--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/Transforms/IndVarSimplify/loop-invariant-conditions.ll	Tue Oct 13 17:48:58 2015 +0900
@@ -0,0 +1,279 @@
+; RUN: opt -S -indvars %s | FileCheck %s
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @test1(i64 %start) {
+; CHECK-LABEL: @test1
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %loop ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, 1
+; CHECK: %cmp1 = icmp slt i64 %start, -1
+  %cmp1 = icmp slt i64 %indvars.iv, -1
+  br i1 %cmp1, label %for.end, label %loop
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+define void @test2(i64 %start) {
+; CHECK-LABEL: @test2
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %loop ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, 1
+; CHECK: %cmp1 = icmp sle i64 %start, -1
+  %cmp1 = icmp sle i64 %indvars.iv, -1
+  br i1 %cmp1, label %for.end, label %loop
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+; As long as the test dominates the backedge, we're good
+define void @test3(i64 %start) {
+; CHECK-LABEL: @test3
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %backedge ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, 1
+  %cmp = icmp eq i64 %indvars.iv.next, 25
+  br i1 %cmp, label %backedge, label %for.end
+
+backedge:
+  ; prevent flattening, needed to make sure we're testing what we intend
+  call void @foo() 
+; CHECK: %cmp1 = icmp slt i64 %start, -1
+  %cmp1 = icmp slt i64 %indvars.iv, -1
+  br i1 %cmp1, label %for.end, label %loop
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+define void @test4(i64 %start) {
+; CHECK-LABEL: @test4
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %backedge ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, 1
+  %cmp = icmp eq i64 %indvars.iv.next, 25
+  br i1 %cmp, label %backedge, label %for.end
+
+backedge:
+  ; prevent flattening, needed to make sure we're testing what we intend
+  call void @foo() 
+; CHECK: %cmp1 = icmp sgt i64 %start, -1
+  %cmp1 = icmp sgt i64 %indvars.iv, -1
+  br i1 %cmp1, label %loop, label %for.end
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+define void @test5(i64 %start) {
+; CHECK-LABEL: @test5
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %backedge ]
+  %indvars.iv.next = add nuw i64 %indvars.iv, 1
+  %cmp = icmp eq i64 %indvars.iv.next, 25
+  br i1 %cmp, label %backedge, label %for.end
+
+backedge:
+  ; prevent flattening, needed to make sure we're testing what we intend
+  call void @foo() 
+; CHECK: %cmp1 = icmp ugt i64 %start, 100
+  %cmp1 = icmp ugt i64 %indvars.iv, 100
+  br i1 %cmp1, label %loop, label %for.end
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+define void @test6(i64 %start) {
+; CHECK-LABEL: @test6
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %backedge ]
+  %indvars.iv.next = add nuw i64 %indvars.iv, 1
+  %cmp = icmp eq i64 %indvars.iv.next, 25
+  br i1 %cmp, label %backedge, label %for.end
+
+backedge:
+  ; prevent flattening, needed to make sure we're testing what we intend
+  call void @foo() 
+; CHECK: %cmp1 = icmp ult i64 %start, 100
+  %cmp1 = icmp ult i64 %indvars.iv, 100
+  br i1 %cmp1, label %for.end, label %loop
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+define void @test7(i64 %start, i64* %inc_ptr) {
+; CHECK-LABEL: @test7
+entry:
+  %inc = load i64, i64* %inc_ptr, !range !0
+  %ok = icmp sge i64 %inc, 0
+  br i1 %ok, label %loop, label %for.end
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %loop ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, %inc
+; CHECK: %cmp1 = icmp slt i64 %start, -1
+  %cmp1 = icmp slt i64 %indvars.iv, -1
+  br i1 %cmp1, label %for.end, label %loop
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+!0 = !{i64 0, i64 100}
+
+; Negative test - we can't show that the internal branch executes, so we can't
+; fold the test to a loop invariant one.
+define void @test1_neg(i64 %start) {
+; CHECK-LABEL: @test1_neg
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %backedge ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, 1
+  %cmp = icmp eq i64 %indvars.iv.next, 25
+  br i1 %cmp, label %backedge, label %skip
+skip:
+  ; prevent flattening, needed to make sure we're testing what we intend
+  call void @foo() 
+; CHECK: %cmp1 = icmp slt i64 %indvars.iv, -1
+  %cmp1 = icmp slt i64 %indvars.iv, -1
+  br i1 %cmp1, label %for.end, label %backedge
+backedge:
+  ; prevent flattening, needed to make sure we're testing what we intend
+  call void @foo() 
+  br label %loop
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+; Slightly subtle version of @test4 where the icmp dominates the backedge,
+; but the exit branch doesn't.  
+define void @test2_neg(i64 %start) {
+; CHECK-LABEL: @test2_neg
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %backedge ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, 1
+  %cmp = icmp eq i64 %indvars.iv.next, 25
+; CHECK: %cmp1 = icmp slt i64 %indvars.iv, -1
+  %cmp1 = icmp slt i64 %indvars.iv, -1
+  br i1 %cmp, label %backedge, label %skip
+skip:
+  ; prevent flattening, needed to make sure we're testing what we intend
+  call void @foo() 
+  br i1 %cmp1, label %for.end, label %backedge
+backedge:
+  ; prevent flattening, needed to make sure we're testing what we intend
+  call void @foo() 
+  br label %loop
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+; The branch has to exit the loop if the condition is true
+define void @test3_neg(i64 %start) {
+; CHECK-LABEL: @test3_neg
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %loop ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, 1
+; CHECK: %cmp1 = icmp slt i64 %indvars.iv, -1
+  %cmp1 = icmp slt i64 %indvars.iv, -1
+  br i1 %cmp1, label %loop, label %for.end
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+define void @test4_neg(i64 %start) {
+; CHECK-LABEL: @test4_neg
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %backedge ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, 1
+  %cmp = icmp eq i64 %indvars.iv.next, 25
+  br i1 %cmp, label %backedge, label %for.end
+
+backedge:
+  ; prevent flattening, needed to make sure we're testing what we intend
+  call void @foo() 
+; CHECK: %cmp1 = icmp sgt i64 %indvars.iv, -1
+  %cmp1 = icmp sgt i64 %indvars.iv, -1
+
+; %cmp1 can be made loop invariant only if the branch below goes to
+; %the header when %cmp1 is true.
+  br i1 %cmp1, label %for.end, label %loop
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+define void @test5_neg(i64 %start, i64 %inc) {
+; CHECK-LABEL: @test5_neg
+entry:
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %loop ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, %inc
+; CHECK: %cmp1 = icmp slt i64 %indvars.iv, -1
+  %cmp1 = icmp slt i64 %indvars.iv, -1
+  br i1 %cmp1, label %for.end, label %loop
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+define void @test8(i64 %start, i64* %inc_ptr) {
+; CHECK-LABEL: @test8
+entry:
+  %inc = load i64, i64* %inc_ptr, !range !1
+  %ok = icmp sge i64 %inc, 0
+  br i1 %ok, label %loop, label %for.end
+
+loop:
+  %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %loop ]
+  %indvars.iv.next = add nsw i64 %indvars.iv, %inc
+; CHECK: %cmp1 = icmp slt i64 %indvars.iv, -1
+  %cmp1 = icmp slt i64 %indvars.iv, -1
+  br i1 %cmp1, label %for.end, label %loop
+
+for.end:                                          ; preds = %if.end, %entry
+  ret void
+}
+
+!1 = !{i64 -1, i64 100}
+
+
+declare void @foo()