[FastISel] Add support for the stackmap intrinsic.

This implements target-independent FastISel lowering for the stackmap intrinsic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210742 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 271 insertions, 0 deletions

diff --git a/include/llvm/CodeGen/FastISel.h b/include/llvm/CodeGen/FastISel.h
index b1bb8eb170..7d9e207838 100644
--- a/include/llvm/CodeGen/FastISel.h
+++ b/include/llvm/CodeGen/FastISel.h
@@ -23,6 +23,7 @@ namespace llvm {
 class AllocaInst;
 class Constant;
 class ConstantFP;
+class CallInst;
 class DataLayout;
 class FunctionLoweringInfo;
 class Instruction;
@@ -411,6 +412,9 @@ private:
   /// beginning of the block. It helps to avoid spilling cached variables across
   /// heavy instructions like calls.
   void flushLocalValueMap();
+
+  bool addStackMapLiveVars(SmallVectorImpl<MachineOperand> &Ops,
+                           const CallInst *CI, unsigned StartIdx);
 };
 
 }
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 99931c14eb..94d3be90cb 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -45,9 +45,11 @@
 #include "llvm/Analysis/Loads.h"
 #include "llvm/CodeGen/Analysis.h"
 #include "llvm/CodeGen/FunctionLoweringInfo.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/StackMaps.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/Function.h"
@@ -558,6 +560,36 @@ bool FastISel::SelectGetElementPtr(const User *I) {
   return true;
 }
 
+/// \brief Add a stack map intrinsic call's live variable operands to a stackmap
+/// or patchpoint machine instruction.
+///
+bool FastISel::addStackMapLiveVars(SmallVectorImpl<MachineOperand> &Ops,
+                                   const CallInst *CI, unsigned StartIdx) {
+  for (unsigned i = StartIdx, e = CI->getNumArgOperands(); i != e; ++i) {
+    Value *Val = CI->getArgOperand(i);
+    if (auto *C = dyn_cast<ConstantInt>(Val)) {
+      Ops.push_back(MachineOperand::CreateImm(StackMaps::ConstantOp));
+      Ops.push_back(MachineOperand::CreateImm(C->getSExtValue()));
+    } else if (isa<ConstantPointerNull>(Val)) {
+      Ops.push_back(MachineOperand::CreateImm(StackMaps::ConstantOp));
+      Ops.push_back(MachineOperand::CreateImm(0));
+    } else if (auto *AI = dyn_cast<AllocaInst>(Val)) {
+      auto SI = FuncInfo.StaticAllocaMap.find(AI);
+      if (SI != FuncInfo.StaticAllocaMap.end())
+        Ops.push_back(MachineOperand::CreateFI(SI->second));
+      else
+        return false;
+    } else {
+      unsigned Reg = getRegForValue(Val);
+      if (Reg == 0)
+        return false;
+      Ops.push_back(MachineOperand::CreateReg(Reg, /*IsDef=*/false));
+    }
+  }
+
+  return true;
+}
+
 bool FastISel::SelectCall(const User *I) {
   const CallInst *Call = cast<CallInst>(I);
 
@@ -713,6 +745,76 @@ bool FastISel::SelectCall(const User *I) {
     UpdateValueMap(Call, ResultReg);
     return true;
   }
+  case Intrinsic::experimental_stackmap: {
+    // void @llvm.experimental.stackmap(i64 <id>, i32 <numShadowBytes>,
+    //                                  [live variables...])
+
+    assert(Call->getCalledFunction()->getReturnType()->isVoidTy() &&
+           "Stackmap cannot return a value.");
+
+    // The stackmap intrinsic only records the live variables (the arguments
+    // passed to it) and emits NOPS (if requested). Unlike the patchpoint
+    // intrinsic, this won't be lowered to a function call. This means we don't
+    // have to worry about calling conventions and target-specific lowering
+    // code. Instead we perform the call lowering right here.
+    //
+    // CALLSEQ_START(0)
+    // STACKMAP(id, nbytes, ...)
+    // CALLSEQ_END(0, 0)
+    //
+
+    SmallVector<MachineOperand, 32> Ops;
+
+    // Add the <id> and <numBytes> constants.
+    assert(isa<ConstantInt>(Call->getOperand(PatchPointOpers::IDPos)) &&
+           "Expected a constant integer.");
+    auto IDVal = cast<ConstantInt>(Call->getOperand(PatchPointOpers::IDPos));
+    Ops.push_back(MachineOperand::CreateImm(IDVal->getZExtValue()));
+
+    assert(isa<ConstantInt>(Call->getOperand(PatchPointOpers::NBytesPos)) &&
+           "Expected a constant integer.");
+    auto NBytesVal =
+      cast<ConstantInt>(Call->getOperand(PatchPointOpers::NBytesPos));
+    Ops.push_back(MachineOperand::CreateImm(NBytesVal->getZExtValue()));
+
+    // Push live variables for the stack map.
+    if (!addStackMapLiveVars(Ops, Call, 2))
+      return false;
+
+    // We are not adding any register mask info here, because the stackmap
+    // doesn't clobber anything.
+
+    // Add scratch registers as implicit def and early clobber.
+    CallingConv::ID CC = Call->getCallingConv();
+    const MCPhysReg *ScratchRegs = TLI.getScratchRegisters(CC);
+    for (unsigned i = 0; ScratchRegs[i]; ++i)
+      Ops.push_back(MachineOperand::CreateReg(
+        ScratchRegs[i], /*IsDef=*/true, /*IsImp=*/true, /*IsKill=*/false,
+        /*IsDead=*/false, /*IsUndef=*/false, /*IsEarlyClobber=*/true));
+
+    // Issue CALLSEQ_START
+    unsigned AdjStackDown = TII.getCallFrameSetupOpcode();
+    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AdjStackDown))
+      .addImm(0);
+
+    // Issue STACKMAP.
+    MachineInstrBuilder MIB;
+    MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
+                  TII.get(TargetOpcode::STACKMAP));
+
+    for (auto const &MO : Ops)
+      MIB.addOperand(MO);
+
+    // Issue CALLSEQ_END
+    unsigned AdjStackUp = TII.getCallFrameDestroyOpcode();
+    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AdjStackUp))
+      .addImm(0).addImm(0);
+
+    // Inform the Frame Information that we have a stackmap in this function.
+    FuncInfo.MF->getFrameInfo()->setHasStackMap();
+
+    return true;
+  }
   }
 
   // Usually, it does not make sense to initialize a value,
diff --git a/test/CodeGen/X86/stackmap-fast-isel.ll b/test/CodeGen/X86/stackmap-fast-isel.ll
new file mode 100644
index 0000000000..0b7e6dbdc7
--- /dev/null
+++ b/test/CodeGen/X86/stackmap-fast-isel.ll
@@ -0,0 +1,165 @@
+; RUN: llc < %s -mtriple=x86_64-apple-darwin -mcpu=corei7 -disable-fp-elim                             | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-apple-darwin -mcpu=corei7 -disable-fp-elim -fast-isel -fast-isel-abort | FileCheck %s
+
+; CHECK-LABEL:  .section  __LLVM_STACKMAPS,__llvm_stackmaps
+; CHECK-NEXT:  __LLVM_StackMaps:
+; Header
+; CHECK-NEXT:   .byte 1
+; CHECK-NEXT:   .byte 0
+; CHECK-NEXT:   .short 0
+; Num Functions
+; CHECK-NEXT:   .long 4
+; Num LargeConstants
+; CHECK-NEXT:   .long 3
+; Num Callsites
+; CHECK-NEXT:   .long 7
+
+; Functions and stack size
+; CHECK-NEXT:   .quad _constantargs
+; CHECK-NEXT:   .quad 8
+; CHECK-NEXT:   .quad _liveConstant
+; CHECK-NEXT:   .quad 8
+; CHECK-NEXT:   .quad _directFrameIdx
+; CHECK-NEXT:   .quad 40
+; CHECK-NEXT:   .quad _longid
+; CHECK-NEXT:   .quad 8
+
+; Large Constants
+; CHECK-NEXT:   .quad   2147483648
+; CHECK-NEXT:   .quad   4294967295
+; CHECK-NEXT:   .quad   4294967296
+
+; Callsites
+; Constant arguments
+;
+; CHECK-NEXT:   .quad   1
+; CHECK-NEXT:   .long   L{{.*}}-_constantargs
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .short  12
+; SmallConstant
+; CHECK-NEXT:   .byte   4
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   -1
+; SmallConstant
+; CHECK-NEXT:   .byte   4
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   -1
+; SmallConstant
+; CHECK-NEXT:   .byte   4
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   65536
+; SmallConstant
+; CHECK-NEXT:   .byte   4
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   2000000000
+; SmallConstant
+; CHECK-NEXT:   .byte   4
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   2147483647
+; SmallConstant
+; CHECK-NEXT:   .byte   4
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   -1
+; SmallConstant
+; CHECK-NEXT:   .byte   4
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   -1
+; SmallConstant
+; CHECK-NEXT:   .byte   4
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   0
+; LargeConstant at index 0
+; CHECK-NEXT:   .byte   5
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   0
+; LargeConstant at index 1
+; CHECK-NEXT:   .byte   5
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   1
+; LargeConstant at index 2
+; CHECK-NEXT:   .byte   5
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   2
+; SmallConstant
+; CHECK-NEXT:   .byte   4
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   -1
+
+define void @constantargs() {
+entry:
+  tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 1, i32 15, i16 65535, i16 -1, i32 65536, i32 2000000000, i32 2147483647, i32 -1, i32 4294967295, i32 4294967296, i64 2147483648, i64 4294967295, i64 4294967296, i64 -1)
+  ret void
+}
+
+; Map a constant value.
+;
+; CHECK-LABEL:  .long L{{.*}}-_liveConstant
+; CHECK-NEXT:   .short 0
+; 1 location
+; CHECK-NEXT:   .short 1
+; Loc 0: SmallConstant
+; CHECK-NEXT:   .byte   4
+; CHECK-NEXT:   .byte   8
+; CHECK-NEXT:   .short  0
+; CHECK-NEXT:   .long   33
+
+define void @liveConstant() {
+  tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 15, i32 5, i32 33)
+  ret void
+}
+
+; Directly map an alloca's address.
+;
+; Callsite 16
+; CHECK-LABEL:  .long L{{.*}}-_directFrameIdx
+; CHECK-NEXT:   .short 0
+; 1 location
+; CHECK-NEXT:   .short	1
+; Loc 0: Direct RBP - ofs
+; CHECK-NEXT:   .byte	2
+; CHECK-NEXT:   .byte	8
+; CHECK-NEXT:   .short	6
+; CHECK-NEXT:   .long
+
+define void @directFrameIdx() {
+entry:
+  %metadata1 = alloca i64, i32 3, align 8
+  store i64 11, i64* %metadata1
+  store i64 12, i64* %metadata1
+  store i64 13, i64* %metadata1
+  call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 16, i32 0, i64* %metadata1)
+  ret void
+}
+
+; Test a 64-bit ID.
+;
+; CHECK:        .quad 4294967295
+; CHECK-LABEL:  .long L{{.*}}-_longid
+; CHECK:        .quad 4294967296
+; CHECK-LABEL:  .long L{{.*}}-_longid
+; CHECK:        .quad 9223372036854775807
+; CHECK-LABEL:  .long L{{.*}}-_longid
+; CHECK:        .quad -1
+; CHECK-LABEL:  .long L{{.*}}-_longid
+define void @longid() {
+entry:
+  tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 4294967295, i32 0)
+  tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 4294967296, i32 0)
+  tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 9223372036854775807, i32 0)
+  tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 -1, i32 0)
+  ret void
+}
+
+declare void @llvm.experimental.stackmap(i64, i32, ...)