diff options
Diffstat (limited to 'llvm/lib/Target/WebAssembly/WebAssemblyCFGSort.cpp')
| -rw-r--r-- | llvm/lib/Target/WebAssembly/WebAssemblyCFGSort.cpp | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyCFGSort.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyCFGSort.cpp index eb3e9b91d40d..2257d1562513 100644 --- a/llvm/lib/Target/WebAssembly/WebAssemblyCFGSort.cpp +++ b/llvm/lib/Target/WebAssembly/WebAssemblyCFGSort.cpp @@ -17,11 +17,11 @@ ////===----------------------------------------------------------------------===// #include "MCTargetDesc/WebAssemblyMCTargetDesc.h" +#include "Utils/WebAssemblyUtilities.h" #include "WebAssembly.h" #include "WebAssemblyExceptionInfo.h" #include "WebAssemblySortRegion.h" #include "WebAssemblySubtarget.h" -#include "WebAssemblyUtilities.h" #include "llvm/ADT/PriorityQueue.h" #include "llvm/ADT/SetVector.h" #include "llvm/CodeGen/MachineDominators.h" @@ -29,6 +29,7 @@ #include "llvm/CodeGen/MachineLoopInfo.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/Passes.h" +#include "llvm/CodeGen/WasmEHFuncInfo.h" #include "llvm/Support/Debug.h" #include "llvm/Support/raw_ostream.h" using namespace llvm; @@ -218,6 +219,7 @@ static void sortBlocks(MachineFunction &MF, const MachineLoopInfo &MLI, CompareBlockNumbersBackwards> Ready; + const auto *EHInfo = MF.getWasmEHFuncInfo(); SortRegionInfo SRI(MLI, WEI); SmallVector<Entry, 4> Entries; for (MachineBasicBlock *MBB = &MF.front();;) { @@ -245,8 +247,34 @@ static void sortBlocks(MachineFunction &MF, const MachineLoopInfo &MLI, if (SuccL->getHeader() == Succ && SuccL->contains(MBB)) continue; // Decrement the predecessor count. If it's now zero, it's ready. - if (--NumPredsLeft[Succ->getNumber()] == 0) + if (--NumPredsLeft[Succ->getNumber()] == 0) { + // When we are in a SortRegion, we allow sorting of not only BBs that + // belong to the current (innermost) region but also BBs that are + // dominated by the current region header. But we should not do this for + // exceptions because there can be cases in which, for example: + // EHPad A's unwind destination (where the exception lands when it is + // not caught by EHPad A) is EHPad B, so EHPad B does not belong to the + // exception dominated by EHPad A. But EHPad B is dominated by EHPad A, + // so EHPad B can be sorted within EHPad A's exception. This is + // incorrect because we may end up delegating/rethrowing to an inner + // scope in CFGStackify. So here we make sure those unwind destinations + // are deferred until their unwind source's exception is sorted. + if (EHInfo && EHInfo->hasUnwindSrcs(Succ)) { + SmallPtrSet<MachineBasicBlock *, 4> UnwindSrcs = + EHInfo->getUnwindSrcs(Succ); + bool IsDeferred = false; + for (Entry &E : Entries) { + if (UnwindSrcs.count(E.TheRegion->getHeader())) { + E.Deferred.push_back(Succ); + IsDeferred = true; + break; + } + } + if (IsDeferred) + continue; + } Preferred.push(Succ); + } } // Determine the block to follow MBB. First try to find a preferred block, // to preserve the original block order when possible. |