added constant folding & branch elimination to skslc

tests/SkSLGLSLTest.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkSLCompiler.h"
 
 #include "Test.h"
@@ skipping 846 matching lines @@
          "    switch (3) {\n"
          "        case 0:\n"
          "            x = 0.0;\n"
          "        case 1:\n"
          "            x = 1.0;\n"
          "    }\n"
          "    sk_FragColor = vec4(x);\n"
          "}\n");
 }
 
+DEF_TEST(SkSLRectangleTexture, r) {
+    test(r,
+         "uniform sampler2D test;"
+         "void main() {"
+         "    sk_FragColor = texture(test, vec2(1));"
+         "}",
+         *SkSL::ShaderCapsFactory::Default(),
+         "#version 400\n"
+         "out vec4 sk_FragColor;\n"
+         "uniform sampler2D test;\n"
+         "void main() {\n"
+         "    sk_FragColor = texture(test, vec2(1.0));\n"
+         "}\n");
+    test(r,
+         "uniform sampler2DRect test;"
+         "void main() {"
+         "    sk_FragColor = texture(test, vec2(1));"
+         "}",
+         *SkSL::ShaderCapsFactory::Default(),
+         "#version 400\n"
+         "out vec4 sk_FragColor;\n"
+         "uniform sampler2DRect test;\n"
+         "void main() {\n"
+         "    sk_FragColor = texture(test, textureSize(test) * vec2(1.0));\n"
+         "}\n");
+    test(r,
+         "uniform sampler2DRect test;"
+         "void main() {"
+         "    sk_FragColor = texture(test, vec3(1));"
+         "}",
+         *SkSL::ShaderCapsFactory::Default(),
+         "#version 400\n"
+         "out vec4 sk_FragColor;\n"
+         "uniform sampler2DRect test;\n"
+         "void main() {\n"
+         "    sk_FragColor = texture(test, vec3(textureSize(test), 1.0) * vec3(1.0));\n"
+         "}\n");
+}
+
 #endif