Support PHI in LowerAddrSpaceCastPass (#1348)

* Support PHI in LowerAddrSpaceCastPass * Update test/AddressSpaceCast/issue-1341.ll Co-authored-by: Romaric Jodin <[email protected]> --------- Co-authored-by: Romaric Jodin <[email protected]>
google · May 14, 2024 · cfa6067 · cfa6067
1 parent ee4e850
commit cfa6067
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diff --git a/lib/LowerAddrSpaceCastPass.cpp b/lib/LowerAddrSpaceCastPass.cpp
@@ -350,6 +350,25 @@ Value *clspv::LowerAddrSpaceCastPass::visitPtrToIntInst(PtrToIntInst &I) {
   return ptrToInt;
 }
 
+Value *clspv::LowerAddrSpaceCastPass::visitPHINode(llvm::PHINode &I) {
+  IRBuilder<> B(&I);
+  // NOTE: We assume that the first incoming value does not depend on I.
+  auto *V1 = visit(I.getIncomingValue(0));
+  auto *B1 = I.getIncomingBlock(0);
+
+  // Register the replacement early in order to avoid recursive calls
+  // when an incoming value depends on this PHI node.
+  auto Phi = B.CreatePHI(V1->getType(), I.getNumIncomingValues());
+  registerReplacement(&I, Phi);
+
+  Phi->addIncoming(V1, B1);
+  for (unsigned i = 1; i < I.getNumIncomingValues(); ++i) {
+    Phi->addIncoming(visit(I.getIncomingValue(i)), I.getIncomingBlock(i));
+  }
+
+  return Phi;
+}
+
 Value *clspv::LowerAddrSpaceCastPass::visitInstruction(Instruction &I) {
 #ifndef NDEBUG
   dbgs() << "Instruction not handled: " << I << '\n';
@@ -456,6 +475,11 @@ void clspv::LowerAddrSpaceCastPass::cleanDeadInstructions() {
           }
         },
         [&NextBatch](Instruction *AliveInstruction) {
+          if (PHINode *Phi = dyn_cast<PHINode>(AliveInstruction)) {
+            if (RecursivelyDeleteDeadPHINode(Phi)) {
+              return;
+            }
+          }
           NextBatch.push_back(AliveInstruction);
         });
 

diff --git a/lib/LowerAddrSpaceCastPass.h b/lib/LowerAddrSpaceCastPass.h
@@ -45,6 +45,7 @@ struct LowerAddrSpaceCastPass
   llvm::Value *visitCallInst(llvm::CallInst &I);
   llvm::Value *visitIntToPtrInst(llvm::IntToPtrInst &I);
   llvm::Value *visitPtrToIntInst(llvm::PtrToIntInst &I);
+  llvm::Value *visitPHINode(llvm::PHINode &I);
   llvm::Value *visitInstruction(llvm::Instruction &I);
 
   void runOnFunction(llvm::Function &F);

diff --git a/test/AddressSpaceCast/issue-1341.ll b/test/AddressSpaceCast/issue-1341.ll
@@ -0,0 +1,24 @@
+; RUN: clspv-opt %s -o %t.ll --passes=lower-addrspacecast
+; RUN: FileCheck %s < %t.ll
+
+; CHECK: arrayinit.body:
+; CHECK-NEXT: {{.*}} = phi ptr [ %{{.*}}, %entry ], [ %{{.*}}, %arrayinit.body ]
+; CHECK-NOT: %arrayinit.cur = phi ptr addrspace(4) [ %arrayinit.begin, %entry ], [ %arrayinit.next, %arrayinit.body ]
+
+define dso_local spir_kernel void @fun() {
+entry:
+  %mem = alloca [4 x float]
+  %data = addrspacecast ptr %mem to ptr addrspace(4)
+  %arrayinit.begin = getelementptr inbounds [4 x float], ptr addrspace(4) %data, i32 0, i32 0
+  %arrayinit.end = getelementptr inbounds float, ptr addrspace(4) %arrayinit.begin, i32 4
+  br label %arrayinit.body
+
+arrayinit.body:
+  %arrayinit.cur = phi ptr addrspace(4) [ %arrayinit.begin, %entry ], [ %arrayinit.next, %arrayinit.body ]
+  %arrayinit.next = getelementptr inbounds float, ptr addrspace(4) %arrayinit.cur, i32 1
+  %arrayinit.done = icmp eq ptr addrspace(4) %arrayinit.next, %arrayinit.end
+  br i1 %arrayinit.done, label %arrayinit.end2, label %arrayinit.body
+
+arrayinit.end2:
+  ret void
+}