1 files changed, 128 insertions, 0 deletions
diff --git a/test/Analysis/ScalarEvolution/smax-br-phi-idioms.ll b/test/Analysis/ScalarEvolution/smax-br-phi-idioms.ll
new file mode 100644
index 000000000000..500f3e16c8f5
--- /dev/null
+++ b/test/Analysis/ScalarEvolution/smax-br-phi-idioms.ll
@@ -0,0 +1,128 @@
+; RUN: opt -analyze -scalar-evolution < %s | FileCheck %s
+
+define i32 @f0(i32 %x, i32 %y) {
+; CHECK-LABEL: Classifying expressions for: @f0
+ entry:
+  %c = icmp sgt i32 %y, 0
+  br i1 %c, label %add, label %merge
+
+ add:
+  %sum = add i32 %x, %y
+  br label %merge
+
+ merge:
+  %v = phi i32 [ %sum, %add ], [ %x, %entry ]
+; CHECK:  %v = phi i32 [ %sum, %add ], [ %x, %entry ]
+; CHECK-NEXT:  -->  ((0 smax %y) + %x) U: full-set S: full-set
+  ret i32 %v
+}
+
+define i32 @f1(i32 %x, i32 %y) {
+; CHECK-LABEL: Classifying expressions for: @f1
+ entry:
+  %c = icmp sge i32 %y, 0
+  br i1 %c, label %add, label %merge
+
+ add:
+  %sum = add i32 %x, %y
+  br label %merge
+
+ merge:
+  %v = phi i32 [ %sum, %add ], [ %x, %entry ]
+; CHECK:  %v = phi i32 [ %sum, %add ], [ %x, %entry ]
+; CHECK-NEXT:  -->  ((0 smax %y) + %x) U: full-set S: full-set
+  ret i32 %v
+}
+
+define i32 @f2(i32 %x, i32 %y, i32* %ptr) {
+; CHECK-LABEL: Classifying expressions for: @f2
+ entry:
+  %c = icmp sge i32 %y, 0
+  br i1 %c, label %add, label %merge
+
+ add:
+  %lv = load i32, i32* %ptr
+  br label %merge
+
+ merge:
+  %v = phi i32 [ %lv, %add ], [ %x, %entry ]
+; CHECK:  %v = phi i32 [ %lv, %add ], [ %x, %entry ]
+; CHECK-NEXT:  -->  %v U: full-set S: full-set
+  ret i32 %v
+}
+
+define i32 @f3(i32 %x, i32 %init, i32 %lim) {
+; CHECK-LABEL: Classifying expressions for: @f3
+ entry:
+  br label %loop
+
+loop:
+  %iv = phi i32 [ %init, %entry ], [ %iv.inc, %merge ]
+  %iv.inc = add i32 %iv, 1
+  %c = icmp sge i32 %iv, 0
+  br i1 %c, label %add, label %merge
+
+ add:
+  %sum = add i32 %x, %iv
+  br label %merge
+
+ merge:
+  %v = phi i32 [ %sum, %add ], [ %x, %loop ]
+; CHECK:  %v = phi i32 [ %sum, %add ], [ %x, %loop ]
+; CHECK-NEXT:  -->  ((0 smax {%init,+,1}<%loop>) + %x) U: full-set S: full-set
+  %be.cond = icmp eq i32 %iv.inc, %lim
+  br i1 %be.cond, label %loop, label %leave
+
+ leave:
+  ret i32 0
+}
+
+define i32 @f4(i32 %x, i32 %init, i32 %lim) {
+; CHECK-LABEL: Classifying expressions for: @f4
+ entry:
+  %c = icmp sge i32 %init, 0
+  br i1 %c, label %add, label %merge
+
+ add:
+  br label %loop
+
+ loop:
+  %iv = phi i32 [ %init, %add ], [ %iv.inc, %loop ]
+  %iv.inc = add i32 %iv, 1
+  %be.cond = icmp eq i32 %iv.inc, %lim
+  br i1 %be.cond, label %loop, label %add.cont
+
+ add.cont:
+  %sum = add i32 %x, %iv
+  br label %merge
+
+ merge:
+  %v = phi i32 [ %sum, %add.cont ], [ %x, %entry ]
+; CHECK:  %v = phi i32 [ %sum, %add.cont ], [ %x, %entry ]
+; CHECK-NEXT:  -->  %v U: full-set S: full-set
+  ret i32 %v
+}
+
+define i32 @f5(i32* %val) {
+; CHECK-LABEL: Classifying expressions for: @f5
+entry:
+  br label %for.end
+
+for.condt:
+  br i1 true, label %for.cond.0, label %for.end
+
+for.end:
+  %inc = load i32, i32* %val
+  br i1 false, label %for.condt, label %for.cond.0
+
+for.cond.0:
+  %init = phi i32 [ 0, %for.condt ], [ %inc, %for.end ]
+
+; CHECK:  %init = phi i32 [ 0, %for.condt ], [ %inc, %for.end ]
+; CHECK-NEXT:  -->  %init U: full-set S: full-set
+
+; Matching "through" %init will break LCSSA at the SCEV expression
+; level.
+
+  ret i32 %init
+}