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author | Michael Gottesman <mgottesman@apple.com> | 2013-07-07 01:52:55 +0000 |
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committer | Michael Gottesman <mgottesman@apple.com> | 2013-07-07 01:52:55 +0000 |
commit | 0a80c1240284c764c0f9cd043a2a18ff4152a203 (patch) | |
tree | 0180e95a679e83f462135f92bcd25675bb95d9d0 | |
parent | 09f8ca3986cbe89d897765926462476f345a25d0 (diff) | |
download | llvm-0a80c1240284c764c0f9cd043a2a18ff4152a203.tar.gz llvm-0a80c1240284c764c0f9cd043a2a18ff4152a203.tar.bz2 llvm-0a80c1240284c764c0f9cd043a2a18ff4152a203.tar.xz |
[objc-arc] Teach the ARC optimizer that objc_sync_enter/objc_sync_exit do not modify the ref count of an objc object and additionally are inert for modref purposes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185769 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.cpp | 8 | ||||
-rw-r--r-- | lib/Transforms/ObjCARC/ObjCARCUtil.cpp | 2 | ||||
-rw-r--r-- | test/Transforms/ObjCARC/basic.ll | 23 | ||||
-rw-r--r-- | test/Transforms/ObjCARC/gvn.ll | 24 |
4 files changed, 52 insertions, 5 deletions
diff --git a/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.cpp b/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.cpp index 46b2de7137..1a3f383d4c 100644 --- a/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.cpp +++ b/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.cpp @@ -150,6 +150,14 @@ ObjCARCAliasAnalysis::getModRefInfo(ImmutableCallSite CS, const Location &Loc) { break; } + // Handle special objective c calls defaulting to chaining. + const Function *F = CS.getCalledFunction(); + if (F) + return StringSwitch<AliasAnalysis::ModRefResult>(F->getName()) + .Case("objc_sync_start", NoModRef) + .Case("objc_sync_stop", NoModRef) + .Default(AliasAnalysis::getModRefInfo(CS, Loc)); + return AliasAnalysis::getModRefInfo(CS, Loc); } diff --git a/lib/Transforms/ObjCARC/ObjCARCUtil.cpp b/lib/Transforms/ObjCARC/ObjCARCUtil.cpp index 03e12d4fd7..415e76355d 100644 --- a/lib/Transforms/ObjCARC/ObjCARCUtil.cpp +++ b/lib/Transforms/ObjCARC/ObjCARCUtil.cpp @@ -112,6 +112,8 @@ InstructionClass llvm::objcarc::GetFunctionClass(const Function *F) { .Case("objc_retain_autorelease", IC_FusedRetainAutorelease) .Case("objc_retainAutorelease", IC_FusedRetainAutorelease) .Case("objc_retainAutoreleaseReturnValue",IC_FusedRetainAutoreleaseRV) + .Case("objc_sync_enter", IC_User) + .Case("objc_sync_exit", IC_User) .Default(IC_CallOrUser); // Argument is i8** diff --git a/test/Transforms/ObjCARC/basic.ll b/test/Transforms/ObjCARC/basic.ll index ca12792065..2bb312bf26 100644 --- a/test/Transforms/ObjCARC/basic.ll +++ b/test/Transforms/ObjCARC/basic.ll @@ -3037,9 +3037,28 @@ end: ; preds = %if.end125, %if.end1 ret void } -!0 = metadata !{} - declare i32 @__gxx_personality_v0(...) +declare i32 @objc_sync_enter(i8*) +declare i32 @objc_sync_exit(i8*) + +; Make sure that we understand that objc_sync_{enter,exit} are IC_User not +; IC_Call/IC_CallOrUser. + +; CHECK: define void @test67 +; CHECK-NEXT: call i32 @objc_sync_enter(i8* %x) +; CHECK-NEXT: call i32 @objc_sync_exit(i8* %x) +; CHECK-NEXT: ret void +; CHECK-NEXT: } +define void @test67(i8* %x) { + call i8* @objc_retain(i8* %x) + call i32 @objc_sync_enter(i8* %x) + call i32 @objc_sync_exit(i8* %x) + call void @objc_release(i8* %x), !clang.imprecise_release !0 + ret void +} + +!0 = metadata !{} + ; CHECK: attributes #0 = { nounwind readnone } ; CHECK: attributes [[NUW]] = { nounwind } diff --git a/test/Transforms/ObjCARC/gvn.ll b/test/Transforms/ObjCARC/gvn.ll index a828b5485f..0773b69ee1 100644 --- a/test/Transforms/ObjCARC/gvn.ll +++ b/test/Transforms/ObjCARC/gvn.ll @@ -3,20 +3,38 @@ @x = common global i8* null, align 8 declare i8* @objc_retain(i8*) +declare i32 @objc_sync_start(i8*) +declare i32 @objc_sync_stop(i8*) ; GVN should be able to eliminate this redundant load, with ARC-specific ; alias analysis. -; CHECK: define i8* @foo(i32 %n) +; CHECK: define i8* @test0(i32 %n) ; CHECK-NEXT: entry: ; CHECK-NEXT: %s = load i8** @x ; CHECK-NOT: load ; CHECK: ret i8* %s ; CHECK-NEXT: } -define i8* @foo(i32 %n) nounwind { +define i8* @test0(i32 %n) nounwind { entry: %s = load i8** @x %0 = tail call i8* @objc_retain(i8* %s) nounwind %t = load i8** @x - ret i8* %s + ret i8* %t +} + +; CHECK: define i8* @test1(i32 %n) +; CHECK-NEXT: entry: +; CHECK-NEXT: %s = load i8** @x +; CHECK-NEXT: call i32 @objc_sync_start +; CHECK-NEXT: call i32 @objc_sync_stop +; CHECK-NEXT: ret i8* %s +; CHECK-NEXT: } +define i8* @test1(i32 %n) nounwind { +entry: + %s = load i8** @x + %0 = call i32 @objc_sync_start(i8* %s) + %t = load i8** @x + %1 = call i32 @objc_sync_stop(i8* %s) + ret i8* %t } |