ww/test/wcc/916_arr_float_call_index_run.c

/*
 * 916_arr_float_call_index_run — runtime + byte-id net for #125: in
 * the `arr[i] = v` ASSIGN path, when the element type is float and the
 * INDEX sub-expression clobbers X0 (e.g. a fn-call index), the value
 * was LOST pre-fix because both stages PUSHed AX (junk for floats) +
 * never spilled X0 across the idx/base eval, then re-emitted MOVSS/
 * MOVSD X0, (BX) using the already-clobbered X0.
 *
 * The bug was load-bearing only after #122 routed the value through
 * X0 (pre-#122 it sat in AX and the existing PUSH AX accidentally
 * protected it). Broken byte-identically between cstage and wwstage,
 * so pre-existing + non-regression but exposed by #122.
 *
 * Fix mirrors the *p = v float deref-store at cmd/w6c/cgen.c:4187
 * (the only other arr[i]= /-style float store): for float elements,
 * substitute the PUSHQ AX / POPQ AX pair around the idx/base eval
 * with SUBQ $8,SP + MOVSS/MOVSD X0,(SP) ... MOVSS/MOVSD (SP),X0 +
 * ADDQ $8,SP. Non-float keeps PUSHQ AX (the original) so the str/
 * slice 3-word pop order at the end of the branch is undisturbed.
 *
 * The fix changes asm shape for ALL float arr[i]= stores (its own
 * scoped fold, byte-identical between stages); covered by the 990-
 * 997 byte-id gates + this test's standalone w6c vs w6c_ww cmp.
 *
 * Rows cover:
 *   - f64_call_index: a[geti(1.0)] = 1.5f64 — the canonical repro,
 *     geti is a fn that adds 1 and returns i32 (its body clobbers X0).
 *     Pre-fix exit=2 (a[2] held geti's last X0=2.0 → cast i32=2);
 *     post-fix exit=1 (a[2] = 1.5 → cast i32 = 1).
 *   - f32_call_index: same shape, f32 element — pre-fix even worse
 *     because CVTSD2SS at #104 only touched X0; AX store would be
 *     garbage. Post-fix exit=1 same as f64.
 *   - f64_lit_index: a[2] = 1.5f64 with a LITERAL index — pre-fix
 *     this already worked (cgexpr of an int literal doesn't clobber
 *     X0). Regression guard.
 *   - f64_localvar_index: a[k] = 1.5f64 with k = 2 (local var) —
 *     pre-fix also worked (MOVQ off(BP), AX doesn't clobber X0).
 *     Regression guard.
 *   - f64_arith_index: a[k + 1] = 1.5f64 — integer arith on locals
 *     doesn't clobber X0 either; pre-fix worked. Regression guard.
 *
 * Each row carries (a) cstage `ww build` + run asserting exit code
 * and (b) w6c vs w6c_ww `.s` cmp (rule-10 byte-id).
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>

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_exit; };

static const struct row rows[] = {
	{ "f64_call_index",
	  "package main;\n"
	  "export fn geti(x: f64) i32 = {\n"
	  "	let y: f64 = x + 1.0;\n"
	  "	return (y: i32);\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "	let a: [4]f64 = [99.0, 99.0, 99.0, 99.0];\n"
	  "	a[geti(1.0)] = 1.5f64;\n"
	  "	let v: i32 = (a[2]: i32);\n"
	  "	return v;\n"
	  "};\n", 1 },
	/* Body of getj uses f64 arith → clobbers X0 via the materialise-
	 * literal-in-X0 sequence and the ADDSD. The call's argument is
	 * int (not float), so the call-arg-push goes through the integer
	 * convention and avoids a pre-existing cs/ww f32-arg-push MOVSD-
	 * vs-MOVSS divergence in pre-call arg materialisation (sibling
	 * bug, filed separately). Pre-fix the post-call X0 (set to the
	 * residue of 1.0+1.0 = 2.0) would overwrite the 1.5f32 in X0,
	 * yielding garbage. */
	{ "f32_call_index",
	  "package main;\n"
	  "export fn getj(seed: i32) i32 = {\n"
	  "	let y: f64 = (seed: f64) + 1.0;\n"
	  "	return (y: i32);\n"
	  "};\n"
	  "export fn main() i32 = {\n"
	  "	let a: [4]f32 = [99.0f32, 99.0f32, 99.0f32, 99.0f32];\n"
	  "	a[getj(1)] = 1.5f32;\n"
	  "	let v: i32 = (a[2]: i32);\n"
	  "	return v;\n"
	  "};\n", 1 },
	{ "f64_lit_index",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: [4]f64 = [99.0, 99.0, 99.0, 99.0];\n"
	  "	a[2] = 1.5f64;\n"
	  "	let v: i32 = (a[2]: i32);\n"
	  "	return v;\n"
	  "};\n", 1 },
	{ "f64_localvar_index",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: [4]f64 = [99.0, 99.0, 99.0, 99.0];\n"
	  "	let k: i32 = 2;\n"
	  "	a[k] = 1.5f64;\n"
	  "	let v: i32 = (a[2]: i32);\n"
	  "	return v;\n"
	  "};\n", 1 },
	{ "f64_arith_index",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: [4]f64 = [99.0, 99.0, 99.0, 99.0];\n"
	  "	let k: i32 = 1;\n"
	  "	a[k + 1] = 1.5f64;\n"
	  "	let v: i32 = (a[2]: i32);\n"
	  "	return v;\n"
	  "};\n", 1 },
	{ NULL, NULL, 0 }
};

static int
slurp_eq(const char *a, const char *b)
{
	FILE *fa = fopen(a, "rb");
	FILE *fb = fopen(b, "rb");
	if (!fa || !fb) { if (fa) fclose(fa); if (fb) fclose(fb); return -1; }
	int rc = 0;
	for (;;) {
		int ca = fgetc(fa);
		int cb = fgetc(fb);
		if (ca != cb) { rc = -1; break; }
		if (ca == EOF) break;
	}
	fclose(fa); fclose(fb);
	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 w6c[1100], w6c_ww[1100];
	snprintf(w6c, sizeof w6c, "%s/w6c", bin);
	snprintf(w6c_ww, sizeof w6c_ww, "%s/w6c_ww", bin);
	if (access(w6c_ww, X_OK) != 0) {
		fprintf(stderr, "arrfcidx: w6c_ww missing — cannot run "
		    "the cs==ww byte-id gate (the whole point of this test)\n");
		return 1;
	}

	int n = 0, fail = 0;
	for (int i = 0; rows[i].src; i++, n++) {
		char src[64];
		snprintf(src, sizeof src, "/tmp/wwafc_%d_%d.ww", getpid(), i);
		FILE *f = fopen(src, "wb");
		if (f == NULL) { fail++; continue; }
		fputs(rows[i].src, f);
		fclose(f);

		char tmpdir[64];
		snprintf(tmpdir, sizeof tmpdir, "/tmp/wwafc_%d_d_%d",
		    getpid(), i);
		mkdir(tmpdir, 0755);

		char cmd[2048];
		snprintf(cmd, sizeof cmd, "cd %s && %s/ww build %s",
		    tmpdir, bin, src);
		if (runwait(cmd) != 0) {
			fprintf(stderr, "row[%s]: cstage build failed\n",
			    rows[i].label);
			fail++;
			unlink(src); rmdir(tmpdir);
			continue;
		}

		char outbin[128];
		const char *base = strrchr(src, '/');
		base = base ? base + 1 : src;
		snprintf(outbin, sizeof outbin, "%s/%s", tmpdir, base);
		char *dot = strrchr(outbin, '.');
		if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';

		int got = runwait(outbin);
		if (got != rows[i].want_exit) {
			fprintf(stderr, "row[%s]: cstage exit %d, want %d\n",
			    rows[i].label, got, rows[i].want_exit);
			fail++;
		}
		unlink(outbin); rmdir(tmpdir);

		char cs_s[64], ws_s[64];
		snprintf(cs_s, sizeof cs_s, "/tmp/wwafc_%d_%d_cs.s",
		    getpid(), i);
		snprintf(ws_s, sizeof ws_s, "/tmp/wwafc_%d_%d_ww.s",
		    getpid(), i);

		snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null",
		    w6c, cs_s, src);
		if (runwait(cmd) != 0) {
			fprintf(stderr, "row[%s]: w6c failed\n", rows[i].label);
			fail++; unlink(src); continue;
		}
		snprintf(cmd, sizeof cmd, "%s -o %s %s 2>/dev/null",
		    w6c_ww, ws_s, src);
		if (runwait(cmd) != 0) {
			fprintf(stderr, "row[%s]: w6c_ww failed\n",
			    rows[i].label);
			fail++; unlink(src); unlink(cs_s); continue;
		}
		if (slurp_eq(cs_s, ws_s) != 0) {
			fprintf(stderr,
			    "row[%s]: cstage/wwstage .s DIFFER (rule-10 "
			    "byte-id violation)\n", rows[i].label);
			fail++;
		}
		unlink(src); unlink(cs_s); unlink(ws_s);
	}

	if (fail) {
		fprintf(stderr, "%d/%d arr-float-call-idx tests failed\n", fail, n);
		return 1;
	}
	printf("arrfcidx: %d/%d ok (cstage run + cs==ww byte-id)\n",
	    n, n);
	return 0;
}