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 25 matching lines @@
          default_caps(),
          "#version 400\n"
          "void main() {\n"
          "    gl_FragColor = vec4(0.75);\n"
          "}\n");
 }
 
 DEF_TEST(SkSLControl, r) {
     test(r,
          "void main() {"
-         "if (1 + 2 + 3 > 5) { sk_FragColor = vec4(0.75); } else { discard; }"
+         "if (sqrt(2) > 5) { sk_FragColor = vec4(0.75); } else { discard; }"
          "int i = 0;"
          "while (i < 10) sk_FragColor *= 0.5;"
          "do { sk_FragColor += 0.01; } while (sk_FragColor.x < 0.7);"
          "for (int i = 0; i < 10; i++) {"
          "if (i % 0 == 1) break; else continue;"
          "}"
          "return;"
          "}",
          default_caps(),
          "#version 400\n"
          "void main() {\n"
-         "    if ((1 + 2) + 3 > 5) {\n"
+         "    if (sqrt(2.0) > 5.0) {\n"
          "        gl_FragColor = vec4(0.75);\n"
          "    } else {\n"
          "        discard;\n"
          "    }\n"
          "    int i = 0;\n"
          "    while (i < 10) gl_FragColor *= 0.5;\n"
          "    do {\n"
          "        gl_FragColor += 0.01;\n"
          "    } while (gl_FragColor.x < 0.7);\n"
          "    for (int i = 0;i < 10; i++) {\n"
@@ skipping 28 matching lines @@
 }
 
 DEF_TEST(SkSLOperators, r) {
     test(r,
          "void main() {"
          "float x = 1, y = 2;"
          "int z = 3;"
          "x = x + y * z * x * (y - z);"
          "y = x / y / z;"
          "z = (z / 2 % 3 << 4) >> 2 << 1;"
-         "bool b = (x > 4) == x < 2 || 2 >= 5 && y <= z && 12 != 11;"
+         "bool b = (x > 4) == x < 2 || 2 >= sqrt(2) && y <= z;"
          "x += 12;"
          "x -= 12;"
          "x *= y /= z = 10;"
          "b ||= false;"
          "b &&= true;"
          "b ^^= false;"
          "z |= 0;"
          "z &= -1;"
          "z ^= 0;"
          "z >>= 2;"
          "z <<= 4;"
          "z %= 5;"
          "}",
          default_caps(),
          "#version 400\n"
          "void main() {\n"
          "    float x = 1.0, y = 2.0;\n"
          "    int z = 3;\n"
          "    x = x + ((y * float(z)) * x) * (y - float(z));\n"
          "    y = (x / y) / float(z);\n"
          "    z = (((z / 2) % 3 << 4) >> 2) << 1;\n"
-         "    bool b = x > 4.0 == x < 2.0 || (2 >= 5 && y <= float(z)) && 12 != 11;\n"
+         "    bool b = x > 4.0 == x < 2.0 || 2.0 >= sqrt(2.0) && y <= float(z);\n"
          "    x += 12.0;\n"
          "    x -= 12.0;\n"
          "    x *= (y /= float(z = 10));\n"
          "    b ||= false;\n"
          "    b &&= true;\n"
          "    b ^^= false;\n"
          "    z |= 0;\n"
          "    z &= -1;\n"
          "    z ^= 0;\n"
          "    z >>= 2;\n"
@@ skipping 283 matching lines @@
          "}\n");
     test(r,
          "void main() { float x = dFdx(1); }",
          caps,
          "#version 400\n"
          "#extension GL_OES_standard_derivatives : require\n"
          "void main() {\n"
          "    float x = dFdx(1.0);\n"
          "}\n");
 }
+
+DEF_TEST(SkSLConstantFolding, r) {
+    test(r,
+         "void main() {"
+         "float f_add = 32 + 2;"
+         "float f_sub = 32 - 2;"
+         "float f_mul = 32 * 2;"
+         "float f_div = 32 / 2;"
+         "float mixed = (12 > 2.0) ? (10 * 2 / 5 + 18 - 3) : 0;"
+         "int i_add = 32 + 2;"
+         "int i_sub = 32 - 2;"
+         "int i_mul = 32 * 2;"
+         "int i_div = 32 / 2;"
+         "int i_or = 12 | 6;"
+         "int i_and = 254 & 7;"
+         "int i_xor = 2 ^ 7;"
+         "int i_shl = 1 << 4;"
+         "int i_shr = 128 >> 2;"
+         "bool gt_it = 6 > 5;"
+         "bool gt_if = 6 > 6;"
+         "bool gt_ft = 6.0 > 5.0;"
+         "bool gt_ff = 6.0 > 6.0;"
+         "bool gte_it = 6 >= 6;"
+         "bool gte_if = 6 >= 7;"
+         "bool gte_ft = 6.0 >= 6.0;"
+         "bool gte_ff = 6.0 >= 7.0;"
+         "bool lte_it = 6 <= 6;"
+         "bool lte_if = 6 <= 5;"
+         "bool lte_ft = 6.0 <= 6.0;"
+         "bool lte_ff = 6.0 <= 5.0;"
+         "bool or_t = 1 == 1 || 2 == 8;"
+         "bool or_f = 1 > 1 || 2 == 8;"
+         "bool and_t = 1 == 1 && 2 <= 8;"
+         "bool and_f = 1 == 2 && 2 == 8;"
+         "bool xor_t = 1 == 1 ^^ 1 != 1;"
+         "bool xor_f = 1 == 1 ^^ 1 == 1;"
+         "int ternary = 10 > 5 ? 10 : 5;"
+         "}",
+         default_caps(),
+         "#version 400\n"
+         "void main() {\n"
+         "    float f_add = 34.0;\n"
+         "    float f_sub = 30.0;\n"
+         "    float f_mul = 64.0;\n"
+         "    float f_div = 16.0;\n"
+         "    float mixed = 19.0;\n"
+         "    int i_add = 34;\n"
+         "    int i_sub = 30;\n"
+         "    int i_mul = 64;\n"
+         "    int i_div = 16;\n"
+         "    int i_or = 14;\n"
+         "    int i_and = 6;\n"
+         "    int i_xor = 5;\n"
+         "    int i_shl = 16;\n"
+         "    int i_shr = 32;\n"
+         "    bool gt_it = true;\n"
+         "    bool gt_if = false;\n"
+         "    bool gt_ft = true;\n"
+         "    bool gt_ff = false;\n"
+         "    bool gte_it = true;\n"
+         "    bool gte_if = false;\n"
+         "    bool gte_ft = true;\n"
+         "    bool gte_ff = false;\n"
+         "    bool lte_it = true;\n"
+         "    bool lte_if = false;\n"
+         "    bool lte_ft = true;\n"
+         "    bool lte_ff = false;\n"
+         "    bool or_t = true;\n"
+         "    bool or_f = false;\n"
+         "    bool and_t = true;\n"
+         "    bool and_f = false;\n"
+         "    bool xor_t = true;\n"
+         "    bool xor_f = false;\n"
+         "    int ternary = 10;\n"
+         "}\n");
+}
+
+DEF_TEST(SkSLStaticIf, r) {
+    test(r,
+         "void main() {"
+         "int x;"
+         "if (true) x = 1;"
+         "if (2 > 1) x = 2; else x = 3;"
+         "if (1 > 2) x = 4; else x = 5;"
+         "if (false) x = 6;"
+         "}",
+         default_caps(),
+         "#version 400\n"
+         "void main() {\n"
+         "    int x;\n"
+         "    x = 1;\n"
+         "    x = 2;\n"
+         "    x = 5;\n"
+         "    {\n"
+         "    }\n"
+         "}\n");
+}