Commit Graph

3 Commits

Author SHA1 Message Date
James Molloy 7e9bdd5d01 Revert "Revert "[FunctionAttrs] Identify norecurse functions""
This reapplies this patch, with test fixes.

llvm-svn: 252871
2015-11-12 10:55:20 +00:00
James Molloy 9a32da74f7 Revert "[FunctionAttrs] Identify norecurse functions"
This reverts commit r252862. This introduced test failures and I'm reverting while I investigate how this happened.

llvm-svn: 252863
2015-11-12 09:05:43 +00:00
James Molloy b14994e752 [FunctionAttrs] Identify norecurse functions
A function can be marked as norecurse if:
  * The SCC to which it belongs has cardinality 1; and either
    a) It does not call any non-norecurse function. This includes self-recursion; or
    b) It only has one callsite and the function that callsite is within is marked norecurse.

a) is best propagated bottom-up and b) is best propagated top-down.

We build up the norecurse attributes bottom-up using the existing SCC pass, and mark functions with no obvious recursion (but not provably norecurse) to sweep later, top-down.

llvm-svn: 252862
2015-11-12 08:53:04 +00:00