Remove LoopID metadata from the branch instruction

that follows the peeled iterations.

Differential Revision: https://reviews.llvm.org/D52176

llvm-svn: 343054

3 files changed, 62 insertions, 16 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopUnrollPeel.cpp b/llvm/lib/Transforms/Utils/LoopUnrollPeel.cpp
index 78afe748e59..86ac1a71d5e 100644
--- a/llvm/lib/Transforms/Utils/LoopUnrollPeel.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnrollPeel.cpp
@@ -618,8 +618,12 @@ bool llvm::peelLoop(Loop *L, unsigned PeelCount, LoopInfo *LI,
       assert(DT->verify(DominatorTree::VerificationLevel::Fast));
     }
 
-    updateBranchWeights(InsertBot, cast<BranchInst>(VMap[LatchBR]), Iter,
+    auto *LatchBRCopy = cast<BranchInst>(VMap[LatchBR]);
+    updateBranchWeights(InsertBot, LatchBRCopy, Iter,
                         PeelCount, ExitWeight);
+    // Remove Loop metadata from the latch branch instruction
+    // because it is not the Loop's latch branch anymore.
+    LatchBRCopy->setMetadata(LLVMContext::MD_loop, nullptr);
 
     InsertTop = InsertBot;
     InsertBot = SplitBlock(InsertBot, InsertBot->getTerminator(), DT, LI);
diff --git a/llvm/test/Transforms/LoopUnroll/peel-loop-conditions.ll b/llvm/test/Transforms/LoopUnroll/peel-loop-conditions.ll
index 98570c01d70..a9937d9db99 100644
--- a/llvm/test/Transforms/LoopUnroll/peel-loop-conditions.ll
+++ b/llvm/test/Transforms/LoopUnroll/peel-loop-conditions.ll
@@ -23,7 +23,9 @@ define void @test1(i32 %k) {
 ; CHECK:       for.inc.peel:
 ; CHECK-NEXT:    [[INC_PEEL:%.*]] = add nsw i32 0, 1
 ; CHECK-NEXT:    [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
-; CHECK-NEXT:    br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%[^,]*]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK:       for.body.peel.next:
 ; CHECK-NEXT:    br label [[FOR_BODY_PEEL2:%.*]]
 ; CHECK:       for.body.peel2:
@@ -39,6 +41,8 @@ define void @test1(i32 %k) {
 ; CHECK-NEXT:    [[INC_PEEL7:%.*]] = add nsw i32 [[INC_PEEL]], 1
 ; CHECK-NEXT:    [[CMP_PEEL8:%.*]] = icmp slt i32 [[INC_PEEL7]], [[K]]
 ; CHECK-NEXT:    br i1 [[CMP_PEEL8]], label [[FOR_BODY_PEEL_NEXT1:%.*]], label [[FOR_END]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK:       for.body.peel.next1:
 ; CHECK-NEXT:    br label [[FOR_BODY_PEEL_NEXT9:%.*]]
 ; CHECK:       for.body.peel.next9:
@@ -57,7 +61,7 @@ define void @test1(i32 %k) {
 ; CHECK:       for.inc:
 ; CHECK-NEXT:    [[INC]] = add nuw nsw i32 [[I_05]], 1
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
-; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !0
+; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !{{.*}}
 ; CHECK:       for.end.loopexit:
 ; CHECK-NEXT:    br label [[FOR_END]]
 ; CHECK:       for.end:
@@ -82,12 +86,14 @@ if.else:
 for.inc:
   %inc = add nsw i32 %i.05, 1
   %cmp = icmp slt i32 %inc, %k
-  br i1 %cmp, label %for.body, label %for.end
+  br i1 %cmp, label %for.body, label %for.end, !llvm.loop !1
 
 for.end:
   ret void
 }
 
+!1 = distinct !{!1}
+
 ; Check we peel off the maximum number of iterations that make conditions true.
 define void @test2(i32 %k) {
 ; CHECK-LABEL: @test2(
@@ -113,7 +119,9 @@ define void @test2(i32 %k) {
 ; CHECK:       for.inc.peel:
 ; CHECK-NEXT:    [[INC_PEEL:%.*]] = add nsw i32 0, 1
 ; CHECK-NEXT:    [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
-; CHECK-NEXT:    br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%[^,]*]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK:       for.body.peel.next:
 ; CHECK-NEXT:    br label [[FOR_BODY_PEEL2:%.*]]
 ; CHECK:       for.body.peel2:
@@ -135,6 +143,8 @@ define void @test2(i32 %k) {
 ; CHECK-NEXT:    [[INC_PEEL10:%.*]] = add nsw i32 [[INC_PEEL]], 1
 ; CHECK-NEXT:    [[CMP_PEEL11:%.*]] = icmp slt i32 [[INC_PEEL10]], [[K]]
 ; CHECK-NEXT:    br i1 [[CMP_PEEL11]], label [[FOR_BODY_PEEL_NEXT1:%.*]], label [[FOR_END]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK:       for.body.peel.next1:
 ; CHECK-NEXT:    br label [[FOR_BODY_PEEL13:%.*]]
 ; CHECK:       for.body.peel13:
@@ -156,6 +166,8 @@ define void @test2(i32 %k) {
 ; CHECK-NEXT:    [[INC_PEEL21:%.*]] = add nsw i32 [[INC_PEEL10]], 1
 ; CHECK-NEXT:    [[CMP_PEEL22:%.*]] = icmp slt i32 [[INC_PEEL21]], [[K]]
 ; CHECK-NEXT:    br i1 [[CMP_PEEL22]], label [[FOR_BODY_PEEL_NEXT12:%.*]], label [[FOR_END]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK:       for.body.peel.next12:
 ; CHECK-NEXT:    br label [[FOR_BODY_PEEL24:%.*]]
 ; CHECK:       for.body.peel24:
@@ -177,6 +189,8 @@ define void @test2(i32 %k) {
 ; CHECK-NEXT:    [[INC_PEEL32:%.*]] = add nsw i32 [[INC_PEEL21]], 1
 ; CHECK-NEXT:    [[CMP_PEEL33:%.*]] = icmp slt i32 [[INC_PEEL32]], [[K]]
 ; CHECK-NEXT:    br i1 [[CMP_PEEL33]], label [[FOR_BODY_PEEL_NEXT23:%.*]], label [[FOR_END]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK:       for.body.peel.next23:
 ; CHECK-NEXT:    br label [[FOR_BODY_PEEL_NEXT34:%.*]]
 ; CHECK:       for.body.peel.next34:
@@ -200,7 +214,7 @@ define void @test2(i32 %k) {
 ; CHECK:       for.inc:
 ; CHECK-NEXT:    [[INC]] = add nuw nsw i32 [[I_05]], 1
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
-; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !2
+; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !{{.*}}
 ; CHECK:       for.end.loopexit:
 ; CHECK-NEXT:    br label [[FOR_END]]
 ; CHECK:       for.end:
@@ -233,12 +247,14 @@ if.then2:
 for.inc:
   %inc = add nsw i32 %i.05, 1
   %cmp = icmp slt i32 %inc, %k
-  br i1 %cmp, label %for.body, label %for.end
+  br i1 %cmp, label %for.body, label %for.end, !llvm.loop !2
 
 for.end:
   ret void
 }
 
+!2 = distinct !{!2}
+
 ; Check that we can peel off iterations that make a condition false.
 define void @test3(i32 %k) {
 ; CHECK-LABEL: @test3(
@@ -258,7 +274,9 @@ define void @test3(i32 %k) {
 ; CHECK:       for.inc.peel:
 ; CHECK-NEXT:    [[INC_PEEL:%.*]] = add nsw i32 0, 1
 ; CHECK-NEXT:    [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
-; CHECK-NEXT:    br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%[^,]*]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK:       for.body.peel.next:
 ; CHECK-NEXT:    br label [[FOR_BODY_PEEL2:%.*]]
 ; CHECK:       for.body.peel2:
@@ -274,6 +292,8 @@ define void @test3(i32 %k) {
 ; CHECK-NEXT:    [[INC_PEEL7:%.*]] = add nsw i32 [[INC_PEEL]], 1
 ; CHECK-NEXT:    [[CMP_PEEL8:%.*]] = icmp slt i32 [[INC_PEEL7]], [[K]]
 ; CHECK-NEXT:    br i1 [[CMP_PEEL8]], label [[FOR_BODY_PEEL_NEXT1:%.*]], label [[FOR_END]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK:       for.body.peel.next1:
 ; CHECK-NEXT:    br label [[FOR_BODY_PEEL10:%.*]]
 ; CHECK:       for.body.peel10:
@@ -289,6 +309,8 @@ define void @test3(i32 %k) {
 ; CHECK-NEXT:    [[INC_PEEL15:%.*]] = add nsw i32 [[INC_PEEL7]], 1
 ; CHECK-NEXT:    [[CMP_PEEL16:%.*]] = icmp slt i32 [[INC_PEEL15]], [[K]]
 ; CHECK-NEXT:    br i1 [[CMP_PEEL16]], label [[FOR_BODY_PEEL_NEXT9:%.*]], label [[FOR_END]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK:       for.body.peel.next9:
 ; CHECK-NEXT:    br label [[FOR_BODY_PEEL_NEXT17:%.*]]
 ; CHECK:       for.body.peel.next17:
@@ -307,7 +329,7 @@ define void @test3(i32 %k) {
 ; CHECK:       for.inc:
 ; CHECK-NEXT:    [[INC]] = add nuw nsw i32 [[I_05]], 1
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
-; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !3
+; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !{{.*}}
 ; CHECK:       for.end.loopexit:
 ; CHECK-NEXT:    br label [[FOR_END]]
 ; CHECK:       for.end:
@@ -332,12 +354,14 @@ if.else:
 for.inc:
   %inc = add nsw i32 %i.05, 1
   %cmp = icmp slt i32 %inc, %k
-  br i1 %cmp, label %for.body, label %for.end
+  br i1 %cmp, label %for.body, label %for.end, !llvm.loop !3
 
 for.end:
   ret void
 }
 
+!3 = distinct !{!3}
+
 ; Test that we only peel off iterations if it simplifies a condition in the
 ; loop body after peeling at most MaxPeelCount iterations.
 define void @test4(i32 %k) {
diff --git a/llvm/test/Transforms/LoopUnroll/peel-loop.ll b/llvm/test/Transforms/LoopUnroll/peel-loop.ll
index 55e818244a7..d535414b3eb 100644
--- a/llvm/test/Transforms/LoopUnroll/peel-loop.ll
+++ b/llvm/test/Transforms/LoopUnroll/peel-loop.ll
@@ -8,17 +8,24 @@
 ; CHECK: [[NEXT0]]:
 ; CHECK: store i32 0, i32* %p, align 4
 ; CHECK: %[[CMP1:.*]] = icmp eq i32 %k, 1
-; CHECK: br i1 %[[CMP1]], label %for.end, label %[[NEXT1:.*]]
+; CHECK: br i1 %[[CMP1]], label %for.end, label %[[NEXT1:[^,]*]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK: [[NEXT1]]:
 ; CHECK: %[[INC1:.*]] = getelementptr inbounds i32, i32* %p, i64 1
 ; CHECK: store i32 1, i32* %[[INC1]], align 4
 ; CHECK: %[[CMP2:.*]] = icmp sgt i32 %k, 2
 ; CHECK: br i1 %[[CMP2]], label %[[NEXT2:.*]], label %for.end
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK: [[NEXT2]]:
 ; CHECK: %[[INC2:.*]] = getelementptr inbounds i32, i32* %p, i64 2
 ; CHECK: store i32 2, i32* %[[INC2]], align 4
 ; CHECK: %[[CMP3:.*]] = icmp eq i32 %k, 3
-; CHECK: br i1 %[[CMP3]], label %for.end, label %[[LOOP_PH:.*]]
+; CHECK: br i1 %[[CMP3]], label %for.end, label %[[LOOP_PH:[^,]*]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
+; CHECK: br i1 %[[CMP4:.*]], label %[[LOOP_PH]], label %for.end, !llvm.loop !{{.*}}
 ; CHECK: for.end:
 ; CHECK: ret void
 
@@ -37,7 +44,7 @@ for.body:                                         ; preds = %for.body.lr.ph, %fo
   store i32 %i.05, i32* %p.addr.04, align 4
   %inc = add nsw i32 %i.05, 1
   %cmp = icmp slt i32 %inc, %k
-  br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge
+  br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge, !llvm.loop !1
 
 for.cond.for.end_crit_edge:                       ; preds = %for.body
   br label %for.end
@@ -46,6 +53,8 @@ for.end:                                          ; preds = %for.cond.for.end_cr
   ret void
 }
 
+!1 = distinct !{!1}
+
 ; Make sure peeling works correctly when a value defined in a loop is used
 ; in later code - we need to correctly plumb the phi depending on which
 ; iteration is actually used.
@@ -55,17 +64,24 @@ for.end:                                          ; preds = %for.cond.for.end_cr
 ; CHECK: [[NEXT0]]:
 ; CHECK: store i32 0, i32* %p, align 4
 ; CHECK: %[[CMP1:.*]] = icmp eq i32 %k, 1
-; CHECK: br i1 %[[CMP1]], label %for.end, label %[[NEXT1:.*]]
+; CHECK: br i1 %[[CMP1]], label %for.end, label %[[NEXT1:[^,]*]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK: [[NEXT1]]:
 ; CHECK: %[[INC1:.*]] = getelementptr inbounds i32, i32* %p, i64 1
 ; CHECK: store i32 1, i32* %[[INC1]], align 4
 ; CHECK: %[[CMP2:.*]] = icmp sgt i32 %k, 2
 ; CHECK: br i1 %[[CMP2]], label %[[NEXT2:.*]], label %for.end
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
 ; CHECK: [[NEXT2]]:
 ; CHECK: %[[INC2:.*]] = getelementptr inbounds i32, i32* %p, i64 2
 ; CHECK: store i32 2, i32* %[[INC2]], align 4
 ; CHECK: %[[CMP3:.*]] = icmp eq i32 %k, 3
-; CHECK: br i1 %[[CMP3]], label %for.end, label %[[LOOP_PH:.*]]
+; CHECK: br i1 %[[CMP3]], label %for.end, label %[[LOOP_PH:[^,]*]]
+; Verify that MD_loop metadata is dropped.
+; CHECK-NOT:   , !llvm.loop !{{[0-9]*}}
+; CHECK: br i1 %[[CMP4:.*]], label %[[LOOP_PH]], label %for.end, !llvm.loop !{{.*}}
 ; CHECK: for.end:
 ; CHECK: %ret = phi i32 [ 0, %entry ], [ 1, %[[NEXT0]] ], [ 2, %[[NEXT1]] ], [ 3, %[[NEXT2]] ], [ %inc, %for.body ]
 ; CHECK: ret i32 %ret
@@ -84,7 +100,7 @@ for.body:                                         ; preds = %for.body.lr.ph, %fo
   store i32 %i.05, i32* %p.addr.04, align 4
   %inc = add nsw i32 %i.05, 1
   %cmp = icmp slt i32 %inc, %k
-  br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge
+  br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge, !llvm.loop !2
 
 for.cond.for.end_crit_edge:                       ; preds = %for.body
   br label %for.end
@@ -93,3 +109,5 @@ for.end:                                          ; preds = %for.cond.for.end_cr
   %ret = phi i32 [ 0, %entry], [ %inc, %for.cond.for.end_crit_edge ]
   ret i32 %ret
 }
+
+!2 = distinct !{!2}