diff options
| -rw-r--r-- | tools/js-optimizer.js | 82 | ||||
| -rw-r--r-- | tools/test-js-optimizer-regs-output.js | 14 |
2 files changed, 40 insertions, 56 deletions
diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js index 11130a9f..d1f164d4 100644 --- a/tools/js-optimizer.js +++ b/tools/js-optimizer.js @@ -1144,36 +1144,49 @@ function loopOptimizer(ast) { // Very simple 'registerization', coalescing of variables into a smaller number. function registerize(ast) { 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 = {}; - var varAssigns = {}; + // Replace all var definitions with assignments; we will add var definitions at the top after we registerize + // We also mark local variables - i.e., having a var definition + var localVars = {}; traverse(fun, function(node, type) { if (type == 'var') { - node[1].forEach(function(arg) { - var name = arg[0]; - if (!varUses[name]) varUses[name] = 0; // may have multiple var definitions - varUses[name]++; - if (arg[1]) { - if (!varAssigns[name]) varAssigns[name] = 0; - varAssigns[name]++; + node[1].forEach(function(defined) { localVars[defined[0]] = 1 }); + var vars = node[1].filter(function(varr) { return varr[1] }); + if (vars.length > 1) { + var ret = ['stat', []]; + var curr = ret[1]; + for (var i = 0; i < vars.length-1; i++) { + curr[0] = 'seq'; + curr[1] = ['assign', true, ['name', vars[i][0]], vars[i][1]]; + if (i != vars.length-2) curr = curr[2] = []; } - }); - } else if (type in ASSIGN_OR_ALTER) { - if (node[2] && node[2][0] == 'name') { - var name = node[2][1]; - if (!varAssigns[name]) varAssigns[name] = 0; - varAssigns[name]++; + curr[2] = ['assign', true, ['name', vars[vars.length-1][0]], vars[vars.length-1][1]]; + return ret; + } else if (vars.length == 1) { + return ['assign', true, ['name', vars[0][0]], vars[0][1]]; + } else { + return emptyNode(); } } }); - // Find uses of those variables + vacuum(fun); + // Find the # of uses of each variable + var varUses = {}; + var varAssigns = {}; traverse(fun, function(node, type) { if (type == 'name') { var name = node[1]; - if (varUses[name]) { + if (localVars[name]) { + if (!varUses[name]) varUses[name] = 0; varUses[name]++; } + } else if (type in ASSIGN_OR_ALTER) { + if (node[2] && node[2][0] == 'name') { + var name = node[2][1]; + if (localVars[name]) { + if (!varAssigns[name]) varAssigns[name] = 0; + varAssigns[name]++; + } + } } }); // Go through the function's code, assigning 'registers'. @@ -1214,14 +1227,7 @@ function registerize(ast) { 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') { + if (type == 'name') { var name = node[1]; if (decUse(name)) { node[1] = fullNames[varRegs[name]]; @@ -1238,28 +1244,6 @@ function registerize(ast) { } } }); - // Remove all vars - traverse(fun, function(node, type) { - if (type == 'var') { - var vars = node[1].filter(function(varr) { return varr[1] }); - if (vars.length > 1) { - var ret = ['stat', []]; - var curr = ret[1]; - for (var i = 0; i < vars.length-1; i++) { - curr[0] = 'seq'; - curr[1] = ['assign', true, ['name', vars[i][0]], vars[i][1]]; - if (i != vars.length-2) curr = curr[2] = []; - } - curr[2] = ['assign', true, ['name', vars[vars.length-1][0]], vars[vars.length-1][1]]; - return ret; - } else if (vars.length == 1) { - return ['assign', true, ['name', vars[0][0]], vars[0][1]]; - } else { - return emptyNode(); - } - } - }); - vacuum(fun); // Add vars at the beginning if (nextReg > 1) { var vars = []; diff --git a/tools/test-js-optimizer-regs-output.js b/tools/test-js-optimizer-regs-output.js index f3322e11..f038a11c 100644 --- a/tools/test-js-optimizer-regs-output.js +++ b/tools/test-js-optimizer-regs-output.js @@ -64,15 +64,15 @@ function primes() { } function atomic() { var r1, r2, r3, r4; - r2 = STACKTOP; + r1 = STACKTOP; STACKTOP += 4; - r1 = r2 >> 2; - HEAP32[r1] = 10; - r3 = (tempValue = HEAP32[r1], HEAP32[r1] == 10 && (HEAP32[r1] = 7), tempValue); + r2 = r1 >> 2; + HEAP32[r2] = 10; + r3 = (tempValue = HEAP32[r2], HEAP32[r2] == 10 && (HEAP32[r2] = 7), tempValue); r4 = (r3 | 0) == 10 & 1; - r3 = HEAP32[r1]; - r1 = _printf(STRING_TABLE.__str | 0, (tempInt = STACKTOP, STACKTOP += 8, HEAP32[tempInt >> 2] = r3, HEAP32[tempInt + 4 >> 2] = r4, tempInt)); - STACKTOP = r2; + r3 = HEAP32[r2]; + r2 = _printf(STRING_TABLE.__str | 0, (tempInt = STACKTOP, STACKTOP += 8, HEAP32[tempInt >> 2] = r3, HEAP32[tempInt + 4 >> 2] = r4, tempInt)); + STACKTOP = r1; return 0; return null; } |