Lifted restrictions on shift.

Author: lvella

integration/src/const_collapse.rs

@@ -24,29 +24,18 @@ pub fn collapse_const_if_possible(op: &Operator, inputs: &[MaybeConstant]) {
         | Operator::I64Or
         | Operator::I32And
         | Operator::I64And
-        | Operator::I32Shl
-        | Operator::I64Shl
-        | Operator::I32ShrS
-        | Operator::I64ShrS
-        | Operator::I32ShrU
-        | Operator::I64ShrU
         | Operator::I32LtS
         | Operator::I64LtS
         | Operator::I32LtU
         | Operator::I64LtU
-        | Operator::I32Eq
-        | Operator::I64Eq
-        | Operator::I32Ne
-        | Operator::I64Ne
         | Operator::I32GeS
         | Operator::I64GeS
         | Operator::I32GeU
-        | Operator::I64GeU
-        //| Operator::I32Rotl
-        //| Operator::I64Rotl
-        //| Operator::I32Rotr
-        //| Operator::I64Rotr
-        => {
+        | Operator::I64GeU 
+        | Operator::I32Eq
+        | Operator::I64Eq
+        | Operator::I32Ne
+        | Operator::I64Ne => {
             if let [
                 _,
                 MaybeConstant::ReferenceConstant {
@@ -73,6 +62,22 @@ pub fn collapse_const_if_possible(op: &Operator, inputs: &[MaybeConstant]) {
             }
         }
 
+        // Shift and rot operations are special because they can handle immediates bigger than i16,
+        // as the value is masked to the bitwidth of the type.
+        Operator::I32Shl
+        | Operator::I64Shl
+        | Operator::I32ShrS
+        | Operator::I64ShrS
+        | Operator::I32ShrU
+        | Operator::I64ShrU
+        //| Operator::I32Rotl
+        //| Operator::I64Rotl
+        //| Operator::I32Rotr
+        //| Operator::I64Rotr
+        => if let [_, MaybeConstant::ReferenceConstant { must_collapse, .. }] = inputs {
+            must_collapse.replace(true);
+        }
+
         // GT is special because the left operand is the one that can be immediate
         Operator::I32GtS
         | Operator::I32GtU

integration/src/womir_translation.rs

@@ -787,9 +787,8 @@ impl<'a, F: PrimeField32> Settings<'a> for OpenVMSettings<F> {
                         // Doesn't matter the order, because only commutative operations will
                         // have the constant operand on the left side, as const folding ensures.
 
-                        // The constant has already been validated to be in i16 range during
-                        // const folding, now we need to sign-extend it to 24-bits and then
-                        // convert to field element.
+                        // The constant folding step guarantees that the constant can be safely
+                        // truncated to i16.
                         let c = const_i16_as_field(c);
 
                         return Directive::Instruction(ib::instr_i(
@@ -856,14 +855,14 @@ impl<'a, F: PrimeField32> Settings<'a> for OpenVMSettings<F> {
 
         // Handle the complex instructions that supports constant inlining
         match &op {
-            Op::I32LeS
-            | Op::I32LeU
-            | Op::I32GeS
+            Op::I32GeS
             | Op::I32GeU
-            | Op::I64LeS
-            | Op::I64LeU
             | Op::I64GeS
-            | Op::I64GeU => {
+            | Op::I64GeU
+            | Op::I32LeS
+            | Op::I32LeU
+            | Op::I64LeS
+            | Op::I64LeU => {
                 let inverse_result = c.register_gen.allocate_type(ValType::I32).start as usize;
                 let output = output.unwrap().start as usize;