Access to memory with volatile qualifier is optimized out by compiler ( only first access is generated to IL/ISA , following reads from the same address are removed ).
global volatile flot4* v;
a1 = v; <- this read is generated
a2 = v; <- optimized out
a3 = v; <- optimized out
The standard says "The type qualifiers const, restrict, volatile as defined by the C99 specification are supported". So I think this needs to be corrected.