OpenGL ES2.0 Shader Internal return statement returns failure and data precision loss, flower screen problem

Recent customer feedback encountered our product a very strange problem, font flower screen phenomenon

Shader use two texture map (icon and text texture) to do multi-texture mapping, some phones appear flower screen phenomenon, Dicard does not work, the following statement continues to execute

Added return statement the same problem

Tangled for two or three days, today finally find out why, title

Shader internal return statement failed and data precision lost, most of the phone is normal.

Problem Machine Model id:hm2013022
Android. VERSION. release:4.2.1

GL_VERSION:OPENGL ES 2.0 build [email protected]

Gl_renderer:powervr SGX 544MP

Gl_vendor:imagination

and a specific model of Samsung unknown

OpenGL ES2.0 Shader Internal return statement returns failure and data precision loss, flower screen problem