Don't generate jump for last when condition

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt

@@ -603,6 +603,7 @@ class ExpressionCodegen(
         assert(exhaustive || expression.type.isUnit()) {
             "non-exhaustive conditional should return Unit: ${expression.dump()}"
         }
+        val lastBranch = expression.branches.lastOrNull()
         for (branch in expression.branches) {
             val elseLabel = Label()
             if (branch.condition.isFalseConst() || branch.condition.isTrueConst()) {
@@ -628,7 +629,10 @@ class ExpressionCodegen(
                     return materializedResult
                 }
             }
-            mv.goTo(endLabel)
+
+            if (branch != lastBranch) {
+                mv.goTo(endLabel)
+            }
             mv.mark(elseLabel)
         }
         mv.mark(endLabel)

compiler/testData/codegen/bytecodeText/disabledOptimizations/noJumpInLastBranch.kt

@@ -0,0 +1,17 @@
+// KOTLIN_CONFIGURATION_FLAGS: +JVM.DISABLE_OPTIMIZATION
+
+fun consume(i: Int) {}
+
+fun foo(a: String) {
+    var b = 1
+    if (a[1] == 'b') {
+        b = 2
+    } else if (a[0] == 'a') {
+        b = 3
+    }
+
+    consume(b)
+}
+
+// 1 GOTO
+// 2 IF

compiler/testData/codegen/bytecodeText/disabledOptimizations/noJumpInSingleBranch.kt

@@ -0,0 +1,15 @@
+// KOTLIN_CONFIGURATION_FLAGS: +JVM.DISABLE_OPTIMIZATION
+
+fun consume(i: Int) {}
+
+fun foo(a: Boolean) {
+    var b = 1
+    if (a) {
+        b = 2
+    }
+
+    consume(b)
+}
+
+// 0 GOTO
+// 1 IF

compiler/tests/org/jetbrains/kotlin/codegen/BytecodeTextTestGenerated.java

@@ -1614,6 +1614,29 @@ public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
         }
     }
 
+    @TestMetadata("compiler/testData/codegen/bytecodeText/disabledOptimizations")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class DisabledOptimizations extends AbstractBytecodeTextTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, TargetBackend.JVM, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInDisabledOptimizations() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/bytecodeText/disabledOptimizations"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
+        }
+
+        @TestMetadata("noJumpInLastBranch.kt")
+        public void testNoJumpInLastBranch() throws Exception {
+            runTest("compiler/testData/codegen/bytecodeText/disabledOptimizations/noJumpInLastBranch.kt");
+        }
+
+        @TestMetadata("noJumpInSingleBranch.kt")
+        public void testNoJumpInSingleBranch() throws Exception {
+            runTest("compiler/testData/codegen/bytecodeText/disabledOptimizations/noJumpInSingleBranch.kt");
+        }
+    }
+
     @TestMetadata("compiler/testData/codegen/bytecodeText/enum")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBytecodeTextTestGenerated.java

@@ -1569,6 +1569,29 @@ public class IrBytecodeTextTestGenerated extends AbstractIrBytecodeTextTest {
         }
     }
 
+    @TestMetadata("compiler/testData/codegen/bytecodeText/disabledOptimizations")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class DisabledOptimizations extends AbstractIrBytecodeTextTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, TargetBackend.JVM_IR, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInDisabledOptimizations() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/bytecodeText/disabledOptimizations"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM_IR, true);
+        }
+
+        @TestMetadata("noJumpInLastBranch.kt")
+        public void testNoJumpInLastBranch() throws Exception {
+            runTest("compiler/testData/codegen/bytecodeText/disabledOptimizations/noJumpInLastBranch.kt");
+        }
+
+        @TestMetadata("noJumpInSingleBranch.kt")
+        public void testNoJumpInSingleBranch() throws Exception {
+            runTest("compiler/testData/codegen/bytecodeText/disabledOptimizations/noJumpInSingleBranch.kt");
+        }
+    }
+
     @TestMetadata("compiler/testData/codegen/bytecodeText/enum")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)