[PATCH] D69534: [X86] Lower frame references with large offsets

[David Greene via Phabricator via llvm-commits]

greened marked 2 inline comments as done.
greened added inline comments.


================
Comment at: llvm/lib/Target/X86/X86RegisterInfo.cpp:791
+      RS.enterBasicBlockEnd(MBB);
+      RS.backward(II);
+
----------------
arsenm wrote:
> I think this is redundant with passing the iterator to scavengeRegisterBackwards but I could be misremembering
It's actually not.  I thought the same but the way scavengeRegisterBackward works is it tries to find a free register over the entire range of the current position and the iterator passed to it.  So if you don't call backward() ahead of time you end up saying you require a register free from the passed iterator to the end of the block, which is not likely to be available.  :) . I found that out the hard way.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D69534/new/

https://reviews.llvm.org/D69534