[llvm] r194083 - [objc-arc] Convert the one directional retain/release relation assert to a conditional check + fail.
Michael Gottesman
mgottesman at apple.com
Tue Nov 5 08:02:41 PST 2013
Author: mgottesman
Date: Tue Nov 5 10:02:40 2013
New Revision: 194083
URL: http://llvm.org/viewvc/llvm-project?rev=194083&view=rev
Log:
[objc-arc] Convert the one directional retain/release relation assert to a conditional check + fail.
Due to the previously added overflow checks, we can have a retain/release
relation that is one directional. This occurs specifically when we run into an
additive overflow causing us to drop state in only one direction. If that
occurs, we should bail and not optimize that retain/release instead of
asserting.
Apologies for the size of the testcase. It is necessary to cause the additive
cfg overflow to trigger.
rdar://15377890
Modified:
llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
llvm/trunk/test/Transforms/ObjCARC/path-overflow.ll
Modified: llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp?rev=194083&r1=194082&r2=194083&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp (original)
+++ llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp Tue Nov 5 10:02:40 2013
@@ -2405,7 +2405,15 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseM
if (Jt == Releases.end())
return false;
const RRInfo &NewRetainReleaseRRI = Jt->second;
- assert(NewRetainReleaseRRI.Calls.count(NewRetain));
+
+ // If the release does not have a reference to the retain as well,
+ // something happened which is unaccounted for. Do not do anything.
+ //
+ // This can happen if we catch an additive overflow during path count
+ // merging.
+ if (!NewRetainReleaseRRI.Calls.count(NewRetain))
+ return false;
+
if (ReleasesToMove.Calls.insert(NewRetainRelease)) {
// If we overflow when we compute the path count, don't remove/move
@@ -2481,9 +2489,16 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseM
if (Jt == Retains.end())
return false;
const RRInfo &NewReleaseRetainRRI = Jt->second;
- assert(NewReleaseRetainRRI.Calls.count(NewRelease));
- if (RetainsToMove.Calls.insert(NewReleaseRetain)) {
+ // If the retain does not have a reference to the release as well,
+ // something happened which is unaccounted for. Do not do anything.
+ //
+ // This can happen if we catch an additive overflow during path count
+ // merging.
+ if (!NewReleaseRetainRRI.Calls.count(NewRelease))
+ return false;
+
+ if (RetainsToMove.Calls.insert(NewReleaseRetain)) {
// If we overflow when we compute the path count, don't remove/move
// anything.
const BBState &NRRBBState = BBStates[NewReleaseRetain->getParent()];
Modified: llvm/trunk/test/Transforms/ObjCARC/path-overflow.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ObjCARC/path-overflow.ll?rev=194083&r1=194082&r2=194083&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/ObjCARC/path-overflow.ll (original)
+++ llvm/trunk/test/Transforms/ObjCARC/path-overflow.ll Tue Nov 5 10:02:40 2013
@@ -2,6 +2,7 @@
; rdar://12277446
; rdar://12480535
; rdar://14590914
+; rdar://15377890
; The total number of paths grows exponentially with the number of branches, and a
; computation of this number can overflow any reasonable fixed-sized
@@ -15,6 +16,7 @@ target triple = "thumbv7-apple-ios5.0.0"
%struct.CGPoint = type { float, float }
@_unnamed_cfstring = external constant %struct.NSConstantString, section "__DATA,__cfstring"
+ at _unnamed_cfstring_2 = external constant %struct.NSConstantString, section "__DATA,__cfstring"
declare i8* @objc_retain(i8*) nonlazybind
declare i8* @objc_retainAutoreleasedReturnValue(i8*) nonlazybind
@@ -24,6 +26,7 @@ declare i8* @objc_msgSend(i8*, i8*, ...)
declare void @NSLog(i8*, ...)
declare void @objc_msgSend_stret(i8*, i8*, ...)
declare i32 @__gxx_personality_sj0(...)
+declare i32 @__objc_personality_v0(...)
define hidden void @test1() {
@@ -1914,4 +1917,277 @@ eh.resume:
resume { i8*, i32 } undef
}
+@"OBJC_EHTYPE_$_NSException" = external global i8
+
+define void @test4() {
+entry:
+ br i1 undef, label %if.end13, label %if.then10
+
+if.then10: ; preds = %entry
+ br label %if.end13
+
+if.end13: ; preds = %if.then10, %entry
+ %0 = call i8* bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to i8* (i8*, i8*, i8*, i64, i8*, i8)*)(i8* undef, i8* undef, i8* bitcast (%struct.NSConstantString* @_unnamed_cfstring to i8*), i64 2, i8* bitcast (%struct.NSConstantString* @_unnamed_cfstring_2 to i8*), i8 signext 0), !clang.arc.no_objc_arc_exceptions !0
+ br i1 undef, label %if.then17, label %if.end18
+
+if.then17: ; preds = %if.end13
+ br label %if.end18
+
+if.end18: ; preds = %if.then17, %if.end13
+ br i1 undef, label %if.then64, label %if.end73
+
+if.then64: ; preds = %if.end18
+ br i1 undef, label %cond.end71, label %cond.true68
+
+cond.true68: ; preds = %if.then64
+ br label %cond.end71
+
+cond.end71: ; preds = %cond.true68, %if.then64
+ br i1 undef, label %cleanup.action, label %cleanup.done
+
+cleanup.action: ; preds = %cond.end71
+ br label %cleanup.done
+
+cleanup.done: ; preds = %cleanup.action, %cond.end71
+ br label %if.end73
+
+if.end73: ; preds = %cleanup.done, %if.end18
+ br i1 undef, label %forcoll.empty, label %forcoll.loopinit
+
+forcoll.loopinit: ; preds = %if.end73
+ br label %forcoll.loopbody.outer
+
+forcoll.loopbody.outer: ; preds = %forcoll.refetch, %forcoll.loopinit
+ br label %forcoll.loopbody
+
+forcoll.loopbody: ; preds = %forcoll.notmutated, %forcoll.loopbody.outer
+ br i1 undef, label %forcoll.notmutated, label %forcoll.mutated
+
+forcoll.mutated: ; preds = %forcoll.loopbody
+ br label %forcoll.notmutated
+
+forcoll.notmutated: ; preds = %forcoll.mutated, %forcoll.loopbody
+ br i1 undef, label %forcoll.loopbody, label %forcoll.refetch
+
+forcoll.refetch: ; preds = %forcoll.notmutated
+ br i1 undef, label %forcoll.empty, label %forcoll.loopbody.outer
+
+forcoll.empty: ; preds = %forcoll.refetch, %if.end73
+ br i1 undef, label %if.end85, label %if.then82
+
+if.then82: ; preds = %forcoll.empty
+ br label %if.end85
+
+if.end85: ; preds = %if.then82, %forcoll.empty
+ br i1 undef, label %if.then87, label %if.end102
+
+if.then87: ; preds = %if.end85
+ br i1 undef, label %if.end94, label %if.then91
+
+if.then91: ; preds = %if.then87
+ br label %if.end94
+
+if.end94: ; preds = %if.then91, %if.then87
+ br i1 undef, label %if.end101, label %if.then98
+
+if.then98: ; preds = %if.end94
+ br label %if.end101
+
+if.end101: ; preds = %if.then98, %if.end94
+ br label %if.end102
+
+if.end102: ; preds = %if.end101, %if.end85
+ br i1 undef, label %do.body113, label %if.then107
+
+if.then107: ; preds = %if.end102
+ br label %do.body113
+
+do.body113: ; preds = %if.then107, %if.end102
+ br i1 undef, label %if.then116, label %if.end117
+
+if.then116: ; preds = %do.body113
+ br label %if.end117
+
+if.end117: ; preds = %if.then116, %do.body113
+ br i1 undef, label %if.then125, label %if.end126
+
+if.then125: ; preds = %if.end117
+ br label %if.end126
+
+if.end126: ; preds = %if.then125, %if.end117
+ br i1 undef, label %do.end166, label %cond.true132
+
+cond.true132: ; preds = %if.end126
+ br i1 undef, label %do.body148, label %cond.true151
+
+do.body148: ; preds = %cond.true132
+ br i1 undef, label %do.end166, label %cond.true151
+
+cond.true151: ; preds = %do.body148, %cond.true132
+ br i1 undef, label %if.then162, label %do.end166
+
+if.then162: ; preds = %cond.true151
+ br label %do.end166
+
+do.end166: ; preds = %if.then162, %cond.true151, %do.body148, %if.end126
+ br i1 undef, label %if.then304, label %if.then170
+
+if.then170: ; preds = %do.end166
+ br i1 undef, label %do.end193, label %cond.true179
+
+cond.true179: ; preds = %if.then170
+ br i1 undef, label %if.then190, label %do.end193
+
+if.then190: ; preds = %cond.true179
+ br label %do.end193
+
+do.end193: ; preds = %if.then190, %cond.true179, %if.then170
+ br i1 undef, label %do.body200, label %do.body283
+
+do.body200: ; preds = %do.end193
+ br i1 undef, label %do.end254, label %cond.true203
+
+cond.true203: ; preds = %do.body200
+ br i1 undef, label %do.body218, label %cond.true221
+
+do.body218: ; preds = %cond.true203
+ br i1 undef, label %do.end254, label %cond.true221
+
+cond.true221: ; preds = %do.body218, %cond.true203
+ br i1 undef, label %if.then232, label %do.body236
+
+if.then232: ; preds = %cond.true221
+ br label %do.body236
+
+do.body236: ; preds = %if.then232, %cond.true221
+ br i1 undef, label %do.end254, label %cond.true239
+
+cond.true239: ; preds = %do.body236
+ br i1 undef, label %if.then250, label %do.end254
+
+if.then250: ; preds = %cond.true239
+ br label %do.end254
+
+do.end254: ; preds = %if.then250, %cond.true239, %do.body236, %do.body218, %do.body200
+ br i1 undef, label %do.end277, label %cond.true263
+
+cond.true263: ; preds = %do.end254
+ br i1 undef, label %if.then274, label %do.end277
+
+if.then274: ; preds = %cond.true263
+ unreachable
+
+do.end277: ; preds = %cond.true263, %do.end254
+ br i1 undef, label %if.then280, label %do.body283
+
+if.then280: ; preds = %do.end277
+ br label %do.body283
+
+do.body283: ; preds = %if.then280, %do.end277, %do.end193
+ br i1 undef, label %if.end301, label %cond.true286
+
+cond.true286: ; preds = %do.body283
+ br i1 undef, label %if.then297, label %if.end301
+
+if.then297: ; preds = %cond.true286
+ br label %if.end301
+
+if.end301: ; preds = %if.then297, %cond.true286, %do.body283
+ br i1 undef, label %if.then304, label %do.body351
+
+if.then304: ; preds = %if.end301, %do.end166
+ br i1 undef, label %do.body309.lr.ph, label %do.body351
+
+do.body309.lr.ph: ; preds = %if.then304
+ br label %do.body309
+
+do.body309: ; preds = %for.cond.backedge, %do.body309.lr.ph
+ br i1 undef, label %do.end328, label %cond.true312
+
+cond.true312: ; preds = %do.body309
+ br i1 undef, label %if.then323, label %do.end328
+
+if.then323: ; preds = %cond.true312
+ br label %do.end328
+
+do.end328: ; preds = %if.then323, %cond.true312, %do.body309
+ br i1 undef, label %for.cond.backedge, label %cond.true335
+
+for.cond.backedge: ; preds = %if.then346, %cond.true335, %do.end328
+ br i1 undef, label %do.body309, label %do.body351
+
+cond.true335: ; preds = %do.end328
+ br i1 undef, label %if.then346, label %for.cond.backedge
+
+if.then346: ; preds = %cond.true335
+ br label %for.cond.backedge
+
+do.body351: ; preds = %for.cond.backedge, %if.then304, %if.end301
+ br i1 undef, label %if.then354, label %if.end355
+
+if.then354: ; preds = %do.body351
+ br label %if.end355
+
+if.end355: ; preds = %if.then354, %do.body351
+ br i1 undef, label %if.else, label %if.then364
+
+if.then364: ; preds = %if.end355
+ br label %do.body366
+
+if.else: ; preds = %if.end355
+ br label %do.body366
+
+do.body366: ; preds = %if.else, %if.then364
+ br i1 undef, label %if.then369, label %if.end377.critedge
+
+if.then369: ; preds = %do.body366
+ br label %if.end377
+
+if.end377.critedge: ; preds = %do.body366
+ br label %if.end377
+
+if.end377: ; preds = %if.end377.critedge, %if.then369
+ br i1 undef, label %if.then383, label %if.end392.critedge
+
+if.then383: ; preds = %if.end377
+ br label %if.end392
+
+if.end392.critedge: ; preds = %if.end377
+ br label %if.end392
+
+if.end392: ; preds = %if.end392.critedge, %if.then383
+ br i1 undef, label %if.then398, label %if.end399
+
+if.then398: ; preds = %if.end392
+ br label %if.end399
+
+if.end399: ; preds = %if.then398, %if.end392
+ invoke void bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*, i8*)*)(i8* undef, i8* undef)
+ to label %eh.cont unwind label %lpad, !clang.arc.no_objc_arc_exceptions !0
+
+eh.cont: ; preds = %if.end399
+ br i1 undef, label %if.then430, label %if.end439.critedge
+
+if.then430: ; preds = %eh.cont
+ %1 = call i8* @objc_retain(i8* %0)
+ br label %if.end439
+
+lpad: ; preds = %if.end399
+ %2 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__objc_personality_v0 to i8*)
+ catch i8* @"OBJC_EHTYPE_$_NSException"
+ unreachable
+
+if.end439.critedge: ; preds = %eh.cont
+ %3 = call i8* @objc_retain(i8* %0)
+ br label %if.end439
+
+if.end439: ; preds = %if.end439.critedge, %if.then430
+ call void @objc_release(i8* %0), !clang.imprecise_release !0
+ unreachable
+
+return: ; No predecessors!
+ ret void
+}
+
+
!0 = metadata !{}
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