diff --git a/src/coreclr/jit/compiler.h b/src/coreclr/jit/compiler.h index e49916d0f21b5..0bfe717ed903b 100644 --- a/src/coreclr/jit/compiler.h +++ b/src/coreclr/jit/compiler.h @@ -4534,6 +4534,7 @@ class Compiler bool fgRemoveRestOfBlock; // true if we know that we will throw bool fgStmtRemoved; // true if we remove statements -> need new DFA + bool fgRemarkGlobalUses; // true if morph should remark global uses after processing a statement enum FlowGraphOrder { @@ -5820,6 +5821,7 @@ class Compiler GenTreeCall* fgMorphArgs(GenTreeCall* call); void fgMakeOutgoingStructArgCopy(GenTreeCall* call, CallArg* arg); + void fgMarkGlobalUses(Statement* stmt); GenTree* fgMorphLocal(GenTreeLclVarCommon* lclNode); #ifdef TARGET_X86 diff --git a/src/coreclr/jit/morph.cpp b/src/coreclr/jit/morph.cpp index 4d01281e61fa1..3d97c19f06cf4 100644 --- a/src/coreclr/jit/morph.cpp +++ b/src/coreclr/jit/morph.cpp @@ -3981,7 +3981,7 @@ void Compiler::fgMakeOutgoingStructArgCopy(GenTreeCall* call, CallArg* arg) // bool omitCopy = call->IsTailCall(); - if (!omitCopy && fgDidEarlyLiveness) + if (!omitCopy && fgGlobalMorph) { omitCopy = !varDsc->lvPromoted && ((lcl->gtFlags & GTF_VAR_DEATH) != 0); } @@ -4016,6 +4016,17 @@ void Compiler::fgMakeOutgoingStructArgCopy(GenTreeCall* call, CallArg* arg) // Copy prop could allow creating another later use of lcl if there are live assertions about it. fgKillDependentAssertions(varNum DEBUGARG(lcl)); + + // We may have seen previous uses of this local already, + // and those uses should now be marked as GTF_GLOB_REF + // since otherwise they could be reordered with the call. + // The only known issues are under stress mode and happen + // in the same statement, so we only handle this case currently. + // TODO: A more complete fix will likely entail identifying + // these candidates before morph and address exposing them + // at that point, which first requires ABI determination to + // be moved earlier. + fgRemarkGlobalUses = true; } JITDUMP("did not need to make outgoing copy for last use of V%02d\n", varNum); @@ -4096,6 +4107,51 @@ void Compiler::fgMakeOutgoingStructArgCopy(GenTreeCall* call, CallArg* arg) arg->SetEarlyNode(argNode); } +//------------------------------------------------------------------------ +// fgMarkNewlyGlobalUses: Given a local that is newly address exposed, add +// GTF_GLOB_REF whever necessary in the specified statement. +// +// Arguments: +// stmt - The statement +// lclNum - The local that is newly address exposed +// +// Notes: +// See comment in fgMakeOutgoingStructArgCopy. +// +void Compiler::fgMarkGlobalUses(Statement* stmt) +{ + struct Visitor : GenTreeVisitor + { + enum + { + DoPostOrder = true, + }; + + Visitor(Compiler* comp) : GenTreeVisitor(comp) + { + } + + fgWalkResult PostOrderVisit(GenTree** use, GenTree* user) + { + GenTree* node = *use; + if (node->OperIsLocal() && m_compiler->lvaGetDesc(node->AsLclVarCommon()->GetLclNum())->IsAddressExposed()) + { + node->gtFlags |= GTF_GLOB_REF; + } + + if (user != nullptr) + { + user->gtFlags |= node->gtFlags & GTF_GLOB_REF; + } + + return WALK_CONTINUE; + } + }; + + Visitor visitor(this); + visitor.WalkTree(stmt->GetRootNodePointer(), nullptr); +} + /***************************************************************************** * * A little helper used to rearrange nested commutative operations. The @@ -13349,6 +13405,7 @@ bool Compiler::fgMorphBlockStmt(BasicBlock* block, Statement* stmt DEBUGARG(cons void Compiler::fgMorphStmts(BasicBlock* block) { fgRemoveRestOfBlock = false; + fgRemarkGlobalUses = false; for (Statement* const stmt : block->Statements()) { @@ -13463,6 +13520,12 @@ void Compiler::fgMorphStmts(BasicBlock* block) stmt->SetRootNode(morphedTree); + if (fgRemarkGlobalUses) + { + fgMarkGlobalUses(stmt); + fgRemarkGlobalUses = false; + } + if (fgRemoveRestOfBlock) { continue;