[XRay][compiler-rt+llvm] Update XRay register stashing semantics
Summary:
This change expands the amount of registers stashed by the entry and
`__xray_CustomEvent` trampolines.
We've found that since the `__xray_CustomEvent` trampoline calls can show up in
situations where the scratch registers are being used, and since we don't
typically want to affect the code-gen around the disabled
`__xray_customevent(...)` intrinsic calls, that we need to save and restore the
state of even the scratch registers in the handling of these custom events.
Reviewers: pcc, pelikan, dblaikie, eizan, kpw, echristo, chandlerc
Reviewed By: echristo
Subscribers: chandlerc, echristo, hiraditya, davide, dblaikie, llvm-commits
Differential Revision: https://reviews.llvm.org/D40894
llvm-svn: 323940
diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index 4dcb705..fa5df02 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -985,6 +985,21 @@
return MBB;
}
+MachineBasicBlock *
+TargetLoweringBase::emitXRayCustomEvent(MachineInstr &MI,
+ MachineBasicBlock *MBB) const {
+ assert(MI.getOpcode() == TargetOpcode::PATCHABLE_EVENT_CALL &&
+ "Called emitXRayCustomEvent on the wrong MI!");
+ auto &MF = *MI.getMF();
+ auto MIB = BuildMI(MF, MI.getDebugLoc(), MI.getDesc());
+ for (unsigned OpIdx = 0; OpIdx != MI.getNumOperands(); ++OpIdx)
+ MIB.add(MI.getOperand(OpIdx));
+
+ MBB->insert(MachineBasicBlock::iterator(MI), MIB);
+ MI.eraseFromParent();
+ return MBB;
+}
+
/// findRepresentativeClass - Return the largest legal super-reg register class
/// of the register class for the specified type and its associated "cost".
// This function is in TargetLowering because it uses RegClassForVT which would