Add tests for generating NaN with SIMD.

Author: cseslowpoke

compiler-rt/test/nsan/vec_sqrt.cpp

@@ -0,0 +1,32 @@
+// RUN: %clangxx_nsan -O0 -g -mavx %s -o %t
+// RUN: NSAN_OPTIONS=check_nan=true,halt_on_error=0 %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_nsan -O3 -g -mavx %s -o %t
+// RUN: NSAN_OPTIONS=check_nan=true,halt_on_error=0 %run %t 2>&1 | FileCheck %s
+
+#include <cmath>
+#include <immintrin.h>
+#include <iostream>
+
+void simd_sqrt(const float *input, float *output, size_t size) {
+  size_t i = 0;
+  for (; i + 7 < size; i += 8) {
+    __m256 vec = _mm256_loadu_ps(&input[i]);
+    __m256 result = _mm256_sqrt_ps(vec);
+    _mm256_storeu_ps(&output[i], result);
+  }
+  for (; i < size; ++i) {
+    output[i] = std::sqrt(input[i]);
+  }
+}
+
+int main() {
+  float input[] = {1.0,  2.0,   -3.0,  4.0,   5.0,   6.0,  7.0,
+                   8.0,  9.0,   -10.0, 11.0,  12.0,  13.0, 14.0,
+                   15.0, -16.0, 17.0,  -18.0, -19.0, -20.0};
+  float output[20];
+  simd_sqrt(input, output, 20);
+  for (int i = 0; i < 20; ++i) {
+    std::cout << output[i] << std::endl;
+  }
+  return 0;
+}