Fix potential bug IntelliJ warnings

build-time-compiler/src/main/java/run/endive/build/time/compiler/Generator.java

@@ -168,7 +168,7 @@ public void generateModuleInterface(String moduleInterfaceName) throws IOExcepti
 
     public void generateMetaWasm(Set<Integer> interpretedFunctions) throws IOException {
         byte[] wasmBytes = Files.readAllBytes(config.wasmFile());
-        var module = Parser.builder().includeSectionId(SectionId.CODE).build().parse(wasmBytes);
+        var module = Parser.parse(wasmBytes);
 
         var writer = new WasmWriter();
         Parser.parseWithoutDecoding(

cli/src/main/java/run/endive/experimental/cli/Cli.java

@@ -86,11 +86,7 @@ public void run() {
             var result = export.apply(params);
             if (result != null) {
                 for (var r : result) {
-                    if (result == null) {
-                        System.out.println(0);
-                    } else {
-                        System.out.println(r); // Check floating point results
-                    }
+                    System.out.println(r); // Check floating point results
                 }
             }
         }

runtime/src/main/java/run/endive/runtime/InterpreterMachine.java

@@ -1307,7 +1307,8 @@ private static void I64_SUB(MStack stack) {
     private static void I32_MUL(MStack stack) {
         var a = stack.pop();
         var b = stack.pop();
-        stack.push(a * b);
+        int result = (int) (a * b);
+        stack.push(result);
     }
 
     private static void I64_MUL(MStack stack) {
@@ -1507,6 +1508,9 @@ private static void I32_SHR_S(MStack stack) {
     private static void I32_SHL(MStack stack) {
         var c = (int) stack.pop();
         var v = (int) stack.pop();
+        // Intentionally get the result as 32 bit `int` (despite it being converted to `long` when
+        // pushed to the stack)
+        //noinspection IntegerMultiplicationImplicitCastToLong
         stack.push(v << c);
     }
 
@@ -3239,7 +3243,7 @@ private static void TRY_TABLE(
 
     private static void IF(
             StackFrame frame, MStack stack, Instance instance, AnnotatedInstruction instruction) {
-        var predValue = stack.pop();
+        var predValue = (int) stack.pop();
         var paramsSize = numberOfParams(instance, instruction);
         var returnsSize = numberOfValuesToReturn(instance, instruction);
         frame.pushCtrl(instruction.opcode(), paramsSize, returnsSize, stack.size() - paramsSize);

runtime/src/test/java/run/endive/runtime/WasmModuleTest.java

@@ -58,6 +58,22 @@ public void shouldRunABasicAdd() {
         assertEquals(11L, result);
     }
 
+    @Test
+    public void shouldWrapI32MulOverflow() {
+        var instance = Instance.builder(loadModule("compiled/i32_mul_overflow.wat.wasm")).build();
+        var mul = instance.export("mul");
+        var mulIf = instance.export("mul_if");
+
+        // 65536 * 65536 = 2^32, which wraps to 0 as an i32
+        assertEquals(0L, mul.apply(65536L, 65536L)[0]);
+        assertEquals(0L, mulIf.apply(65536L, 65536L)[0]);
+
+        assertEquals(6L, mul.apply(2L, 3L)[0]);
+        assertEquals(1L, mulIf.apply(2L, 3L)[0]);
+        assertEquals(-6L, mul.apply(-2L, 3L)[0]);
+        assertEquals(1L, mulIf.apply(-2L, 3L)[0]);
+    }
+
     @Test
     public void shouldSupportBrTable() {
         var instance = Instance.builder(loadModule("compiled/br_table.wat.wasm")).build();

simd/src/main/java/run/endive/simd/SimdInterpreterMachine.java

@@ -1369,8 +1369,6 @@ private static byte addSatU(byte a, byte b) {
         int result = Byte.toUnsignedInt(a) + Byte.toUnsignedInt(b);
         if (result >= 0xFF) {
             return (byte) 0xFF;
-        } else if (result < 0) {
-            return 0;
         } else {
             return (byte) result;
         }
@@ -1736,53 +1734,23 @@ private static void BINOP(
     }
 
     private static boolean lt(float a, float b) {
-        if (Float.isNaN(b)) {
-            return false;
-        } else if ((a == 0.0f && b == -0.0f) || (a == -0.0f && b == 0.0f)) {
-            return false;
-        } else {
-            return Float.compare(a, b) < 0;
-        }
+        return a < b;
     }
 
     private static boolean le(float a, float b) {
-        if (Float.isNaN(b)) {
-            return false;
-        } else if ((a == 0.0f && b == -0.0f) || (a == -0.0f && b == 0.0f)) {
-            return true;
-        } else {
-            return Float.compare(a, b) <= 0;
-        }
+        return a <= b;
     }
 
     private static boolean gt(float a, float b) {
-        if (Float.isNaN(a)) {
-            return false;
-        } else if ((a == 0.0f && b == -0.0f) || (a == -0.0f && b == 0.0f)) {
-            return false;
-        } else {
-            return Float.compare(a, b) > 0;
-        }
+        return a > b;
     }
 
     private static boolean ge(float a, float b) {
-        if (Float.isNaN(a)) {
-            return false;
-        } else if ((a == 0.0f && b == -0.0f) || (a == -0.0f && b == 0.0f)) {
-            return true;
-        } else {
-            return Float.compare(a, b) >= 0;
-        }
+        return a >= b;
     }
 
     private static boolean equals(float a, float b) {
-        if (Float.isNaN(a) || Float.isNaN(b)) {
-            return false;
-        } else if ((a == 0.0f && b == -0.0f) || (a == -0.0f && b == 0.0f)) {
-            return true;
-        } else {
-            return Float.compare(a, b) == 0;
-        }
+        return a == b;
     }
 
     private static void F32x4(MStack stack, BiFunction<Float, Float, Long> fn) {
@@ -1925,7 +1893,7 @@ private static void BITMASK(MStack stack, Function<LongVector, long[]> reduce) {
         var result = 0L;
         for (int i = 0; i < vals.length; i++) {
             if (vals[i] < 0) {
-                result |= 1 << i;
+                result |= 1L << i;
             }
         }
 
@@ -2564,7 +2532,7 @@ private static void I64x2_EXTMUL_LOW_I32x4_S(MStack stack) {
 
         var res =
                 new long[] {
-                    v1[0] * v2[0], v1[1] * v2[1],
+                    ((long) v1[0]) * v2[0], ((long) v1[1]) * v2[1],
                 };
         var result = Value.i64ToVec(res);
         System.arraycopy(result, 0, stack.array(), offset, 2);
@@ -2587,7 +2555,7 @@ private static void I64x2_EXTMUL_HIGH_I32x4_S(MStack stack) {
 
         var res =
                 new long[] {
-                    v1[2] * v2[2], v1[3] * v2[3],
+                    ((long) v1[2]) * v2[2], ((long) v1[3]) * v2[3],
                 };
         var result = Value.i64ToVec(res);
         System.arraycopy(result, 0, stack.array(), offset, 2);
@@ -3007,7 +2975,7 @@ private static void I8x16_SWIZZLE(MStack stack) {
             if (id < 8) {
                 base = (baseLow >> (id * 8)) & 0xFFL;
             } else if (id < 16) {
-                base = (baseHigh >> (id * 8)) & 0xFFL;
+                base = (baseHigh >> ((id - 8) * 8)) & 0xFFL;
             } else {
                 base = 0x00L;
             }

wasm-corpus/src/main/resources/wat/i32_mul_overflow.wat

@@ -0,0 +1,13 @@
+(module
+    ;; mul(a, b) returns a*b wrapped to 32 bits
+    (func (export "mul") (param $a i32) (param $b i32) (result i32)
+        (i32.mul (local.get $a) (local.get $b))
+    )
+    ;; mul_if(a, b) returns 1 if the wrapped a*b is non-zero, 0 otherwise
+    (func (export "mul_if") (param $a i32) (param $b i32) (result i32)
+        (if (result i32) (i32.mul (local.get $a) (local.get $b))
+            (then (i32.const 1))
+            (else (i32.const 0))
+        )
+    )
+)

wasm/src/main/java/run/endive/wasm/Parser.java

@@ -1358,7 +1358,7 @@ private static Instruction parseInstruction(ByteBuffer buffer) {
                         operands.add(n);
                         for (var j = 0; j < n; j++) {
                             var catchOp = readByte(buffer);
-                            operands.add(0L | catchOp);
+                            operands.add((long) catchOp);
                             var catchOpcode = CatchOpCode.byOpCode(catchOp);
                             switch (catchOpcode) {
                                 case CATCH: