Commit Graph

5 Commits

Author SHA1 Message Date
David Majnemer 7735a6d07a [WinEH] Create a separate MBB for funclet prologues
Our current emission strategy is to emit the funclet prologue in the
CatchPad's normal destination.  This is problematic because
intra-funclet control flow to the normal destination is not erroneous
and results in us reevaluating the prologue if said control flow is
taken.

Instead, use the CatchPad's location for the funclet prologue.  This
correctly models our desire to have unwind edges evaluate the prologue
but edges to the normal destination result in typical control flow.

Differential Revision: http://reviews.llvm.org/D13424

llvm-svn: 249483
2015-10-06 23:31:59 +00:00
David Majnemer 161935520d [WinEH] Permit branch folding in the face of funclets
Track which basic blocks belong to which funclets.  Permit branch
folding to fire but only if it can prove that doing so will not cause
code in one funclet to be reused in another.

llvm-svn: 249257
2015-10-04 02:22:52 +00:00
David Majnemer 4600c06434 [WinEH] Stop BranchFolding from merging across funclets
BranchFolding would merge two funclets together, this is not OK.
Disable this and strengthen the assertion in FuncletLayout.

llvm-svn: 249069
2015-10-01 21:04:13 +00:00
David Majnemer f828a0ccc7 [WinEH] Make FuncletLayout more robust against catchret
Catchret transfers control from a catch funclet to an earlier funclet.
However, it is not completely clear which funclet the catchret target is
part of.  Make this clear by stapling the catchret target's funclet
membership onto the CATCHRET SDAG node.

llvm-svn: 249052
2015-10-01 18:44:59 +00:00
David Majnemer 978902309a [WinEH] Add a funclet layout pass
Windows EH funclets need to be contiguous.  The FuncletLayout pass will
ensure that the funclets are together and begin with a funclet entry MBB.

Differential Revision: http://reviews.llvm.org/D12943

llvm-svn: 247937
2015-09-17 20:45:18 +00:00