Handle freeze instruction in FindBaseValue (JuliaLang#43728)

LilithHafner · Feb 22, 2022 · 20bc09e · 20bc09e
1 parent 9021ae8
commit 20bc09e
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diff --git a/src/llvm-late-gc-lowering.cpp b/src/llvm-late-gc-lowering.cpp
@@ -469,6 +469,8 @@ static std::pair<Value*,int> FindBaseValue(const State &S, Value *V, bool UseCac
             if (getValueAddrSpace(NewV) == 0)
                 break;
             CurrentV = NewV;
+        } else if (auto *Freeze = dyn_cast<FreezeInst>(CurrentV)) {
+            CurrentV = Freeze->getOperand(0); // Can be formed by optimizations, treat as a no-op
         } else if (auto *GEP = dyn_cast<GetElementPtrInst>(CurrentV)) {
             CurrentV = GEP->getOperand(0);
             // GEP can make vectors from a single base pointer

diff --git a/test/llvmpasses/late-lower-gc.ll b/test/llvmpasses/late-lower-gc.ll
@@ -105,6 +105,25 @@ top:
 ; CHECK: ret i32
 }
 
+define i32 @freeze({} addrspace(10)* %v0, {} addrspace(10)* %v1) {
+top:
+; CHECK-LABEL: @freeze
+; CHECK-NOT: @julia.new_gc_frame
+  %v2 = call {}*** @julia.get_pgcstack()
+  %v3 = bitcast {} addrspace(10)* %v0 to {} addrspace(10)* addrspace(10)*
+  %v4 = addrspacecast {} addrspace(10)* addrspace(10)* %v3 to {} addrspace(10)* addrspace(11)*
+  %v5 = load atomic {} addrspace(10)*, {} addrspace(10)* addrspace(11)* %v4 unordered, align 8
+  %v6 = bitcast {} addrspace(10)* %v1 to {} addrspace(10)* addrspace(10)*
+  %v7 = addrspacecast {} addrspace(10)* addrspace(10)* %v6 to {} addrspace(10)* addrspace(11)*
+  %v8 = load atomic {} addrspace(10)*, {} addrspace(10)* addrspace(11)* %v7 unordered, align 8
+  %fv8 = freeze {} addrspace(10)* %v8
+  %v9 = addrspacecast {} addrspace(10)* %v5 to {} addrspace(12)*
+  %v10 = addrspacecast {} addrspace(10)* %fv8 to {} addrspace(12)*
+  %v11 = call i32 @rooting_callee({} addrspace(12)* %v9, {} addrspace(12)* %v10)
+  ret i32 %v11
+; CHECK: ret i32
+}
+
 !0 = !{i64 0, i64 23}
 !1 = !{}
 !2 = distinct !{!2}