Properly cache types for shared control flow nodes (#41665) (#41906)

* Properly cache shared flow node types * Add test Co-authored-by: Anders Hejlsberg <[email protected]>
microsoft · Dec 10, 2020 · 3c73625 · 3c73625
1 parent 1e9518c
commit 3c73625
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Showing 5 changed files with 950 additions and 2 deletions.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -21702,6 +21702,7 @@ namespace ts {
                     return errorType;
                 }
                 flowDepth++;
+                let sharedFlow: FlowNode | undefined;
                 while (true) {
                     const flags = flow.flags;
                     if (flags & FlowFlags.Shared) {
@@ -21714,6 +21715,7 @@ namespace ts {
                                 return sharedFlowTypes[i];
                             }
                         }
+                        sharedFlow = flow;
                     }
                     let type: FlowType | undefined;
                     if (flags & FlowFlags.Assignment) {
@@ -21777,9 +21779,9 @@ namespace ts {
                         // simply return the non-auto declared type to reduce follow-on errors.
                         type = convertAutoToAny(declaredType);
                     }
-                    if (flags & FlowFlags.Shared) {
+                    if (sharedFlow) {
                         // Record visited node and the associated type in the cache.
-                        sharedFlowNodes[sharedFlowCount] = flow;
+                        sharedFlowNodes[sharedFlowCount] = sharedFlow;
                         sharedFlowTypes[sharedFlowCount] = type;
                         sharedFlowCount++;
                     }

diff --git a/tests/baselines/reference/controlFlowManyCallExpressionStatementsPerf.js b/tests/baselines/reference/controlFlowManyCallExpressionStatementsPerf.js
@@ -0,0 +1,127 @@
+//// [controlFlowManyCallExpressionStatementsPerf.ts]
+function test(x: boolean): boolean { return x; }
+
+let state = true;
+
+if (state) {
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+  test(state as any && state);
+}
+
+
+//// [controlFlowManyCallExpressionStatementsPerf.js]
+"use strict";
+function test(x) { return x; }
+var state = true;
+if (state) {
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+    test(state && state);
+}