Fix issues with computing discontinuous loops

AST analysis to narrow down usage of [[loop]] and [[unroll]] failed to account for break statements inside switch statements. Add switch statement handling. This fixes asserts/crashes in dEQP tests. BUG=angleproject:937 TEST=dEQP-GLES3.functional.shaders.switch.* Change-Id: I04fdfe4733772a2a234934123bbfacf0376df562 Reviewed-on: https://chromium-review.googlesource.com/265191Tested-by: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Geoff Lang <geofflang@chromium.org>

Fix issues with computing discontinuous loops
3873cd0b · Olli Etuaho · 5f2feee4 · 3873cd0b
Commit 3873cd0b authored Apr 10, 2015 by Olli Etuaho
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Showing with 52 additions and 14 deletions

ASTMetadataHLSL.cpp src/compiler/translator/ASTMetadataHLSL.cpp +52 -14

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--- a/src/compiler/translator/ASTMetadataHLSL.cpp
+++ b/src/compiler/translator/ASTMetadataHLSL.cpp
@@ -156,7 +156,7 @@ class PullComputeDiscontinuousLoops : public TIntermTraverser
    void traverse(TIntermAggregate *node)
    {
        node->traverse(this);
-        ASSERT(mLoops.empty());
+        ASSERT(mLoopsAndSwitches.empty());
        ASSERT(mIfs.empty());
    }

@@ -172,22 +172,22 @@ class PullComputeDiscontinuousLoops : public TIntermTraverser
        }
    }

-    bool visitLoop(Visit visit, TIntermLoop *loop)
+    bool visitLoop(Visit visit, TIntermLoop *loop) override
    {
        if (visit == PreVisit)
        {
-            mLoops.push_back(loop);
+            mLoopsAndSwitches.push_back(loop);
        }
        else if (visit == PostVisit)
        {
-            ASSERT(mLoops.back() == loop);
-            mLoops.pop_back();
+            ASSERT(mLoopsAndSwitches.back() == loop);
+            mLoopsAndSwitches.pop_back();
        }

        return true;
    }

-    bool visitSelection(Visit visit, TIntermSelection *node)
+    bool visitSelection(Visit visit, TIntermSelection *node) override
    {
        if (visit == PreVisit)
        {
@@ -207,7 +207,7 @@ class PullComputeDiscontinuousLoops : public TIntermTraverser
        return true;
    }

-    bool visitBranch(Visit visit, TIntermBranch *node)
+    bool visitBranch(Visit visit, TIntermBranch *node) override
    {
        if (visit == PreVisit)
        {
@@ -216,18 +216,42 @@ class PullComputeDiscontinuousLoops : public TIntermTraverser
              case EOpKill:
                break;
              case EOpBreak:
+                {
+                    ASSERT(!mLoopsAndSwitches.empty());
+                    TIntermLoop *loop = mLoopsAndSwitches.back()->getAsLoopNode();
+                    if (loop != nullptr)
+                    {
+                        mMetadata->mDiscontinuousLoops.insert(loop);
+                        onDiscontinuousLoop();
+                    }
+                }
+                break;
              case EOpContinue:
-                ASSERT(!mLoops.empty());
-                mMetadata->mDiscontinuousLoops.insert(mLoops.back());
-                onDiscontinuousLoop();
+                {
+                    ASSERT(!mLoopsAndSwitches.empty());
+                    TIntermLoop *loop = nullptr;
+                    size_t i = mLoopsAndSwitches.size();
+                    while (loop == nullptr && i > 0)
+                    {
+                        --i;
+                        loop = mLoopsAndSwitches.at(i)->getAsLoopNode();
+                    }
+                    ASSERT(loop != nullptr);
+                    mMetadata->mDiscontinuousLoops.insert(loop);
+                    onDiscontinuousLoop();
+                }
                break;
              case EOpReturn:
                // A return jumps out of all the enclosing loops
-                if (!mLoops.empty())
+                if (!mLoopsAndSwitches.empty())
                {
-                    for (TIntermLoop* loop : mLoops)
+                    for (TIntermNode* node : mLoopsAndSwitches)
                    {
-                        mMetadata->mDiscontinuousLoops.insert(loop);
+                        TIntermLoop *loop = node->getAsLoopNode();
+                        if (loop)
+                        {
+                            mMetadata->mDiscontinuousLoops.insert(loop);
+                        }
                    }
                    onDiscontinuousLoop();
                }
@@ -259,13 +283,27 @@ class PullComputeDiscontinuousLoops : public TIntermTraverser
        return true;
    }

+    bool visitSwitch(Visit visit, TIntermSwitch *node) override
+    {
+        if (visit == PreVisit)
+        {
+            mLoopsAndSwitches.push_back(node);
+        }
+        else if (visit == PostVisit)
+        {
+            ASSERT(mLoopsAndSwitches.back() == node);
+            mLoopsAndSwitches.pop_back();
+        }
+        return true;
+    }
+
  private:
    MetadataList *mMetadataList;
    ASTMetadataHLSL *mMetadata;
    size_t mIndex;
    const CallDAG &mDag;

-    std::vector<TIntermLoop*> mLoops;
+    std::vector<TIntermNode*> mLoopsAndSwitches;
    std::vector<TIntermSelection*> mIfs;
 };