diff options
| -rw-r--r-- | llvm/lib/Transforms/IPO/Inliner.cpp | 13 | ||||
| -rw-r--r-- | llvm/test/Transforms/Inline/cgscc-cycle.ll | 109 | ||||
| -rw-r--r-- | llvm/test/Transforms/Inline/monster_scc.ll | 46 |
3 files changed, 128 insertions, 40 deletions
diff --git a/llvm/lib/Transforms/IPO/Inliner.cpp b/llvm/lib/Transforms/IPO/Inliner.cpp index 3275226925c..66aea45323f 100644 --- a/llvm/lib/Transforms/IPO/Inliner.cpp +++ b/llvm/lib/Transforms/IPO/Inliner.cpp @@ -1158,10 +1158,19 @@ PreservedAnalyses InlinerPass::run(LazyCallGraph::SCC &InitialC, // SCC splits and merges. To avoid this, we capture the originating caller // node and the SCC containing the call edge. This is a slight over // approximation of the possible inlining decisions that must be avoided, - // but is relatively efficient to store. + // but is relatively efficient to store. We use C != OldC to know when + // a new SCC is generated and the original SCC may be generated via merge + // in later iterations. + // + // It is also possible that even if no new SCC is generated + // (i.e., C == OldC), the original SCC could be split and then merged + // into the same one as itself. and the original SCC will be added into + // UR.CWorklist again, we want to catch such cases too. + // // FIXME: This seems like a very heavyweight way of retaining the inline // history, we should look for a more efficient way of tracking it. - if (C != OldC && llvm::any_of(InlinedCallees, [&](Function *Callee) { + if ((C != OldC || UR.CWorklist.count(OldC)) && + llvm::any_of(InlinedCallees, [&](Function *Callee) { return CG.lookupSCC(*CG.lookup(*Callee)) == OldC; })) { LLVM_DEBUG(dbgs() << "Inlined an internal call edge and split an SCC, " diff --git a/llvm/test/Transforms/Inline/cgscc-cycle.ll b/llvm/test/Transforms/Inline/cgscc-cycle.ll index 69874c3ef2f..bc3bdc99fff 100644 --- a/llvm/test/Transforms/Inline/cgscc-cycle.ll +++ b/llvm/test/Transforms/Inline/cgscc-cycle.ll @@ -5,7 +5,7 @@ ; some out-of-band way to prevent infinitely re-inlining and re-transforming the ; code. ; -; RUN: opt < %s -passes='cgscc(inline,function(sroa,instcombine))' -S | FileCheck %s +; RUN: opt < %s -passes='cgscc(inline,function(sroa,instcombine))' -inline-threshold=50 -S | FileCheck %s ; The `test1_*` collection of functions form a directly cycling pattern. @@ -123,3 +123,110 @@ bb2: ret void } + +; Another infinite inlining case. The initial callgraph is like following: +; +; test3_a <---> test3_b +; | ^ +; v | +; test3_c <---> test3_d +; +; For all the call edges in the call graph, only test3_c and test3_d can be +; inlined into test3_a, and no other call edge can be inlined. +; +; After test3_c is inlined into test3_a, the original call edge test3_a->test3_c +; will be removed, a new call edge will be added and the call graph becomes: +; +; test3_a <---> test3_b +; \ ^ +; v / +; test3_c <---> test3_d +; But test3_a, test3_b, test3_c and test3_d still belong to the same SCC. +; +; Then after test3_a->test3_d is inlined, when test3_a->test3_d is converted to +; a ref edge, the original SCC will be split into two: {test3_c, test3_d} and +; {test3_a, test3_b}, immediately after the newly added ref edge +; test3_a->test3_c will be converted to a call edge, and the two SCCs will be +; merged into the original one again. During this cycle, the original SCC will +; be added into UR.CWorklist again and this creates an infinite loop. + +@a = global i64 0 +@b = global i64 0 + +define void @test3_c(i32 %i) { +entry: + %cmp = icmp eq i32 %i, 5 + br i1 %cmp, label %if.end, label %if.then + +if.then: ; preds = %entry + %call = tail call i64 @random() + %t0 = load i64, i64* @a + %add = add nsw i64 %t0, %call + store i64 %add, i64* @a + br label %if.end + +if.end: ; preds = %entry, %if.then + tail call void @test3_d(i32 %i) + %t6 = load i64, i64* @a + %add85 = add nsw i64 %t6, 1 + store i64 %add85, i64* @a + ret void +} + +declare i64 @random() + +define void @test3_d(i32 %i) { +entry: + %cmp = icmp eq i32 %i, 5 + br i1 %cmp, label %if.end, label %if.then + +if.then: ; preds = %entry + %call = tail call i64 @random() + %t0 = load i64, i64* @a + %add = add nsw i64 %t0, %call + store i64 %add, i64* @a + br label %if.end + +if.end: ; preds = %entry, %if.then + tail call void @test3_c(i32 %i) + tail call void @test3_b() + %t6 = load i64, i64* @a + %add79 = add nsw i64 %t6, 3 + store i64 %add79, i64* @a + ret void +} + +; Function Attrs: noinline +define void @test3_b() #0 { +entry: + tail call void @test3_a() + %t0 = load i64, i64* @a + %add = add nsw i64 %t0, 2 + store i64 %add, i64* @a + ret void +} + +; Check test3_c is inlined into test3_a once and only once. +; CHECK-LABEL: @test3_a( +; CHECK: tail call void @test3_b() +; CHECK-NEXT: tail call void @test3_d(i32 5) +; CHECK-NEXT: %[[LD1:.*]] = load i64, i64* @a +; CHECK-NEXT: %[[ADD1:.*]] = add nsw i64 %[[LD1]], 1 +; CHECK-NEXT: store i64 %[[ADD1]], i64* @a +; CHECK-NEXT: %[[LD2:.*]] = load i64, i64* @b +; CHECK-NEXT: %[[ADD2:.*]] = add nsw i64 %[[LD2]], 5 +; CHECK-NEXT: store i64 %[[ADD2]], i64* @b +; CHECK-NEXT: ret void + +; Function Attrs: noinline +define void @test3_a() #0 { +entry: + tail call void @test3_b() + tail call void @test3_c(i32 5) + %t0 = load i64, i64* @b + %add = add nsw i64 %t0, 5 + store i64 %add, i64* @b + ret void +} + +attributes #0 = { noinline } diff --git a/llvm/test/Transforms/Inline/monster_scc.ll b/llvm/test/Transforms/Inline/monster_scc.ll index 0f8f1f21c8b..b32a2aed331 100644 --- a/llvm/test/Transforms/Inline/monster_scc.ll +++ b/llvm/test/Transforms/Inline/monster_scc.ll @@ -154,11 +154,7 @@ if.end3: ; NEW-NOT: call ; NEW: call void @_Z1fILb1ELi2EEvPbS0_( ; NEW-NOT: call -; NEW: call void @_Z1gi( -; NEW-NOT: call -; NEW: call void @_Z1fILb1ELi0EEvPbS0_( -; NEW-NOT: call -; NEW: call void @_Z1fILb0ELi0EEvPbS0_( +; NEW: call void @_Z1fILb1ELi3EEvPbS0_( ; NEW-NOT: call ; NEW: call void @_Z1fILb0ELi3EEvPbS0_( ; NEW-NOT: call @@ -198,19 +194,11 @@ if.end3: ; NEW-NOT: call ; NEW: call void @_Z1gi( ; NEW-NOT: call -; NEW: call void @_Z1gi( -; NEW-NOT: call -; NEW: call void @_Z1fILb1ELi0EEvPbS0_( -; NEW-NOT: call -; NEW: call void @_Z1fILb0ELi0EEvPbS0_( +; NEW: call void @_Z1fILb1ELi3EEvPbS0_( ; NEW-NOT: call ; NEW: call void @_Z1fILb0ELi3EEvPbS0_( ; NEW-NOT: call -; NEW: call void @_Z1gi( -; NEW-NOT: call -; NEW: call void @_Z1fILb1ELi0EEvPbS0_( -; NEW-NOT: call -; NEW: call void @_Z1fILb0ELi0EEvPbS0_( +; NEW: call void @_Z1fILb1ELi3EEvPbS0_( ; NEW-NOT: call ; NEW: call void @_Z1fILb0ELi3EEvPbS0_( ; NEW-NOT: call @@ -260,7 +248,7 @@ if.end3: ; NEW-NOT: call ; NEW: call void @_Z1fILb1ELi4EEvPbS0_( ; NEW-NOT: call -; NEW: call void @_Z1fILb0ELi0EEvPbS0_( +; NEW: call void @_Z1fILb0ELi4EEvPbS0_( ; NEW-NOT: call define void @_Z1fILb0ELi2EEvPbS0_(i8* %B, i8* %E) { entry: @@ -304,21 +292,13 @@ if.end3: ; NEW-NOT: call ; NEW: call void @_Z1gi( ; NEW-NOT: call -; NEW: call void @_Z1gi( -; NEW-NOT: call -; NEW: call void @_Z1fILb1ELi1EEvPbS0_( -; NEW-NOT: call -; NEW: call void @_Z1fILb0ELi1EEvPbS0_( -; NEW-NOT: call -; NEW: call void @_Z1fILb0ELi0EEvPbS0_( -; NEW-NOT: call -; NEW: call void @_Z1gi( +; NEW: call void @_Z1fILb1ELi4EEvPbS0_( ; NEW-NOT: call -; NEW: call void @_Z1fILb1ELi1EEvPbS0_( +; NEW: call void @_Z1fILb0ELi4EEvPbS0_( ; NEW-NOT: call -; NEW: call void @_Z1fILb0ELi1EEvPbS0_( +; NEW: call void @_Z1fILb1ELi4EEvPbS0_( ; NEW-NOT: call -; NEW: call void @_Z1fILb0ELi0EEvPbS0_( +; NEW: call void @_Z1fILb0ELi4EEvPbS0_( ; NEW-NOT: call define void @_Z1fILb1ELi2EEvPbS0_(i8* %B, i8* %E) { entry: @@ -433,15 +413,7 @@ entry: ; NEW-NOT: call ; NEW: call void @_Z1fILb1ELi1EEvPbS0_( ; NEW-NOT: call -; NEW: call void @_Z1fILb1ELi2EEvPbS0_( -; NEW-NOT: call -; NEW: call void @_Z1gi( -; NEW-NOT: call -; NEW: call void @_Z1fILb1ELi0EEvPbS0_( -; NEW-NOT: call -; NEW: call void @_Z1fILb0ELi0EEvPbS0_( -; NEW-NOT: call -; NEW: call void @_Z1fILb0ELi3EEvPbS0_( +; NEW: call void @_Z1fILb0ELi1EEvPbS0_( ; NEW-NOT: call define void @_Z1fILb1ELi4EEvPbS0_(i8* %B, i8* %E) { entry: |
