From 6627ac040a14f3a79564fd6ec030f9361f81d20e Mon Sep 17 00:00:00 2001 From: Jim Grosbach Date: Fri, 2 Jul 2010 21:23:37 +0000 Subject: [PATCH] Custom inserters (e.g., conditional moves in Thumb1 can introduce new basic blocks, and if used as a function argument, that can cause call frame setup / destroy pairs to be split across a basic block boundary. That prevents us from doing a simple assertion to check that the pairs match and alloc/ dealloc the same amount of space. Modify the assertion to only check the amount allocated when there are matching pairs in the same basic block. rdar://8022442 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107517 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/PrologEpilogInserter.cpp | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp index 62b7c21cc8a..d573e91a441 100644 --- a/lib/CodeGen/PrologEpilogInserter.cpp +++ b/lib/CodeGen/PrologEpilogInserter.cpp @@ -642,6 +642,9 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) { for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) { +#ifndef NDEBUG + int SPAdjCount = 0; // frame setup / destroy count. +#endif int SPAdj = 0; // SP offset due to call frame setup / destroy. if (RS && !FrameIndexVirtualScavenging) RS->enterBasicBlock(BB); @@ -649,6 +652,10 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) { if (I->getOpcode() == FrameSetupOpcode || I->getOpcode() == FrameDestroyOpcode) { +#ifndef NDEBUG + // Track whether we see even pairs of them + SPAdjCount += I->getOpcode() == FrameSetupOpcode ? 1 : -1; +#endif // Remember how much SP has been adjusted to create the call // frame. int Size = I->getOperand(0).getImm(); @@ -715,7 +722,13 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) { if (RS && !FrameIndexVirtualScavenging && MI) RS->forward(MI); } - assert(SPAdj == 0 && "Unbalanced call frame setup / destroy pairs?"); + // If we have evenly matched pairs of frame setup / destroy instructions, + // make sure the adjustments come out to zero. If we don't have matched + // pairs, we can't be sure the missing bit isn't in another basic block + // due to a custom inserter playing tricks, so just asserting SPAdj==0 + // isn't sufficient. See tMOVCC on Thumb1, for example. + assert((SPAdjCount || SPAdj == 0) && + "Unbalanced call frame setup / destroy pairs?"); } } -- 2.34.1