[PATCH] D137707: Move "auto-init" instructions to the dominator of their users

[serge via Phabricator via llvm-commits]

serge-sans-paille added a comment.

Extra numbers: this is the result of compiling the codes from compile-time-tracker with -ftrivial-auto-var-init=pattern:

-ftrivial-auto-var-init=none vs  -ftrivial-auto-var-init=pattern:

  https://llvm-compile-time-tracker.com/compare.php?from=50a1c9b1073d7842ef687e486dc842ffea39457c&to=0cc74fe5d7f455e8dd2a34c4cfd9c276aae9ee57&stat=instructions:u

Adding the transformation from this patch on top of -ftrivial-auto-var-init=pattern adds a very slight overhead:

-ftrivial-auto-var-init=pattern vs  -ftrivial-auto-var-init=pattern + this pass:

  https://llvm-compile-time-tracker.com/compare.php?from=0cc74fe5d7f455e8dd2a34c4cfd9c276aae9ee57&to=67cd4b64768d74a2335d5268967951558bca3226&stat=instructions:u

Basically as is, this pass doesn't add much overhead in compilation time.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D137707/new/

https://reviews.llvm.org/D137707