IndependentBlocks: Do not assert for PHI nodes outside of scops

There does not seem to be a reason that we can not support PHI nodes outside of
the scop that reference values within the SCoP. Or at least, the attached test
case seems to do the right thing. We remove the assert for now.

llvm-svn: 200427

2 files changed, 36 insertions, 1 deletions

diff --git a/polly/lib/IndependentBlocks.cpp b/polly/lib/IndependentBlocks.cpp
index 44455ddb50c..fdf28baee33 100644
--- a/polly/lib/IndependentBlocks.cpp
+++ b/polly/lib/IndependentBlocks.cpp
@@ -419,7 +419,6 @@ bool IndependentBlocks::translateScalarToArray(Instruction *Inst,
 
     while (!LoadOutside.empty()) {
       Instruction *U = LoadOutside.pop_back_val();
-      assert(!isa<PHINode>(U) && "Can not handle PHI node outside!");
       SE->forgetValue(U);
       U->replaceUsesOfWith(Inst, ExitLoad);
     }
diff --git a/polly/test/IndependentBlocks/phi_outside_scop.ll b/polly/test/IndependentBlocks/phi_outside_scop.ll
new file mode 100644
index 00000000000..2172fabd80d
--- /dev/null
+++ b/polly/test/IndependentBlocks/phi_outside_scop.ll
@@ -0,0 +1,36 @@
+; RUN: opt %loadPolly -basicaa -polly-independent -S < %s | FileCheck %s
+; RUN: opt %loadPolly -basicaa -polly-independent -polly-codegen-scev -S < %s | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @phi_nodes_outside() {
+entry:
+  br label %for.i.1
+
+for.i.1:
+  %i.1 = phi i32 [ %i.1.next, %for.i.1 ], [ 0, %entry ]
+  %i.1.next = add nsw i32 %i.1, 1
+  br i1 false, label %for.i.1 , label %for.i.2.preheader
+
+for.i.2.preheader:
+  br label %for.i.2
+
+for.i.2:
+; The value of %i.1.next is used outside of the scop in a PHI node.
+  %i.2 = phi i32 [ %i.2.next , %for.i.2 ], [ %i.1.next, %for.i.2.preheader ]
+  %i.2.next = add nsw i32 %i.2, 1
+  fence seq_cst
+  br i1 false, label %for.i.2, label %cleanup
+
+cleanup:
+  ret void
+}
+
+; CHECK:  store i32 %i.1.next, i32* %i.1.next.s2a
+
+; CHECK: for.i.2.preheader:
+; CHECK:    %i.1.next.loadoutside = load i32* %i.1.next.s2a
+
+; CHECK: for.i.2:
+; CHECK:    %i.2 = phi i32 [ %i.2.next, %for.i.2 ], [ %i.1.next.loadoutside, %for.i.2.preheader ]
+