Merge branch 'master' of ssh://bitbucket.org/czan/honours

1 files changed, 27 insertions, 0 deletions

diff --git a/clang/INPUTS/cfg-big-switch.c b/clang/INPUTS/cfg-big-switch.c
new file mode 100644
index 0000000..a48b51a
--- /dev/null
+++ b/clang/INPUTS/cfg-big-switch.c
@@ -0,0 +1,27 @@
+#define EXPAND_2_CASES(i, x, y)    CASE(i, x, y);             CASE(i + 1, x, y);
+#define EXPAND_4_CASES(i, x, y)    EXPAND_2_CASES(i, x, y)    EXPAND_2_CASES(i + 2, x, y)
+#define EXPAND_8_CASES(i, x, y)    EXPAND_4_CASES(i, x, y)    EXPAND_4_CASES(i + 4, x, y)
+#define EXPAND_16_CASES(i, x, y)   EXPAND_8_CASES(i, x, y)    EXPAND_8_CASES(i + 8, x, y)
+#define EXPAND_32_CASES(i, x, y)   EXPAND_16_CASES(i, x, y)   EXPAND_16_CASES(i + 16, x, y)
+#define EXPAND_64_CASES(i, x, y)   EXPAND_32_CASES(i, x, y)   EXPAND_32_CASES(i + 32, x, y)
+#define EXPAND_128_CASES(i, x, y)  EXPAND_64_CASES(i, x, y)   EXPAND_64_CASES(i + 64, x, y)
+#define EXPAND_256_CASES(i, x, y)  EXPAND_128_CASES(i, x, y)  EXPAND_128_CASES(i + 128, x, y)
+#define EXPAND_512_CASES(i, x, y)  EXPAND_256_CASES(i, x, y)  EXPAND_256_CASES(i + 256, x, y)
+#define EXPAND_1024_CASES(i, x, y) EXPAND_512_CASES(i, x, y)  EXPAND_512_CASES(i + 512, x, y)
+#define EXPAND_2048_CASES(i, x, y) EXPAND_1024_CASES(i, x, y) EXPAND_1024_CASES(i + 1024, x, y)
+#define EXPAND_4096_CASES(i, x, y) EXPAND_2048_CASES(i, x, y) EXPAND_2048_CASES(i + 2048, x, y)
+
+// This has a *monstrous* single fan-out in the CFG, across 8000 blocks inside
+// the while loop.
+unsigned cfg_big_switch(int x) {
+  unsigned y = 0;
+  while (x > 0) {
+    switch(x) {
+#define CASE(i, x, y) \
+      case i: { int case_var = 3*x + i; y += case_var - 1; break; }
+EXPAND_4096_CASES(0, x, y);
+    }
+    --x;
+  }
+  return y;
+}