HLSL: Fix #1249: Always execute both sides of ternary "?:".

This is semantically required by HLSL, and frequently results in using
OpSelect instead of control flow.

glslang/Include/intermediate.h

@@ -1336,9 +1336,11 @@ class TIntermSelection : public TIntermTyped {
 public:
     TIntermSelection(TIntermTyped* cond, TIntermNode* trueB, TIntermNode* falseB) :
         TIntermTyped(EbtVoid), condition(cond), trueBlock(trueB), falseBlock(falseB),
+        shortCircuit(true),
         flatten(false), dontFlatten(false) {}
     TIntermSelection(TIntermTyped* cond, TIntermNode* trueB, TIntermNode* falseB, const TType& type) :
         TIntermTyped(type), condition(cond), trueBlock(trueB), falseBlock(falseB),
+        shortCircuit(true),
         flatten(false), dontFlatten(false) {}
     virtual void traverse(TIntermTraverser*);
     virtual TIntermTyped* getCondition() const { return condition; }
@@ -1347,6 +1349,9 @@ public:
     virtual       TIntermSelection* getAsSelectionNode()       { return this; }
     virtual const TIntermSelection* getAsSelectionNode() const { return this; }
 
+    void setNoShortCircuit() { shortCircuit = false; }
+    bool getShortCircuit() const { return shortCircuit; }
+
     void setFlatten()     { flatten = true; }
     void setDontFlatten() { dontFlatten = true; }
     bool getFlatten()     const { return flatten; }
@@ -1356,8 +1361,9 @@ protected:
     TIntermTyped* condition;
     TIntermNode* trueBlock;
     TIntermNode* falseBlock;
-    bool flatten;     // true if flatten requested
-    bool dontFlatten; // true if requested to not flatten
+    bool shortCircuit; // normally all if-then-else and all GLSL ?: short-circuit, but HLSL ?: does not
+    bool flatten;      // true if flatten requested
+    bool dontFlatten;  // true if requested to not flatten
 };
 
 //

glslang/MachineIndependent/Intermediate.cpp

@@ -1672,7 +1672,11 @@ TIntermTyped* TIntermediate::addSelection(TIntermTyped* cond, TIntermTyped* true
     // If it's void, go to the if-then-else selection()
     if (trueBlock->getBasicType() == EbtVoid && falseBlock->getBasicType() == EbtVoid) {
         TIntermNodePair pair = { trueBlock, falseBlock };
-        return addSelection(cond, pair, loc);
+        TIntermSelection* selection = addSelection(cond, pair, loc);
+        if (getSource() == EShSourceHlsl)
+            selection->setNoShortCircuit();
+
+        return selection;
     }
 
     //
@@ -1743,6 +1747,9 @@ TIntermTyped* TIntermediate::addSelection(TIntermTyped* cond, TIntermTyped* true
     else
         node->getQualifier().makeTemporary();
 
+    if (getSource() == EShSourceHlsl)
+        node->setNoShortCircuit();
+
     return node;
 }
 

glslang/MachineIndependent/intermOut.cpp

@@ -819,6 +819,8 @@ bool TOutputTraverser::visitSelection(TVisit /* visit */, TIntermSelection* node
     out.debug << "Test condition and select";
     out.debug << " (" << node->getCompleteString() << ")";
 
+    if (node->getShortCircuit() == false)
+        out.debug << ": no shortcircuit";
     if (node->getFlatten())
         out.debug << ": Flatten";
     if (node->getDontFlatten())