1 #define EXPAND_2_CASES(i, x, y) CASE(i, x, y); CASE(i + 1, x, y);
2 #define EXPAND_4_CASES(i, x, y) EXPAND_2_CASES(i, x, y) EXPAND_2_CASES(i + 2, x, y)
3 #define EXPAND_8_CASES(i, x, y) EXPAND_4_CASES(i, x, y) EXPAND_4_CASES(i + 4, x, y)
4 #define EXPAND_16_CASES(i, x, y) EXPAND_8_CASES(i, x, y) EXPAND_8_CASES(i + 8, x, y)
5 #define EXPAND_32_CASES(i, x, y) EXPAND_16_CASES(i, x, y) EXPAND_16_CASES(i + 16, x, y)
6 #define EXPAND_64_CASES(i, x, y) EXPAND_32_CASES(i, x, y) EXPAND_32_CASES(i + 32, x, y)
7 #define EXPAND_128_CASES(i, x, y) EXPAND_64_CASES(i, x, y) EXPAND_64_CASES(i + 64, x, y)
8 #define EXPAND_256_CASES(i, x, y) EXPAND_128_CASES(i, x, y) EXPAND_128_CASES(i + 128, x, y)
9 #define EXPAND_512_CASES(i, x, y) EXPAND_256_CASES(i, x, y) EXPAND_256_CASES(i + 256, x, y)
10 #define EXPAND_1024_CASES(i, x, y) EXPAND_512_CASES(i, x, y) EXPAND_512_CASES(i + 512, x, y)
11 #define EXPAND_2048_CASES(i, x, y) EXPAND_1024_CASES(i, x, y) EXPAND_1024_CASES(i + 1024, x, y)
12 #define EXPAND_4096_CASES(i, x, y) EXPAND_2048_CASES(i, x, y) EXPAND_2048_CASES(i + 2048, x, y)
13
14 // This has a *monstrous* single fan-out in the CFG, across 8000 blocks inside
15 // the while loop.
cfg_big_switch(int x)16 unsigned cfg_big_switch(int x) {
17 unsigned y = 0;
18 while (x > 0) {
19 switch(x) {
20 #define CASE(i, x, y) \
21 case i: { int case_var = 3*x + i; y += case_var - 1; break; }
22 EXPAND_4096_CASES(0, x, y);
23 }
24 --x;
25 }
26 return y;
27 }
28