encode2: Add new encoder API, one func per instr.

This is an *experimental* (read: unstable) API which exposes encoding
functionality as one function per instruction. This makes the encoding
process itself significantly faster, at the cost of a much larger binary
size (~1 MiB of code, no data) and much higher compilation time.

encode2-test.c

@@ -0,0 +1,63 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include <fadec-enc2.h>
+
+
+static
+void print_hex(const uint8_t* buf, size_t len) {
+    for (size_t i = 0; i < len; i++)
+        printf("%02x", buf[i]);
+}
+
+static int
+check(const uint8_t* buf, const void* exp, size_t exp_len, unsigned res, const char* name) {
+    if (__builtin_expect(res == exp_len && !memcmp(buf, exp, exp_len), 1))
+        return 0;
+    printf("Failed case (new) %s:\n", name);
+    printf("  Exp (%2zu): ", exp_len);
+    print_hex((const uint8_t*)exp, exp_len);
+    printf("\n  Got (%2u): ", res);
+    print_hex(buf, res);
+    printf("\n");
+    return -1;
+}
+
+#define TEST1(str, exp, name, ...) do { \
+            memset(buf, 0, sizeof buf); \
+            unsigned res = fe64_ ## name(buf, __VA_ARGS__); \
+            failed |= check(buf, exp, sizeof(exp) - 1, res, str); \
+        } while (0)
+#define TEST(exp, ...) TEST1(#__VA_ARGS__, exp, __VA_ARGS__)
+
+int
+main(void) {
+    int failed = 0;
+    uint8_t buf[16];
+
+    // This API is type safe and prohibits compilation of reg-type mismatches
+#define ENC_TEST_TYPESAFE
+    // Silence -Warray-bounds with double cast
+#define FE_PTR(off) (const void*) ((uintptr_t) buf + (off))
+#include "encode-test.inc"
+
+    TEST("\x90", NOP, 0);
+    TEST("\x90", NOP, 1);
+    TEST("\x66\x90", NOP, 2);
+    TEST("\x0f\x1f\x00", NOP, 3);
+    TEST("\x0f\x1f\x40\x00", NOP, 4);
+    TEST("\x0f\x1f\x44\x00\x00", NOP, 5);
+    TEST("\x66\x0f\x1f\x44\x00\x00", NOP, 6);
+    TEST("\x0f\x1f\x80\x00\x00\x00\x00", NOP, 7);
+    TEST("\x0f\x1f\x84\x00\x00\x00\x00\x00", NOP, 8);
+    TEST("\x66\x0f\x1f\x84\x00\x00\x00\x00\x00", NOP, 9);
+    TEST("\x66\x0f\x1f\x84\x00\x00\x00\x00\x00\x90", NOP, 10);
+    TEST("\x66\x0f\x1f\x84\x00\x00\x00\x00\x00\x66\x90", NOP, 11);
+    TEST("\x66\x0f\x1f\x84\x00\x00\x00\x00\x00\x0f\x1f\x00", NOP, 12);
+
+    puts(failed ? "Some tests FAILED" : "All tests PASSED");
+    return failed ? EXIT_FAILURE : EXIT_SUCCESS;
+}