cfg-nested-switches.c source code [clang_source_code/INPUTS/cfg-nested-switches.c]

1	#define EXPAND_2_INNER_CASES(i, x, y) INNER_CASE(i, x, y); INNER_CASE(i + 1, x, y);
2	#define EXPAND_4_INNER_CASES(i, x, y) EXPAND_2_INNER_CASES(i, x, y) EXPAND_2_INNER_CASES(i + 2, x, y)
3	#define EXPAND_8_INNER_CASES(i, x, y) EXPAND_4_INNER_CASES(i, x, y) EXPAND_4_INNER_CASES(i + 4, x, y)
4	#define EXPAND_16_INNER_CASES(i, x, y) EXPAND_8_INNER_CASES(i, x, y) EXPAND_8_INNER_CASES(i + 8, x, y)
5	#define EXPAND_32_INNER_CASES(i, x, y) EXPAND_16_INNER_CASES(i, x, y) EXPAND_16_INNER_CASES(i + 16, x, y)
6	#define EXPAND_64_INNER_CASES(i, x, y) EXPAND_32_INNER_CASES(i, x, y) EXPAND_32_INNER_CASES(i + 32, x, y)
7
8	#define EXPAND_2_OUTER_CASES(i, x, y) OUTER_CASE(i, x, y); OUTER_CASE(i + 1, x, y);
9	#define EXPAND_4_OUTER_CASES(i, x, y) EXPAND_2_OUTER_CASES(i, x, y) EXPAND_2_OUTER_CASES(i + 2, x, y)
10	#define EXPAND_8_OUTER_CASES(i, x, y) EXPAND_4_OUTER_CASES(i, x, y) EXPAND_4_OUTER_CASES(i + 4, x, y)
11	#define EXPAND_16_OUTER_CASES(i, x, y) EXPAND_8_OUTER_CASES(i, x, y) EXPAND_8_OUTER_CASES(i + 8, x, y)
12	#define EXPAND_32_OUTER_CASES(i, x, y) EXPAND_16_OUTER_CASES(i, x, y) EXPAND_16_OUTER_CASES(i + 16, x, y)
13	#define EXPAND_64_OUTER_CASES(i, x, y) EXPAND_32_OUTER_CASES(i, x, y) EXPAND_32_OUTER_CASES(i + 32, x, y)
14
15	// Rather than a single monstrous fan-out, this fans out in smaller increments,
16	// but to a similar size.
17	unsigned cfg_nested_switch(int x) {
18	unsigned y = 0;
19	while (x > 0) {
20	switch (x) {
21	#define INNER_CASE(i, x, y) \
22	case i: { int case_var = 3*x + i; y += case_var - 1; break; }
23	#define OUTER_CASE(i, x, y) \
24	case i: { \
25	int case_var = y >> 8; \
26	switch (case_var) { \
27	EXPAND_64_INNER_CASES(0, x, y); \
28	} \
29	break; \
30	}
31	EXPAND_64_OUTER_CASES(0, x, y);
32	}
33	--x;
34	}
35	return y;
36	}
37

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