Disable optimization on _swrast_write_zoomed_stencil_span

src/mesa/swrast/s_zoom.c

Index: src/mesa/swrast/s_zoom.c
diff --git a/src/mesa/swrast/s_zoom.c b/src/mesa/swrast/s_zoom.c
index 768bbbafd9b1297573449f464c51f117fea4939a..cf9feb86f2aba9137a1689e2813b498e3fbe7b58 100644
--- a/src/mesa/swrast/s_zoom.c
+++ b/src/mesa/swrast/s_zoom.c
@@ -395,6 +395,10 @@ _swrast_write_zoomed_stencil_span(struct gl_context *ctx, GLint imgX, GLint imgY
    free(zoomedVals);
 }
 
+// http://crbug.com/348397
+#ifdef _MSC_VER
+#pragma optimize("", off)
+#endif
 
 /**
  * Zoom/write 32-bit Z values.
@@ -440,3 +444,7 @@ _swrast_write_zoomed_z_span(struct gl_context *ctx, GLint imgX, GLint imgY,
 
    free(zoomedVals);
 }
+
+#ifdef _MSC_VER
+#pragma optimize("", off)
+#endif