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-rw-r--r--tools/js-optimizer.js87
1 files changed, 55 insertions, 32 deletions
diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js
index 07317e0a..b02ae3cc 100644
--- a/tools/js-optimizer.js
+++ b/tools/js-optimizer.js
@@ -429,19 +429,47 @@ function simplifyExpressionsPre(ast) {
// 'useful' mathops already |0 anyhow.
function simplifyBitops(ast) {
- var SAFE_BINARY_OPS = set('+', '-', '*'); // division is unsafe as it creates non-ints in JS; mod is unsafe as signs matter so we can't remove |0's
+ var SAFE_BINARY_OPS;
+ if (asm) {
+ SAFE_BINARY_OPS = set('+', '-'); // division is unsafe as it creates non-ints in JS; mod is unsafe as signs matter so we can't remove |0's; mul does not nest with +,- in asm
+ } else {
+ SAFE_BINARY_OPS = set('+', '-', '*');
+ }
+ var COERCION_REQUIRING_OPS = set('sub', 'unary-prefix'); // ops that in asm must be coerced right away
+ var COERCION_REQUIRING_BINARIES = set('*', '/', '%'); // binary ops that in asm must be coerced
var ZERO = ['num', 0];
- var rerun = true;
- while (rerun) {
- rerun = false;
- traverse(ast, function process(node, type, stack) {
- if (type == 'binary' && node[1] == '|') {
- if (node[2][0] == 'num' && node[3][0] == 'num') {
- return ['num', node[2][1] | node[3][1]];
- } else if (jsonCompare(node[2], ZERO) || jsonCompare(node[3], ZERO)) {
+
+ function removeMultipleOrZero() {
+ var rerun = true;
+ while (rerun) {
+ rerun = false;
+ traverse(ast, function process(node, type, stack) {
+ if (type == 'binary' && node[1] == '|') {
+ if (node[2][0] == 'num' && node[3][0] == 'num') {
+ return ['num', node[2][1] | node[3][1]];
+ }
+ var go = false;
+ if (jsonCompare(node[2], ZERO)) {
+ // canonicalize order
+ var temp = node[3];
+ node[3] = node[2];
+ node[2] = temp;
+ go = true;
+ } else if (jsonCompare(node[3], ZERO)) {
+ go = true;
+ }
+ if (!go) {
+ stack.push(1);
+ return;
+ }
// We might be able to remove this correction
for (var i = stack.length-1; i >= 0; i--) {
- if (stack[i] == 1) {
+ if (stack[i] >= 1) {
+ if (asm) {
+ if (stack[stack.length-1] < 2 && node[2][0] == 'call') break; // we can only remove multiple |0s on these
+ if (stack[stack.length-1] < 1 && (node[2][0] in COERCION_REQUIRING_OPS ||
+ (node[2][0] == 'binary' && node[2][1] in COERCION_REQUIRING_BINARIES))) break; // we can remove |0 or >>2
+ }
// we will replace ourselves with the non-zero side. Recursively process that node.
var result = jsonCompare(node[2], ZERO) ? node[3] : node[2], other;
// replace node in-place
@@ -453,23 +481,23 @@ function simplifyExpressionsPre(ast) {
return process(result, result[0], stack);
} else if (stack[i] == -1) {
break; // Too bad, we can't
- } else if (asm) {
- break; // we must keep a coercion right on top of a heap access in asm mode
}
}
+ stack.push(2); // From here on up, no need for this kind of correction, it's done at the top
+ // (Add this at the end, so it is only added if we did not remove it)
+ } else if (type == 'binary' && node[1] in USEFUL_BINARY_OPS) {
+ stack.push(1);
+ } else if ((type == 'binary' && node[1] in SAFE_BINARY_OPS) || type == 'num' || type == 'name') {
+ stack.push(0); // This node is safe in that it does not interfere with this optimization
+ } else {
+ stack.push(-1); // This node is dangerous! Give up if you see this before you see '1'
}
- stack.push(1); // From here on up, no need for this kind of correction, it's done at the top
- // (Add this at the end, so it is only added if we did not remove it)
- } else if (type == 'binary' && node[1] in USEFUL_BINARY_OPS) {
- stack.push(1);
- } else if ((type == 'binary' && node[1] in SAFE_BINARY_OPS) || type == 'num' || type == 'name') {
- stack.push(0); // This node is safe in that it does not interfere with this optimization
- } else {
- stack.push(-1); // This node is dangerous! Give up if you see this before you see '1'
- }
- }, null, []);
+ }, null, []);
+ }
}
+ removeMultipleOrZero();
+
// & and heap-related optimizations
var heapBits, heapUnsigned;
@@ -480,7 +508,7 @@ function simplifyExpressionsPre(ast) {
return true;
}
- var hasTempDoublePtr = false;
+ var hasTempDoublePtr = false, rerunOrZeroPass = false;
traverse(ast, function(node, type) {
if (type == 'name') {
@@ -515,7 +543,6 @@ function simplifyExpressionsPre(ast) {
node[2][0] == 'binary' && node[2][1] == '<<' && node[2][3][0] == 'num' &&
node[2][2][0] == 'sub' && node[2][2][1][0] == 'name') {
// collapse HEAPU?8[..] << 24 >> 24 etc. into HEAP8[..] | 0
- // TODO: run this before | 0 | 0 removal, because we generate | 0
var amount = node[3][1];
var name = node[2][2][1][1];
if (amount == node[2][3][1] && parseHeap(name)) {
@@ -524,6 +551,7 @@ function simplifyExpressionsPre(ast) {
node[1] = '|';
node[2] = node[2][2];
node[3][1] = 0;
+ rerunOrZeroPass = true;
return node;
}
}
@@ -556,6 +584,8 @@ function simplifyExpressionsPre(ast) {
}
});
+ if (rerunOrZeroPass) removeMultipleOrZero();
+
if (asm) {
if (hasTempDoublePtr) {
traverse(ast, function(node, type) {
@@ -707,18 +737,11 @@ function simplifyExpressionsPre(ast) {
}
function asmOpts(fun) {
- // 1. Add final returns when necessary
- // 2. Remove unneeded coercions on function calls that have no targets (eliminator removed it)
+ // Add final returns when necessary
var returnType = null;
traverse(fun, function(node, type) {
if (type == 'return' && node[1]) {
returnType = detectAsmCoercion(node[1]);
- } else if (type == 'stat') {
- var inner = node[1];
- if ((inner[0] == 'binary' && inner[1] in ASSOCIATIVE_BINARIES && inner[2][0] == 'call' && inner[3][0] == 'num') ||
- (inner[0] == 'unary-prefix' && inner[1] == '+' && inner[2][0] == 'call')) {
- node[1] = inner[2];
- }
}
});
// Add a final return if one is missing.
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-07-26 08:41:06 +0000