[LoopUnroll] Add a test case for rG7873376bb36b.

rG7873376bb36b fixes a build failure for allyesconfig.

The problem happened when the single exiting block doesn't dominate the
loop latch, then the immediate dominator of the exit block should not be
the exiting block after unrolling. As the exiting block of
different unrolled iteration can branch to the exit block, and the ith
exiting block doesn't dominate (i+1)th exiting block, the immediate
dominator of the exit block should not the nearest common dominator of
the exiting block and the loop latch of the same iteration.

Differential Revision: https://reviews.llvm.org/D80477

diff --git a/llvm/test/Transforms/LoopUnroll/nonlatchcondbr.ll b/llvm/test/Transforms/LoopUnroll/nonlatchcondbr.ll
index 547b05d..351f3fa 100644 (file)
--- a/llvm/test/Transforms/LoopUnroll/nonlatchcondbr.ll
+++ b/llvm/test/Transforms/LoopUnroll/nonlatchcondbr.ll
@@ -1,9 +1,12 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -loop-unroll -S | FileCheck %s
-; RUN: opt < %s -passes='require<opt-remark-emit>,unroll' -S | FileCheck %s
+; RUN: opt < %s -loop-unroll -unroll-runtime -unroll-count=4 -S | FileCheck %s
+; RUN: opt < %s -passes='require<opt-remark-emit>,unroll' -unroll-runtime -unroll-count=4 -S | FileCheck %s
 
-define void @foo(i32* noalias %A) {
-; CHECK-LABEL: @foo(
+; Check that loop unroll pass correctly handle loops with
+; single exiting block not the loop header or latch.
+
+define void @test1(i32* noalias %A) {
+; CHECK-LABEL: @test1(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* [[A:%.*]], align 4
 ; CHECK-NEXT:    call void @bar(i32 [[TMP0]])
@@ -66,4 +69,91 @@ for.end:
   ret void
 }
 
+; Check that loop unroll pass correctly handle loops with
+; (1) exiting block not dominating the loop latch; and
+; (2) exiting terminator instructions cannot be simplified to unconditional.
+
+define void @test2(i32* noalias %A) {
+; CHECK-LABEL: @test2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br i1 true, label [[FOR_PREHEADER:%.*]], label [[FOR_END:%.*]]
+; CHECK:       for.preheader:
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* [[A:%.*]], align 4
+; CHECK-NEXT:    call void @bar(i32 [[TMP0]])
+; CHECK-NEXT:    br label [[FOR_HEADER:%.*]]
+; CHECK:       for.header:
+; CHECK-NEXT:    [[TMP1:%.*]] = phi i32 [ [[TMP0]], [[FOR_PREHEADER]] ], [ [[DOTPRE_3:%.*]], [[FOR_BODY_FOR_BODY_CRIT_EDGE_3:%.*]] ]
+; CHECK-NEXT:    [[I:%.*]] = phi i64 [ 0, [[FOR_PREHEADER]] ], [ [[INC_3:%.*]], [[FOR_BODY_FOR_BODY_CRIT_EDGE_3]] ]
+; CHECK-NEXT:    call void @bar(i32 [[TMP1]])
+; CHECK-NEXT:    [[INC:%.*]] = add nuw nsw i64 [[I]], 1
+; CHECK-NEXT:    br i1 true, label [[FOR_BODY:%.*]], label [[FOR_BODY_FOR_BODY_CRIT_EDGE:%.*]]
+; CHECK:       for.body:
+; CHECK-NEXT:    [[CMP:%.*]] = call i1 @foo(i64 [[I]])
+; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY_FOR_BODY_CRIT_EDGE]], label [[FOR_END_LOOPEXIT:%.*]]
+; CHECK:       for.body.for.body_crit_edge:
+; CHECK-NEXT:    [[ARRAYIDX_PHI_TRANS_INSERT:%.*]] = getelementptr inbounds i32, i32* [[A]], i64 [[INC]]
+; CHECK-NEXT:    [[DOTPRE:%.*]] = load i32, i32* [[ARRAYIDX_PHI_TRANS_INSERT]], align 4
+; CHECK-NEXT:    call void @bar(i32 [[DOTPRE]])
+; CHECK-NEXT:    [[INC_1:%.*]] = add nuw nsw i64 [[INC]], 1
+; CHECK-NEXT:    br i1 true, label [[FOR_BODY_1:%.*]], label [[FOR_BODY_FOR_BODY_CRIT_EDGE_1:%.*]]
+; CHECK:       for.end.loopexit:
+; CHECK-NEXT:    br label [[FOR_END]]
+; CHECK:       for.end:
+; CHECK-NEXT:    ret void
+; CHECK:       for.body.1:
+; CHECK-NEXT:    [[CMP_1:%.*]] = call i1 @foo(i64 [[INC]])
+; CHECK-NEXT:    br i1 [[CMP_1]], label [[FOR_BODY_FOR_BODY_CRIT_EDGE_1]], label [[FOR_END_LOOPEXIT]]
+; CHECK:       for.body.for.body_crit_edge.1:
+; CHECK-NEXT:    [[ARRAYIDX_PHI_TRANS_INSERT_1:%.*]] = getelementptr inbounds i32, i32* [[A]], i64 [[INC_1]]
+; CHECK-NEXT:    [[DOTPRE_1:%.*]] = load i32, i32* [[ARRAYIDX_PHI_TRANS_INSERT_1]], align 4
+; CHECK-NEXT:    call void @bar(i32 [[DOTPRE_1]])
+; CHECK-NEXT:    [[INC_2:%.*]] = add nuw nsw i64 [[INC_1]], 1
+; CHECK-NEXT:    br i1 true, label [[FOR_BODY_2:%.*]], label [[FOR_BODY_FOR_BODY_CRIT_EDGE_2:%.*]]
+; CHECK:       for.body.2:
+; CHECK-NEXT:    [[CMP_2:%.*]] = call i1 @foo(i64 [[INC_1]])
+; CHECK-NEXT:    br i1 [[CMP_2]], label [[FOR_BODY_FOR_BODY_CRIT_EDGE_2]], label [[FOR_END_LOOPEXIT]]
+; CHECK:       for.body.for.body_crit_edge.2:
+; CHECK-NEXT:    [[ARRAYIDX_PHI_TRANS_INSERT_2:%.*]] = getelementptr inbounds i32, i32* [[A]], i64 [[INC_2]]
+; CHECK-NEXT:    [[DOTPRE_2:%.*]] = load i32, i32* [[ARRAYIDX_PHI_TRANS_INSERT_2]], align 4
+; CHECK-NEXT:    call void @bar(i32 [[DOTPRE_2]])
+; CHECK-NEXT:    [[INC_3]] = add nsw i64 [[INC_2]], 1
+; CHECK-NEXT:    br i1 true, label [[FOR_BODY_3:%.*]], label [[FOR_BODY_FOR_BODY_CRIT_EDGE_3]]
+; CHECK:       for.body.3:
+; CHECK-NEXT:    [[CMP_3:%.*]] = call i1 @foo(i64 [[INC_2]])
+; CHECK-NEXT:    br i1 [[CMP_3]], label [[FOR_BODY_FOR_BODY_CRIT_EDGE_3]], label [[FOR_END_LOOPEXIT]]
+; CHECK:       for.body.for.body_crit_edge.3:
+; CHECK-NEXT:    [[ARRAYIDX_PHI_TRANS_INSERT_3:%.*]] = getelementptr inbounds i32, i32* [[A]], i64 [[INC_3]]
+; CHECK-NEXT:    [[DOTPRE_3]] = load i32, i32* [[ARRAYIDX_PHI_TRANS_INSERT_3]], align 4
+; CHECK-NEXT:    br label [[FOR_HEADER]], !llvm.loop !0
+;
+entry:
+  br i1 true, label %for.preheader, label %for.end
+
+for.preheader:
+  %0 = load i32, i32* %A, align 4
+  call void @bar(i32 %0)
+  br label %for.header
+
+for.header:
+  %1 = phi i32 [ %0, %for.preheader ], [ %.pre, %for.body.for.body_crit_edge ]
+  %i = phi i64 [ 0, %for.preheader ], [ %inc, %for.body.for.body_crit_edge ]
+  %arrayidx = getelementptr inbounds i32, i32* %A, i64 %i
+  call void @bar(i32 %1)
+  %inc = add nsw i64 %i, 1
+  br i1 true, label %for.body, label %for.body.for.body_crit_edge
+
+for.body:
+  %cmp = call i1 @foo(i64 %i)
+  br i1 %cmp, label %for.body.for.body_crit_edge, label %for.end
+
+for.body.for.body_crit_edge:
+  %arrayidx.phi.trans.insert = getelementptr inbounds i32, i32* %A, i64 %inc
+  %.pre = load i32, i32* %arrayidx.phi.trans.insert, align 4
+  br label %for.header
+
+for.end:
+  ret void
+}
+
 declare void @bar(i32)
+declare i1 @foo(i64)