For SCALARIZE_VEC_AND_MAT_CONSTRUCTOR_ARGS, assign precision to temp variables.

src/compiler/translator/Compiler.cpp

@@ -258,7 +258,8 @@ bool TCompiler::compile(const char* const shaderStrings[],
 
         if (success && (compileOptions & SH_SCALARIZE_VEC_AND_MAT_CONSTRUCTOR_ARGS))
         {
-            ScalarizeVecAndMatConstructorArgs scalarizer;
+            ScalarizeVecAndMatConstructorArgs scalarizer(
+                shaderType, fragmentPrecisionHigh);
             root->traverse(&scalarizer);
         }
 

src/compiler/translator/ScalarizeVecAndMatConstructorArgs.cpp

@@ -9,6 +9,7 @@
 
 #include <algorithm>
 
+#include "angle_gl.h"
 #include "common/angleutils.h"
 
 namespace
@@ -249,6 +250,16 @@ TString ScalarizeVecAndMatConstructorArgs::createTempVariable(TIntermTyped *orig
     TType type = original->getType();
     type.setQualifier(EvqTemporary);
 
+    if (mShaderType == GL_FRAGMENT_SHADER &&
+        type.getBasicType() == EbtFloat &&
+        type.getPrecision() == EbpUndefined)
+    {
+        // We use the highest available precision for the temporary variable
+        // to avoid computing the actual precision using the rules defined
+        // in GLSL ES 1.0 Section 4.5.2.
+        type.setPrecision(mFragmentPrecisionHigh ? EbpHigh : EbpMedium);
+    }
+
     TIntermBinary *init = new TIntermBinary(EOpInitialize);
     TIntermSymbol *symbolNode = new TIntermSymbol(-1, tempVarName, type);
     init->setLeft(symbolNode);

src/compiler/translator/ScalarizeVecAndMatConstructorArgs.h

@@ -12,8 +12,11 @@
 class ScalarizeVecAndMatConstructorArgs : public TIntermTraverser
 {
   public:
-    ScalarizeVecAndMatConstructorArgs()
-        : mTempVarCount(0) {}
+    ScalarizeVecAndMatConstructorArgs(sh::GLenum shaderType,
+                                      bool fragmentPrecisionHigh)
+        : mTempVarCount(0),
+          mShaderType(shaderType),
+          mFragmentPrecisionHigh(fragmentPrecisionHigh) {}
 
   protected:
     virtual bool visitAggregate(Visit visit, TIntermAggregate *node);
@@ -36,6 +39,9 @@ class ScalarizeVecAndMatConstructorArgs : public TIntermTraverser
 
     std::vector<TIntermSequence> mSequenceStack;
     int mTempVarCount;
+
+    sh::GLenum mShaderType;
+    bool mFragmentPrecisionHigh;
 };
 
 #endif  // COMPILER_TRANSLATOR_SCALARIZE_VEC_AND_MAT_CONSTRUCTOR_ARGS_H_