fix bug where close-together tempDoublePtr operations could cross each other

3 files changed, 40 insertions, 0 deletions

diff --git a/tests/core/closebitcasts.c b/tests/core/closebitcasts.c
new file mode 100644
index 00000000..2c9d5ab5
--- /dev/null
+++ b/tests/core/closebitcasts.c
@@ -0,0 +1,32 @@
+#include <stdio.h>
+
+int main(int argc, char **argv) {
+  float x = argc%17, y = (argc+1)*(argc+2)*(argc+3)*(argc+4)*(argc*5);
+  y *= 1<<30;
+  y *= -13;
+  if (argc == 17) { x++; y--; }
+  int *xi = (int*)&x;
+  int *yi = (int*)&y;
+  int z = *xi - *yi;
+  while (z % 15) {
+    z++;
+  }
+  printf("!%d\n", z);
+
+  double xd = x, yd = y;
+  yd = yd*yd;
+  yd = yd*yd;
+  int *xl = (int*)&xd;
+  int *xh = &((int*)&xd)[1];
+  int *yl = (int*)&yd;
+  int *yh = &((int*)&yd)[1];
+  int l = *xl - *yl;
+  int h = *xh - *yh;
+  while (l % 15) {
+    l++;
+    h += 3;
+  }
+  printf("%d,%d!\n", l, h);
+  return 0;
+}
+
diff --git a/tests/core/closebitcasts.txt b/tests/core/closebitcasts.txt
new file mode 100644
index 00000000..f97366cd
--- /dev/null
+++ b/tests/core/closebitcasts.txt
@@ -0,0 +1,2 @@
+!1787576325
+589815810,-179981561!
diff --git a/tests/test_core.py b/tests/test_core.py
index 2430aa1c..5a19ef0c 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -771,6 +771,12 @@ class T(RunnerCore): # Short name, to make it more fun to use manually on the co
 
     self.do_run_from_file(src, output)
 
+  def test_closebitcasts(self):
+    if Settings.USE_TYPED_ARRAYS != 2: return self.skip('requires ta2')
+    test_path = path_from_root('tests', 'core', 'closebitcasts')
+    src, output = (test_path + s for s in ('.c', '.txt'))
+    self.do_run_from_file(src, output)
+
   def test_fast_math(self):
     if self.emcc_args is None: return self.skip('requires emcc')
     Building.COMPILER_TEST_OPTS += ['-ffast-math']