Compiler/C2000-CGT: About TI v6.4.2 compiler OR Operation [Optimization level : 3 interprocedure optimization]

Tool/software: TI C/C++ Compiler

TI v6.4.2 compiler, when the [3 interprocedure optimization] is selected, the first type OR operation of the test code will be optimized as follows,

The high eight bits of the variable tmp_1st are not assigned, which results in an error in the result of the operation. The second type OR operation has no problem.

I tried to use a higher version of the compiler (TI v18.1.4.LTS) and confirmed the phenomenon.

The above problems will not occur when the same code is executed and the [3 interprocedure optimization] are executed.

Is it a problem with the compiler TI v6.4.2?

#include <stdio.h>

unsigned pData[2] = {1,2};

typedef union{
	unsigned Word[2];
	unsigned long Dword;
}wordDWord;

long value_1st,value_2nd = 0;

int main(void) {
	
	long tmp_1st,tmp_2nd;

	if(0x0080 & tmp_1st){
		tmp_1st |= 0xFFFFFF00;
	}

	if(0x0080 & tmp_2nd){
		tmp_2nd = tmp_2nd | 0xFFFFFF00;
	}

	value_1st = tmp_1st;
	value_2nd = tmp_2nd;

	return 0;
}