[lmi-commits] [lmi] valyuta/004 7306944 2/4: Fix rounding for whole-dollar currency amounts

[Greg Chicares]

branch: valyuta/004
commit 73069441add067dadc8e6173fbbc7f96320acc9e
Author: Gregory W. Chicares <gchicares@sbcglobal.net>
Commit: Gregory W. Chicares <gchicares@sbcglobal.net>

    Fix rounding for whole-dollar currency amounts
    
    For 'sample*' products (and for some companies' actual products),
    specified amount is rounded to whole dollars. For other currency
    amounts, any integral number of cents is okay, and to round an
    already-integral amount to the nearest integer, it suffices to pass
    it through unmodified; but that's not the case for values such as
    specified amount that are to be rounded to whole dollars.
    
    This change is required for correctness, but unfortunately it imposes
    a runtime cost of about five percent. That seems outlandish on the
    face of it; the reason is that AccountValue::TxSpecAmtChange() is
    called extremely often with an argument of zero, even though its
    inline documentation says:
      // TODO ?? Changing specamt by zero is absurd.
    But that's an ancient defect that won't be fixed today.
---
 Speed_gcc_i686-w64-mingw32 | 12 ++++++------
 round_to.hpp               |  4 ++++
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/Speed_gcc_i686-w64-mingw32 b/Speed_gcc_i686-w64-mingw32
index ec9d7ad..96434ea 100644
--- a/Speed_gcc_i686-w64-mingw32
+++ b/Speed_gcc_i686-w64-mingw32
@@ -1,7 +1,7 @@
 Test speed:
-  naic, no solve      : 6.199e-02 s mean;      61318 us least of  17 runs
-  naic, specamt solve : 1.093e-01 s mean;     108222 us least of  10 runs
-  naic, ee prem solve : 1.001e-01 s mean;      99517 us least of  10 runs
-  finra, no solve     : 2.358e-02 s mean;      23235 us least of  43 runs
-  finra, specamt solve: 6.669e-02 s mean;      65938 us least of  15 runs
-  finra, ee prem solve: 6.192e-02 s mean;      61419 us least of  17 runs
+  naic, no solve      : 6.500e-02 s mean;      64214 us least of  16 runs
+  naic, specamt solve : 1.158e-01 s mean;     113670 us least of   9 runs
+  naic, ee prem solve : 1.047e-01 s mean;     103533 us least of  10 runs
+  finra, no solve     : 2.501e-02 s mean;      23474 us least of  40 runs
+  finra, specamt solve: 6.883e-02 s mean;      67903 us least of  15 runs
+  finra, ee prem solve: 6.379e-02 s mean;      63007 us least of  16 runs
diff --git a/round_to.hpp b/round_to.hpp
index 443fdcb..9b924f3 100644
--- a/round_to.hpp
+++ b/round_to.hpp
@@ -439,6 +439,10 @@ inline currency round_to<RealType>::c(currency z) const
 {
     LMI_ASSERT(decimals() <= 2); // ROUNDING similarly restrict rounding_rules
     // instead, this ought to verify proper rounding
+    if(decimals() < 2)
+        {
+        z = c(z.d());
+        }
     return z;
 }