /* u16_idx — stride 2 / MOVW. */ { "u16_idx", "package main;\n" "export fn main() i32 = {\n" "\tlet a: [4]u16 = [10u16, 20u16, 30u16, 40u16];\n" "\tlet i: int = 2;\n" "\treturn ((&a): *[4]u16)[i]: i32;\n" "};\n", 30 }, /* u8_idx — stride 1 / MOVB. */ { "u8_idx", "package main;\n" "export fn main() i32 = {\n" "\tlet a: [4]u8 = [10u8, 20u8, 30u8, 40u8];\n" "\tlet i: int = 3;\n" "\treturn ((&a): *[4]u8)[i]: i32;\n" "};\n", 40 }, /* u64_ctl — stride 8 control: already correct (matches the 8B * default), guards no-regress for the wide-element cast base. */ { "u64_ctl", "package main;\n" "export fn main() i32 = {\n" "\tlet a: [4]u64 = [10u64, 20u64, 30u64, 40u64];\n" "\tlet i: int = 1;\n" "\treturn ((&a): *[4]u64)[i]: i32;\n" "};\n", 20 }, /* call_idx — N_CALL base mk(&a)[i], stride 4 / MOVL. #19old residual: * a call-returning-pointer base also fell to the 8B default. */ { "call_idx", "package main;\n" "fn mk(p: *[4]u32) *[4]u32 = { return p; };\n" "export fn main() i32 = {\n" "\tlet a: [4]u32 = [10u32, 20u32, 30u32, 40u32];\n" "\tlet i: int = 2;\n" "\treturn mk(&a)[i]: i32;\n" "};\n", 30 }, /* slc_idx — N_SLICE base a[0:4][i], stride 2 / MOVZWQ. #19old * residual: a slice-expression base also fell to the 8B default. */ { "slc_idx", "package main;\n" "export fn main() i32 = {\n" "\tlet a: [4]u16 = [10u16, 20u16, 30u16, 40u16];\n" "\tlet i: int = 2;\n" "\treturn a[0:4][i]: i32;\n" "};\n", 30 }, /* asrt_idx — N_TYPEASSERT base (v as *[4]u16)[i], stride 2 / MOVZWQ. * #19old residual: a type-assert base also fell to the 8B default. */ { "asrt_idx", "package main;\n" "type IP = (*[4]u16 | int);\n" "export fn main() i32 = {\n" "\tlet a: [4]u16 = [10u16, 20u16, 30u16, 40u16];\n" "\tlet v: IP = &a;\n" "\tlet i: int = 2;\n" "\treturn (v as *[4]u16)[i]: i32;\n" "};\n", 30 }, }; static int run_driver(const char *driver, const struct row *r, int i) { char tmpdir[64], src[128], outbin[128], rmcmd[160], cmd[1024]; snprintf(tmpdir, sizeof tmpdir, "/tmp/cbi_%d_d_%d", getpid(), i); mkdir(tmpdir, 0755); snprintf(src, sizeof src, "%s/cbi_%d_%d.ww", tmpdir, getpid(), i); snprintf(outbin, sizeof outbin, "%s/cbi_%d_%d", tmpdir, getpid(), i); snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir); FILE *f = fopen(src, "wb"); if (!f) { runwait(rmcmd); return -1; } fputs(r->src, f); fclose(f); snprintf(cmd, sizeof cmd, "%s build -o %s %s 2>/dev/null", driver, outbin, src); if (runwait(cmd) != 0) { fprintf(stderr, "row[%s]: build via %s failed\n", r->label, driver); runwait(rmcmd); return -1; } int got = runwait(outbin); runwait(rmcmd); return got; } /* asm_byte_identical — w6c vs w6c_ww .s for the same source must match. */ static int asm_byte_identical(const char *bin, const struct row *r, int i) { char src[64], cs[64], ws[64], cmd[1024]; snprintf(src, sizeof src, "/tmp/cbi_asm_%d_%d.ww", getpid(), i); snprintf(cs, sizeof cs, "/tmp/cbi_asm_%d_%d_c.s", getpid(), i); snprintf(ws, sizeof ws, "/tmp/cbi_asm_%d_%d_w.s", getpid(), i); FILE *f = fopen(src, "wb"); if (!f) return -1; fputs(r->src, f); fclose(f); snprintf(cmd, sizeof cmd, "%s/w6c -o %s %s 2>/dev/null", bin, cs, src); if (runwait(cmd) != 0) { fprintf(stderr, "row[%s]: w6c errored\n", r->label); unlink(src); return -1; } snprintf(cmd, sizeof cmd, "%s/w6c_ww -o %s %s 2>/dev/null", bin, ws, src); if (runwait(cmd) != 0) { fprintf(stderr, "row[%s]: w6c_ww errored\n", r->label); unlink(src); unlink(cs); return -1; } FILE *fc = fopen(cs, "rb"); FILE *fw = fopen(ws, "rb"); int rc = 0; if (!fc || !fw) { rc = -1; } else { for (;;) { int a = fgetc(fc); int b = fgetc(fw); if (a != b) { rc = -1; break; } if (a == EOF) break; } } if (fc) fclose(fc); if (fw) fclose(fw); if (rc != 0) fprintf(stderr, "row[%s]: cstage vs wwstage asm differs\n", r->label); unlink(src); unlink(cs); unlink(ws); return rc; } int main(void) { const char *bin = getenv("BIN"); if (!bin) bin = "out/bin"; char absbin[1024]; if (bin[0] != '/') { char cwd[1024]; if (getcwd(cwd, sizeof cwd) == NULL) return 1; snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin); bin = absbin; } char cdrv[1024]; snprintf(cdrv, sizeof cdrv, "%s/ww", bin); char wdrv[1024]; snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin); struct { const char *name; const char *path; int gated_on_existence; } drivers[] = { { "cstage", cdrv, 0 }, { "wwstage", wdrv, 1 }, { NULL, NULL, 0 }, }; int n = (int)(sizeof rows / sizeof rows[0]); int total = 0, fail = 0; for (int d = 0; drivers[d].name; d++) { if (drivers[d].gated_on_existence && access(drivers[d].path, X_OK) != 0) { fprintf(stderr, "cast_base_index: skip %s (no %s)\n", drivers[d].name, drivers[d].path); continue; } for (int i = 0; i < n; i++) { int got = run_driver(drivers[d].path, &rows[i], i); total++; if (got != rows[i].want) { fprintf(stderr, "cast_base_index[%s][%s]: exit=%d want=%d\n", drivers[d].name, rows[i].label, got, rows[i].want); fail++; } } } if (access(wdrv, X_OK) == 0) { for (int i = 0; i < n; i++) { total++; if (asm_byte_identical(bin, &rows[i], i) != 0) fail++; } } if (fail) { fprintf(stderr, "cast_base_index: %d/%d fixtures failed\n", fail, total); return 1; } printf("cast_base_index: %d/%d ok\n", total, total); return 0; }