/*
 * 955_f64xmm_run — runtime + byte-id regression net for #103: an f64
 * value failing to materialise in XMM (X0) before an SSE op. Two faces,
 * same class, both GATE-BLIND (cstage cgen.c and wwstage cgenexpr.ww
 * emitted byte-identical-but-wrong asm, so the 990-997 byte-id gates
 * could never catch a reintroduction — only an executed-and-checked
 * runtime probe can).
 *
 *   FACE X — a no-decimal float-typed integer literal (`0f64`, `8f64`)
 *     is an N_INTLIT carrying float TYPE; the integer-immediate path
 *     stranded it in AX, so `n == 0f64` compared a stale X0 (true for
 *     all n) and `(8f64 * 10.0): i32` read garbage. Fixed by routing
 *     the float-typed N_INTLIT through the float-constant-in-X0 emit
 *     (cgen.c cgexpr_float / cgenexpr.ww cgfloatbits), plus the wwstage
 *     exprfloatkind N_INTLIT arm so the downstream f64->i32 cast emits
 *     CVTTSD2SI not MOVSXD (the #101 structural-vs-stamped asymmetry).
 *   FACE Z — a tuple positional f64 field read (`r.0`, r:(f64,i64))
 *     loaded via the integer op into AX, so `r.0 == 0.0` was wrongly
 *     true. Fixed by a fld_isfloat branch -> MOVSD/MOVSS into X0
 *     (cgen.c:5910 / cgenexpr.ww tuple arm), mirroring the struct-field
 *     float load at cgen.c:1462,1838 (the #96 pattern).
 *
 * Each row carries BOTH dimensions (like 953_f64crossmod_run):
 *   (a) cstage `ww build` + run, asserting the exit code.
 *   (b) w6c vs w6c_ww `.s` cmp — FAILS if the stages diverge. Both
 *       stages are fixed identically, so this stays byte-identical
 *       before and after; it catches one stage being fixed without the
 *       other.
 */
#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[] = {
	/* FACE X false-case: g(8.0) must be 0. On the bug `n == 0f64`
	 * compares against a stale X0 (true for all n) -> 1. */
	{ "x_cmp_false",
	  "package main;\n"
	  "fn g(n: f64) i32 = { if (n == 0f64) { return 1; }; return 0; };\n"
	  "export fn main() i32 = { return g(8.0); };\n", 0 },
	/* FACE X true-case: g(0.0) must still be 1 — the genuine equal
	 * case must survive the fix. */
	{ "x_cmp_true",
	  "package main;\n"
	  "fn g(n: f64) i32 = { if (n == 0f64) { return 1; }; return 0; };\n"
	  "export fn main() i32 = { return g(0.0); };\n", 1 },
	/* FACE X arith: (8f64 * 10.0): i32 == 80. On the bug 8f64 never
	 * reaches X0, the MULSD reads stale X0 -> garbage. */
	{ "x_arith",
	  "package main;\n"
	  "export fn main() i32 = { return (8f64 * 10.0): i32; };\n", 80 },
	/* FACE X negative-lit: `-8f64` is N_UN(TK_MINUS) wrapping a float-
	 * typed N_INTLIT, so the wwstage exprfloatkind must recurse through
	 * the unary into the new N_INTLIT-float arm. g(-8.0) == -8f64 must be
	 * true -> 1; on the bug the literal never reaches X0, the compare is
	 * always false, and g(-8.0) wrongly returns 0. */
	{ "x_neg_cmp_true",
	  "package main;\n"
	  "fn g(n: f64) i32 = { if (n == -8f64) { return 1; }; return 0; };\n"
	  "export fn main() i32 = { return g(-8.0); };\n", 1 },
	/* FACE X negative-lit control: g(8.0) == -8f64 must stay false -> 0.
	 * Guards the negative-literal path against over-reach. */
	{ "x_neg_cmp_false",
	  "package main;\n"
	  "fn g(n: f64) i32 = { if (n == -8f64) { return 1; }; return 0; };\n"
	  "export fn main() i32 = { return g(8.0); };\n", 0 },
	/* FACE Z: tuple positional f64 field compare. r.0 == 0.0 with
	 * r = (8.0, 0) must be false -> 9. On the bug r.0 loads into AX
	 * (integer op), `== 0.0` reads stale X0 -> wrongly true -> 5. */
	{ "z_tuple_field",
	  "package main;\n"
	  "fn norm(n: f64) (f64, i64) = { return (n, 0); };\n"
	  "export fn main() i32 = {\n"
	  "	const r = norm(8.0);\n"
	  "	if (r.0 == 0.0) { return 5; };\n"
	  "	return 9;\n"
	  "};\n", 9 },
	/* CONTROL: the let-bound spelling (`const m = r.0; m == 0.0`) was
	 * already correct (the let-init is float-aware) and must STAY
	 * correct -> 9. Guards against the FACE-Z fix over- or
	 * under-reaching. */
	{ "z_letbound_control",
	  "package main;\n"
	  "fn norm(n: f64) (f64, i64) = { return (n, 0); };\n"
	  "export fn main() i32 = {\n"
	  "	const r = norm(8.0);\n"
	  "	const m = r.0;\n"
	  "	if (m == 0.0) { return 5; };\n"
	  "	return 9;\n"
	  "};\n", 9 },
	{ 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, "f64xmm: 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/wwf64m_%d_%d.ww", getpid(), i);
		FILE *f = fopen(src, "wb");
		if (f == NULL) { fail++; continue; }
		fputs(rows[i].src, f);
		fclose(f);

		/* (a) cstage build + run. */
		char tmpdir[64];
		snprintf(tmpdir, sizeof tmpdir, "/tmp/wwf64m_%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);

		/* (b) cs==ww byte-id gate: emit .s from both stages, cmp. */
		char cs_s[64], ws_s[64];
		snprintf(cs_s, sizeof cs_s, "/tmp/wwf64m_%d_%d_cs.s",
		    getpid(), i);
		snprintf(ws_s, sizeof ws_s, "/tmp/wwf64m_%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 f64 xmm-materialise tests failed\n",
		    fail, n);
		return 1;
	}
	printf("f64xmm: %d/%d ok (cstage run + cs==ww byte-id)\n", n, n);
	return 0;
}