Add several CFG-stress-testing input source files. These use the

preprocessor to build up very large CFGs in various shapes that can
produce different algorithmic behavior in CFG-walking code.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134698 91177308-0d34-0410-b5e6-96231b3b80d8

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 0000000000..3db10b443d
--- /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;
+}