v8/test/mjsunit/codegen-coverage.js

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// Copyright 2009 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Flags: --nofull-compiler --nofast-compiler
// Test paths in the code generator where values in specific registers
// get moved around.
function identity(x) {
return x;
}
function lookup(w, a) {
// This function tests a code path in the generation of a keyed load IC
// where the key and the value are both in the same register.
a = a;
w[a] = a;
}
function cover_codegen_paths() {
var x = 1;
// This test depends on the fixed order of register allocation. We try to
// get values in specific registers (ia32, x64):
var a; // Register eax, rax.
var b; // Register ebx, rbx.
var c; // Register ecx, rcx.
var d; // Register edx, rdx.
var di; // Register edi, rdi.
while (x == 1) {
// The call will spill registers and leave x in {eax,rax}.
x = identity(1);
// The add will spill x and reuse {eax,rax} for the result.
a = x + 1;
// A fresh register {ebx,rbx} will be allocated for x, then reused for
// the result.
b = x + 1;
// Et cetera.
c = x + 1;
d = x + 1;
di = x + 1;
// Locals are in the corresponding registers here.
assertEquals(8, c << a);
x = identity(1);
a = x + 1;
b = x + 1;
c = x + 1;
d = x + 1;
di = x + 1;
assertEquals(8, a << c);
x = identity(1);
a = x + 1;
b = x + 1;
c = x + 1;
d = x + 1;
di = x + 1;
c = 0; // Free register ecx.
assertEquals(8, a << d);
x = identity(1);
a = x + 1;
b = x + 1;
c = x + 1;
d = x + 1;
di = x + 1;
b = 0; // Free register ebx.
assertEquals(8, a << d);
// Test the non-commutative subtraction operation with a smi on the
// left, all available registers on the right, and a non-smi result.
x = identity(-1073741824); // Least (31-bit) smi.
a = x + 1; // Still a smi, the greatest smi negated.
b = x + 1;
c = x + 1;
d = x + 1;
di = x + 1;
// Subtraction should overflow the 31-bit smi range. The result
// (1073741824) is outside the 31-bit smi range so it doesn't hit the
// "unsafe smi" code that spills a register.
assertEquals(1073741824, 1 - a);
x = identity(-1073741824);
a = x + 1;
b = x + 1;
c = x + 1;
d = x + 1;
di = x + 1;
assertEquals(1073741824, 1 - b);
x = identity(-1073741824);
a = x + 1;
b = x + 1;
c = x + 1;
d = x + 1;
di = x + 1;
assertEquals(1073741824, 1 - c);
x = identity(-1073741824);
a = x + 1;
b = x + 1;
c = x + 1;
d = x + 1;
di = x + 1;
assertEquals(1073741824, 1 - d);
x = identity(-1073741824);
a = x + 1;
b = x + 1;
c = x + 1;
d = x + 1;
di = x + 1;
assertEquals(1073741824, 1 - di);
x = 3;
var w = { };
lookup(w, x);
lookup(w, x);
lookup(w, x);
x = 3; // Terminate while loop.
}
}
cover_codegen_paths();