[GSoC] Do not process SCoPs with infeasible runtime context

  Do not process SCoPs with infeasible runtime context in the new
  ScopInfoWrapperPass. Do not compute dependences for such SCoPs in the new
  DependenceInfoWrapperPass.

Patch by Utpal Bora <cs14mtech11017@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D22402

llvm-svn: 276631

polly/lib/Analysis/DependenceInfo.cpp

@@ -830,8 +830,10 @@ const Dependences &DependenceInfoWrapperPass::recomputeDependences(
 
 bool DependenceInfoWrapperPass::runOnFunction(Function &F) {
   auto &SI = getAnalysis<ScopInfoWrapperPass>();
-  for (auto &It : SI)
+  for (auto &It : SI) {
+    assert(It.second && "Invalid SCoP object!");
     recomputeDependences(It.second.get(), Dependences::AL_Access);
+  }
   return false;
 }
 

polly/lib/Analysis/ScopInfo.cpp

@@ -4273,8 +4273,11 @@ bool ScopInfoWrapperPass::runOnFunction(Function &F) {
       continue;
 
     ScopBuilder SB(R, AC, AA, DL, DT, LI, SD, SE);
+    std::unique_ptr<Scop> S = SB.getScop();
+    if (!S)
+      continue;
     bool Inserted =
-        RegionToScopMap.insert(std::make_pair(R, SB.getScop())).second;
+        RegionToScopMap.insert(std::make_pair(R, std::move(S))).second;
     assert(Inserted && "Building Scop for the same region twice!");
     (void)Inserted;
   }

polly/test/DependenceInfo/infeasible_context.ll

@@ -0,0 +1,69 @@
+; RUN: opt %loadPolly -polly-function-scops -analyze < %s \
+; RUN:  | FileCheck %s -check-prefix=FUNC-SCOP
+; RUN: opt %loadPolly -polly-function-dependences -analyze < %s \
+; RUN:  | FileCheck %s -check-prefix=FUNC-DEPS
+;
+; FUNC-SCOP-NOT: Statement
+; FUNC-DEPS-LABEL: Printing analysis 'Polly - Calculate dependences for all the SCoPs of a function' for function 'readgeo'
+; FUNC-DEPS-NOT: RAW dependences
+;
+; Due to an infeasible run-time check, scop object is empty and we do not compute dependences.
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+%struct.tnode.1.7.13.67.121.175.217.307.325.337.349.367.379.391.433.445.667.727.733.739 = type { i32, i32, %struct.tnode.1.7.13.67.121.175.217.307.325.337.349.367.379.391.433.445.667.727.733.739*, %struct.tnode.1.7.13.67.121.175.217.307.325.337.349.367.379.391.433.445.667.727.733.739*, %struct.tnode.1.7.13.67.121.175.217.307.325.337.349.367.379.391.433.445.667.727.733.739*, %struct.tnode.1.7.13.67.121.175.217.307.325.337.349.367.379.391.433.445.667.727.733.739*, %struct.tnode.1.7.13.67.121.175.217.307.325.337.349.367.379.391.433.445.667.727.733.739*, i32, i32, %struct.plist.0.6.12.66.120.174.216.306.324.336.348.366.378.390.432.444.666.726.732.738* }
+%struct.plist.0.6.12.66.120.174.216.306.324.336.348.366.378.390.432.444.666.726.732.738 = type { i32, %struct.plist.0.6.12.66.120.174.216.306.324.336.348.366.378.390.432.444.666.726.732.738* }
+
+@vFixedEdgeRoot = external global %struct.tnode.1.7.13.67.121.175.217.307.325.337.349.367.379.391.433.445.667.727.733.739*, align 8
+@hEdgeRoot = external global %struct.tnode.1.7.13.67.121.175.217.307.325.337.349.367.379.391.433.445.667.727.733.739*, align 8
+
+; Function Attrs: nounwind uwtable
+define void @readgeo() #0 {
+entry:
+  %vx = alloca i32, align 4
+  br label %if.end64
+
+if.end64:                                         ; preds = %entry
+  br label %for.body73
+
+for.body73:                                       ; preds = %for.inc216, %if.end64
+  %v.0101 = phi i32 [ 0, %for.inc216 ], [ 1, %if.end64 ]
+  br i1 undef, label %if.then93, label %if.else
+
+if.then93:                                        ; preds = %for.body73
+  br label %for.inc216
+
+if.else:                                          ; preds = %for.body73
+  br i1 undef, label %if.then111, label %if.end116
+
+if.then111:                                       ; preds = %if.else
+  br label %if.end116
+
+if.end116:                                        ; preds = %if.then111, %if.else
+  %rippleCount.2 = phi i32 [ 1, %if.then111 ], [ undef, %if.else ]
+  %rem11790 = and i32 %v.0101, 1
+  %cmp118 = icmp eq i32 %rem11790, 0
+  br i1 %cmp118, label %if.then120, label %if.else154
+
+if.then120:                                       ; preds = %if.end116
+  call void @tinsert()
+  br label %if.end193
+
+if.else154:                                       ; preds = %if.end116
+  call void @tinsert()
+  br label %if.end193
+
+if.end193:                                        ; preds = %if.else154, %if.then120
+  %0 = load i32, i32* %vx, align 4
+  br label %for.inc216
+
+for.inc216:                                       ; preds = %if.end193, %if.then93
+  %rippleCount.3 = phi i32 [ undef, %if.then93 ], [ %rippleCount.2, %if.end193 ]
+  %ux.2 = phi i32 [ undef, %if.then93 ], [ %0, %if.end193 ]
+  br i1 undef, label %for.body73, label %for.end218
+
+for.end218:                                       ; preds = %for.inc216
+  unreachable
+}
+
+declare void @tinsert()