Compiler/TMS320F28069: Left shift << use case issue, please look into

Tool/software: TI C/C++ Compiler

Hi CCS champion,

My customer reported a compiler question about left *** use case, please help to look into:

uint16_t a = 0;
uint32_t b = 0;
uint32_t c = 0;
uint32_t d = 0;

main{

....

a = 0x10;
b = 0x55;
d = (uint32_t)a<<16 -b; // get wrong result 0x80000000

if(d==0)
d =1;

a = 0x10;
b = 0x55;
c = (uint32_t)a<<16;    // correct 0x00100000
d = c - b;    // get correct result  0x000FFFAB

if(d==0)
d=1;

....

}

If change the equation as d = (uint32_t)(a<<16) -b;, it work fine.

I checked the disassembly code, the previous one used LSLL, while correct one use LSL. 

Please give your comments of this case.

Thank you!