add get_u32_range to impl VirtualMachine add get_u32 and get_u32_range to impl Memory

Author: ohad-nir-starkware

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 #### Upcoming Changes
 
+* feat: add `get_u32_range` to `impl VirtualMachine` add `get_u32` and `get_u32_range` to `impl Memory` [#1936](https://github.com/lambdaclass/cairo-vm/pull/1936)
+
 * feat: add the field `opcode_extension` to the structure of `Instruction` [#1933](https://github.com/lambdaclass/cairo-vm/pull/1933)
 
 * fix(BREAKING): Fix no trace padding flow in proof mode [#1909](https://github.com/lambdaclass/cairo-vm/pull/1909)

vm/src/vm/decoding/decoder.rs

@@ -31,6 +31,7 @@ pub fn decode_instruction(encoded_instr: u64) -> Result<Instruction, VirtualMach
 
     // Flags start on the 48th bit.
     const FLAGS_OFFSET: u64 = 48;
+    const FLAGS_MASK: u64 = 0x7FFF;
     const OFF0_OFF: u64 = 0;
     const OFF1_OFF: u64 = 16;
     const OFF2_OFF: u64 = 32;
@@ -42,7 +43,7 @@ pub fn decode_instruction(encoded_instr: u64) -> Result<Instruction, VirtualMach
     let off2 = decode_offset(encoded_instr >> OFF2_OFF & OFFX_MASK);
 
     // Grab flags
-    let flags = encoded_instr >> FLAGS_OFFSET;
+    let flags = (encoded_instr >> FLAGS_OFFSET) & FLAGS_MASK;
     // Grab individual flags
     let dst_reg_num = (flags & DST_REG_MASK) >> DST_REG_OFF;
     let op0_reg_num = (flags & OP0_REG_MASK) >> OP0_REG_OFF;

vm/src/vm/vm_core.rs

@@ -929,6 +929,12 @@ impl VirtualMachine {
         self.segments.memory.get_integer_range(addr, size)
     }
 
+    /// Gets n u32 values from memory starting from addr (n being size).
+    /// Returns an error if any of the values inside the range is missing (memory gap) or is not a u32.
+    pub fn get_u32_range(&self, addr: Relocatable, size: usize) -> Result<Vec<u32>, MemoryError> {
+        self.segments.memory.get_u32_range(addr, size)
+    }
+
     pub fn get_range_check_builtin(
         &self,
     ) -> Result<&RangeCheckBuiltinRunner<RC_N_PARTS_STANDARD>, VirtualMachineError> {
@@ -4373,6 +4379,39 @@ mod tests {
         );
     }
 
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn get_u32_range_ok() {
+        let mut vm = vm!();
+        vm.segments.memory = memory![((0, 0), 0), ((0, 1), 1), ((0, 2), 4294967295), ((0, 3), 3)];
+        let expected_vector = vec![1, 4294967295];
+        assert_eq!(vm.get_u32_range((0, 1).into(), 2), Ok(expected_vector));
+    }
+
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn get_u32_range_relocatable() {
+        let mut vm = vm!();
+        vm.segments.memory = memory![((0, 0), 0), ((0, 1), 1), ((0, 2), (0, 0)), ((0, 3), 3)];
+        assert_matches!(vm.get_u32_range((0, 1).into(), 2), Err(MemoryError::ExpectedInteger(bx)) if *bx == (0, 2).into());
+    }
+
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn get_u32_range_over_32_bits() {
+        let mut vm = vm!();
+        vm.segments.memory = memory![((0, 0), 0), ((0, 1), 1), ((0, 2), 4294967296), ((0, 3), 3)];
+        assert_matches!(vm.get_u32_range((0, 1).into(), 2), Err(MemoryError::Math(MathError::Felt252ToU32Conversion(bx))) if *bx == Felt252::from(4294967296_u64));
+    }
+
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn get_u32_range_memory_gap() {
+        let mut vm = vm!();
+        vm.segments.memory = memory![((0, 0), 0), ((0, 1), 1), ((0, 3), 3)];
+        assert_matches!(vm.get_u32_range((0, 1).into(), 3), Err(MemoryError::UnknownMemoryCell(bx)) if *bx == (0, 2).into());
+    }
+
     #[test]
     #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
     fn get_traceback_entries_bad_usort() {

vm/src/vm/vm_memory/memory.rs

@@ -414,6 +414,14 @@ impl Memory {
         }
     }
 
+    /// Gets a u32 value from memory address.
+    /// Returns an Error if the value at the memory address is missing or not a u32.
+    pub fn get_u32(&self, key: Relocatable) -> Result<u32, MemoryError> {
+        let felt = self.get_integer(key)?.into_owned();
+        felt.to_u32()
+            .ok_or_else(|| MemoryError::Math(MathError::Felt252ToU32Conversion(Box::new(felt))))
+    }
+
     /// Gets the value from memory address as a usize.
     /// Returns an Error if the value at the memory address is missing not a Felt252, or can't be converted to usize.
     pub fn get_usize(&self, key: Relocatable) -> Result<usize, MemoryError> {
@@ -623,6 +631,18 @@ impl Memory {
         Ok(values)
     }
 
+    /// Gets a range of u32 memory values from addr to addr + size
+    /// Fails if any of the values inside the range is missing (memory gap) or is not a u32
+    pub fn get_u32_range(&self, addr: Relocatable, size: usize) -> Result<Vec<u32>, MemoryError> {
+        let mut values = Vec::new();
+
+        for i in 0..size {
+            values.push(self.get_u32((addr + i)?)?);
+        }
+
+        Ok(values)
+    }
+
     pub fn mark_as_accessed(&mut self, addr: Relocatable) {
         let (i, j) = from_relocatable_to_indexes(addr);
         let data = if addr.segment_index < 0 {
@@ -1135,6 +1155,23 @@ mod memory_tests {
         );
     }
 
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn get_u32_too_big() {
+        let mut segments = MemorySegmentManager::new();
+        segments.add();
+        segments
+            .memory
+            .insert(Relocatable::from((0, 0)), &Felt252::from(1_u64 << 32))
+            .unwrap();
+        assert_matches!(
+            segments.memory.get_u32(Relocatable::from((0, 0))),
+            Err(MemoryError::Math(MathError::Felt252ToU32Conversion(
+                bx
+            ))) if *bx == Felt252::from(1_u64 << 32)
+        );
+    }
+
     #[test]
     #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
     fn default_memory() {
@@ -1350,6 +1387,35 @@ mod memory_tests {
         );
     }
 
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn get_u32_range_ok() {
+        let memory = memory![((0, 0), 0), ((0, 1), 1), ((0, 2), 4294967295), ((0, 3), 3)];
+        let expected_vector = vec![1, 4294967295];
+        assert_eq!(memory.get_u32_range((0, 1).into(), 2), Ok(expected_vector));
+    }
+
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn get_u32_range_relocatable() {
+        let memory = memory![((0, 0), 0), ((0, 1), 1), ((0, 2), (0, 0)), ((0, 3), 3)];
+        assert_matches!(memory.get_u32_range((0, 1).into(), 2), Err(MemoryError::ExpectedInteger(bx)) if *bx == (0, 2).into());
+    }
+
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn get_u32_range_over_32_bits() {
+        let memory = memory![((0, 0), 0), ((0, 1), 1), ((0, 2), 4294967296), ((0, 3), 3)];
+        assert_matches!(memory.get_u32_range((0, 1).into(), 2), Err(MemoryError::Math(MathError::Felt252ToU32Conversion(bx))) if *bx == Felt252::from(4294967296_u64));
+    }
+
+    #[test]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    fn get_u32_range_memory_gap() {
+        let memory = memory![((0, 0), 0), ((0, 1), 1), ((0, 3), 3)];
+        assert_matches!(memory.get_u32_range((0, 1).into(), 3), Err(MemoryError::UnknownMemoryCell(bx)) if *bx == (0, 2).into());
+    }
+
     /// Test that relocate_memory() works when there are no relocation rules.
     #[test]
     #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]