ICU-66108.tar.gz

[apple/icu.git] / icuSources / i18n / gregoimp.h

diff --git a/icuSources/i18n/gregoimp.h b/icuSources/i18n/gregoimp.h
index b30741679df2f575d17e01269dab3a40e6b5745e..06eb32384511e48924b0b41acd00aeacd1ef213b 100644 (file)
--- a/icuSources/i18n/gregoimp.h
+++ b/icuSources/i18n/gregoimp.h
@@ -40,6 +40,17 @@ class ClockMath {
      */
     static int32_t floorDivide(int32_t numerator, int32_t denominator);
 
+    /**
+     * Divide two integers, returning the floor of the quotient.
+     * Unlike the built-in division, this is mathematically
+     * well-behaved.  E.g., <code>-1/4</code> => 0 but
+     * <code>floorDivide(-1,4)</code> => -1.
+     * @param numerator the numerator
+     * @param denominator a divisor which must be != 0
+     * @return the floor of the quotient
+     */
+    static int64_t floorDivide(int64_t numerator, int64_t denominator);
+
     /**
      * Divide two numbers, returning the floor of the quotient.
      * Unlike the built-in division, this is mathematically
@@ -288,8 +299,8 @@ inline int32_t Grego::millisToJulianDay(double millis) {
 }
 
 inline int32_t Grego::gregorianShift(int32_t eyear) {
-  int32_t y = eyear-1;
-  int32_t gregShift = ClockMath::floorDivide(y, 400) - ClockMath::floorDivide(y, 100) + 2;
+  int64_t y = (int64_t)eyear-1;
+  int32_t gregShift = static_cast<int32_t>(ClockMath::floorDivide(y, (int64_t)400) - ClockMath::floorDivide(y, (int64_t)100) + 2);
   return gregShift;
 }