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-rw-r--r--polly/lib/Analysis/ScopDetection.cpp8
-rw-r--r--polly/lib/Analysis/ScopInfo.cpp27
-rw-r--r--polly/test/ScopInfo/schedule-constuction-endless-loop1.ll34
-rw-r--r--polly/test/ScopInfo/schedule-constuction-endless-loop2.ll37
-rw-r--r--polly/test/ScopInfo/two-loops-one-infinite.ll12
5 files changed, 103 insertions, 15 deletions
diff --git a/polly/lib/Analysis/ScopDetection.cpp b/polly/lib/Analysis/ScopDetection.cpp
index 594d656a284..c0dba128beb 100644
--- a/polly/lib/Analysis/ScopDetection.cpp
+++ b/polly/lib/Analysis/ScopDetection.cpp
@@ -1029,8 +1029,14 @@ bool ScopDetection::canUseISLTripCount(Loop *L,
// Ensure the loop has valid exiting blocks as well as latches, otherwise we
// need to overapproximate it as a boxed loop.
SmallVector<BasicBlock *, 4> LoopControlBlocks;
- L->getLoopLatches(LoopControlBlocks);
L->getExitingBlocks(LoopControlBlocks);
+
+ // Loops without exiting blocks cannot be handled by the schedule generation
+ // as it depends on a region covering that is not given.
+ if (LoopControlBlocks.empty())
+ return false;
+
+ L->getLoopLatches(LoopControlBlocks);
for (BasicBlock *ControlBB : LoopControlBlocks) {
if (!isValidCFG(*ControlBB, true, false, Context))
return false;
diff --git a/polly/lib/Analysis/ScopInfo.cpp b/polly/lib/Analysis/ScopInfo.cpp
index b61d9fa81d7..f3271c20334 100644
--- a/polly/lib/Analysis/ScopInfo.cpp
+++ b/polly/lib/Analysis/ScopInfo.cpp
@@ -3618,8 +3618,15 @@ void Scop::buildSchedule(ScopDetection &SD, LoopInfo &LI) {
Loop *L = getLoopSurroundingRegion(getRegion(), LI);
LoopStackTy LoopStack({LoopStackElementTy(L, nullptr, 0)});
buildSchedule(getRegion().getNode(), LoopStack, SD, LI);
- assert(LoopStack.size() == 1 && LoopStack.back().L == L);
- Schedule = LoopStack[0].Schedule;
+ assert(!LoopStack.empty());
+ if (LoopStack.size() == 1 && LoopStack.back().L == L) {
+ Schedule = LoopStack[0].Schedule;
+ } else {
+ // If something went wrong we have to cleanup.
+ assert(!hasFeasibleRuntimeContext());
+ while (!LoopStack.empty())
+ isl_schedule_free(LoopStack.pop_back_val().Schedule);
+ }
}
/// To generate a schedule for the elements in a Region we traverse the Region
@@ -3662,9 +3669,22 @@ void Scop::buildSchedule(Region *R, LoopStackTy &LoopStack, ScopDetection &SD,
// iterator. If it is set we have to explore the next sub-region/block from
// the iterator (if any) to guarantee progress. If it is not set we first try
// the next queued sub-region/blocks.
+ unsigned RemainingWork = WorkList.size() + DelayList.size() + 1;
while (!WorkList.empty() || !DelayList.empty()) {
+ Loop *LastLoop = LoopStack.back().L;
RegionNode *RN;
+ // FIXME: We will bail out if we cannot make progress. So far that is only
+ // known to happen in the presence of infinite loops without an exit
+ // edge. For such cases there is no region covering only the loop and
+ // our reasoning fails.
+ if (WorkList.size() + DelayList.size() >= RemainingWork) {
+ invalidate(INFINITELOOP, R->getEntry()->getTerminator()->getDebugLoc());
+ LastLoop = nullptr;
+ }
+
+ RemainingWork = WorkList.size() + DelayList.size();
+
if ((LastRNWaiting && !WorkList.empty()) || DelayList.size() == 0) {
RN = WorkList.front();
WorkList.pop_front();
@@ -3678,9 +3698,8 @@ void Scop::buildSchedule(Region *R, LoopStackTy &LoopStack, ScopDetection &SD,
if (!getRegion().contains(L))
L = OuterScopLoop;
- Loop *LastLoop = LoopStack.back().L;
if (LastLoop != L) {
- if (!LastLoop->contains(L)) {
+ if (LastLoop && !LastLoop->contains(L)) {
LastRNWaiting = true;
DelayList.push_back(RN);
continue;
diff --git a/polly/test/ScopInfo/schedule-constuction-endless-loop1.ll b/polly/test/ScopInfo/schedule-constuction-endless-loop1.ll
new file mode 100644
index 00000000000..50af71bb2fe
--- /dev/null
+++ b/polly/test/ScopInfo/schedule-constuction-endless-loop1.ll
@@ -0,0 +1,34 @@
+; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
+;
+; Check that we do not build a SCoP and do not crash.
+;
+; CHECK-NOT: Statements
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+; Function Attrs: nounwind uwtable
+define void @int_upsample(i32* %A) {
+entry:
+ %0 = load i8, i8* undef, align 1
+ %conv7 = zext i8 %0 to i32
+ br label %while.body.preheader
+
+while.body.preheader: ; preds = %entry
+ br label %while.body
+
+while.body: ; preds = %if.end, %while.body.preheader
+ %outrow.036 = phi i32 [ %add23, %if.end ], [ 0, %while.body.preheader ]
+ br i1 true, label %if.end, label %while.body16
+
+while.body16: ; preds = %while.body16, %while.body
+ br label %while.body16
+
+if.end: ; preds = %while.body
+ store i32 0, i32* %A
+ %add23 = add nuw nsw i32 %outrow.036, 1
+ %cmp = icmp slt i32 %add23, 0
+ br i1 %cmp, label %while.body, label %while.end24
+
+while.end24: ; preds = %if.end
+ ret void
+}
diff --git a/polly/test/ScopInfo/schedule-constuction-endless-loop2.ll b/polly/test/ScopInfo/schedule-constuction-endless-loop2.ll
new file mode 100644
index 00000000000..d190ddd6321
--- /dev/null
+++ b/polly/test/ScopInfo/schedule-constuction-endless-loop2.ll
@@ -0,0 +1,37 @@
+; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
+;
+; Check that we do not build a SCoP and do not crash.
+;
+; CHECK-NOT: Statements
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+; Function Attrs: nounwind uwtable
+define void @int_upsample(i32* %A) {
+entry:
+ %0 = load i8, i8* undef, align 1
+ %conv7 = zext i8 %0 to i32
+ br label %while.body.preheader
+
+while.body.preheader: ; preds = %entry
+ br label %while.body
+
+while.body: ; preds = %if.end, %while.body.preheader
+ %outrow.036 = phi i32 [ %add23, %if.end ], [ 0, %while.body.preheader ]
+ br i1 true, label %if.end, label %while.body16
+
+while.body16: ; preds = %while.body16, %while.body
+ br label %while.body16.split
+
+while.body16.split:
+ br label %while.body16
+
+if.end: ; preds = %while.body
+ store i32 0, i32* %A
+ %add23 = add nuw nsw i32 %outrow.036, 1
+ %cmp = icmp slt i32 %add23, 0
+ br i1 %cmp, label %while.body, label %while.end24
+
+while.end24: ; preds = %if.end
+ ret void
+}
diff --git a/polly/test/ScopInfo/two-loops-one-infinite.ll b/polly/test/ScopInfo/two-loops-one-infinite.ll
index 21a4f4ec413..974194f04ca 100644
--- a/polly/test/ScopInfo/two-loops-one-infinite.ll
+++ b/polly/test/ScopInfo/two-loops-one-infinite.ll
@@ -1,16 +1,8 @@
; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
;
-; Verify we detect and create the SCoP correctly
+; Verify we do not create a SCoP in the presence of infinite loops.
;
-; CHECK: Statements {
-; CHECK-NEXT: Stmt_while_body_us
-; CHECK-NEXT: Domain :=
-; CHECK-NEXT: [a13] -> { Stmt_while_body_us[] };
-; CHECK-NEXT: Schedule :=
-; CHECK-NEXT: [a13] -> { Stmt_while_body_us[] -> [] };
-; CHECK-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
-; CHECK-NEXT: [a13] -> { Stmt_while_body_us[] -> MemRef_uuu[] };
-; CHECK-NEXT: }
+; CHECK-NOT: Statements
;
target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n8:16:32-S64"
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