[llvm] r183489 - [objc-arc] Ensure that the cfg path count does not overflow when we multiply TopDownPathCount/BottomUpPathCount.
Michael Gottesman
mgottesman at apple.com
Thu Jun 6 23:16:49 PDT 2013
Author: mgottesman
Date: Fri Jun 7 01:16:49 2013
New Revision: 183489
URL: http://llvm.org/viewvc/llvm-project?rev=183489&view=rev
Log:
[objc-arc] Ensure that the cfg path count does not overflow when we multiply TopDownPathCount/BottomUpPathCount.
rdar://12480535
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=183489&r1=183488&r2=183489&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp (original)
+++ llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp Fri Jun 7 01:16:49 2013
@@ -670,13 +670,20 @@ namespace {
void MergePred(const BBState &Other);
void MergeSucc(const BBState &Other);
- /// Return the number of possible unique paths from an entry to an exit
+ /// Compute the number of possible unique paths from an entry to an exit
/// which pass through this block. This is only valid after both the
/// top-down and bottom-up traversals are complete.
- unsigned GetAllPathCount() const {
+ ///
+ /// Returns true if overflow occured. Returns false if overflow did not
+ /// occur.
+ bool GetAllPathCountWithOverflow(unsigned &PathCount) const {
assert(TopDownPathCount != 0);
assert(BottomUpPathCount != 0);
- return TopDownPathCount * BottomUpPathCount;
+ unsigned long long Product =
+ (unsigned long long)TopDownPathCount*BottomUpPathCount;
+ PathCount = Product;
+ // Overflow occured if any of the upper bits of Product are set.
+ return Product >> 32;
}
// Specialized CFG utilities.
@@ -2543,8 +2550,14 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseM
const RRInfo &NewRetainReleaseRRI = Jt->second;
assert(NewRetainReleaseRRI.Calls.count(NewRetain));
if (ReleasesToMove.Calls.insert(NewRetainRelease)) {
- OldDelta -=
- BBStates[NewRetainRelease->getParent()].GetAllPathCount();
+
+ // If we overflow when we compute the path count, don't remove/move
+ // anything.
+ const BBState &NRRBBState = BBStates[NewRetainRelease->getParent()];
+ unsigned PathCount;
+ if (NRRBBState.GetAllPathCountWithOverflow(PathCount))
+ return false;
+ OldDelta -= PathCount;
// Merge the ReleaseMetadata and IsTailCallRelease values.
if (FirstRelease) {
@@ -2569,8 +2582,14 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseM
RE = NewRetainReleaseRRI.ReverseInsertPts.end();
RI != RE; ++RI) {
Instruction *RIP = *RI;
- if (ReleasesToMove.ReverseInsertPts.insert(RIP))
- NewDelta -= BBStates[RIP->getParent()].GetAllPathCount();
+ if (ReleasesToMove.ReverseInsertPts.insert(RIP)) {
+ // If we overflow when we compute the path count, don't
+ // remove/move anything.
+ const BBState &RIPBBState = BBStates[RIP->getParent()];
+ if (RIPBBState.GetAllPathCountWithOverflow(PathCount))
+ return false;
+ NewDelta -= PathCount;
+ }
}
NewReleases.push_back(NewRetainRelease);
}
@@ -2600,8 +2619,13 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseM
const RRInfo &NewReleaseRetainRRI = Jt->second;
assert(NewReleaseRetainRRI.Calls.count(NewRelease));
if (RetainsToMove.Calls.insert(NewReleaseRetain)) {
- unsigned PathCount =
- BBStates[NewReleaseRetain->getParent()].GetAllPathCount();
+
+ // If we overflow when we compute the path count, don't remove/move
+ // anything.
+ const BBState &NRRBBState = BBStates[NewReleaseRetain->getParent()];
+ unsigned PathCount;
+ if (NRRBBState.GetAllPathCountWithOverflow(PathCount))
+ return false;
OldDelta += PathCount;
OldCount += PathCount;
@@ -2613,7 +2637,11 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseM
RI != RE; ++RI) {
Instruction *RIP = *RI;
if (RetainsToMove.ReverseInsertPts.insert(RIP)) {
- PathCount = BBStates[RIP->getParent()].GetAllPathCount();
+ // If we overflow when we compute the path count, don't
+ // remove/move anything.
+ const BBState &RIPBBState = BBStates[RIP->getParent()];
+ if (RIPBBState.GetAllPathCountWithOverflow(PathCount))
+ return false;
NewDelta += PathCount;
NewCount += PathCount;
}
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=183489&r1=183488&r2=183489&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/ObjCARC/path-overflow.ll (original)
+++ llvm/trunk/test/Transforms/ObjCARC/path-overflow.ll Fri Jun 7 01:16:49 2013
@@ -1,8 +1,11 @@
; RUN: opt -objc-arc -S < %s
; rdar://12277446
+; rdar://12480535
; The total number of paths grows exponentially with the number of branches, and a
-; computation of this number can overflow any reasonable fixed-sized integer.
+; computation of this number can overflow any reasonable fixed-sized
+; integer. This can occur in both the addition phase when we are adding up the
+; total bottomup/topdown paths and when we multiply them together at the end.
target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n32-S32"
target triple = "thumbv7-apple-ios5.0.0"
@@ -12,10 +15,11 @@ target triple = "thumbv7-apple-ios5.0.0"
@_unnamed_cfstring_591 = external constant %struct.NSConstantString.11.33.55.77.99.121.143.332.1130.1340.2768, section "__DATA,__cfstring"
declare i8* @objc_retain(i8*) nonlazybind
-
+declare i8* @objc_retainAutoreleasedReturnValue(i8*) nonlazybind
declare void @objc_release(i8*) nonlazybind
+declare i8* @returner()
-define hidden void @foo() {
+define hidden void @test1() {
entry:
br i1 undef, label %msgSend.nullinit, label %msgSend.call
@@ -326,4 +330,528 @@ msgSend.cont507:
ret void
}
+; Function Attrs: optsize ssp uwtable
+define void @test2() unnamed_addr align 2 {
+bb:
+ br i1 undef, label %bb3, label %bb2
+
+bb2: ; preds = %bb
+ br label %bb3
+
+bb3: ; preds = %bb2, %bb
+ br i1 undef, label %bb5, label %bb4
+
+bb4: ; preds = %bb3
+ br label %bb5
+
+bb5: ; preds = %bb4, %bb3
+ br i1 undef, label %bb7, label %bb6
+
+bb6: ; preds = %bb5
+ br label %bb7
+
+bb7: ; preds = %bb6, %bb5
+ br i1 undef, label %bb9, label %bb8
+
+bb8: ; preds = %bb7
+ unreachable
+
+bb9: ; preds = %bb7
+ br i1 undef, label %bb11, label %bb10
+
+bb10: ; preds = %bb9
+ br label %bb11
+
+bb11: ; preds = %bb10, %bb9
+ br i1 undef, label %bb13, label %bb12
+
+bb12: ; preds = %bb11
+ br label %bb13
+
+bb13: ; preds = %bb12, %bb11
+ br i1 undef, label %bb15, label %bb14
+
+bb14: ; preds = %bb13
+ br label %bb15
+
+bb15: ; preds = %bb14, %bb13
+ br i1 undef, label %bb17, label %bb16
+
+bb16: ; preds = %bb15
+ br label %bb17
+
+bb17: ; preds = %bb16, %bb15
+ br i1 undef, label %bb19, label %bb18
+
+bb18: ; preds = %bb17
+ br label %bb19
+
+bb19: ; preds = %bb18, %bb17
+ br i1 undef, label %bb222, label %bb20
+
+bb20: ; preds = %bb19
+ br i1 undef, label %bb222, label %bb21
+
+bb21: ; preds = %bb20
+ br i1 undef, label %bb22, label %bb30
+
+bb22: ; preds = %bb21
+ br i1 undef, label %bb23, label %bb32
+
+bb23: ; preds = %bb22
+ br i1 undef, label %bb24, label %bb34
+
+bb24: ; preds = %bb23
+ br i1 undef, label %bb26, label %bb25
+
+bb25: ; preds = %bb24
+ br label %bb27
+
+bb26: ; preds = %bb24
+ br label %bb27
+
+bb27: ; preds = %bb26, %bb25
+ br i1 undef, label %bb28, label %bb42
+
+bb28: ; preds = %bb27
+ br i1 undef, label %bb36, label %bb29
+
+bb29: ; preds = %bb28
+ br label %bb36
+
+bb30: ; preds = %bb210, %bb207, %bb203, %bb199, %bb182, %bb176, %bb174, %bb171, %bb136, %bb132, %bb21
+ br label %bb213
+
+bb32: ; preds = %bb22
+ unreachable
+
+bb34: ; preds = %bb23
+ unreachable
+
+bb36: ; preds = %bb29, %bb28
+ br i1 undef, label %bb38, label %bb37
+
+bb37: ; preds = %bb36
+ br label %bb39
+
+bb38: ; preds = %bb36
+ br label %bb39
+
+bb39: ; preds = %bb38, %bb37
+ br i1 undef, label %bb41, label %bb40
+
+bb40: ; preds = %bb39
+ unreachable
+
+bb41: ; preds = %bb39
+ br label %bb42
+
+bb42: ; preds = %bb41, %bb27
+ br i1 undef, label %bb43, label %bb214
+
+bb43: ; preds = %bb42
+ br i1 undef, label %bb47, label %bb45
+
+bb45: ; preds = %bb130, %bb128, %bb126, %bb124, %bb122, %bb120, %bb118, %bb116, %bb114, %bb112, %bb110, %bb108, %bb105, %bb102, %bb100, %bb96, %bb94, %bb90, %bb88, %bb84, %bb82, %bb78, %bb76, %bb72, %bb70, %bb66, %bb64, %bb60, %bb58, %bb54, %bb51, %bb43
+ unreachable
+
+bb47: ; preds = %bb43
+ br i1 undef, label %bb48, label %bb106
+
+bb48: ; preds = %bb47
+ br i1 undef, label %bb50, label %bb49
+
+bb49: ; preds = %bb48
+ br label %bb51
+
+bb50: ; preds = %bb48
+ br label %bb51
+
+bb51: ; preds = %bb50, %bb49
+ br i1 undef, label %bb53, label %bb45
+
+bb53: ; preds = %bb51
+ br i1 undef, label %bb54, label %bb134
+
+bb54: ; preds = %bb53
+ br i1 undef, label %bb55, label %bb45
+
+bb55: ; preds = %bb54
+ br i1 undef, label %bb57, label %bb56
+
+bb56: ; preds = %bb55
+ br label %bb58
+
+bb57: ; preds = %bb55
+ br label %bb58
+
+bb58: ; preds = %bb57, %bb56
+ br i1 undef, label %bb60, label %bb45
+
+bb60: ; preds = %bb58
+ br i1 undef, label %bb61, label %bb45
+
+bb61: ; preds = %bb60
+ br i1 undef, label %bb63, label %bb62
+
+bb62: ; preds = %bb61
+ br label %bb64
+
+bb63: ; preds = %bb61
+ br label %bb64
+
+bb64: ; preds = %bb63, %bb62
+ br i1 undef, label %bb66, label %bb45
+
+bb66: ; preds = %bb64
+ br i1 undef, label %bb67, label %bb45
+
+bb67: ; preds = %bb66
+ br i1 undef, label %bb69, label %bb68
+
+bb68: ; preds = %bb67
+ br label %bb70
+
+bb69: ; preds = %bb67
+ br label %bb70
+
+bb70: ; preds = %bb69, %bb68
+ br i1 undef, label %bb72, label %bb45
+
+bb72: ; preds = %bb70
+ br i1 undef, label %bb73, label %bb45
+
+bb73: ; preds = %bb72
+ br i1 undef, label %bb75, label %bb74
+
+bb74: ; preds = %bb73
+ br label %bb76
+
+bb75: ; preds = %bb73
+ br label %bb76
+
+bb76: ; preds = %bb75, %bb74
+ br i1 undef, label %bb78, label %bb45
+
+bb78: ; preds = %bb76
+ br i1 undef, label %bb79, label %bb45
+
+bb79: ; preds = %bb78
+ br i1 undef, label %bb81, label %bb80
+
+bb80: ; preds = %bb79
+ br label %bb82
+
+bb81: ; preds = %bb79
+ br label %bb82
+
+bb82: ; preds = %bb81, %bb80
+ br i1 undef, label %bb84, label %bb45
+
+bb84: ; preds = %bb82
+ br i1 undef, label %bb85, label %bb45
+
+bb85: ; preds = %bb84
+ br i1 undef, label %bb87, label %bb86
+
+bb86: ; preds = %bb85
+ br label %bb88
+
+bb87: ; preds = %bb85
+ br label %bb88
+
+bb88: ; preds = %bb87, %bb86
+ br i1 undef, label %bb90, label %bb45
+
+bb90: ; preds = %bb88
+ br i1 undef, label %bb91, label %bb45
+
+bb91: ; preds = %bb90
+ br i1 undef, label %bb93, label %bb92
+
+bb92: ; preds = %bb91
+ br label %bb94
+
+bb93: ; preds = %bb91
+ br label %bb94
+
+bb94: ; preds = %bb93, %bb92
+ br i1 undef, label %bb96, label %bb45
+
+bb96: ; preds = %bb94
+ br i1 undef, label %bb97, label %bb45
+
+bb97: ; preds = %bb96
+ br i1 undef, label %bb99, label %bb98
+
+bb98: ; preds = %bb97
+ br label %bb100
+
+bb99: ; preds = %bb97
+ br label %bb100
+
+bb100: ; preds = %bb99, %bb98
+ br i1 undef, label %bb102, label %bb45
+
+bb102: ; preds = %bb100
+ br i1 undef, label %bb104, label %bb45
+
+bb104: ; preds = %bb102
+ br i1 undef, label %bb108, label %bb105
+
+bb105: ; preds = %bb104
+ br i1 undef, label %bb108, label %bb45
+
+bb106: ; preds = %bb47
+ unreachable
+
+bb108: ; preds = %bb105, %bb104
+ br i1 undef, label %bb110, label %bb45
+
+bb110: ; preds = %bb108
+ br i1 undef, label %bb112, label %bb45
+
+bb112: ; preds = %bb110
+ br i1 undef, label %bb114, label %bb45
+
+bb114: ; preds = %bb112
+ br i1 undef, label %bb116, label %bb45
+
+bb116: ; preds = %bb114
+ br i1 undef, label %bb118, label %bb45
+
+bb118: ; preds = %bb116
+ br i1 undef, label %bb120, label %bb45
+
+bb120: ; preds = %bb118
+ br i1 undef, label %bb122, label %bb45
+
+bb122: ; preds = %bb120
+ br i1 undef, label %bb124, label %bb45
+
+bb124: ; preds = %bb122
+ br i1 undef, label %bb126, label %bb45
+
+bb126: ; preds = %bb124
+ br i1 undef, label %bb128, label %bb45
+
+bb128: ; preds = %bb126
+ br i1 undef, label %bb130, label %bb45
+
+bb130: ; preds = %bb128
+ br i1 undef, label %bb132, label %bb45
+
+bb132: ; preds = %bb130
+ br i1 undef, label %bb135, label %bb30
+
+bb134: ; preds = %bb53
+ unreachable
+
+bb135: ; preds = %bb132
+ br i1 undef, label %bb139, label %bb136
+
+bb136: ; preds = %bb135
+ br i1 undef, label %bb138, label %bb30
+
+bb138: ; preds = %bb136
+ br label %bb139
+
+bb139: ; preds = %bb138, %bb135
+ br i1 undef, label %bb140, label %bb141
+
+bb140: ; preds = %bb139
+ unreachable
+
+bb141: ; preds = %bb139
+ br i1 undef, label %bb142, label %bb215
+
+bb142: ; preds = %bb141
+ br i1 undef, label %bb144, label %bb143
+
+bb143: ; preds = %bb142
+ br label %bb145
+
+bb144: ; preds = %bb142
+ br label %bb145
+
+bb145: ; preds = %bb144, %bb143
+ br i1 undef, label %bb146, label %bb151
+
+bb146: ; preds = %bb145
+ br i1 undef, label %bb148, label %bb153
+
+bb148: ; preds = %bb146
+ br i1 undef, label %bb155, label %bb149
+
+bb149: ; preds = %bb148
+ br i1 undef, label %bb150, label %bb153
+
+bb150: ; preds = %bb149
+ br label %bb155
+
+bb151: ; preds = %bb145
+ unreachable
+
+bb153: ; preds = %bb158, %bb149, %bb146
+ unreachable
+
+bb155: ; preds = %bb150, %bb148
+ br i1 undef, label %bb157, label %bb156
+
+bb156: ; preds = %bb155
+ br label %bb158
+
+bb157: ; preds = %bb155
+ br label %bb158
+
+bb158: ; preds = %bb157, %bb156
+ br i1 undef, label %bb160, label %bb153
+
+bb160: ; preds = %bb158
+ br i1 undef, label %bb162, label %bb161
+
+bb161: ; preds = %bb160
+ br label %bb163
+
+bb162: ; preds = %bb160
+ br label %bb163
+
+bb163: ; preds = %bb162, %bb161
+ br i1 undef, label %bb165, label %bb164
+
+bb164: ; preds = %bb163
+ br label %bb165
+
+bb165: ; preds = %bb164, %bb163
+ br i1 undef, label %bb170, label %bb166
+
+bb166: ; preds = %bb165
+ br i1 undef, label %bb167, label %bb168
+
+bb167: ; preds = %bb166
+ unreachable
+
+bb168: ; preds = %bb166
+ unreachable
+
+bb170: ; preds = %bb165
+ br i1 undef, label %bb215, label %bb171
+
+bb171: ; preds = %bb170
+ br i1 undef, label %bb173, label %bb30
+
+bb173: ; preds = %bb171
+ br i1 undef, label %bb174, label %bb215
+
+bb174: ; preds = %bb173
+ br i1 undef, label %bb176, label %bb30
+
+bb176: ; preds = %bb174
+ br i1 undef, label %bb178, label %bb30
+
+bb178: ; preds = %bb176
+ br i1 undef, label %bb179, label %bb193
+
+bb179: ; preds = %bb178
+ br i1 undef, label %bb181, label %bb180
+
+bb180: ; preds = %bb179
+ br label %bb182
+
+bb181: ; preds = %bb179
+ br label %bb182
+
+bb182: ; preds = %bb181, %bb180
+ br i1 undef, label %bb184, label %bb30
+
+bb184: ; preds = %bb182
+ %tmp185 = call i8* @returner()
+ br i1 undef, label %bb186, label %bb195
+
+bb186: ; preds = %bb184
+ %tmp188 = call i8* @objc_retainAutoreleasedReturnValue(i8* %tmp185)
+ %tmp189 = call i8* @objc_retain(i8* %tmp188)
+ call void @objc_release(i8* %tmp189), !clang.imprecise_release !0
+ br i1 undef, label %bb197, label %bb190
+
+bb190: ; preds = %bb186
+ br i1 undef, label %bb192, label %bb195
+
+bb192: ; preds = %bb190
+ br i1 undef, label %bb197, label %bb195
+
+bb193: ; preds = %bb178
+ br label %bb213
+
+bb195: ; preds = %bb192, %bb190, %bb184
+ unreachable
+
+bb197: ; preds = %bb192, %bb186
+ br i1 undef, label %bb198, label %bb215
+
+bb198: ; preds = %bb197
+ br i1 undef, label %bb202, label %bb199
+
+bb199: ; preds = %bb198
+ br i1 undef, label %bb201, label %bb30
+
+bb201: ; preds = %bb199
+ br label %bb202
+
+bb202: ; preds = %bb201, %bb198
+ br i1 undef, label %bb206, label %bb203
+
+bb203: ; preds = %bb202
+ br i1 undef, label %bb205, label %bb30
+
+bb205: ; preds = %bb203
+ br label %bb206
+
+bb206: ; preds = %bb205, %bb202
+ br i1 undef, label %bb210, label %bb207
+
+bb207: ; preds = %bb206
+ br i1 undef, label %bb209, label %bb30
+
+bb209: ; preds = %bb207
+ br label %bb210
+
+bb210: ; preds = %bb209, %bb206
+ br i1 undef, label %bb212, label %bb30
+
+bb212: ; preds = %bb210
+ unreachable
+
+bb213: ; preds = %bb193, %bb30
+ resume { i8*, i32 } undef
+
+bb214: ; preds = %bb42
+ br label %bb219
+
+bb215: ; preds = %bb197, %bb173, %bb170, %bb141
+ br i1 undef, label %bb217, label %bb216
+
+bb216: ; preds = %bb215
+ br label %bb217
+
+bb217: ; preds = %bb216, %bb215
+ br i1 undef, label %bb219, label %bb218
+
+bb218: ; preds = %bb217
+ br label %bb219
+
+bb219: ; preds = %bb218, %bb217, %bb214
+ br i1 undef, label %bb221, label %bb220
+
+bb220: ; preds = %bb219
+ unreachable
+
+bb221: ; preds = %bb219
+ unreachable
+
+bb222: ; preds = %bb20, %bb19
+ ret void
+}
+
+
!0 = metadata !{}
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