Implement basic support for vectorized instructions.

We use LLVM's Scalarizer pass to remove most vectorized code so that the
Executor only needs to support the InsertElement and ExtractElement
instructions.

This pass was not available in LLVM 3.4 so to support that LLVM version
the pass has been back ported.

To check that the Executor is not receiving vector operand types
that it can't handle assertions have been added.

There are a few limitations to this implementation.

* The InsertElement and ExtractElement index cannot be symbolic.
* There is no support for LLVM < 3.4.

1 files changed, 83 insertions, 0 deletions

diff --git a/test/VectorInstructions/shuffle_element.c b/test/VectorInstructions/shuffle_element.c
new file mode 100644
index 00000000..cf991b03
--- /dev/null
+++ b/test/VectorInstructions/shuffle_element.c
@@ -0,0 +1,83 @@
+// REQUIRES: geq-llvm-3.4
+// RUN: %llvmgcc %s -emit-llvm -O0 -g -c -o %t1.bc
+// RUN: rm -rf %t.klee-out
+// NOTE: Have to pass `--optimize=false` to avoid vector operations being
+// constant folded away.
+// RUN: %klee --output-dir=%t.klee-out --optimize=false --exit-on-error %t1.bc
+#include "klee/klee.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#define ASSERT_EQ_V4(X, Y) \
+  assert(X[0] == Y[0]); \
+  assert(X[1] == Y[1]); \
+  assert(X[2] == Y[2]); \
+  assert(X[3] == Y[3]);
+
+#define ASSERT_EQ_V8(X, Y) \
+  assert(X[0] == Y[0]); \
+  assert(X[1] == Y[1]); \
+  assert(X[2] == Y[2]); \
+  assert(X[3] == Y[3]); \
+  assert(X[4] == Y[4]); \
+  assert(X[5] == Y[5]); \
+  assert(X[6] == Y[6]); \
+  assert(X[7] == Y[7]); \
+
+typedef uint32_t v4ui __attribute__ ((vector_size (16)));
+typedef uint32_t v8ui __attribute__ ((vector_size (32)));
+int main() {
+  v4ui f = { 0, 19, 129, 255 };
+  klee_make_symbolic(&f, sizeof(v4ui), "f");
+  klee_print_expr("f:=", f);
+
+  // Test Single vector shuffle.
+
+  // Extract same element uniformly
+  for (int index=0; index < 4; ++index) {
+    v4ui mask = { index, index, index, index };
+    v4ui result = __builtin_shufflevector(f, mask);
+    v4ui expectedResult = { f[index], f[index], f[index], f[index]};
+    ASSERT_EQ_V4(result, expectedResult);
+  }
+
+  // Reverse vector
+  v4ui mask = { 3, 2, 1, 0 };
+  v4ui result = __builtin_shufflevector(f, mask);
+  v4ui expectedResult = {f[3], f[2], f[1], f[0]};
+  ASSERT_EQ_V4(result, expectedResult);
+
+  // Extract a single element (Clang requires the mask to be constants so we can't use a for a loop).
+#define TEST_SINGLE_EXTRACT(I)\
+  do \
+  { \
+    uint32_t v __attribute__((vector_size(sizeof(uint32_t)))) = __builtin_shufflevector(f, f, I); \
+    uint32_t expected = f[ I % 4 ]; \
+    assert(v[0] == expected); \
+  } while(0);
+  TEST_SINGLE_EXTRACT(0);
+  TEST_SINGLE_EXTRACT(1);
+  TEST_SINGLE_EXTRACT(2);
+  TEST_SINGLE_EXTRACT(3);
+  TEST_SINGLE_EXTRACT(4);
+  TEST_SINGLE_EXTRACT(5);
+  TEST_SINGLE_EXTRACT(6);
+  TEST_SINGLE_EXTRACT(7);
+
+  // Test two vector shuffle
+  v4ui a = { 0, 1, 2, 3 };
+  v4ui b = { 4, 5, 6, 7 };
+
+  {
+    // [a] + [b]
+    v8ui result = __builtin_shufflevector(a, b, 0, 1, 2, 3, 4, 5, 6, 7);
+    v8ui expected = { a[0], a[1], a[2], a[3], b[0], b[1], b[2], b[3] };
+    ASSERT_EQ_V8(result, expected);
+  }
+
+
+
+  return 0;
+}