Corrected branch table probability calculation.

ttldtor · Mar 28, 2022 · 9f9f702 · 9f9f702
1 parent 1776a7f
commit 9f9f702
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Showing 2 changed files with 13 additions and 6 deletions.
diff --git a/wasm/src/org.graalvm.wasm/src/org/graalvm/wasm/WasmCodeEntry.java b/wasm/src/org.graalvm.wasm/src/org/graalvm/wasm/WasmCodeEntry.java
@@ -158,20 +158,25 @@ public static void updateTableConditionProfile(int[] profileArray, int counterIn
     }
 
     public static boolean injectTableConditionProfile(int[] profileArray, int counterIndex, int profileIndex, boolean condition) {
-        int t = profileArray[profileIndex];
         int sum = profileArray[counterIndex];
-        double probability = (double) t / (double) sum;
-        if (condition) {
+        int t = profileArray[profileIndex];
+        boolean val = condition;
+        if (val) {
             if (t == 0) {
                 CompilerDirectives.transferToInterpreterAndInvalidate();
             }
-            return CompilerDirectives.injectBranchProbability(probability, true);
+            if (t == sum) {
+                val = true;
+            }
         } else {
             if (t == sum) {
                 CompilerDirectives.transferToInterpreterAndInvalidate();
             }
-            return CompilerDirectives.injectBranchProbability(1.0 - probability, false);
+            if (t == 0) {
+                val = false;
+            }
         }
+        return CompilerDirectives.injectBranchProbability((double) t / (double) sum, val);
     }
 
     public void errorBranch() {

diff --git a/wasm/src/org.graalvm.wasm/src/org/graalvm/wasm/nodes/WasmFunctionNode.java b/wasm/src/org.graalvm.wasm/src/org/graalvm/wasm/nodes/WasmFunctionNode.java
@@ -564,6 +564,7 @@ public Object executeBodyFromOffset(WasmContext context, VirtualFrame frame, int
                         offset = extraData[indexLocation + BR_TABLE_ENTRY_BYTECODE_INDEX];
                         extraOffset = extraData[indexLocation + BR_TABLE_ENTRY_EXTRA_INDEX];
                         stackPointer = targetStackPointer + targetReturnLength;
+                        break;
                     } else {
                         // This loop is implemented to create a separate path for every index. This
                         // guarantees that all values inside the if statement are treated as compile
@@ -585,7 +586,8 @@ public Object executeBodyFromOffset(WasmContext context, VirtualFrame frame, int
                             }
                         }
                     }
-                    break;
+                    enterErrorBranch();
+                    throw WasmException.create(Failure.UNSPECIFIED_INTERNAL, this, "Should not reach here");
                 }
                 case RETURN: {
                     // A return statement causes the termination of the current function, i.e.