Index: lib/Analysis/ScopInfo.cpp
===================================================================
--- lib/Analysis/ScopInfo.cpp
+++ lib/Analysis/ScopInfo.cpp
@@ -24,6 +24,7 @@
 #include "polly/ScopDetection.h"
 #include "polly/Support/GICHelper.h"
 #include "polly/Support/ISLOStream.h"
+#include "polly/Support/ISLTools.h"
 #include "polly/Support/SCEVAffinator.h"
 #include "polly/Support/SCEVValidator.h"
 #include "polly/Support/ScopHelper.h"
@@ -2311,9 +2312,10 @@
   isl::ctx Ctx = Set.get_ctx();
 
   Set = Set.remove_divs();
+  polly::simplify(Set);
 
-  if (isl_set_n_basic_set(Set.get()) >= MaxDisjunctsInDomain)
-    return isl::stat::error;
+  if (isl_set_n_basic_set(Set.get()) > RunTimeChecksMaxAccessDisjuncts)
+    Set = Set.simple_hull();
 
   // Restrict the number of parameters involved in the access as the lexmin/
   // lexmax computation will take too long if this number is high.
@@ -2339,15 +2341,9 @@
       return isl::stat::error;
   }
 
-  if (isl_set_n_basic_set(Set.get()) > RunTimeChecksMaxAccessDisjuncts)
-    return isl::stat::error;
-
   MinPMA = Set.lexmin_pw_multi_aff();
   MaxPMA = Set.lexmax_pw_multi_aff();
 
-  if (isl_ctx_last_error(Ctx.get()) == isl_error_quota)
-    return isl::stat::error;
-
   MinPMA = MinPMA.coalesce();
   MaxPMA = MaxPMA.coalesce();
 
@@ -2355,7 +2351,9 @@
   // enclose the accessed memory region by MinPMA and MaxPMA. The pointer
   // we test during code generation might now point after the end of the
   // allocated array but we will never dereference it anyway.
-  assert(MaxPMA.dim(isl::dim::out) && "Assumed at least one output dimension");
+  assert((!MaxPMA || MaxPMA.dim(isl::dim::out)) &&
+         "Assumed at least one output dimension");
+
   Pos = MaxPMA.dim(isl::dim::out) - 1;
   LastDimAff = MaxPMA.get_pw_aff(Pos);
   OneAff = isl::aff(isl::local_space(LastDimAff.get_domain_space()));
@@ -2363,6 +2361,9 @@
   LastDimAff = LastDimAff.add(OneAff);
   MaxPMA = MaxPMA.set_pw_aff(Pos, LastDimAff);
 
+  if (!MinPMA || !MaxPMA)
+    return isl::stat::error;
+
   MinMaxAccesses.push_back(std::make_pair(MinPMA, MaxPMA));
 
   return isl::stat::ok;
@@ -2387,8 +2388,6 @@
 
   Accesses = Accesses.intersect_domain(Domains);
   isl::union_set Locations = Accesses.range();
-  Locations = Locations.coalesce();
-  Locations = Locations.detect_equalities();
 
   auto Lambda = [&MinMaxAccesses, &S](isl::set Set) -> isl::stat {
     return buildMinMaxAccess(Set, MinMaxAccesses, S);
Index: test/ScopInfo/run-time-check-many-piecewise-aliasing.ll
===================================================================
--- /dev/null
+++ test/ScopInfo/run-time-check-many-piecewise-aliasing.ll
@@ -0,0 +1,109 @@
+; RUN: opt %loadPolly -polly-detect -analyze < %s \
+; RUN: | FileCheck %s -check-prefix=DETECT
+; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
+;
+; DETECT: Valid Region for Scop: for => return
+; 
+; Check that this SCoP is allowed, even though the number of disjunct memory accesses of A
+; is 11, greater than RunTimeChecksMaxAccessDisjuncts.
+;
+; CHECK: Function: func
+; CHECK-NEXT: Region: %for---%return
+
+define void @func(i64 %n, double* nonnull %A, double * nonnull %B, i64 %d) {
+entry:
+	  br label %for
+for:
+  %j = phi i64 [0, %entry], [%j.inc, %inc]
+  %j.cmp = icmp slt i64 %j, %n
+  br i1 %j.cmp, label %body, label %exit
+
+body:
+      %add.i.i = add nsw i64 1, %j
+      %sub.i.i = sub nsw i64 %add.i.i, 1
+      %cmp.i.i.i = icmp sgt i64 %sub.i.i, 0
+      %cond.i.i.i = select i1 %cmp.i.i.i, i64 %sub.i.i, i64 0
+      %mul.i.i = mul nsw i64 %cond.i.i.i, 7
+      %sub1.i.i = sub nsw i64 1, %j
+      %add2.i.i = add nsw i64 %sub1.i.i, 1
+      %cmp.i8.i.i = icmp sgt i64 %add2.i.i, 0
+      %cond.i11.i.i = select i1 %cmp.i8.i.i, i64 %add2.i.i, i64 0
+      %mul4.i.i = mul nsw i64 %cond.i11.i.i, 7
+      %add5.i.i = add nsw i64 %mul.i.i, %mul4.i.i
+      %add.i113.i = add nsw i64 1, %j
+      %sub.i114.i = sub nsw i64 %add.i113.i, 3
+      %cmp.i.i115.i = icmp sgt i64 %sub.i114.i, 0
+      %cond.i.i118.i = select i1 %cmp.i.i115.i, i64 %sub.i114.i, i64 0
+      %mul.i119.i = mul nsw i64 %cond.i.i118.i, 9
+      %sub1.i120.i = sub nsw i64 1, %j
+      %add2.i121.i = add nsw i64 %sub1.i120.i, 3
+      %cmp.i8.i122.i = icmp sgt i64 %add2.i121.i, 0
+      %cond.i11.i126.i = select i1 %cmp.i8.i122.i, i64 %add2.i121.i, i64 0
+      %mul4.i127.i = mul nsw i64 %cond.i11.i126.i, 9
+      %add5.i128.i = add nsw i64 %mul.i119.i, %mul4.i127.i
+      %add.i = add nsw i64 %add5.i.i, %add5.i128.i
+      %add.i89.i = add nsw i64 1, %j
+      %sub.i90.i = sub nsw i64 %add.i89.i, 4
+      %cmp.i.i91.i = icmp sgt i64 %sub.i90.i, 0
+      %cond.i.i94.i = select i1 %cmp.i.i91.i, i64 %sub.i90.i, i64 0
+      %mul.i95.i = mul nsw i64 %cond.i.i94.i, 11
+      %sub1.i96.i = sub nsw i64 1, %j
+      %add2.i97.i = add nsw i64 %sub1.i96.i, 4
+      %cmp.i8.i98.i = icmp sgt i64 %add2.i97.i, 0
+      %cond.i11.i102.i = select i1 %cmp.i8.i98.i, i64 %add2.i97.i, i64 0
+      %mul4.i103.i = mul nsw i64 %cond.i11.i102.i, 11
+      %add5.i104.i = add nsw i64 %mul.i95.i, %mul4.i103.i
+      %add3.i = add nsw i64 %add.i, %add5.i104.i
+      %add.i65.i = add nsw i64 1, %j
+      %sub.i66.i = sub nsw i64 %add.i65.i, 6
+      %cmp.i.i67.i = icmp sgt i64 %sub.i66.i, 0
+      %cond.i.i70.i = select i1 %cmp.i.i67.i, i64 %sub.i66.i, i64 0
+      %mul.i71.i = mul nsw i64 %cond.i.i70.i, 13
+      %sub1.i72.i = sub nsw i64 1, %j
+      %add2.i73.i = add nsw i64 %sub1.i72.i, 6
+      %cmp.i8.i74.i = icmp sgt i64 %add2.i73.i, 0
+      %cond.i11.i78.i = select i1 %cmp.i8.i74.i, i64 %add2.i73.i, i64 0
+      %mul4.i79.i = mul nsw i64 %cond.i11.i78.i, 13
+      %add5.i80.i = add nsw i64 %mul.i71.i, %mul4.i79.i
+      %add5.i = add nsw i64 %add3.i, %add5.i80.i
+      %add.i41.i = add nsw i64 1, %j
+      %sub.i42.i = sub nsw i64 %add.i41.i, 8
+      %cmp.i.i43.i = icmp sgt i64 %sub.i42.i, 0
+      %cond.i.i46.i = select i1 %cmp.i.i43.i, i64 %sub.i42.i, i64 0
+      %mul.i47.i = mul nsw i64 %cond.i.i46.i, 17
+      %sub1.i48.i = sub nsw i64 1, %j
+      %add2.i49.i = add nsw i64 %sub1.i48.i, 8
+      %cmp.i8.i50.i = icmp sgt i64 %add2.i49.i, 0
+      %cond.i11.i54.i = select i1 %cmp.i8.i50.i, i64 %add2.i49.i, i64 0
+      %mul4.i55.i = mul nsw i64 %cond.i11.i54.i, 17
+      %add5.i56.i = add nsw i64 %mul.i47.i, %mul4.i55.i
+      %add7.i = add nsw i64 %add5.i, %add5.i56.i
+      %add.i17.i = add nsw i64 1, %j
+      %sub.i18.i = sub nsw i64 %add.i17.i, 10
+      %cmp.i.i19.i = icmp sgt i64 %sub.i18.i, 0
+      %cond.i.i22.i = select i1 %cmp.i.i19.i, i64 %sub.i18.i, i64 0
+      %mul.i23.i = mul nsw i64 %cond.i.i22.i, 19
+      %sub1.i24.i = sub nsw i64 1, %j
+      %add2.i25.i = add nsw i64 %sub1.i24.i, 10
+      %cmp.i8.i26.i = icmp sgt i64 %add2.i25.i, 0
+      %cond.i11.i30.i = select i1 %cmp.i8.i26.i, i64 %add2.i25.i, i64 0
+      %mul4.i31.i = mul nsw i64 %cond.i11.i30.i, 19
+      %add5.i32.i = add nsw i64 %mul.i23.i, %mul4.i31.i
+      %idxprom = add nsw i64 %add7.i, %add5.i32.i
+
+      %A_idx = getelementptr inbounds double, double* %A, i64 %idxprom
+      %val = load double, double* %A_idx
+      %B_idx = getelementptr inbounds double, double* %B, i64 %j
+      store double %val, double* %B_idx
+      br label %inc
+
+inc:
+	%j.inc = add nuw nsw i64 %j, 1
+	br label %for
+
+exit:
+	br label %return
+return:
+	ret void
+}
+