[PATCH] D13220: Optimize DeadCodeEliminationPass

[Sanjoy Das via llvm-commits]

sanjoy added a subscriber: sanjoy.
sanjoy added a comment.

Minor generic comments inline.


================
Comment at: lib/Transforms/Scalar/DCE.cpp:102
@@ +101,3 @@
+    // dead as we go.
+    for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
+      Value *OpV = I->getOperand(i);
----------------
I think this can be a range for loop, like

```
for (Use &Op : I->uses()) {
  ...
```

================
Comment at: lib/Transforms/Scalar/DCE.cpp:112
@@ +111,3 @@
+      // iteration.
+      if (Instruction *OpI = dyn_cast<Instruction>(OpV))
+        if (isInstructionTriviallyDead(OpI, TLI))
----------------
I find `auto *OpI` better -- that way you'll not repeat the type name.

================
Comment at: lib/Transforms/Scalar/DCE.cpp:136
@@ +135,3 @@
+  // the worklist with the entire function's worth of instructions.
+  for (inst_iterator FI = inst_begin(F), FE = inst_end(F); FI != FE;) {
+    Instruction *I = &*FI;
----------------
Can you use `inst_range` here?


Repository:
  rL LLVM

http://reviews.llvm.org/D13220