From 9bcaed867a547bc4a8b3fb66c1ee8b165c626de9 Mon Sep 17 00:00:00 2001 From: Dean Michael Berris Date: Mon, 8 May 2017 05:45:21 +0000 Subject: [XRay] Custom event logging intrinsic This patch introduces an LLVM intrinsic and a target opcode for custom event logging in XRay. Initially, its use case will be to allow users of XRay to log some type of string ("poor man's printf"). The target opcode compiles to a noop sled large enough to enable calling through to a runtime-determined relative function call. At runtime, when X-Ray is enabled, the sled is replaced by compiler-rt with a trampoline to the logic for creating the custom log entries. Future patches will implement the compiler-rt parts and clang-side support for emitting the IR corresponding to this intrinsic. Reviewers: timshen, dberris Subscribers: igorb, pelikan, rSerge, timshen, echristo, dberris, llvm-commits Differential Revision: https://reviews.llvm.org/D27503 llvm-svn: 302405 --- llvm/lib/CodeGen/SelectionDAG/FastISel.cpp | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'llvm/lib/CodeGen/SelectionDAG/FastISel.cpp') diff --git a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp index 6fb26fc3b73..8c98e3740f6 100644 --- a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp @@ -861,6 +861,25 @@ bool FastISel::selectPatchpoint(const CallInst *I) { return true; } +bool FastISel::selectXRayCustomEvent(const CallInst *I) { + const auto &Triple = TM.getTargetTriple(); + if (Triple.getArch() != Triple::x86_64 || !Triple.isOSLinux()) + return true; // don't do anything to this instruction. + SmallVector Ops; + Ops.push_back(MachineOperand::CreateReg(getRegForValue(I->getArgOperand(0)), + /*IsDef=*/false)); + Ops.push_back(MachineOperand::CreateReg(getRegForValue(I->getArgOperand(1)), + /*IsDef=*/false)); + MachineInstrBuilder MIB = + BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, + TII.get(TargetOpcode::PATCHABLE_EVENT_CALL)); + for (auto &MO : Ops) + MIB.add(MO); + // Insert the Patchable Event Call instruction, that gets lowered properly. + return true; +} + + /// Returns an AttributeList representing the attributes applied to the return /// value of the given call. static AttributeList getReturnAttrs(FastISel::CallLoweringInfo &CLI) { @@ -1252,6 +1271,9 @@ bool FastISel::selectIntrinsicCall(const IntrinsicInst *II) { case Intrinsic::experimental_patchpoint_void: case Intrinsic::experimental_patchpoint_i64: return selectPatchpoint(II); + + case Intrinsic::xray_customevent: + return selectXRayCustomEvent(II); } return fastLowerIntrinsicCall(II); -- cgit v1.2.3