From dcd5404185e8212d8446a475bd2e0cf5747e5780 Mon Sep 17 00:00:00 2001
From: MITSUNARI Shigeo <herumi@nifty.com>
Date: Fri, 30 Apr 2021 15:09:26 +0900
Subject: [PATCH] setArray on big endian

---
 include/mcl/vint.hpp |  25 +++++++----
 test/vint_test.cpp   | 105 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 122 insertions(+), 8 deletions(-)

diff --git a/include/mcl/vint.hpp b/include/mcl/vint.hpp
index aed0880..e642cb6 100644
--- a/include/mcl/vint.hpp
+++ b/include/mcl/vint.hpp
@@ -1176,7 +1176,7 @@ public:
 	}
 	/*
 		set positive value
-		@note assume little endian system
+		@note x is treated as a little endian
 	*/
 	template<class S>
 	void setArray(bool *pb, const S *x, size_t size)
@@ -1190,14 +1190,23 @@ public:
 		size_t unitSize = (sizeof(S) * size + sizeof(Unit) - 1) / sizeof(Unit);
 		buf_.alloc(pb, unitSize);
 		if (!*pb) return;
-		char *dst = (char *)&buf_[0];
-		const char *src = (const char *)x;
+		size_t pos = 0;
 		size_t i = 0;
-		for (; i < sizeof(S) * size; i++) {
-			dst[i] = src[i];
-		}
-		for (; i < sizeof(Unit) * unitSize; i++) {
-			dst[i] = 0;
+		while (i < unitSize) {
+			if (sizeof(Unit) < sizeof(S)) {
+				S s = x[pos++];
+				for (size_t j = 0; j < sizeof(S); j += sizeof(Unit)) {
+					buf_[i++] = Unit(s);
+					s >>= sizeof(Unit) * 8;
+				}
+			} else {
+				Unit u = 0;
+				for (size_t j = 0; j < sizeof(Unit); j += sizeof(S)) {
+					S s = (pos < size) ? x[pos++] : 0;
+					u |= Unit(s) << (j * 8);
+				}
+				buf_[i++] = u;
+			}
 		}
 		trim(unitSize);
 	}
diff --git a/test/vint_test.cpp b/test/vint_test.cpp
index 39c3688..6f34ede 100644
--- a/test/vint_test.cpp
+++ b/test/vint_test.cpp
@@ -25,6 +25,111 @@ struct V {
 	unsigned int p[16];
 };
 
+CYBOZU_TEST_AUTO(setArray_u8)
+{
+	struct {
+		uint8_t x[12];
+		size_t size;
+		const char *s;
+	} tbl[] = {
+		{
+			{ 0x12 },
+			1,
+			"12"
+		},
+		{
+			{ 0x12, 0x34 },
+			2,
+			"3412"
+		},
+		{
+			{ 0x12, 0x34, 0x56 },
+			3,
+			"563412",
+		},
+		{
+			{ 0x12, 0x34, 0x56, 0x78 },
+			4,
+			"78563412",
+		},
+		{
+			{ 0x12, 0x34, 0x56, 0x78, 0x9a },
+			5,
+			"9a78563412",
+		},
+		{
+			{ 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88 },
+			8,
+			"8877665544332211",
+		},
+		{
+			{ 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99 },
+			9,
+			"998877665544332211",
+		},
+	};
+	for (size_t i = 0; i < CYBOZU_NUM_OF_ARRAY(tbl); i++) {
+		Vint v;
+		v.setArray(tbl[i].x, tbl[i].size);
+		CYBOZU_TEST_EQUAL(v.getStr(16), tbl[i].s);
+	}
+}
+
+CYBOZU_TEST_AUTO(setArray_u32)
+{
+	struct {
+		uint32_t x[4];
+		size_t size;
+		const char *s;
+	} tbl[] = {
+		{
+			{ 0x12345678 },
+			1,
+			"12345678"
+		},
+		{
+			{ 0x12345678, 0x11223344 },
+			2,
+			"1122334412345678"
+		},
+		{
+			{ 0x12345678, 0x11223344, 0x55667788 },
+			3,
+			"556677881122334412345678"
+		},
+	};
+	for (size_t i = 0; i < CYBOZU_NUM_OF_ARRAY(tbl); i++) {
+		Vint v;
+		v.setArray(tbl[i].x, tbl[i].size);
+		CYBOZU_TEST_EQUAL(v.getStr(16), tbl[i].s);
+	}
+}
+
+CYBOZU_TEST_AUTO(setArray_u64)
+{
+	struct {
+		uint64_t x[2];
+		size_t size;
+		const char *s;
+	} tbl[] = {
+		{
+			{ uint64_t(0x1122334455667788ull) },
+			1,
+			"1122334455667788"
+		},
+		{
+			{ uint64_t(0x1122334455667788ull), uint64_t(0x8877665544332211ull) },
+			2,
+			"88776655443322111122334455667788"
+		},
+	};
+	for (size_t i = 0; i < CYBOZU_NUM_OF_ARRAY(tbl); i++) {
+		Vint v;
+		v.setArray(tbl[i].x, tbl[i].size);
+		CYBOZU_TEST_EQUAL(v.getStr(16), tbl[i].s);
+	}
+}
+
 CYBOZU_TEST_AUTO(addSub)
 {
 	static const struct {