UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36

Example URL:
https://www.shadertoy.com/view/wdSGRh

Steps to reproduce the problem:
cf https://www.shadertoy.com/view/wdSGRh
1. uvec3 A = uvec3( 0xFFFF0000U , 0x80000000U, 0U )
2. uvec3 B = vec3( apply uintBitsToFloat on each component of A)

What is the expected behavior?
B[2] == 0

What went wrong?
B[2] == B [1]  != 0 

Does it occur on multiple sites: Yes

Is it a problem with a plugin? No 

Did this work before? N/A 

Does this work in other browsers? No
 firefow

Chrome version: 71.0.3578.98  Channel: stable
OS Version: 
Flash Version: 

- Only on OpenGL, even with recent driver
- not occuring if A is made non const ( e.g. by adding uint(min(0.,fragCoord.x)) )

May somebody please set the flags	
Blink>WebGL
Internals>GPU>ANGLE
?  thanks !