[FIX] Only constant integer branch conditions are always affine

There are several different kinds of constants that could occur in a
  branch condition, however we can only handle the most interesting one
  namely constant integers. To this end we have to treat others as
  non-affine.

  This fixes bug 25244.

llvm-svn: 250669

polly/lib/Analysis/ScopDetection.cpp

@@ -421,8 +421,8 @@ bool ScopDetection::isValidCFG(BasicBlock &BB, bool IsLoopBranch,
   if (isa<UndefValue>(Condition))
     return invalid<ReportUndefCond>(Context, /*Assert=*/true, TI, &BB);
 
-  // Constant conditions are always affine.
-  if (isa<Constant>(Condition))
+  // Constant integer conditions are always affine.
+  if (isa<ConstantInt>(Condition))
     return true;
 
   if (BranchInst *BI = dyn_cast<BranchInst>(TI))

polly/test/ScopInfo/constant-non-integer-branch-condition.ll

@@ -0,0 +1,27 @@
+; RUN: opt %loadPolly -analyze -polly-scops %s | FileCheck %s
+;
+; At some point this caused a problem in the domain generation as we
+; assumed any constant branch condition to be valid. However, only constant
+; integers are interesting and can be handled.
+;
+; CHECK: Stmt_entry_split__TO__cleanup
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+; Function Attrs: nounwind uwtable
+define i32 @main(i32* %A) #0 {
+entry:
+  br label %entry.split
+
+entry.split:                                      ; preds = %entry
+  br i1 icmp ne (i32 (...)* @test_weak, i32 (...)* null), label %if.then, label %cleanup
+
+if.then:                                          ; preds = %entry.split
+  store i32 0, i32* %A
+  br label %cleanup
+
+cleanup:                                          ; preds = %if.then, %entry.split
+  ret i32 0
+}
+
+declare extern_weak i32 @test_weak(...)