[PATCH] D67404: [ARM] LE support in ConstantIslands

[Dave Green via Phabricator via llvm-commits]

dmgreen added a comment.

Nice. I was expecting this to happen earlier, maybe in the other branch optimisations. This seems like a good place for it, though.

What does it do for codesize?



================
Comment at: lib/Target/ARM/ARMConstantIslandPass.cpp:1935
+  // branches, will succeed.
+  for (unsigned i = ImmBranches.size(); i != 0; --i) {
+    ImmBranch &Br = ImmBranches[i-1];
----------------
for (ImmBranch &Br : reverse(ImmBranches))


================
Comment at: lib/Target/ARM/ARMConstantIslandPass.cpp:1986
+      Br.MI = NewBR;
+    } else if (&MBB->back() != Br.MI) {
+      MachineInstr &LastMI = MBB->back();
----------------
Can you explain this? Is it that we know that this is the LE case, and the other br at the end of the block is being deleted? Can you add a comment.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D67404/new/

https://reviews.llvm.org/D67404