diff options
| -rwxr-xr-x | tests/runner.py | 2 | ||||
| -rw-r--r-- | tools/js-optimizer.js | 88 | ||||
| -rw-r--r-- | tools/test-js-optimizer-regs-output.js | 26 | ||||
| -rw-r--r-- | tools/test-js-optimizer-regs.js | 26 |
4 files changed, 142 insertions, 0 deletions
diff --git a/tests/runner.py b/tests/runner.py index 434f71a1..39614139 100755 --- a/tests/runner.py +++ b/tests/runner.py @@ -6707,6 +6707,8 @@ f.close() ['simplifyExpressionsPre', 'optimizeShiftsConservative']), (path_from_root('tools', 'test-js-optimizer-t2.js'), open(path_from_root('tools', 'test-js-optimizer-t2-output.js')).read(), ['simplifyExpressionsPre', 'optimizeShiftsAggressive']), + (path_from_root('tools', 'test-js-optimizer-regs.js'), open(path_from_root('tools', 'test-js-optimizer-regs-output.js')).read(), + ['registerize']), ]: output = Popen([NODE_JS, JS_OPTIMIZER, input] + passes, stdin=PIPE, stdout=PIPE).communicate()[0] self.assertIdentical(expected, output.replace('\n\n', '\n')) diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js index b51fe22e..d51c1c18 100644 --- a/tools/js-optimizer.js +++ b/tools/js-optimizer.js @@ -1140,6 +1140,93 @@ function loopOptimizer(ast) { vacuum(ast); } +// Very simple 'registerization', coalescing of variables into a smaller number. +function registerize(ast, conservative) { + traverseGeneratedFunctions(ast, function(fun) { + // Find the # of uses of each variable. The definition is considered a 'use' + // First, find all the var definitions + var varUses = {}; + traverse(fun, function(node, type) { + if (type == 'var') { + node[1].forEach(function(arg) { + var name = arg[0]; + varUses[name] = 1; + }); + } + }); + // Find uses of those variables + traverse(fun, function(node, type) { + if (type == 'name') { + var name = node[1]; + if (varUses[name]) { + varUses[name]++; + } + } + }); + // Go through the function's code, assigning 'registers'. + // The only tricky bit is to keep variables locked on a register through loops, + // since they can potentially be returned to. We use a simple approach of + // locking the register to the topmost loop. + var varRegs = {}; // maps variables to the register they will use all their life + var freeRegs = []; + var nextReg = 1; + var fullNames = {}; + var loopRegs = []; + var loops = 0; + function decUse(name) { + if (!varUses[name]) return varRegs[name]; // no uses left, but still need to replace the name if it has a register + var reg = varRegs[name]; + if (!reg) { + // acquire register + if (freeRegs.length > 0) { + reg = freeRegs.pop(); + } else { + reg = nextReg++; + fullNames[reg] = 'r' + reg; + } + varRegs[name] = reg; + } + varUses[name]--; + assert(varUses[name] >= 0); + if (varUses[name] == 0) { + if (loops == 0) { + // free register + freeRegs.push(reg); + } else { + loopRegs.push(reg); + } + } + return true; + } + traverse(fun, function(node, type) { // XXX we rely on traversal order being the same as execution order here + if (type == 'var') { + node[1].forEach(function(arg) { + var name = arg[0]; + if (decUse(name)) { + arg[0] = fullNames[varRegs[name]]; + } + }); + } else if (type == 'name') { + var name = node[1]; + if (decUse(name)) { + node[1] = fullNames[varRegs[name]]; + } + } else if (type in LOOP) { + loops++; + } + }, function(node, type) { + if (type in LOOP) { + loops--; + if (loops == 0 && loopRegs.length > 0) { + freeRegs = freeRegs.concat(loopRegs); + loopRegs = []; + } + } + }); + }); + //printErr('zz post: ' + dump(ast)); +} + // Passes table var compress = false; @@ -1156,6 +1243,7 @@ var passes = { simplifyExpressionsPost: simplifyExpressionsPost, hoistMultiples: hoistMultiples, loopOptimizer: loopOptimizer, + registerize: registerize, compress: function() { compress = true; } }; diff --git a/tools/test-js-optimizer-regs-output.js b/tools/test-js-optimizer-regs-output.js new file mode 100644 index 00000000..30b504be --- /dev/null +++ b/tools/test-js-optimizer-regs-output.js @@ -0,0 +1,26 @@ +function test() { + var r1 = 0; + f(r1); + r1++; + var r2 = r1 + 2; + g(r1, r2); + f(r1); + var r1 = cheez(); + var r2 = r1 + 2; + g(r2, r2); + var r2 = 200; + var r2 = 203; + var r2 = 205; + var r1 = 208; + c(r2); + while (f()) { + var r2 = 5; + var r1 = 12; + gg(r2, r1 * 2); + var r3 = 100; + gg(r3, 20); + } + var r3 = f(), r1 = 100, r1 = 1e3, r1 = 1e5; + f(r3()); +} +// EMSCRIPTEN_GENERATED_FUNCTIONS: ["test"] diff --git a/tools/test-js-optimizer-regs.js b/tools/test-js-optimizer-regs.js new file mode 100644 index 00000000..2be4ee6a --- /dev/null +++ b/tools/test-js-optimizer-regs.js @@ -0,0 +1,26 @@ +function test() { + var i = 0; + f(i); + i++; + var j = i + 2; + g(i, j); + f(i); + var i2 = cheez(); + var j2 = i2 + 2; + g(j2, j2); + var k1 = 200; + var k2 = 203; + var k3 = 205; + var k4 = 208; + c(k3); + while (f()) { + var apple = 5; + var orange = 12; + gg(apple, orange*2); + var tangerine = 100; + gg(tangerine, 20); + } + var ck = f(), ck2 = 100, ck3 = 1000, ck4 = 100000; + f(ck()); +} +// EMSCRIPTEN_GENERATED_FUNCTIONS: ["test"] |