node/deps/v8/test/mjsunit/codegen-coverage.js

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// Test the paths in the code generator where values in specific
// registers get moved around so that the shift operation can use
// register ECX on ia32 for the shift amount.  Other codegen coverage
// tests should go here too.



function identity(x) {
  return x;
}

function cover_codegen_paths() {
  var x = 1;
  var a;  // Register EAX
  var b;  // Register EBX
  var c;  // Register ECX
  var d;  // Register EDX
  // Register ESI is already used.
  var di;  // Register EDI

  while (x == 1) {
    x = identity(1);
    a = x + 1;
    c = x + 1;
    d = x + 1;
    b = x + 1;
    di = x + 1;
    // Locals are in the corresponding registers here.
    assertEquals(c << a, 8);

    x = identity(1);
    a = x + 1;
    c = x + 1;
    d = x + 1;
    b = x + 1;
    di = x + 1;
    // Locals are in the corresponding registers here.
    assertEquals(a << c, 8);

    x = identity(1);
    a = x + 1;
    c = x + 1;
    d = x + 1;
    b = x + 1;
    di = x + 1;
    // Locals are in the corresponding registers here.
    c = 0; // Free register ecx.
    assertEquals(a << d, 8);

    x = identity(1);
    a = x + 1;
    c = x + 1;
    d = x + 1;
    b = x + 1;
    di = x + 1;
    // Locals are in the corresponding registers here.
    b = 0; // Free register ebx.
    assertEquals(a << d, 8);

    x = 3;
  }
}

cover_codegen_paths();