[FIX] Special case for branch users of scalar values

llvm-svn: 228832

polly/lib/Analysis/TempScopInfo.cpp

@@ -158,6 +158,12 @@ bool TempScopInfo::buildScalarDependences(Instruction *Inst, Region *R) {
     if (UI == 0)
       continue;
 
+    // Ignore branches as the can only use a synthesizable condition.
+    if (isa<BranchInst>(UI)) {
+      assert(canSynthesizeInst && "Branch condition was not synthesizable.");
+      continue;
+    }
+
     BasicBlock *UseParent = UI->getParent();
 
     // Ignore the users in the same BB (statement)

polly/test/ScopInfo/scalar_dependence_cond_br.ll

@@ -0,0 +1,42 @@
+; RUN: opt %loadPolly -polly-scops -disable-polly-intra-scop-scalar-to-array -polly-model-phi-nodes -analyze < %s | FileCheck %s
+;
+; CHECK: Statements
+;
+;    void f(int *A, int c, int d) {
+;      for (int i = 0; i < 1024; i++)
+;        if (c < i)
+;          A[i]++;
+;    }
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @f(i32* %A, i64 %c) {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
+  %exitcond = icmp ne i64 %indvars.iv, 1024
+  %cmp1 = icmp slt i64 %c, %indvars.iv
+  br i1 %exitcond, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  br i1 %cmp1, label %if.then, label %if.end
+
+if.then:                                          ; preds = %for.body
+  %arrayidx = getelementptr inbounds i32* %A, i64 %indvars.iv
+  %tmp = load i32* %arrayidx, align 4
+  %inc = add nsw i32 %tmp, 1
+  store i32 %inc, i32* %arrayidx, align 4
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %for.body
+  br label %for.inc
+
+for.inc:                                          ; preds = %if.end
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  ret void
+}