-C does not require consistent evaluation
-precision: the compiler may store intermediate
-results and round them to double while keep
-other parts in higher precision.
-(And the precision the compiler choses can
-be inconsistent: adding a printf to the code
-may change the result of a nearby calculation).
+C with FLT_EVAL_METHOD>=0 requires consistent evaluation
+precision, but gcc does not follow this on i386 and may
+store intermediate results and round them to double while keep
+other parts in extended precision.
+(And the precision gcc uses can be inconsistent:
+adding a printf to the code may spill 80bit float registers
+into memory changing the result of a nearby calculation).