add test of setArrayMask

src/fp.cpp

@@ -322,11 +322,7 @@ void copyAndMask(Unit *y, const void *x, size_t xByteSize, const Op& op, bool do
 		if (compareArray(y, op.p, op.N) >= 0) throw cybozu::Exception("fp:copyAndMask:large x");
 		return;
 	}
-	/*
-		x &= mask(op.bitSize - 1);
-	*/
-	const Unit r = op.bitSize % UnitBitSize;
-	y[op.N - 1] &= r ? (Unit(1) << (r - 1)) - 1 : Unit(-1);
+	maskArray(y, op.N, op.bitSize - 1);
 	assert(compareArray(y, op.p, op.N) < 0);
 }
 

test/fp_test.cpp

@@ -347,6 +347,7 @@ CYBOZU_TEST_AUTO(setArrayMask)
 		{ { 0x234567a4, 0x00000001, 0x00100000}, 1, "0x234567a4" },
 		{ { 0x234567a4, 0x00000001, 0x00100000}, 2, "0x1234567a4" },
 		{ { 0x234567a4, 0x00000001, 0x00100000}, 3, "0x00000000000001234567a4" },
+		{ { 0x234567a5, 0xfffffff1, 0xffffffff}, 3, "0x0ffffffffffff1234567a5" },
 	};
 	for (size_t i = 0; i < CYBOZU_NUM_OF_ARRAY(tbl); i++) {
 		x.setArrayMask(tbl[i].buf, tbl[i].bufN);