From 5c9fe816e3b6b9cdbf75758f2744a45f97c489f0 Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo@fhahn.com>
Date: Mon, 31 May 2021 20:23:43 +0100
Subject: [PATCH] [LoopDeletion] Add additional test cases with more nested
 loops.

Also remove mustprogress function attribute from one of the tests

Extends test coverage for D103382.
---
 .../LoopDeletion/noop-loops-with-subloops.ll       | 75 +++++++++++++++++++++-
 1 file changed, 73 insertions(+), 2 deletions(-)

diff --git a/llvm/test/Transforms/LoopDeletion/noop-loops-with-subloops.ll b/llvm/test/Transforms/LoopDeletion/noop-loops-with-subloops.ll
index 95a048f..23eb324 100644
--- a/llvm/test/Transforms/LoopDeletion/noop-loops-with-subloops.ll
+++ b/llvm/test/Transforms/LoopDeletion/noop-loops-with-subloops.ll
@@ -202,7 +202,7 @@ exit:
 
 ; Similar to @inner_loop_may_be_infinite, but the parent loop loop1 is marked
 ; as mustprogress. The loops can be removed.
-define void @inner_loop_may_be_infinite_but_top_loop_mustprogress(i1 %c1, i1 %c2) mustprogress {
+define void @inner_loop_may_be_infinite_but_top_loop_mustprogress(i1 %c1, i1 %c2) {
 ; CHECK-LABEL: @inner_loop_may_be_infinite_but_top_loop_mustprogress(
 ; CHECK-NEXT:    br label [[EXIT:%.*]]
 ; CHECK:       exit:
@@ -269,7 +269,7 @@ loop2:
   br i1 %c2, label %loop3, label %loop2, !llvm.loop !4
 
 loop3:
-  br i1 %c2, label %loop1.latch, label %loop3
+  br i1 %c3, label %loop1.latch, label %loop3
 
 loop1.latch:
   br i1 false, label %loop1, label %exit
@@ -278,7 +278,78 @@ exit:
   ret void
 }
 
+define void @loop2_finite_but_child_is_not(i1 %c1, i1 %c2, i1 %c3) {
+; CHECK-LABEL: @loop2_finite_but_child_is_not(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop1
+
+loop1:
+  %iv1 = phi i32 [ 0, %entry ], [ %iv1.next, %loop1.latch ]
+  br i1 %c1, label %loop1.latch, label %loop2
+
+loop2:
+  %iv = phi i32 [ 0, %loop1 ], [ %iv.next, %loop2.latch ]
+  br label %loop3
+
+loop3:
+  br i1 %c2, label %loop2.latch, label %loop3
+
+loop2.latch:
+  %iv.next = add nuw i32 %iv, 1
+  %c = icmp ugt i32 %iv, 200
+  br i1 %c, label %loop1.latch, label %loop2
+
+loop1.latch:
+  %iv1.next = add nuw i32 %iv1, 1
+  %c4 = icmp ult i32 %iv1.next, 200
+  br i1 %c4, label %loop1, label %exit
+
+exit:
+  ret void
+}
+
+define void @loop2_finite_and_child_is_mustprogress(i1 %c1, i1 %c2, i1 %c3) {
+; CHECK-LABEL: @loop2_finite_and_child_is_mustprogress(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop1
+
+loop1:
+  %iv1 = phi i32 [ 0, %entry ], [ %iv1.next, %loop1.latch ]
+  br i1 %c1, label %loop1.latch, label %loop2
+
+loop2:
+  %iv = phi i32 [ 0, %loop1 ], [ %iv.next, %loop2.latch ]
+  br label %loop3
+
+loop3:
+  br i1 %c2, label %loop2.latch, label %loop3, !llvm.loop !5
+
+loop2.latch:
+  %iv.next = add nuw i32 %iv, 1
+  %c = icmp ugt i32 %iv, 200
+  br i1 %c, label %loop1.latch, label %loop2
+
+loop1.latch:
+  %iv1.next = add nuw i32 %iv1, 1
+  %c4 = icmp ult i32 %iv1.next, 200
+  br i1 %c4, label %loop1, label %exit
+
+exit:
+  ret void
+}
+
 !1 = !{!"llvm.loop.mustprogress"}
 !2 = distinct !{!2, !1}
 !3 = distinct !{!3, !1}
 !4 = distinct !{!4, !1}
+!5 = distinct !{!5, !1}
-- 
2.7.4