ww/test/wcc/964_f32lit_run.c

/*
 * 964_f32lit_run — runtime + byte-id regression net for #104 fold-1: an
 * f32-typed float literal must NARROW to single precision in X0 before
 * the f32 consumer reads it. Both stages (cstage cgen.c cgexpr_float,
 * wwstage cgenexpr.ww cgfloatbits) materialise a float literal as a
 * 64-bit DOUBLE in X0 (MOVQ bits -> MOVSD). For an f32-typed literal the
 * downstream MOVSS store/return then reads the LOW 4 BYTES of that
 * double — garbage (0x00000000 == 0.0f for most clean values, which is
 * why 0.0 coincidentally survived the bug). fold-1 appends CVTSD2SS
 * X0,X0 at both literal sites (N_FLOATLIT + the float-typed N_INTLIT
 * arm) when the node is f32-typed, so the value reaches X0 as a true
 * single. Both stages emit byte-identical asm, so the 990-997 byte-id
 * gates can NEVER catch a reintroduction — only an executed-and-checked
 * runtime probe can. (951_f64cgen is GATE-BLIND here: its f32 rows only
 * assert NaN ordering, never a concrete f32 value.)
 *
 * SCOPE: fold-1 covers literals that carry an explicit f32 TYPE — the
 * `f32` suffix (`1.0f32`, `1.5f32`) and the no-decimal N_INTLIT-float
 * arm (`8f32`). An UN-suffixed literal in an f32 context (`let x: f32 =
 * 1.0`) stays ty_untyped_float through the checker, so the literal node
 * is never f32-typed and fold-1's branch can't fire — materialised as a
 * double, stored low-4-bytes -> 0.0f. Fixing that needs fold-2: the
 * checker lowering untyped-float literals to their f32 context type
 * (#104, both checkers). This probe therefore uses suffixed literals
 * exclusively; the un-suffixed gap is tracked under #104 fold-2.
 *
 * Each row carries BOTH dimensions (like 955_f64xmm_run):
 *   (a) cstage `ww build` + run, asserting the exit code.
 *   (b) w6c vs w6c_ww `.s` cmp — FAILS if the stages diverge (rule-10).
 */
#include <stdio.h>
#include <stdlib.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[] = {
	/* The hole 951 misses: a CONCRETE non-trivial f32 value. On the
	 * bug `let x: f32 = 1.0f32` stores the low 4 bytes of double 1.0
	 * (== 0x00000000 == 0.0f), so x:f64 == 0.0 != 1.0 -> 1. */
	{ "bare_value",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let x: f32 = 1.0f32;\n"
	  "	if (x: f64 != 1.0) { return 1; };\n"
	  "	return 0;\n"
	  "};\n", 0 },
	/* arith on f32 literals: 1.5 + 2.5 == 4.0. On the bug both operands
	 * land as 0.0f -> sum 0.0 != 4.0. */
	{ "arith",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let a: f32 = 1.5f32;\n"
	  "	let b: f32 = 2.5f32;\n"
	  "	let s: f32 = a + b;\n"
	  "	if (s: f64 != 4.0) { return 1; };\n"
	  "	return 0;\n"
	  "};\n", 0 },
	/* value-propagation: f32 returned through an f32 fn + arith on an
	 * f32 literal, truncated to i32. 2.5 + 1.5 == 4.0 -> 4. */
	{ "return_arith",
	  "package main;\n"
	  "fn g() f32 = { return 2.5f32; };\n"
	  "export fn main() i32 = {\n"
	  "	let r: f32 = g() + 1.5f32;\n"
	  "	return r: i32;\n"
	  "};\n", 4 },
	/* the float-typed N_INTLIT arm (`8f32` — no decimal, f32 suffix).
	 * Same materialiser, same fold-1 branch. -> 8. */
	{ "intlit_f32_arm",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let y: f32 = 8f32;\n"
	  "	return y: i32;\n"
	  "};\n", 8 },
	/* genuine single-rounding: 2^24 + 1 is NOT representable in f32 and
	 * rounds back to 2^24 (round-to-even). If the add ran in double it
	 * would be 16777217.0 != 16777216.0 -> 1. Proves the value is a
	 * true single, not the low half of a double. */
	{ "single_round",
	  "package main;\n"
	  "export fn main() i32 = {\n"
	  "	let big: f32 = 16777216.0f32;\n"
	  "	let r: f32 = big + 1.0f32;\n"
	  "	if (r: f64 != 16777216.0) { return 1; };\n"
	  "	return 0;\n"
	  "};\n", 0 },
	{ 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, "f32lit: 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 tmpdir[64];
		snprintf(tmpdir, sizeof tmpdir, "/tmp/wwf32l_%d_d_%d",
		    getpid(), i);
		mkdir(tmpdir, 0755);

		char src[128], outbin[128], cs_s[128], ws_s[128], rmcmd[160];
		snprintf(src, sizeof src, "%s/wwf32l_%d_%d.ww",
		    tmpdir, getpid(), i);
		snprintf(outbin, sizeof outbin, "%s/wwf32l_%d_%d",
		    tmpdir, getpid(), i);
		snprintf(cs_s, sizeof cs_s, "%s/wwf32l_%d_%d_cs.s",
		    tmpdir, getpid(), i);
		snprintf(ws_s, sizeof ws_s, "%s/wwf32l_%d_%d_ww.s",
		    tmpdir, getpid(), i);
		snprintf(rmcmd, sizeof rmcmd, "rm -rf %s", tmpdir);

		FILE *f = fopen(src, "wb");
		if (f == NULL) { runwait(rmcmd); fail++; continue; }
		fputs(rows[i].src, f);
		fclose(f);

		/* (a) cstage build + run. */
		char cmd[2048];
		snprintf(cmd, sizeof cmd, "%s/ww build -o %s %s",
		    bin, outbin, src);
		if (runwait(cmd) != 0) {
			fprintf(stderr, "row[%s]: cstage build failed\n",
			    rows[i].label);
			fail++;
			runwait(rmcmd);
			continue;
		}

		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++;
		}

		/* (b) cs==ww byte-id gate: emit .s from both stages, cmp. */
		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++; runwait(rmcmd); 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++; runwait(rmcmd); 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++;
		}
		runwait(rmcmd);
	}

	if (fail) {
		fprintf(stderr, "%d/%d f32 literal-materialise tests failed\n",
		    fail, n);
		return 1;
	}
	printf("f32lit: %d/%d ok (cstage run + cs==ww byte-id)\n", n, n);
	return 0;
}