Improve fixSandwich for mul,add,mul operations (#632)

Author: loader3229

src/eval/optimizer.cpp

@@ -666,11 +666,9 @@ bool Optimizer::fixSandwich(Program &p) const {
         std::swap(op1, op2);
         op1.source.value *= op2.source.value;
         changed = true;
-      } else if (op1.type == Operation::Type::MUL &&
-                 Semantics::mod(op2.source.value, op1.source.value) ==
-                     Number::ZERO) {
-        std::swap(op1, op2);
-        op1.source.value /= op2.source.value;
+      } else if (op1.type == Operation::Type::MUL) {
+        std::swap(op3, op2);
+        op3.source.value *= op2.source.value;
         changed = true;
       }
     } else if (ProgramUtil::isAdditive(op2.type) &&

tests/optimizer/E031.asm

@@ -3,5 +3,5 @@ mul $0,6
 sub $0,12
 mul $0,3
 ; out
-sub $0,2
 mul $0,18
+sub $0,36

tests/optimizer/E082.asm

@@ -0,0 +1,7 @@
+; in
+mul $0,2
+add $0,1
+mul $0,4
+; out
+mul $0,8
+add $0,4