diff options
Diffstat (limited to 'INPUTS/cfg-nested-switches.c')
-rw-r--r-- | INPUTS/cfg-nested-switches.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/INPUTS/cfg-nested-switches.c b/INPUTS/cfg-nested-switches.c new file mode 100644 index 0000000..3db10b4 --- /dev/null +++ b/INPUTS/cfg-nested-switches.c @@ -0,0 +1,36 @@ +#define EXPAND_2_INNER_CASES(i, x, y) INNER_CASE(i, x, y); INNER_CASE(i + 1, x, y); +#define EXPAND_4_INNER_CASES(i, x, y) EXPAND_2_INNER_CASES(i, x, y) EXPAND_2_INNER_CASES(i + 2, x, y) +#define EXPAND_8_INNER_CASES(i, x, y) EXPAND_4_INNER_CASES(i, x, y) EXPAND_4_INNER_CASES(i + 4, x, y) +#define EXPAND_16_INNER_CASES(i, x, y) EXPAND_8_INNER_CASES(i, x, y) EXPAND_8_INNER_CASES(i + 8, x, y) +#define EXPAND_32_INNER_CASES(i, x, y) EXPAND_16_INNER_CASES(i, x, y) EXPAND_16_INNER_CASES(i + 16, x, y) +#define EXPAND_64_INNER_CASES(i, x, y) EXPAND_32_INNER_CASES(i, x, y) EXPAND_32_INNER_CASES(i + 32, x, y) + +#define EXPAND_2_OUTER_CASES(i, x, y) OUTER_CASE(i, x, y); OUTER_CASE(i + 1, x, y); +#define EXPAND_4_OUTER_CASES(i, x, y) EXPAND_2_OUTER_CASES(i, x, y) EXPAND_2_OUTER_CASES(i + 2, x, y) +#define EXPAND_8_OUTER_CASES(i, x, y) EXPAND_4_OUTER_CASES(i, x, y) EXPAND_4_OUTER_CASES(i + 4, x, y) +#define EXPAND_16_OUTER_CASES(i, x, y) EXPAND_8_OUTER_CASES(i, x, y) EXPAND_8_OUTER_CASES(i + 8, x, y) +#define EXPAND_32_OUTER_CASES(i, x, y) EXPAND_16_OUTER_CASES(i, x, y) EXPAND_16_OUTER_CASES(i + 16, x, y) +#define EXPAND_64_OUTER_CASES(i, x, y) EXPAND_32_OUTER_CASES(i, x, y) EXPAND_32_OUTER_CASES(i + 32, x, y) + +// Rather than a single monstrous fan-out, this fans out in smaller increments, +// but to a similar size. +unsigned cfg_nested_switch(int x) { + unsigned y = 0; + while (x > 0) { + switch (x) { +#define INNER_CASE(i, x, y) \ + case i: { int case_var = 3*x + i; y += case_var - 1; break; } +#define OUTER_CASE(i, x, y) \ + case i: { \ + int case_var = y >> 8; \ + switch (case_var) { \ + EXPAND_64_INNER_CASES(0, x, y); \ + } \ + break; \ + } +EXPAND_64_OUTER_CASES(0, x, y); + } + --x; + } + return y; +} |