[llvm] 4f7ee55 - Revert "[Statepoints] Allow deopt GC pointer on VReg if gc-live bundle is empty."

[Denis Antrushin via llvm-commits]

Author: Denis Antrushin
Date: 2020-10-23T21:55:06+07:00
New Revision: 4f7ee55971e7f7a27af69c501e4b395c4079decb

URL: https://github.com/llvm/llvm-project/commit/4f7ee55971e7f7a27af69c501e4b395c4079decb
DIFF: https://github.com/llvm/llvm-project/commit/4f7ee55971e7f7a27af69c501e4b395c4079decb.diff

LOG: Revert "[Statepoints] Allow deopt GC pointer on VReg if gc-live bundle is empty."

Downstream testing revealed some problems with this patch.
Reverting while investigating.
This reverts commit 2b96dcebfae65485859d956954f10f409abaae79.

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
    llvm/test/CodeGen/X86/statepoint-vreg-details.ll

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
index 13881bb6eaaa..2d2eb252e4e2 100644
--- a/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
@@ -555,10 +555,6 @@ lowerStatepointMetaArgs(SmallVectorImpl<SDValue> &Ops,
 
   unsigned CurNumVRegs = 0;
 
-  auto canPassGCPtrOnVReg = [&](SDValue SDV) {
-    return !(willLowerDirectly(SDV) || SDV.getValueType().isVector());
-  };
-
   auto processGCPtr = [&](const Value *V) {
     SDValue PtrSD = Builder.getValue(V);
     if (!LoweredGCPtrs.insert(PtrSD))
@@ -568,9 +564,7 @@ lowerStatepointMetaArgs(SmallVectorImpl<SDValue> &Ops,
     assert(!LowerAsVReg.count(PtrSD) && "must not have been seen");
     if (LowerAsVReg.size() == MaxVRegPtrs)
       return;
-    assert(V->getType()->isVectorTy() == PtrSD.getValueType().isVector() &&
-           "IR and SD types disagree");
-    if (!canPassGCPtrOnVReg(PtrSD)) {
+    if (willLowerDirectly(PtrSD) || V->getType()->isVectorTy()) {
       LLVM_DEBUG(dbgs() << "direct/spill "; PtrSD.dump(&Builder.DAG));
       return;
     }
@@ -597,12 +591,8 @@ lowerStatepointMetaArgs(SmallVectorImpl<SDValue> &Ops,
   };
 
   auto requireSpillSlot = [&](const Value *V) {
-    if (isGCValue(V)) {
-      SDValue SDV = Builder.getValue(V);
-      if (!LoweredGCPtrs.empty())
-        return !LowerAsVReg.count(SDV);
-      return !MaxVRegPtrs || !canPassGCPtrOnVReg(SDV);
-    }
+    if (isGCValue(V))
+      return !LowerAsVReg.count(Builder.getValue(V));
     return !(LiveInDeopt || UseRegistersForDeoptValues);
   };
 

diff  --git a/llvm/test/CodeGen/X86/statepoint-vreg-details.ll b/llvm/test/CodeGen/X86/statepoint-vreg-details.ll
index 51ada08b7fce..814ba3d03fee 100644
--- a/llvm/test/CodeGen/X86/statepoint-vreg-details.ll
+++ b/llvm/test/CodeGen/X86/statepoint-vreg-details.ll
@@ -326,14 +326,16 @@ define void @test_duplicate_ir_values() gc "statepoint-example" personality i32*
 ;CHECK-VREG:     %0:gr64 = STATEPOINT 1, 16, 5, %8, $edi, $rsi, $edx, $ecx, $r8d, 2, 0, 2, 0, 2, 0, 2, 1, killed %1(tied-def 0), 2, 0, 2, 1, 0, 0, csr_64, implicit-def $rsp, implicit-def $ssp, implicit-def $eax
 ;CHECK-VREG:     JMP_1 %bb.1
 ;CHECK-VREG:   bb.1.normal_continue:
+;CHECK-VREG:     MOV64mr %stack.0, 1, $noreg, 0, $noreg, %0 :: (store 8 into %stack.0)
 ;CHECK-VREG:     %13:gr32 = MOV32ri 10
 ;CHECK-VREG:     $edi = COPY %13
-;CHECK-VREG:     STATEPOINT 2882400000, 0, 1, @__llvm_deoptimize, $edi, 2, 0, 2, 2, 2, 2, %0, %0, 2, 0, 2, 0, 2, 0, csr_64, implicit-def $rsp, implicit-def $ssp
+;CHECK-VREG:     STATEPOINT 2882400000, 0, 1, @__llvm_deoptimize, $edi, 2, 0, 2, 2, 2, 2, 1, 8, %stack.0, 0, 1, 8, %stack.0, 0, 2, 0, 2, 0, 2, 0, csr_64, implicit-def $rsp, implicit-def $ssp :: (volatile load store 8 on %stack.0)
 ;CHECK-VREG:   bb.2.exceptional_return (landing-pad):
 ;CHECK-VREG:     EH_LABEL <mcsymbol >
+;CHECK-VREG:     MOV64mr %stack.0, 1, $noreg, 0, $noreg, %0 :: (store 8 into %stack.0)
 ;CHECK-VREG:     %12:gr32 = MOV32ri -271
 ;CHECK-VREG:     $edi = COPY %12
-;CHECK-VREG:     STATEPOINT 2882400000, 0, 1, @__llvm_deoptimize, $edi, 2, 0, 2, 0, 2, 1, %0, 2, 0, 2, 0, 2, 0, csr_64, implicit-def $rsp, implicit-def $ssp
+;CHECK-VREG:     STATEPOINT 2882400000, 0, 1, @__llvm_deoptimize, $edi, 2, 0, 2, 0, 2, 1, 1, 8, %stack.0, 0, 2, 0, 2, 0, 2, 0, csr_64, implicit-def $rsp, implicit-def $ssp :: (volatile load store 8 on %stack.0)
 
 entry:
   %local.0 = load i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* undef, align 8