From bd03657f55405abc2bc149d25baefed154512a1b Mon Sep 17 00:00:00 2001 From: Jim Grosbach Date: Mon, 16 Aug 2010 22:30:41 +0000 Subject: Better handle alignment requirements for local objects in pre-regalloc frame mapping. Have the local block track its alignment requirement, and then apply that when the block itself is allocated. Previously, offsets could get adjusted in PEI to be different, relative to one another, than the block allocation thought they would be, which defeats the point of doing the allocation this way. Continuing rdar://8277890 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111197 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/PrologEpilogInserter.cpp | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) (limited to 'lib/CodeGen/PrologEpilogInserter.cpp') diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp index 8f1d3a6..83aa0c4 100644 --- a/lib/CodeGen/PrologEpilogInserter.cpp +++ b/lib/CodeGen/PrologEpilogInserter.cpp @@ -556,10 +556,20 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign); } - // Store the offset of the start of the local allocation block. This - // will be used later when resolving frame base virtual register pseudos. - MFI->setLocalFrameBaseOffset(Offset); + // FIXME: Once this is working, then enable flag will change to a target + // check for whether the frame is large enough to want to use virtual + // frame index registers. Functions which don't want/need this optimization + // will continue to use the existing code path. if (EnableLocalStackAlloc) { + unsigned Align = MFI->getLocalFrameMaxAlign(); + + // Adjust to alignment boundary. + Offset = (Offset + Align - 1) / Align * Align; + + // Store the offset of the start of the local allocation block. This + // will be used later when resolving frame base virtual register pseudos. + MFI->setLocalFrameBaseOffset(Offset); + // Allocate the local block Offset += MFI->getLocalFrameSize(); @@ -571,10 +581,6 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { AdjustStackOffset(MFI, Entry.first, StackGrowsDown, FIOffset, MaxAlign); } } - // FIXME: Allocate locals. Once the block allocation pass is turned on, - // this simplifies to just the second loop, since all of the large objects - // will have already been handled. The second loop can also simplify a - // bit, as the conditionals inside aren't all necessary. // Make sure that the stack protector comes before the local variables on the // stack. -- cgit v1.1