[llvm-commits] [llvm] r152421 - in /llvm/trunk: lib/Transforms/Scalar/ObjCARC.cpp test/Transforms/ObjCARC/basic.ll test/Transforms/ObjCARC/nested.ll
Dan Gohman
gohman at apple.com
Fri Mar 9 10:50:52 PST 2012
Author: djg
Date: Fri Mar 9 12:50:52 2012
New Revision: 152421
URL: http://llvm.org/viewvc/llvm-project?rev=152421&view=rev
Log:
When identifying exit nodes for the reverse-CFG reverse-post-order
traversal, consider nodes for which the only successors are backedges
which the traversal is ignoring to be exit nodes. This fixes a problem
where the bottom-up traversal was failing to visit split blocks along
split loop backedges. This fixes rdar://10989035.
Modified:
llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp
llvm/trunk/test/Transforms/ObjCARC/basic.ll
llvm/trunk/test/Transforms/ObjCARC/nested.ll
Modified: llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp?rev=152421&r1=152420&r2=152421&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp Fri Mar 9 12:50:52 2012
@@ -2929,11 +2929,17 @@
Visited.clear();
// Compute the exits, which are the starting points for reverse-CFG DFS.
+ // This includes blocks where all the successors are backedges that
+ // we're skipping.
SmallVector<BasicBlock *, 4> Exits;
for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) {
BasicBlock *BB = I;
- if (cast<TerminatorInst>(&BB->back())->getNumSuccessors() == 0)
- Exits.push_back(BB);
+ TerminatorInst *TI = cast<TerminatorInst>(&BB->back());
+ for (succ_iterator SI(TI), SE(TI, true); SI != SE; ++SI)
+ if (!Backedges.count(std::make_pair(BB, *SI)))
+ goto HasNonBackedgeSucc;
+ Exits.push_back(BB);
+ HasNonBackedgeSucc:;
}
// Do reverse-CFG DFS, computing the reverse-CFG PostOrder.
Modified: llvm/trunk/test/Transforms/ObjCARC/basic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ObjCARC/basic.ll?rev=152421&r1=152420&r2=152421&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/ObjCARC/basic.ll (original)
+++ llvm/trunk/test/Transforms/ObjCARC/basic.ll Fri Mar 9 12:50:52 2012
@@ -1721,6 +1721,82 @@
ret void
}
+; Delete a retain matched by releases when one is inside the loop and the
+; other is outside the loop.
+
+; CHECK: define void @test62(
+; CHECK-NOT: @objc_
+; CHECK: }
+define void @test62(i8* %x, i1* %p) nounwind {
+entry:
+ br label %loop
+
+loop:
+ call i8* @objc_retain(i8* %x)
+ %q = load i1* %p
+ br i1 %q, label %loop.more, label %exit
+
+loop.more:
+ call void @objc_release(i8* %x)
+ br label %loop
+
+exit:
+ call void @objc_release(i8* %x)
+ ret void
+}
+
+; Like test62 but with no release in exit.
+; Don't delete anything!
+
+; CHECK: define void @test63(
+; CHECK: loop:
+; CHECK: tail call i8* @objc_retain(i8* %x)
+; CHECK: loop.more:
+; CHECK: call void @objc_release(i8* %x)
+; CHECK: }
+define void @test63(i8* %x, i1* %p) nounwind {
+entry:
+ br label %loop
+
+loop:
+ call i8* @objc_retain(i8* %x)
+ %q = load i1* %p
+ br i1 %q, label %loop.more, label %exit
+
+loop.more:
+ call void @objc_release(i8* %x)
+ br label %loop
+
+exit:
+ ret void
+}
+
+; Like test62 but with no release in loop.more.
+; Don't delete anything!
+
+; CHECK: define void @test64(
+; CHECK: loop:
+; CHECK: tail call i8* @objc_retain(i8* %x)
+; CHECK: exit:
+; CHECK: call void @objc_release(i8* %x)
+; CHECK: }
+define void @test64(i8* %x, i1* %p) nounwind {
+entry:
+ br label %loop
+
+loop:
+ call i8* @objc_retain(i8* %x)
+ %q = load i1* %p
+ br i1 %q, label %loop.more, label %exit
+
+loop.more:
+ br label %loop
+
+exit:
+ call void @objc_release(i8* %x)
+ ret void
+}
+
declare void @bar(i32 ()*)
; A few real-world testcases.
Modified: llvm/trunk/test/Transforms/ObjCARC/nested.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ObjCARC/nested.ll?rev=152421&r1=152420&r2=152421&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/ObjCARC/nested.ll (original)
+++ llvm/trunk/test/Transforms/ObjCARC/nested.ll Fri Mar 9 12:50:52 2012
@@ -484,12 +484,14 @@
ret void
}
-; Delete a nested retain+release pair.
+; TODO: Delete a nested retain+release pair.
+; The optimizer currently can't do this, because of a split loop backedge.
+; See test9b for the same testcase without a split backedge.
; CHECK: define void @test9(
; CHECK: call i8* @objc_retain
; CHECK: call i8* @objc_retain
-; CHECK-NOT: @objc_retain
+; CHECK: call i8* @objc_retain
; CHECK: }
define void @test9() nounwind {
entry:
@@ -551,13 +553,79 @@
ret void
}
-; Delete a nested retain+release pair.
+; Like test9, but without a split backedge. This we can optimize.
-; CHECK: define void @test10(
+; CHECK: define void @test9b(
; CHECK: call i8* @objc_retain
; CHECK: call i8* @objc_retain
; CHECK-NOT: @objc_retain
; CHECK: }
+define void @test9b() nounwind {
+entry:
+ %state.ptr = alloca %struct.__objcFastEnumerationState, align 8
+ %items.ptr = alloca [16 x i8*], align 8
+ %call = call i8* @returner()
+ %0 = call i8* @objc_retainAutoreleasedReturnValue(i8* %call) nounwind
+ %call1 = call i8* @returner()
+ %1 = call i8* @objc_retainAutoreleasedReturnValue(i8* %call1) nounwind
+ %tmp = bitcast %struct.__objcFastEnumerationState* %state.ptr to i8*
+ call void @llvm.memset.p0i8.i64(i8* %tmp, i8 0, i64 64, i32 8, i1 false)
+ %2 = call i8* @objc_retain(i8* %0) nounwind
+ %tmp3 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_", align 8
+ %call4 = call i64 bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to i64 (i8*, i8*, %struct.__objcFastEnumerationState*, [16 x i8*]*, i64)*)(i8* %2, i8* %tmp3, %struct.__objcFastEnumerationState* %state.ptr, [16 x i8*]* %items.ptr, i64 16)
+ %iszero = icmp eq i64 %call4, 0
+ br i1 %iszero, label %forcoll.empty, label %forcoll.loopinit
+
+forcoll.loopinit:
+ %mutationsptr.ptr = getelementptr inbounds %struct.__objcFastEnumerationState* %state.ptr, i64 0, i32 2
+ %mutationsptr = load i64** %mutationsptr.ptr, align 8
+ %forcoll.initial-mutations = load i64* %mutationsptr, align 8
+ br label %forcoll.loopbody.outer
+
+forcoll.loopbody.outer:
+ %forcoll.count.ph = phi i64 [ %call4, %forcoll.loopinit ], [ %call7, %forcoll.refetch ]
+ %tmp9 = icmp ugt i64 %forcoll.count.ph, 1
+ %umax = select i1 %tmp9, i64 %forcoll.count.ph, i64 1
+ br label %forcoll.loopbody
+
+forcoll.loopbody:
+ %forcoll.index = phi i64 [ %phitmp, %forcoll.notmutated ], [ 0, %forcoll.loopbody.outer ]
+ %mutationsptr5 = load i64** %mutationsptr.ptr, align 8
+ %statemutations = load i64* %mutationsptr5, align 8
+ %3 = icmp eq i64 %statemutations, %forcoll.initial-mutations
+ br i1 %3, label %forcoll.notmutated, label %forcoll.mutated
+
+forcoll.mutated:
+ call void @objc_enumerationMutation(i8* %2)
+ br label %forcoll.notmutated
+
+forcoll.notmutated:
+ %phitmp = add i64 %forcoll.index, 1
+ %exitcond = icmp eq i64 %phitmp, %umax
+ br i1 %exitcond, label %forcoll.refetch, label %forcoll.loopbody
+
+forcoll.refetch:
+ %tmp6 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_", align 8
+ %call7 = call i64 bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to i64 (i8*, i8*, %struct.__objcFastEnumerationState*, [16 x i8*]*, i64)*)(i8* %2, i8* %tmp6, %struct.__objcFastEnumerationState* %state.ptr, [16 x i8*]* %items.ptr, i64 16)
+ %4 = icmp eq i64 %call7, 0
+ br i1 %4, label %forcoll.empty, label %forcoll.loopbody.outer
+
+forcoll.empty:
+ call void @objc_release(i8* %2) nounwind
+ call void @objc_release(i8* %1) nounwind, !clang.imprecise_release !0
+ call void @objc_release(i8* %0) nounwind, !clang.imprecise_release !0
+ ret void
+}
+
+; TODO: Delete a nested retain+release pair.
+; The optimizer currently can't do this, because of a split loop backedge.
+; See test10b for the same testcase without a split backedge.
+
+; CHECK: define void @test10(
+; CHECK: call i8* @objc_retain
+; CHECK: call i8* @objc_retain
+; CHECK: call i8* @objc_retain
+; CHECK: }
define void @test10() nounwind {
entry:
%state.ptr = alloca %struct.__objcFastEnumerationState, align 8
@@ -618,3 +686,68 @@
call void @objc_release(i8* %0) nounwind, !clang.imprecise_release !0
ret void
}
+
+; Like test10, but without a split backedge. This we can optimize.
+
+; CHECK: define void @test10b(
+; CHECK: call i8* @objc_retain
+; CHECK: call i8* @objc_retain
+; CHECK-NOT: @objc_retain
+; CHECK: }
+define void @test10b() nounwind {
+entry:
+ %state.ptr = alloca %struct.__objcFastEnumerationState, align 8
+ %items.ptr = alloca [16 x i8*], align 8
+ %call = call i8* @returner()
+ %0 = call i8* @objc_retainAutoreleasedReturnValue(i8* %call) nounwind
+ %call1 = call i8* @returner()
+ %1 = call i8* @objc_retainAutoreleasedReturnValue(i8* %call1) nounwind
+ call void @callee()
+ %tmp = bitcast %struct.__objcFastEnumerationState* %state.ptr to i8*
+ call void @llvm.memset.p0i8.i64(i8* %tmp, i8 0, i64 64, i32 8, i1 false)
+ %2 = call i8* @objc_retain(i8* %0) nounwind
+ %tmp3 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_", align 8
+ %call4 = call i64 bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to i64 (i8*, i8*, %struct.__objcFastEnumerationState*, [16 x i8*]*, i64)*)(i8* %2, i8* %tmp3, %struct.__objcFastEnumerationState* %state.ptr, [16 x i8*]* %items.ptr, i64 16)
+ %iszero = icmp eq i64 %call4, 0
+ br i1 %iszero, label %forcoll.empty, label %forcoll.loopinit
+
+forcoll.loopinit:
+ %mutationsptr.ptr = getelementptr inbounds %struct.__objcFastEnumerationState* %state.ptr, i64 0, i32 2
+ %mutationsptr = load i64** %mutationsptr.ptr, align 8
+ %forcoll.initial-mutations = load i64* %mutationsptr, align 8
+ br label %forcoll.loopbody.outer
+
+forcoll.loopbody.outer:
+ %forcoll.count.ph = phi i64 [ %call4, %forcoll.loopinit ], [ %call7, %forcoll.refetch ]
+ %tmp9 = icmp ugt i64 %forcoll.count.ph, 1
+ %umax = select i1 %tmp9, i64 %forcoll.count.ph, i64 1
+ br label %forcoll.loopbody
+
+forcoll.loopbody:
+ %forcoll.index = phi i64 [ %phitmp, %forcoll.notmutated ], [ 0, %forcoll.loopbody.outer ]
+ %mutationsptr5 = load i64** %mutationsptr.ptr, align 8
+ %statemutations = load i64* %mutationsptr5, align 8
+ %3 = icmp eq i64 %statemutations, %forcoll.initial-mutations
+ br i1 %3, label %forcoll.notmutated, label %forcoll.mutated
+
+forcoll.mutated:
+ call void @objc_enumerationMutation(i8* %2)
+ br label %forcoll.notmutated
+
+forcoll.notmutated:
+ %phitmp = add i64 %forcoll.index, 1
+ %exitcond = icmp eq i64 %phitmp, %umax
+ br i1 %exitcond, label %forcoll.refetch, label %forcoll.loopbody
+
+forcoll.refetch:
+ %tmp6 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_", align 8
+ %call7 = call i64 bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to i64 (i8*, i8*, %struct.__objcFastEnumerationState*, [16 x i8*]*, i64)*)(i8* %2, i8* %tmp6, %struct.__objcFastEnumerationState* %state.ptr, [16 x i8*]* %items.ptr, i64 16)
+ %4 = icmp eq i64 %call7, 0
+ br i1 %4, label %forcoll.empty, label %forcoll.loopbody.outer
+
+forcoll.empty:
+ call void @objc_release(i8* %2) nounwind
+ call void @objc_release(i8* %1) nounwind, !clang.imprecise_release !0
+ call void @objc_release(i8* %0) nounwind, !clang.imprecise_release !0
+ ret void
+}
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