[lmi-commits] [lmi] valyuta/004 780c7c3 4/6: Improve accuracy when CURRENCY_UNIT_IS_CENTS not defined

[Greg Chicares]

branch: valyuta/004
commit 780c7c3ec82bc3d1e27994a8c4ac8a517f52e065
Author: Gregory W. Chicares <gchicares@sbcglobal.net>
Commit: Gregory W. Chicares <gchicares@sbcglobal.net>

    Improve accuracy when CURRENCY_UNIT_IS_CENTS not defined
    
    Without this change, 'AVSepAcct' was often some minuscule amount like
    2.5e-12 due to catastrophic cancellation. With it, regression tests on
    this branch (with CURRENCY_UNIT_IS_CENTS not defined) compare nicely
    with production, which means that it can be cleaned up and merged with
    'master' confidently. Later, defining CURRENCY_UNIT_IS_CENTS will change
    some calculations, but it's easier and safer to test the effect of that
    single change separately. Thus:
     - #undef CURRENCY_UNIT_IS_CENTS: many changes; known minor regressions
     - #define CURRENCY_UNIT_IS_CENTS: one change for which code review is
       simple; some larger regressions (which correct old behavior that
       didn't always round every currency amount).
---
 ihs_avmly.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/ihs_avmly.cpp b/ihs_avmly.cpp
index d9a51a9..8585522 100644
--- a/ihs_avmly.cpp
+++ b/ihs_avmly.cpp
@@ -356,6 +356,10 @@ void AccountValue::IncrementAVProportionally(currency 
increment)
     currency genacct_increment = round_minutiae().c(increment * 
GenAcctPaymentAllocation);
     AVGenAcct += genacct_increment;
     AVSepAcct += increment - genacct_increment;
+#if !defined CURRENCY_UNIT_IS_CENTS
+    AVSepAcct = round_minutiae().c(AVSepAcct.d());
+    if(0.0 == AVSepAcct.d()) AVSepAcct = C0; // Negate negative zeroes.
+#endif // !defined CURRENCY_UNIT_IS_CENTS
 }
 
 //============================================================================
@@ -482,6 +486,10 @@ void AccountValue::DecrementAVProportionally(currency 
decrement)
     currency genacct_decrement = round_minutiae().c(decrement * 
general_account_proportion);
     AVGenAcct -= genacct_decrement;
     AVSepAcct -= decrement - genacct_decrement;
+#if !defined CURRENCY_UNIT_IS_CENTS
+    AVSepAcct = round_minutiae().c(AVSepAcct.d());
+    if(0.0 == AVSepAcct.d()) AVSepAcct = C0; // Negate negative zeroes.
+#endif // !defined CURRENCY_UNIT_IS_CENTS
 }
 
 /// Apportion decrements to account value between separate- and