Refactor flip_endianness

HerodotusDev · Dec 22, 2023 · 6a39b8d · 6a39b8d
1 parent 33c02e0
commit 6a39b8d
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Showing 2 changed files with 64 additions and 6 deletions.
diff --git a/src/common/flip_endianness.cairo b/src/common/flip_endianness.cairo
@@ -15,16 +15,58 @@ impl FlipEndiannessU32 of FlipEndiannessTrait<u32> {
 
 impl FlipEndiannessU256 of FlipEndiannessTrait<u256> {
     fn flip_endianness(self: u256) -> u256 {
-        let mut data = ArrayTrait::<u32>::new();
-        data.append_big_endian(self);
-        data.span().from_span_le()
+        (self % 0x100) * 0x100000000000000000000000000000000000000000000000000000000000000
+            + (self / 0x100 % 0x100) * 0x1000000000000000000000000000000000000000000000000000000000000
+            + (self / 0x10000 % 0x100) * 0x10000000000000000000000000000000000000000000000000000000000
+            + (self / 0x1000000 % 0x100) * 0x100000000000000000000000000000000000000000000000000000000
+            + (self / 0x100000000 % 0x100) * 0x1000000000000000000000000000000000000000000000000000000
+            + (self / 0x10000000000 % 0x100) * 0x10000000000000000000000000000000000000000000000000000
+            + (self / 0x1000000000000 % 0x100) * 0x100000000000000000000000000000000000000000000000000
+            + (self / 0x100000000000000 % 0x100) * 0x1000000000000000000000000000000000000000000000000
+            + (self / 0x10000000000000000 % 0x100) * 0x10000000000000000000000000000000000000000000000
+            + (self / 0x1000000000000000000 % 0x100) * 0x100000000000000000000000000000000000000000000
+            + (self / 0x100000000000000000000 % 0x100) * 0x1000000000000000000000000000000000000000000
+            + (self / 0x10000000000000000000000 % 0x100) * 0x10000000000000000000000000000000000000000
+            + (self / 0x1000000000000000000000000 % 0x100) * 0x100000000000000000000000000000000000000
+            + (self / 0x100000000000000000000000000 % 0x100) * 0x1000000000000000000000000000000000000
+            + (self / 0x10000000000000000000000000000 % 0x100) * 0x10000000000000000000000000000000000
+            + (self / 0x1000000000000000000000000000000 % 0x100) * 0x100000000000000000000000000000000
+            + (self / 0x100000000000000000000000000000000 % 0x100) * 0x1000000000000000000000000000000
+            + (self / 0x10000000000000000000000000000000000 % 0x100) * 0x10000000000000000000000000000
+            + (self / 0x1000000000000000000000000000000000000 % 0x100) * 0x100000000000000000000000000
+            + (self / 0x100000000000000000000000000000000000000 % 0x100) * 0x1000000000000000000000000
+            + (self / 0x10000000000000000000000000000000000000000 % 0x100) * 0x10000000000000000000000
+            + (self / 0x1000000000000000000000000000000000000000000 % 0x100) * 0x100000000000000000000
+            + (self / 0x100000000000000000000000000000000000000000000 % 0x100) * 0x1000000000000000000
+            + (self / 0x10000000000000000000000000000000000000000000000 % 0x100) * 0x10000000000000000
+            + (self / 0x1000000000000000000000000000000000000000000000000 % 0x100) * 0x100000000000000
+            + (self / 0x100000000000000000000000000000000000000000000000000 % 0x100) * 0x1000000000000
+            + (self / 0x10000000000000000000000000000000000000000000000000000 % 0x100) * 0x10000000000
+            + (self / 0x1000000000000000000000000000000000000000000000000000000 % 0x100) * 0x100000000
+            + (self / 0x100000000000000000000000000000000000000000000000000000000 % 0x100) * 0x1000000
+            + (self / 0x10000000000000000000000000000000000000000000000000000000000 % 0x100) * 0x10000
+            + (self / 0x1000000000000000000000000000000000000000000000000000000000000 % 0x100) * 0x100 
+            + (self / 0x100000000000000000000000000000000000000000000000000000000000000 % 0x100)
     }
 }
 
 impl FlipEndiannessU128 of FlipEndiannessTrait<u128> {
     fn flip_endianness(self: u128) -> u128 {
-        let mut data = ArrayTrait::<u32>::new();
-        data.append_big_endian(self);
-        data.span().from_span_le()
+        (self % 0x100) * 0x1000000000000000000000000000000
+            + (self / 0x100 % 0x100) * 0x10000000000000000000000000000
+            + (self / 0x10000 % 0x100) * 0x100000000000000000000000000
+            + (self / 0x1000000 % 0x100) * 0x1000000000000000000000000
+            + (self / 0x100000000 % 0x100) * 0x10000000000000000000000
+            + (self / 0x10000000000 % 0x100) * 0x100000000000000000000
+            + (self / 0x1000000000000 % 0x100) * 0x1000000000000000000
+            + (self / 0x100000000000000 % 0x100) * 0x10000000000000000
+            + (self / 0x10000000000000000 % 0x100) * 0x100000000000000
+            + (self / 0x1000000000000000000 % 0x100) * 0x1000000000000
+            + (self / 0x100000000000000000000 % 0x100) * 0x10000000000
+            + (self / 0x10000000000000000000000 % 0x100) * 0x100000000
+            + (self / 0x1000000000000000000000000 % 0x100) * 0x1000000
+            + (self / 0x100000000000000000000000000 % 0x100) * 0x10000
+            + (self / 0x10000000000000000000000000000 % 0x100) * 0x100 
+            + (self / 0x1000000000000000000000000000000 % 0x100)
     }
 }
diff --git a/src/common/tests/test_flip_endianness.cairo b/src/common/tests/test_flip_endianness.cairo
@@ -5,53 +5,69 @@ use cairo_verifier::common::flip_endianness::FlipEndiannessTrait;
 fn test_flip_endianness_0() {
     let le_val: u128 = 0x10000000000000000000009123092121;
     assert(le_val.flip_endianness() == 0x21210923910000000000000000000010, 'Invalid value');
+    assert(le_val == 0x10000000000000000000009123092121, 'Original value has mutated');
 }
 
 #[test]
 #[available_gas(9999999999)]
 fn test_flip_endianness_1() {
     let le_val: u128 = 0x9123092121;
     assert(le_val.flip_endianness().flip_endianness() == le_val, 'Invalid value');
+    assert(le_val == 0x9123092121, 'Original value has mutated');
 }
 
 #[test]
 #[available_gas(9999999999)]
 fn test_flip_endianness_2() {
     let le_val: u128 = 0x98071087308702187408710847087;
     assert(le_val.flip_endianness().flip_endianness() == le_val, 'Invalid value');
+    assert(le_val == 0x98071087308702187408710847087, 'Original value has mutated');
 }
 
 #[test]
 #[available_gas(9999999999)]
 fn test_flip_endianness_3() {
     let le_val: u128 = 0xABCDEF0123456789ABCDEF0123456789;
     assert(le_val.flip_endianness() == 0x8967452301EFCDAB8967452301EFCDAB, 'Invalid value');
+    assert(le_val == 0xABCDEF0123456789ABCDEF0123456789, 'Original value has mutated');
 }
 
 #[test]
 #[available_gas(9999999999)]
 fn test_flip_endianness_4() {
     let le_val: u128 = 0x00000000000000000000ABCDEF012345;
     assert(le_val.flip_endianness() == 0x452301EFCDAB00000000000000000000, 'Invalid value');
+    assert(le_val == 0x00000000000000000000ABCDEF012345, 'Original value has mutated');
 }
 
 #[test]
 #[available_gas(9999999999)]
 fn test_flip_endianness_5() {
     let le_val: u128 = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF;
     assert(le_val.flip_endianness() == 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF, 'Invalid value');
+    assert(le_val == 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF, 'Original value has mutated');
 }
 
 #[test]
 #[available_gas(9999999999)]
 fn test_flip_endianness_6() {
     let le_val: u128 = 0x00000000000000000000000000000000;
     assert(le_val.flip_endianness() == 0x00000000000000000000000000000000, 'Invalid value');
+    assert(le_val == 0x00000000000000000000000000000000, 'Original value has mutated');
 }
 
 #[test]
 #[available_gas(9999999999)]
 fn test_flip_endianness_7() {
     let le_val: u128 = 0x1234567890ABCDEF1234567890ABCDEF;
     assert(le_val.flip_endianness().flip_endianness() == le_val, 'Invalid value');
+    assert(le_val == 0x1234567890ABCDEF1234567890ABCDEF, 'Original value has mutated');
 }
+
+#[test]
+#[available_gas(9999999999)]
+fn test_flip_endianness_256() {
+    let le_val: u256 = 0xb8c727aa44f32839b875a9323a8f204a330c70f29ca91581be9207a703f70d74;
+    let be_val: u256 = 0x740df703a70792be8115a99cf2700c334a208f3a32a975b83928f344aa27c7b8;
+    assert(le_val.flip_endianness() == be_val, 'Invalid value');
+}