[PATCH] D74465: [Statepoint] Remove redundant clear of call target on register

[Serguei Katkov via Phabricator via llvm-commits]

skatkov created this revision.
skatkov added a reviewer: reames.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.

Patchable statepoint is lowered into sequence of nops, so zeroed call target
should not be on register. It is better to use getTargetConstant instead
of getConstant to select zero constant for call target.


https://reviews.llvm.org/D74465

Files:
  llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
  llvm/test/CodeGen/X86/statepoint-call-lowering.ll


Index: llvm/test/CodeGen/X86/statepoint-call-lowering.ll
===================================================================
--- llvm/test/CodeGen/X86/statepoint-call-lowering.ll
+++ llvm/test/CodeGen/X86/statepoint-call-lowering.ll
@@ -141,7 +141,6 @@
 ; CHECK:       # %bb.0: # %entry
 ; CHECK-NEXT:    pushq %rax
 ; CHECK-NEXT:    .cfi_def_cfa_offset 16
-; CHECK-NEXT:    xorl %eax, %eax
 ; CHECK-NEXT:    nopl (%rax)
 ; CHECK-NEXT:  .Ltmp7:
 ; CHECK-NEXT:    popq %rcx
Index: llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
+++ llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
@@ -859,7 +859,8 @@
     const auto &DL = DAG.getDataLayout();
 
     unsigned AS = ISP.getCalledValue()->getType()->getPointerAddressSpace();
-    ActualCallee = DAG.getConstant(0, getCurSDLoc(), TLI.getPointerTy(DL, AS));
+    ActualCallee =
+        DAG.getTargetConstant(0, getCurSDLoc(), TLI.getPointerTy(DL, AS));
   } else {
     ActualCallee = getValue(ISP.getCalledValue());
   }


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