Compiler/MSP430FR6820: Optimization, eliminating local common expressions

Please search the MSP430 compiler manual for the sub-chapter titled Data Flow Optimizations.  The phrase eliminates local common expressions refers to performing common subexpression elimination within basic blocks.  

For example, something like this ...

/* C-like pseudo-code */

a = b + c;
/* a few lines later, inside the same loop or if block */
d = b + c;

... gets optimized into ...

temp = b + c;
a = temp;
/* a few lines later */
d = temp;

Bart said:

Should we be afraid of inconsistent functions, etc.?

The first rule of any optimization is that it must compute the same result as the original source code.

Thanks and regards,

-George