Index: llvm/trunk/lib/Transforms/Scalar/LoopSink.cpp =================================================================== --- llvm/trunk/lib/Transforms/Scalar/LoopSink.cpp +++ llvm/trunk/lib/Transforms/Scalar/LoopSink.cpp @@ -280,6 +280,7 @@ // Compute alias set. for (BasicBlock *BB : L.blocks()) CurAST.add(*BB); + CurAST.add(*Preheader); // Sort loop's basic blocks by frequency SmallVector ColdLoopBBs; Index: llvm/trunk/test/Transforms/LICM/loopsink-pr39695.ll =================================================================== --- llvm/trunk/test/Transforms/LICM/loopsink-pr39695.ll +++ llvm/trunk/test/Transforms/LICM/loopsink-pr39695.ll @@ -0,0 +1,37 @@ +; RUN: opt -S -loop-sink < %s | FileCheck %s + +; The load instruction should not be sunk into following loop. +; CHECK: @foo +; CHECK-NEXT: entry +; CHECK-NEXT: %ptr = load i8*, i8** %pp, align 8 +; CHECK-NEXT: store i8* null, i8** %pp, align 8 + +define i32 @foo(i32 %n, i8** %pp) !prof !0 { +entry: + %ptr = load i8*, i8** %pp, align 8 + store i8* null, i8** %pp, align 8 + br label %for.cond + +for.cond: ; preds = %for.body, %entry + %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ] + %cmp = icmp ult i32 %i.0, %n + br i1 %cmp, label %for.body, label %for.end, !prof !1 + +for.body: ; preds = %for.cond + %0 = sext i32 %i.0 to i64 + %arrayidx = getelementptr inbounds i8, i8* %ptr, i64 %0 + %1 = load i8, i8* %arrayidx, align 1 + %or19 = call i8 @llvm.bitreverse.i8(i8 %1) + %v = sext i8 %or19 to i32 + %inc = add i32 %i.0, %v + br label %for.cond + +for.end: ; preds = %for.cond + ret i32 %i.0 +} + +declare i8 @llvm.bitreverse.i8(i8) #0 +attributes #0 = { nounwind readnone speculatable } + +!0 = !{!"function_entry_count", i64 1} +!1 = !{!"branch_weights", i32 1, i32 2000}