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-rw-r--r--contrib/llvm/lib/CodeGen/XRayInstrumentation.cpp79
1 files changed, 55 insertions, 24 deletions
diff --git a/contrib/llvm/lib/CodeGen/XRayInstrumentation.cpp b/contrib/llvm/lib/CodeGen/XRayInstrumentation.cpp
index 63bd762..0b4c6e5 100644
--- a/contrib/llvm/lib/CodeGen/XRayInstrumentation.cpp
+++ b/contrib/llvm/lib/CodeGen/XRayInstrumentation.cpp
@@ -1,4 +1,4 @@
-//===-- XRayInstrumentation.cpp - Adds XRay instrumentation to functions. -===//
+//===- XRayInstrumentation.cpp - Adds XRay instrumentation to functions. --===//
//
// The LLVM Compiler Infrastructure
//
@@ -14,18 +14,26 @@
//
//===---------------------------------------------------------------------===//
-#include "llvm/CodeGen/Analysis.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/Support/TargetRegistry.h"
+#include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Pass.h"
#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
namespace {
+
struct XRayInstrumentation : public MachineFunctionPass {
static char ID;
@@ -33,6 +41,14 @@ struct XRayInstrumentation : public MachineFunctionPass {
initializeXRayInstrumentationPass(*PassRegistry::getPassRegistry());
}
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.setPreservesCFG();
+ AU.addRequired<MachineLoopInfo>();
+ AU.addPreserved<MachineLoopInfo>();
+ AU.addPreserved<MachineDominatorTree>();
+ MachineFunctionPass::getAnalysisUsage(AU);
+ }
+
bool runOnMachineFunction(MachineFunction &MF) override;
private:
@@ -43,7 +59,7 @@ private:
// This is the approach to go on CPUs which have a single RET instruction,
// like x86/x86_64.
void replaceRetWithPatchableRet(MachineFunction &MF,
- const TargetInstrInfo *TII);
+ const TargetInstrInfo *TII);
// Prepend the original return instruction with the exit sled code ("patchable
// function exit" pseudo-instruction), preserving the original return
@@ -54,13 +70,13 @@ private:
// have to call the trampoline and return from it to the original return
// instruction of the function being instrumented.
void prependRetWithPatchableExit(MachineFunction &MF,
- const TargetInstrInfo *TII);
+ const TargetInstrInfo *TII);
};
-} // anonymous namespace
-void XRayInstrumentation::replaceRetWithPatchableRet(MachineFunction &MF,
- const TargetInstrInfo *TII)
-{
+} // end anonymous namespace
+
+void XRayInstrumentation::replaceRetWithPatchableRet(
+ MachineFunction &MF, const TargetInstrInfo *TII) {
// We look for *all* terminators and returns, then replace those with
// PATCHABLE_RET instructions.
SmallVector<MachineInstr *, 4> Terminators;
@@ -81,7 +97,7 @@ void XRayInstrumentation::replaceRetWithPatchableRet(MachineFunction &MF,
auto MIB = BuildMI(MBB, T, T.getDebugLoc(), TII->get(Opc))
.addImm(T.getOpcode());
for (auto &MO : T.operands())
- MIB.addOperand(MO);
+ MIB.add(MO);
Terminators.push_back(&T);
}
}
@@ -91,9 +107,8 @@ void XRayInstrumentation::replaceRetWithPatchableRet(MachineFunction &MF,
I->eraseFromParent();
}
-void XRayInstrumentation::prependRetWithPatchableExit(MachineFunction &MF,
- const TargetInstrInfo *TII)
-{
+void XRayInstrumentation::prependRetWithPatchableExit(
+ MachineFunction &MF, const TargetInstrInfo *TII) {
for (auto &MBB : MF) {
for (auto &T : MBB.terminators()) {
unsigned Opc = 0;
@@ -106,7 +121,7 @@ void XRayInstrumentation::prependRetWithPatchableExit(MachineFunction &MF,
if (Opc != 0) {
// Prepend the return instruction with PATCHABLE_FUNCTION_EXIT or
// PATCHABLE_TAIL_CALL .
- BuildMI(MBB, T, T.getDebugLoc(),TII->get(Opc));
+ BuildMI(MBB, T, T.getDebugLoc(), TII->get(Opc));
}
}
}
@@ -125,14 +140,24 @@ bool XRayInstrumentation::runOnMachineFunction(MachineFunction &MF) {
return false; // XRay threshold attribute not found.
if (Attr.getValueAsString().getAsInteger(10, XRayThreshold))
return false; // Invalid value for threshold.
- if (F.size() < XRayThreshold)
- return false; // Function is too small.
+
+ // Count the number of MachineInstr`s in MachineFunction
+ int64_t MICount = 0;
+ for (const auto& MBB : MF)
+ MICount += MBB.size();
+
+ // Check if we have a loop.
+ // FIXME: Maybe make this smarter, and see whether the loops are dependent
+ // on inputs or side-effects?
+ MachineLoopInfo &MLI = getAnalysis<MachineLoopInfo>();
+ if (MLI.empty() && MICount < XRayThreshold)
+ return false; // Function is too small and has no loops.
}
// We look for the first non-empty MachineBasicBlock, so that we can insert
// the function instrumentation in the appropriate place.
- auto MBI =
- find_if(MF, [&](const MachineBasicBlock &MBB) { return !MBB.empty(); });
+ auto MBI = llvm::find_if(
+ MF, [&](const MachineBasicBlock &MBB) { return !MBB.empty(); });
if (MBI == MF.end())
return false; // The function is empty.
@@ -142,12 +167,10 @@ bool XRayInstrumentation::runOnMachineFunction(MachineFunction &MF) {
if (!MF.getSubtarget().isXRaySupported()) {
FirstMI.emitError("An attempt to perform XRay instrumentation for an"
- " unsupported target.");
+ " unsupported target.");
return false;
}
- // FIXME: Do the loop triviality analysis here or in an earlier pass.
-
// First, insert an PATCHABLE_FUNCTION_ENTER as the first instruction of the
// MachineFunction.
BuildMI(FirstMBB, FirstMI, FirstMI.getDebugLoc(),
@@ -157,6 +180,11 @@ bool XRayInstrumentation::runOnMachineFunction(MachineFunction &MF) {
case Triple::ArchType::arm:
case Triple::ArchType::thumb:
case Triple::ArchType::aarch64:
+ case Triple::ArchType::ppc64le:
+ case Triple::ArchType::mips:
+ case Triple::ArchType::mipsel:
+ case Triple::ArchType::mips64:
+ case Triple::ArchType::mips64el:
// For the architectures which don't have a single return instruction
prependRetWithPatchableExit(MF, TII);
break;
@@ -171,5 +199,8 @@ bool XRayInstrumentation::runOnMachineFunction(MachineFunction &MF) {
char XRayInstrumentation::ID = 0;
char &llvm::XRayInstrumentationID = XRayInstrumentation::ID;
-INITIALIZE_PASS(XRayInstrumentation, "xray-instrumentation", "Insert XRay ops",
- false, false)
+INITIALIZE_PASS_BEGIN(XRayInstrumentation, "xray-instrumentation",
+ "Insert XRay ops", false, false)
+INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
+INITIALIZE_PASS_END(XRayInstrumentation, "xray-instrumentation",
+ "Insert XRay ops", false, false)
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