hare

commit 4b4db93c39dd5376aa662931864c2d8018ae728e
parent 88bda176d9875340a95c1c5acb156d8ff35e298d
Author: Drew DeVault <sir@cmpwn.com>
Date:   Fri, 26 Mar 2021 09:29:26 -0400

endian: expand big endian support

Diffstat:
M
endian/big.ha
 | 
31
++++++++++++++++++++++++++++++-

1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/endian/big.ha b/endian/big.ha
@@ -1,6 +1,28 @@
+// Reads a u16 from a buffer in big-endian order.
+export fn begetu16(buf: []u8) u16 = {
+	return
+		(buf[0] << 8u16) |
+		(buf[1] << 0);
+};
+
+// Writes a u16 into a buffer in big-endian order.
+export fn beputu16(buf: []u8, in: u16) void = {
+	buf[1] = (in >> 0): u8;
+	buf[0] = (in >> 8): u8;
+};
+
+// Reads a u32 from a buffer in big-endian order.
+export fn begetu32(buf: []u8) u32 = {
+	return
+		(buf[0] << 24u32) |
+		(buf[1] << 16u32) |
+		(buf[2] << 8u32) |
+		(buf[3] << 0);
+};
+
 // Writes a u32 into a buffer in big-endian order.
 export fn beputu32(buf: []u8, in: u32) void = {
-	buf[3] = (in): u8;
+	buf[3] = (in >> 0): u8;
 	buf[2] = (in >> 8): u8;
 	buf[1] = (in >> 16): u8;
 	buf[0] = (in >> 24): u8;
@@ -20,12 +42,19 @@ export fn beputu64(buf: []u8, in: u64) void = {
 
 @test fn big() void = {
 	let buf: [8]u8 = [0...];
+	beputu16(buf, 0x1234);
+	assert(buf[0] == 0x12 && buf[1] == 0x34);
+	assert(begetu16(buf) == 0x1234);
+
 	beputu32(buf, 0x12345678);
 	assert(buf[0] == 0x12 && buf[1] == 0x34
 		&& buf[2] == 0x56 && buf[3] == 0x78);
+	assert(begetu32(buf) == 0x12345678);
+
 	beputu64(buf, 0x1234567887654321);
 	assert(buf[0] == 0x12 && buf[1] == 0x34
 		&& buf[2] == 0x56 && buf[3] == 0x78
 		&& buf[4] == 0x87 && buf[5] == 0x65
 		&& buf[6] == 0x43 && buf[7] == 0x21);
+	// TODO: begetu64 (has some qbe issues?)
 };