From 9845fd1cf5d5eede92525a30d881f1efeae1f82b Mon Sep 17 00:00:00 2001
From: penguindark <57967770+penguindark@users.noreply.github.com>
Date: Sun, 9 Feb 2020 21:16:03 +0100
Subject: [PATCH] math.bits: tests

---
 vlib/math/bits/bits_test.v | 140 +++++++++++++++++++++++++++++++++++++
 1 file changed, 140 insertions(+)
 create mode 100644 vlib/math/bits/bits_test.v

diff --git a/vlib/math/bits/bits_test.v b/vlib/math/bits/bits_test.v
new file mode 100644
index 0000000000..d808920e94
--- /dev/null
+++ b/vlib/math/bits/bits_test.v
@@ -0,0 +1,140 @@
+module bits
+
+fn test_bits(){
+	mut i := 0
+	mut i1:= u64(0)
+	//
+	// --- LeadingZeros ---
+	//
+	
+	// 8 bit
+	i = 1
+	for x in 0..8 {
+		//C.printf("x:%02x lz: %d cmp: %d\n",i<<x,leading_zeros_8(i<<x), 7-x)
+		assert leading_zeros_8(byte(i<<x)) == 7 - x
+	}
+	// 16 bit
+	i = 1
+	for x in 0..16 {
+		//C.printf("x:%04x lz: %d cmp: %d\n",u16(i)<<x,leading_zeros_16(u16(i)<<x), 15-x)
+		assert leading_zeros_16(u16(i)<<x) == 15 - x
+	}
+	// 32 bit
+	i = 1
+	for x in 0..32 {
+		//C.printf("x:%08x lz: %d cmp: %d\n",u32(i)<<x,leading_zeros_32(u32(i)<<x), 31-x)
+		assert leading_zeros_32(u32(i)<<x) == 31 - x
+	}
+	// 64 bit
+	i = 1
+	for x in 0..64 {
+		//C.printf("x:%016llx lz: %llu cmp: %d\n",u64(i)<<x,leading_zeros_64(u64(i)<<x), 63-x)
+		assert leading_zeros_64(u64(i)<<x) == 63 - x
+	}
+
+	//
+	// --- ones_count ---
+	//
+
+	// 8 bit
+	i = 0
+	for x in 0..9 {
+		//C.printf("x:%02x lz: %llu cmp: %d\n",byte(i),ones_count_8(byte(i)), x)
+		assert ones_count_8(byte(i)) == x
+		i = (i << 1) + 1
+	}
+	// 16 bit
+	i = 0
+	for x in 0..17 {
+		//C.printf("x:%04x lz: %llu cmp: %d\n",u16(i),ones_count_16(u16(i)), x)
+		assert ones_count_16(u16(i)) == x
+		i = (i << 1) + 1
+	}
+	// 32 bit
+	i = 0
+	for x in 0..33 {
+		//C.printf("x:%08x lz: %llu cmp: %d\n",u32(i),ones_count_32(u32(i)), x)
+		assert ones_count_32(u32(i)) == x
+		i = (i << 1) + 1
+	}
+	// 64 bit
+	i1 = 0
+	for x in 0..65 {
+		//C.printf("x:%016llx lz: %llu cmp: %d\n",u64(i1),ones_count_64(u64(i1)), x)
+		assert ones_count_64(u64(i1)) == x
+		i1 = (i1 << 1) + 1
+	}
+
+	//
+	// --- rotate_left/right --- 
+	//
+	assert rotate_left_8( 0x12 , 4) == 0x21
+	assert rotate_left_16( 0x1234 , 8) == 0x3412
+	assert rotate_left_32( 0x12345678 , 16) == 0x56781234
+	assert rotate_left_64( 0x1234567887654321 , 32) == 0x8765432112345678
+
+	//
+	// --- reverse ---
+	//
+	
+	// 8 bit
+	i = 0
+	for x in 0..9 {
+		mut rv := byte(0)
+		mut bc := 0
+		mut n := i
+		for bc < 8 {
+			rv = (rv << 1) | (n & 0x01)
+			bc++
+			n = n >> 1
+		}
+		//C.printf("x:%02x lz: %llu cmp: %d\n",byte(i),reverse_8(byte(i)), rv)
+		assert reverse_8(byte(i)) == rv
+		i = (i << 1) + 1
+	}
+	// 16 bit
+	i = 0
+	for x in 0..17 {
+		mut rv := u16(0)
+		mut bc := 0
+		mut n := i
+		for bc < 16 {
+			rv = (rv << 1) | (n & 0x01)
+			bc++
+			n = n >> 1
+		}
+		//C.printf("x:%04x lz: %llu cmp: %d\n",u16(i),reverse_16(u16(i)), rv)
+		assert reverse_16(u16(i)) == rv
+		i = (i << 1) + 1
+	}
+	// 32 bit
+	i = 0
+	for x in 0..33 {
+		mut rv := u32(0)
+		mut bc := 0
+		mut n := i
+		for bc < 32 {
+			rv = (rv << 1) | (n & 0x01)
+			bc++
+			n = n >> 1
+		}
+		//C.printf("x:%08x lz: %llu cmp: %d\n",u32(i),reverse_32(u32(i)), rv)
+		assert reverse_32(u32(i)) == rv
+		i = (i << 1) + 1
+	}
+	// 64 bit
+	i1 = 0
+	for x in 0..64 {
+		mut rv := u64(0)
+		mut bc := 0
+		mut n := i1
+		for bc < 64 {
+			rv = (rv << 1) | (n & 0x01)
+			bc++
+			n = n >> 1
+		}
+		//C.printf("x:%016llx lz: %016llx cmp: %016llx\n",u64(i1),reverse_64(u64(i1)), rv)
+		assert reverse_64(u64(i1)) == rv
+		i1 = (i1 << 1) + 1
+	}
+}
\ No newline at end of file