fixing derivatives agains

src/Runtime.zig

@@ -448,7 +448,13 @@ pub fn setDerivativeFromMemory(self: *Self, allocator: std.mem.Allocator, result
 
 fn getResultTargetTypeWord(self: *const Self, result: SpvWord) RuntimeError!SpvWord {
     return switch ((try self.results[result].getConstVariant()).*) {
-        .Variable => |v| v.type_word,
+        .Variable => |v| switch ((try self.results[v.type_word].getConstVariant()).*) {
+            .Type => |t| switch (t) {
+                .Pointer => |p| p.target,
+                else => v.type_word,
+            },
+            else => return RuntimeError.InvalidSpirV,
+        },
         .Constant => |c| c.type_word,
         .FunctionParameter => |p| p.type_word,
         .AccessChain => |a| a.target,

src/opcodes.zig

@@ -2885,6 +2885,7 @@ fn MathEngine(comptime T: PrimitiveType, comptime Op: MathOp, comptime IsAtomic:
                 .MatrixTimesMatrix,
                 .MatrixTimesScalar,
                 .MatrixTimesVector,
+                .VectorTimesScalar,
                 .VectorTimesMatrix,
                 => if (comptime is_int) @mulWithOverflow(op1, op2)[0] else op1 * op2,
                 .Div => blk: {
@@ -3253,7 +3254,6 @@ fn MathEngine(comptime T: PrimitiveType, comptime Op: MathOp, comptime IsAtomic:
 
                 else => try vectorRoutines(dst, lhs, rhs, lane_bits),
             }
-
             if (comptime IsAtomic) {
                 try copyValue(lhs, dst);
                 try copyValue(dst, &lhs_save.?);