From 970755e5197afb42a76a24a74cd6dc17721daf50 Mon Sep 17 00:00:00 2001 From: Shuxin Yang Date: Fri, 19 Oct 2012 20:11:16 +0000 Subject: This patch is to fix radar://8426430. It is about llvm support of __builtin_debugtrap() which is supposed to consistently raise SIGTRAP across all systems. In contrast, __builtin_trap() behave differently on different systems. e.g. it raises SIGTRAP on ARM, and SIGILL on X86. The purpose of __builtin_debugtrap() is to consistently provide "trap" functionality, in the mean time preserve the compatibility with on gcc on __builtin_trap(). The X86 backend is already able to handle debugtrap(). This patch is to: 1) make front-end recognize "__builtin_debugtrap()" (emboddied in the one-line change to Clang). 2) In DAG legalization phase, by default, "debugtrap" will be replaced with "trap", which make the __builtin_debugtrap() "available" to all existing ports without the hassle of changing their code. 3) If trap-function is specified (via -trap-func=xyz to llc), both __builtin_debugtrap() and __builtin_trap() will be expanded into the function call of the specified trap function. This behavior may need change in the future. The provided testing-case is to make sure 2) and 3) are working for ARM port, and we already have a testing case for x86. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166300 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Intrinsics.td | 2 +- lib/CodeGen/SelectionDAG/LegalizeDAG.cpp | 13 +++++++++++++ lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 10 +++++----- lib/CodeGen/SelectionDAG/TargetLowering.cpp | 5 +++++ lib/Target/X86/X86ISelLowering.cpp | 1 + test/CodeGen/ARM/trap.ll | 12 ++++++++++++ 6 files changed, 37 insertions(+), 6 deletions(-) diff --git a/include/llvm/Intrinsics.td b/include/llvm/Intrinsics.td index 804db49556..5ccfde9e1a 100644 --- a/include/llvm/Intrinsics.td +++ b/include/llvm/Intrinsics.td @@ -420,7 +420,7 @@ def int_flt_rounds : Intrinsic<[llvm_i32_ty]>, GCCBuiltin<"__builtin_flt_rounds">; def int_trap : Intrinsic<[], [], [IntrNoReturn]>, GCCBuiltin<"__builtin_trap">; -def int_debugtrap : Intrinsic<[]>, +def int_debugtrap : Intrinsic<[], [], [IntrNoReturn]>, GCCBuiltin<"__builtin_debugtrap">; // NOP: calls/invokes to this intrinsic are removed by codegen diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp index 2ec129f730..c46df30935 100644 --- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp +++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp @@ -1240,6 +1240,19 @@ void SelectionDAGLegalize::LegalizeOp(SDNode *Node) { if (Action == TargetLowering::Legal) Action = TargetLowering::Custom; break; + case ISD::DEBUGTRAP: + Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0)); + if (Action == TargetLowering::Expand) { + // replace ISD::DEBUGTRAP with ISD::TRAP + SDValue NewVal; + NewVal = DAG.getNode (ISD::TRAP, Node->getDebugLoc(), Node->getVTList(), + Node->getOperand(0)); + ReplaceNode(Node, NewVal.getNode()); + LegalizeOp(NewVal.getNode()); + return; + } + break; + default: if (Node->getOpcode() >= ISD::BUILTIN_OP_END) { Action = TargetLowering::Legal; diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index cdebff94e5..db15994174 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -5175,10 +5175,13 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) { return 0; } + case Intrinsic::debugtrap: case Intrinsic::trap: { StringRef TrapFuncName = TM.Options.getTrapFunctionName(); if (TrapFuncName.empty()) { - DAG.setRoot(DAG.getNode(ISD::TRAP, dl,MVT::Other, getRoot())); + ISD::NodeType Op = (Intrinsic == Intrinsic::trap) ? + ISD::TRAP : ISD::DEBUGTRAP; + DAG.setRoot(DAG.getNode(Op, dl,MVT::Other, getRoot())); return 0; } TargetLowering::ArgListTy Args; @@ -5193,10 +5196,7 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) { DAG.setRoot(Result.second); return 0; } - case Intrinsic::debugtrap: { - DAG.setRoot(DAG.getNode(ISD::DEBUGTRAP, dl,MVT::Other, getRoot())); - return 0; - } + case Intrinsic::uadd_with_overflow: case Intrinsic::sadd_with_overflow: case Intrinsic::usub_with_overflow: diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp index cd485ac235..5abc55ba8e 100644 --- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -583,6 +583,11 @@ TargetLowering::TargetLowering(const TargetMachine &tm, // Default ISD::TRAP to expand (which turns it into abort). setOperationAction(ISD::TRAP, MVT::Other, Expand); + // On most systems, DEBUGTRAP and TRAP have no difference. The "Expand" + // here is to inform DAG Legalizer to replace DEBUGTRAP with TRAP. + // + setOperationAction(ISD::DEBUGTRAP, MVT::Other, Expand); + IsLittleEndian = TD->isLittleEndian(); PointerTy = MVT::getIntegerVT(8*TD->getPointerSize(0)); memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*)); diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 2e77e64f2f..5034cc0330 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -557,6 +557,7 @@ X86TargetLowering::X86TargetLowering(X86TargetMachine &TM) setOperationAction(ISD::ADJUST_TRAMPOLINE, MVT::Other, Custom); setOperationAction(ISD::TRAP, MVT::Other, Legal); + setOperationAction(ISD::DEBUGTRAP, MVT::Other, Legal); // VASTART needs to be custom lowered to use the VarArgsFrameIndex setOperationAction(ISD::VASTART , MVT::Other, Custom); diff --git a/test/CodeGen/ARM/trap.ll b/test/CodeGen/ARM/trap.ll index 38842a9646..21865f8e4a 100644 --- a/test/CodeGen/ARM/trap.ll +++ b/test/CodeGen/ARM/trap.ll @@ -14,4 +14,16 @@ entry: unreachable } +define void @t2() nounwind { +entry: +; INSTR: t2: +; INSTR: trap + +; FUNC: t2: +; FUNC: bl __trap + call void @llvm.debugtrap() + unreachable +} + declare void @llvm.trap() nounwind +declare void @llvm.debugtrap() nounwind -- cgit v1.2.3-18-g5258