math.bits: added missing functions and test
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				|  | @ -96,6 +96,7 @@ pub fn trailing_zeros_64(x u64) int { | |||
| } | ||||
| 
 | ||||
| // --- OnesCount ---
 | ||||
| 
 | ||||
| // ones_count_8 returns the number of one bits ("population count") in x.
 | ||||
| pub fn ones_count_8(x byte) int { | ||||
| 	return int(pop_8_tab[x]) | ||||
|  | @ -142,6 +143,7 @@ pub fn ones_count_64(x u64) int { | |||
| } | ||||
| 
 | ||||
| // --- RotateLeft ---
 | ||||
| 
 | ||||
| // rotate_left_8 returns the value of x rotated left by (k mod 8) bits.
 | ||||
| // To rotate x right by k bits, call rotate_left_8(x, -k).
 | ||||
| //
 | ||||
|  | @ -187,6 +189,7 @@ pub fn rotate_left_64(x u64, k int) u64 { | |||
| } | ||||
| 
 | ||||
| // --- Reverse ---
 | ||||
| 
 | ||||
| // reverse_8 returns the value of x with its bits in reversed order.
 | ||||
| [inline] | ||||
| pub fn reverse_8(x byte) byte { | ||||
|  | @ -218,6 +221,7 @@ pub fn reverse_64(x u64) u64 { | |||
| } | ||||
| 
 | ||||
| // --- ReverseBytes ---
 | ||||
| 
 | ||||
| // reverse_bytes_16 returns the value of x with its bytes in reversed order.
 | ||||
| //
 | ||||
| // This function's execution time does not depend on the inputs.
 | ||||
|  | @ -246,6 +250,7 @@ pub fn reverse_bytes_64(x u64) u64 { | |||
| } | ||||
| 
 | ||||
| // --- Len ---
 | ||||
| 
 | ||||
| // len_8 returns the minimum number of bits required to represent x; the result is 0 for x == 0.
 | ||||
| pub fn len_8(x byte) int { | ||||
| 	return int(len_8_tab[x]) | ||||
|  | @ -296,3 +301,195 @@ pub fn len_64(x u64) int { | |||
| 	return n + int(len_8_tab[y]) | ||||
| } | ||||
| 
 | ||||
| // --- Add with carry ---
 | ||||
| 
 | ||||
| // Add returns the sum with carry of x, y and carry: sum = x + y + carry.
 | ||||
| // The carry input must be 0 or 1; otherwise the behavior is undefined.
 | ||||
| // The carryOut output is guaranteed to be 0 or 1.
 | ||||
| //
 | ||||
| 
 | ||||
| // add_32 returns the sum with carry of x, y and carry: sum = x + y + carry.
 | ||||
| // The carry input must be 0 or 1; otherwise the behavior is undefined.
 | ||||
| // The carryOut output is guaranteed to be 0 or 1.
 | ||||
| //
 | ||||
| // This function's execution time does not depend on the inputs.
 | ||||
| fn add_32(x u32, y u32, carry u32) (u32, u32) { | ||||
| 	sum64 := u64(x) + u64(y) + u64(carry) | ||||
| 	sum := u32(sum64) | ||||
| 	carry_out := u32(sum64>>32) | ||||
| 	return sum, carry_out | ||||
| } | ||||
| 
 | ||||
| // add_64 returns the sum with carry of x, y and carry: sum = x + y + carry.
 | ||||
| // The carry input must be 0 or 1; otherwise the behavior is undefined.
 | ||||
| // The carryOut output is guaranteed to be 0 or 1.
 | ||||
| //
 | ||||
| // This function's execution time does not depend on the inputs.
 | ||||
| fn add_64(x u64, y u64, carry u64) (u64, u64) { | ||||
| 	sum := x + y + carry | ||||
| 	// The sum will overflow if both top bits are set (x & y) or if one of them
 | ||||
| 	// is (x | y), and a carry from the lower place happened. If such a carry
 | ||||
| 	// happens, the top bit will be 1 + 0 + 1 = 0 (&^ sum).
 | ||||
| 	carry_out := ((x & y) | ((x | y) & ~sum ))>>63 | ||||
| 	return sum, carry_out | ||||
| } | ||||
| 
 | ||||
| // --- Subtract with borrow ---
 | ||||
| 
 | ||||
| // Sub returns the difference of x, y and borrow: diff = x - y - borrow.
 | ||||
| // The borrow input must be 0 or 1; otherwise the behavior is undefined.
 | ||||
| // The borrowOut output is guaranteed to be 0 or 1.
 | ||||
| //
 | ||||
| 
 | ||||
| // sub_32 returns the difference of x, y and borrow, diff = x - y - borrow.
 | ||||
| // The borrow input must be 0 or 1; otherwise the behavior is undefined.
 | ||||
| // The borrowOut output is guaranteed to be 0 or 1.
 | ||||
| //
 | ||||
| // This function's execution time does not depend on the inputs.
 | ||||
| fn sub_32(x u32, y u32, borrow u32) (u32, u32) { | ||||
| 	diff := x - y - borrow | ||||
| 	// The difference will underflow if the top bit of x is not set and the top
 | ||||
| 	// bit of y is set (^x & y) or if they are the same (^(x ^ y)) and a borrow
 | ||||
| 	// from the lower place happens. If that borrow happens, the result will be
 | ||||
| 	// 1 - 1 - 1 = 0 - 0 - 1 = 1 (& diff).
 | ||||
| 	borrow_out := ((~x & y) | (~(x ^ y) & diff))>>31 | ||||
| 	return diff, borrow_out | ||||
| } | ||||
| 
 | ||||
| // sub_64 returns the difference of x, y and borrow: diff = x - y - borrow.
 | ||||
| // The borrow input must be 0 or 1; otherwise the behavior is undefined.
 | ||||
| // The borrowOut output is guaranteed to be 0 or 1.
 | ||||
| //
 | ||||
| // This function's execution time does not depend on the inputs.
 | ||||
| fn sub_64(x u64, y u64, borrow u64) (u64, u64) { | ||||
| 	diff := x - y - borrow | ||||
| 	// See Sub32 for the bit logic.
 | ||||
| 	borrow_out  := ((~x & y) | (~(x ^ y) & diff))>>63 | ||||
| 	return diff, borrow_out | ||||
| } | ||||
| 
 | ||||
| // --- Full-width multiply ---
 | ||||
| 
 | ||||
| const ( | ||||
| 	two32  = u64(0x1_0000_0000) | ||||
| 	mask32 = two32 - 1 | ||||
| 	overflow_error = "Overflow Error" | ||||
| 	divide_error = "Divide Error" | ||||
| ) | ||||
| 
 | ||||
| // mul_32 returns the 64-bit product of x and y: (hi, lo) = x * y
 | ||||
| // with the product bits' upper half returned in hi and the lower
 | ||||
| // half returned in lo.
 | ||||
| //
 | ||||
| // This function's execution time does not depend on the inputs.
 | ||||
| fn mul_32(x u32, y u32) (u32, u32) { | ||||
| 	tmp := u64(x) * u64(y) | ||||
| 	hi := u32(tmp>>32) | ||||
| 	lo := u32(tmp) | ||||
| 	return hi, lo | ||||
| } | ||||
| 
 | ||||
| // mul_64 returns the 128-bit product of x and y: (hi, lo) = x * y
 | ||||
| // with the product bits' upper half returned in hi and the lower
 | ||||
| // half returned in lo.
 | ||||
| //
 | ||||
| // This function's execution time does not depend on the inputs.
 | ||||
| fn mul_64(x u64, y u64) (u64, u64) { | ||||
| 	x0 := x & mask32 | ||||
| 	x1 := x>>32 | ||||
| 	y0 := y & mask32 | ||||
| 	y1 := y>>32 | ||||
| 	w0 := x0 * y0 | ||||
| 	t := x1*y0 + (w0>>32) | ||||
| 	mut w1 := t & mask32 | ||||
| 	w2 := t>>32 | ||||
| 	w1 += x0 * y1 | ||||
| 	hi := x1*y1 + w2 + (w1>>32) | ||||
| 	lo := x * y | ||||
| 	return hi, lo | ||||
| } | ||||
| 
 | ||||
| // --- Full-width divide ---
 | ||||
| 
 | ||||
| // div_32 returns the quotient and remainder of (hi, lo) divided by y:
 | ||||
| // quo = (hi, lo)/y, rem = (hi, lo)%y with the dividend bits' upper
 | ||||
| // half in parameter hi and the lower half in parameter lo.
 | ||||
| // div_32 panics for y == 0 (division by zero) or y <= hi (quotient overflow).
 | ||||
| fn div_32(hi u32, lo u32, y u32) (u32, u32) { | ||||
| 	if y != 0 && y <= hi { | ||||
| 		panic(overflow_error) | ||||
| 	} | ||||
| 	z := (u64(hi)<<32) | u64(lo) | ||||
| 	quo := u32(z/u64(y)) | ||||
| 	rem := u32(z%u64(y)) | ||||
| 	return quo, rem | ||||
| } | ||||
| 
 | ||||
| // div_64 returns the quotient and remainder of (hi, lo) divided by y:
 | ||||
| // quo = (hi, lo)/y, rem = (hi, lo)%y with the dividend bits' upper
 | ||||
| // half in parameter hi and the lower half in parameter lo.
 | ||||
| // div_64 panics for y == 0 (division by zero) or y <= hi (quotient overflow).
 | ||||
| fn div_64(hi u64, lo u64, y1 u64) (u64, u64) { | ||||
| 	mut y := y1 | ||||
| 	if y == 0 { | ||||
| 		panic(overflow_error) | ||||
| 	} | ||||
| 	if y <= hi { | ||||
| 		panic(overflow_error) | ||||
| 	} | ||||
| 
 | ||||
| 	s := u32(leading_zeros_64(y)) | ||||
| 	y <<= s | ||||
| 
 | ||||
| 	yn1 := y>>32 | ||||
| 	yn0 := y & mask32 | ||||
| 	un32 := (hi<<s) | (lo>>(64-s)) | ||||
| 	un10 := lo<<s | ||||
| 	un1 := un10>>32 | ||||
| 	un0 := un10 & mask32 | ||||
| 	mut q1 := un32 / yn1 | ||||
| 	mut rhat := un32 - q1*yn1 | ||||
| 
 | ||||
| 	for q1 >= two32 || q1*yn0 > two32*rhat+un1 { | ||||
| 		q1-- | ||||
| 		rhat += yn1 | ||||
| 		if rhat >= two32 { | ||||
| 			break | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 	un21 := un32*two32 + un1 - q1*y | ||||
| 	mut q0 := un21 / yn1 | ||||
| 	rhat = un21 - q0*yn1 | ||||
| 
 | ||||
| 	for q0 >= two32 || q0*yn0 > two32*rhat+un0 { | ||||
| 		q0-- | ||||
| 		rhat += yn1 | ||||
| 		if rhat >= two32 { | ||||
| 			break | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 	return q1*two32 + q0, (un21*two32 + un0 - q0*y)>>s | ||||
| } | ||||
| 
 | ||||
| // rem_32 returns the remainder of (hi, lo) divided by y. Rem32 panics
 | ||||
| // for y == 0 (division by zero) but, unlike Div32, it doesn't panic
 | ||||
| // on a quotient overflow.
 | ||||
| fn rem_32(hi u32, lo u32, y u32) u32 { | ||||
| 	return u32((u64(hi)<<32 | u64(lo)) % u64(y)) | ||||
| } | ||||
| 
 | ||||
| // rem_64 returns the remainder of (hi, lo) divided by y. Rem64 panics
 | ||||
| // for y == 0 (division by zero) but, unlike div_64, it doesn't panic
 | ||||
| // on a quotient overflow.
 | ||||
| fn rem_64(hi, lo, y u64) u64 { | ||||
| 	// We scale down hi so that hi < y, then use div_64 to compute the
 | ||||
| 	// rem with the guarantee that it won't panic on quotient overflow.
 | ||||
| 	// Given that
 | ||||
| 	//   hi ≡ hi%y    (mod y)
 | ||||
| 	// we have
 | ||||
| 	//   hi<<64 + lo ≡ (hi%y)<<64 + lo    (mod y)
 | ||||
| 	_, rem := div_64(hi%y, lo, y) | ||||
| 	return rem | ||||
| } | ||||
|  |  | |||
|  | @ -1,8 +1,12 @@ | |||
| //
 | ||||
| // test suite for bits and bits math functions
 | ||||
| //
 | ||||
| module bits | ||||
| 
 | ||||
| fn test_bits(){ | ||||
| 	mut i := 0 | ||||
| 	mut i1:= u64(0) | ||||
| 	 | ||||
| 	//
 | ||||
| 	// --- LeadingZeros ---
 | ||||
| 	//
 | ||||
|  | @ -10,26 +14,29 @@ fn test_bits(){ | |||
| 	// 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 | ||||
| 		//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 | ||||
| 		//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 | ||||
| 		//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 | ||||
| 		//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 | ||||
| 	} | ||||
| 
 | ||||
| 	//
 | ||||
|  | @ -39,29 +46,32 @@ fn test_bits(){ | |||
| 	// 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)
 | ||||
| 		//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)
 | ||||
| 		//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)
 | ||||
| 		//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 | ||||
| 		//C.printf("x:%016llx lz: %llu cmp: %d\n", u64(i1), ones_count_64(u64(i1)), x)
 | ||||
| 		assert ones_count_64(i1) == x | ||||
| 		i1 = (i1 << 1) + 1 | ||||
| 	} | ||||
| 
 | ||||
|  | @ -88,10 +98,11 @@ fn test_bits(){ | |||
| 			bc++ | ||||
| 			n = n >> 1 | ||||
| 		} | ||||
| 		//C.printf("x:%02x lz: %llu cmp: %d\n",byte(i),reverse_8(byte(i)), rv)
 | ||||
| 		//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 { | ||||
|  | @ -103,10 +114,11 @@ fn test_bits(){ | |||
| 			bc++ | ||||
| 			n = n >> 1 | ||||
| 		} | ||||
| 		//C.printf("x:%04x lz: %llu cmp: %d\n",u16(i),reverse_16(u16(i)), rv)
 | ||||
| 		//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 { | ||||
|  | @ -118,10 +130,11 @@ fn test_bits(){ | |||
| 			bc++ | ||||
| 			n = n >> 1 | ||||
| 		} | ||||
| 		//C.printf("x:%08x lz: %llu cmp: %d\n",u32(i),reverse_32(u32(i)), rv)
 | ||||
| 		//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 { | ||||
|  | @ -133,8 +146,144 @@ fn test_bits(){ | |||
| 			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 | ||||
| 		//C.printf("x:%016llx lz: %016llx cmp: %016llx\n", u64(i1), reverse_64(u64(i1)), rv)
 | ||||
| 		assert reverse_64(i1) == rv | ||||
| 		i1 = (i1 << 1) + 1 | ||||
| 	} | ||||
| } | ||||
| 
 | ||||
| 	//
 | ||||
| 	// --- add ---
 | ||||
| 	//
 | ||||
| 
 | ||||
| 	// 32 bit
 | ||||
| 	i = 1 | ||||
| 	for x in 0..32 { | ||||
| 		v := u32(i) << x | ||||
| 		sum,carry := add_32(v, v, u32(0)) | ||||
| 		//C.printf("x:%08x [%llu,%llu] %llu\n", u32(i) << x, sum, carry, u64(v) + u64(v))
 | ||||
| 		assert ((u64(carry) << 32) | u64(sum)) == u64(v) + u64(v) | ||||
| 	} | ||||
| 	mut sum_32t, mut carry_32t := add_32(0x8000_0000, 0x8000_0000, u32(0)) | ||||
| 	assert sum_32t == u32(0) | ||||
| 	assert carry_32t == u32(1) | ||||
| 
 | ||||
| 	sum_32t, carry_32t = add_32(0xFFFF_FFFF, 0xFFFF_FFFF, u32(1)) | ||||
| 	assert sum_32t == 0xFFFF_FFFF | ||||
| 	assert carry_32t == u32(1) | ||||
| 
 | ||||
| 	// 64 bit
 | ||||
| 	i = 1 | ||||
| 	for x in 0..63 { | ||||
| 		v := u64(i) << x | ||||
| 		sum,carry := add_64(v, v, u64(0)) | ||||
| 		//C.printf("x:%16x [%llu,%llu] %llu\n", u64(i) << x, sum, carry, u64(v >> 32) + u64(v >> 32))
 | ||||
| 		assert ((carry << 32) | sum) == v + v | ||||
| 	} | ||||
| 	mut sum_64t, mut carry_64t := add_64(0x8000_0000_0000_0000, 0x8000_0000_0000_0000, u64(0)) | ||||
| 	assert sum_64t == u64(0) | ||||
| 	assert carry_64t == u64(1) | ||||
| 
 | ||||
| 	sum_64t, carry_64t = add_64(0xFFFF_FFFF_FFFF_FFFF, 0xFFFF_FFFF_FFFF_FFFF, u64(1)) | ||||
| 	assert sum_64t == 0xFFFF_FFFF_FFFF_FFFF | ||||
| 	assert carry_64t == u64(1) | ||||
| 
 | ||||
| 	//
 | ||||
| 	// --- sub ---
 | ||||
| 	//
 | ||||
| 	 | ||||
| 	// 32 bit
 | ||||
| 	i = 1 | ||||
| 	for x in 1..32 { | ||||
| 		v0 := u32(i) << x | ||||
| 		v1 := v0 >> 1 | ||||
| 		mut diff, mut borrow_out := sub_32(v0, v1, u32(0)) | ||||
| 		//C.printf("x:%08x [%llu,%llu] %08x\n", u32(i) << x, diff, borrow_out, v0 - v1)
 | ||||
| 		assert diff == v1 | ||||
| 
 | ||||
| 		diff, borrow_out = sub_32(v0, v1, u32(1)) | ||||
| 		//C.printf("x:%08x [%llu,%llu] %08x\n", u32(i) << x, diff, borrow_out, v0 - v1)
 | ||||
| 		assert diff == (v1 - 1)  | ||||
| 		assert borrow_out == u32(0) | ||||
| 
 | ||||
| 		diff, borrow_out = sub_32(v1, v0, u32(1)) | ||||
| 		//C.printf("x:%08x [%llu,%llu] %08x\n", u32(i) << x, diff, borrow_out, v1 - v0)
 | ||||
| 		assert borrow_out == u32(1) | ||||
| 	} | ||||
| 
 | ||||
| 	// 64 bit
 | ||||
| 	i = 1 | ||||
| 	for x in 1..64 { | ||||
| 		v0 := u64(i) << x | ||||
| 		v1 := v0 >> 1 | ||||
| 		mut diff, mut borrow_out := sub_64(v0, v1, u64(0)) | ||||
| 		//C.printf("x:%08x [%llu,%llu] %08x\n", u64(i) << x, diff, borrow_out, v0 - v1)
 | ||||
| 		assert diff == v1 | ||||
| 
 | ||||
| 		diff, borrow_out = sub_64(v0, v1, u64(1)) | ||||
| 		//C.printf("x:%08x [%llu,%llu] %08x\n", u64(i) << x, diff, borrow_out, v0 - v1)
 | ||||
| 		assert diff == (v1 - 1)  | ||||
| 		assert borrow_out == u64(0) | ||||
| 
 | ||||
| 		diff, borrow_out = sub_64(v1, v0, u64(1)) | ||||
| 		//C.printf("x:%08x [%llu,%llu] %08x\n",u64(i) << x, diff, borrow_out, v1 - v0)
 | ||||
| 		assert borrow_out == u64(1) | ||||
| 	} | ||||
| 
 | ||||
| 	//
 | ||||
| 	// --- mul ---
 | ||||
| 	//
 | ||||
| 
 | ||||
| 	// 32 bit
 | ||||
| 	i = 1 | ||||
| 	for x in 0..32 { | ||||
| 		v0 := u32(i) << x | ||||
| 		v1 := v0 - 1 | ||||
| 		hi, lo := mul_32(v0, v1) | ||||
| 		//C.printf("x:%08x [%llu,%llu] %llu\n", v0, hi, lo, u64(v0 * v1))
 | ||||
| 		assert (u64(hi) << 32) | (u64(lo)) == u64(v0 * v1) | ||||
| 	} | ||||
| 
 | ||||
| 	// 64 bit
 | ||||
| 	i = 1 | ||||
| 	for x in 0..64 { | ||||
| 		v0 := u64(i) << x | ||||
| 		v1 := v0 - 1 | ||||
| 		hi, lo := mul_64(v0, v1) | ||||
| 		//C.printf("v0: %llu v1: %llu [%llu,%llu] tt: %llu\n", v0, v1, hi, lo, (v0 >> 32) * (v1 >> 32))
 | ||||
| 		assert (hi & 0xFFFF_FFFF_0000_0000) == (((v0 >> 32)*(v1 >> 32)) & 0xFFFF_FFFF_0000_0000) | ||||
| 		assert (lo & 0x0000_0000_FFFF_FFFF) == (((v0 & 0x0000_0000_FFFF_FFFF) * (v1 & 0x0000_0000_FFFF_FFFF)) & 0x0000_0000_FFFF_FFFF) | ||||
| 	} | ||||
| 
 | ||||
| 	//
 | ||||
| 	// --- div ---
 | ||||
| 	//
 | ||||
| 
 | ||||
| 	// 32 bit
 | ||||
| 	i = 1 | ||||
| 	for x in 0..31 { | ||||
| 		hi := u32(i) << x | ||||
| 		lo := hi - 1 | ||||
| 		y  := u32(3) << x | ||||
| 		quo, rem := div_32(hi, lo, y) | ||||
| 		//C.printf("[%08x_%08x] %08x (%08x,%08x)\n", hi, lo, y, quo, rem)
 | ||||
| 		tst := ((u64(hi) << 32) | u64(lo)) | ||||
| 		assert quo == (tst / u64(y)) | ||||
| 		assert rem == (tst % u64(y)) | ||||
| 		assert rem == rem_32(hi, lo, y) | ||||
| 	} | ||||
| 
 | ||||
| 	// 64 bit
 | ||||
| 	i = 1 | ||||
| 	for x in 0..62 { | ||||
| 		hi := u64(i) << x | ||||
| 		lo := u64(2) //hi - 1
 | ||||
| 		y  := 0x4000_0000_0000_0000 | ||||
| 		quo, rem := div_64(hi, lo, y) | ||||
| 		//C.printf("[%016llx_%016llx] %016llx (%016llx,%016llx)\n", hi, lo, y, quo, rem)
 | ||||
| 		assert quo == u64(2)<<(x+1) | ||||
| 		_, rem1 := div_64(hi%y, lo, y) | ||||
| 		assert rem == rem1 | ||||
| 		assert rem == rem_64(hi, lo, y) | ||||
| 	} | ||||
| 	 | ||||
| } | ||||
|  |  | |||
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