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Vyacheslav Zakharin
committed
Remove LoopID metadata from the branch instruction
that follows the peeled iterations. Differential Revision: https://reviews.llvm.org/D52176 llvm-svn: 343054
1 parent 9571033 commit e06831a

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3 files changed

+62
-16
lines changed

3 files changed

+62
-16
lines changed

‎llvm/lib/Transforms/Utils/LoopUnrollPeel.cpp‎

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -618,8 +618,12 @@ bool llvm::peelLoop(Loop *L, unsigned PeelCount, LoopInfo *LI,
618618
assert(DT->verify(DominatorTree::VerificationLevel::Fast));
619619
}
620620

621-
updateBranchWeights(InsertBot, cast<BranchInst>(VMap[LatchBR]), Iter,
621+
auto *LatchBRCopy = cast<BranchInst>(VMap[LatchBR]);
622+
updateBranchWeights(InsertBot, LatchBRCopy, Iter,
622623
PeelCount, ExitWeight);
624+
// Remove Loop metadata from the latch branch instruction
625+
// because it is not the Loop's latch branch anymore.
626+
LatchBRCopy->setMetadata(LLVMContext::MD_loop, nullptr);
623627

624628
InsertTop = InsertBot;
625629
InsertBot = SplitBlock(InsertBot, InsertBot->getTerminator(), DT, LI);

‎llvm/test/Transforms/LoopUnroll/peel-loop-conditions.ll‎

Lines changed: 33 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -23,7 +23,9 @@ define void @test1(i32 %k) {
2323
; CHECK: for.inc.peel:
2424
; CHECK-NEXT: [[INC_PEEL:%.*]] = add nsw i32 0, 1
2525
; CHECK-NEXT: [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
26-
; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
26+
; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%[^,]*]]
27+
; Verify that MD_loop metadata is dropped.
28+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
2729
; CHECK: for.body.peel.next:
2830
; CHECK-NEXT: br label [[FOR_BODY_PEEL2:%.*]]
2931
; CHECK: for.body.peel2:
@@ -39,6 +41,8 @@ define void @test1(i32 %k) {
3941
; CHECK-NEXT: [[INC_PEEL7:%.*]] = add nsw i32 [[INC_PEEL]], 1
4042
; CHECK-NEXT: [[CMP_PEEL8:%.*]] = icmp slt i32 [[INC_PEEL7]], [[K]]
4143
; CHECK-NEXT: br i1 [[CMP_PEEL8]], label [[FOR_BODY_PEEL_NEXT1:%.*]], label [[FOR_END]]
44+
; Verify that MD_loop metadata is dropped.
45+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
4246
; CHECK: for.body.peel.next1:
4347
; CHECK-NEXT: br label [[FOR_BODY_PEEL_NEXT9:%.*]]
4448
; CHECK: for.body.peel.next9:
@@ -57,7 +61,7 @@ define void @test1(i32 %k) {
5761
; CHECK: for.inc:
5862
; CHECK-NEXT: [[INC]] = add nuw nsw i32 [[I_05]], 1
5963
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
60-
; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !0
64+
; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !{{.*}}
6165
; CHECK: for.end.loopexit:
6266
; CHECK-NEXT: br label [[FOR_END]]
6367
; CHECK: for.end:
@@ -82,12 +86,14 @@ if.else:
8286
for.inc:
8387
%inc = add nsw i32 %i.05, 1
8488
%cmp = icmp slt i32 %inc, %k
85-
br i1 %cmp, label %for.body, label %for.end
89+
br i1 %cmp, label %for.body, label %for.end, !llvm.loop !1
8690

8791
for.end:
8892
ret void
8993
}
9094

95+
!1 = distinct !{!1}
96+
9197
; Check we peel off the maximum number of iterations that make conditions true.
9298
define void @test2(i32 %k) {
9399
; CHECK-LABEL: @test2(
@@ -113,7 +119,9 @@ define void @test2(i32 %k) {
113119
; CHECK: for.inc.peel:
114120
; CHECK-NEXT: [[INC_PEEL:%.*]] = add nsw i32 0, 1
115121
; CHECK-NEXT: [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
116-
; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
122+
; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%[^,]*]]
123+
; Verify that MD_loop metadata is dropped.
124+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
117125
; CHECK: for.body.peel.next:
118126
; CHECK-NEXT: br label [[FOR_BODY_PEEL2:%.*]]
119127
; CHECK: for.body.peel2:
@@ -135,6 +143,8 @@ define void @test2(i32 %k) {
135143
; CHECK-NEXT: [[INC_PEEL10:%.*]] = add nsw i32 [[INC_PEEL]], 1
136144
; CHECK-NEXT: [[CMP_PEEL11:%.*]] = icmp slt i32 [[INC_PEEL10]], [[K]]
137145
; CHECK-NEXT: br i1 [[CMP_PEEL11]], label [[FOR_BODY_PEEL_NEXT1:%.*]], label [[FOR_END]]
146+
; Verify that MD_loop metadata is dropped.
147+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
138148
; CHECK: for.body.peel.next1:
139149
; CHECK-NEXT: br label [[FOR_BODY_PEEL13:%.*]]
140150
; CHECK: for.body.peel13:
@@ -156,6 +166,8 @@ define void @test2(i32 %k) {
156166
; CHECK-NEXT: [[INC_PEEL21:%.*]] = add nsw i32 [[INC_PEEL10]], 1
157167
; CHECK-NEXT: [[CMP_PEEL22:%.*]] = icmp slt i32 [[INC_PEEL21]], [[K]]
158168
; CHECK-NEXT: br i1 [[CMP_PEEL22]], label [[FOR_BODY_PEEL_NEXT12:%.*]], label [[FOR_END]]
169+
; Verify that MD_loop metadata is dropped.
170+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
159171
; CHECK: for.body.peel.next12:
160172
; CHECK-NEXT: br label [[FOR_BODY_PEEL24:%.*]]
161173
; CHECK: for.body.peel24:
@@ -177,6 +189,8 @@ define void @test2(i32 %k) {
177189
; CHECK-NEXT: [[INC_PEEL32:%.*]] = add nsw i32 [[INC_PEEL21]], 1
178190
; CHECK-NEXT: [[CMP_PEEL33:%.*]] = icmp slt i32 [[INC_PEEL32]], [[K]]
179191
; CHECK-NEXT: br i1 [[CMP_PEEL33]], label [[FOR_BODY_PEEL_NEXT23:%.*]], label [[FOR_END]]
192+
; Verify that MD_loop metadata is dropped.
193+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
180194
; CHECK: for.body.peel.next23:
181195
; CHECK-NEXT: br label [[FOR_BODY_PEEL_NEXT34:%.*]]
182196
; CHECK: for.body.peel.next34:
@@ -200,7 +214,7 @@ define void @test2(i32 %k) {
200214
; CHECK: for.inc:
201215
; CHECK-NEXT: [[INC]] = add nuw nsw i32 [[I_05]], 1
202216
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
203-
; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !2
217+
; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !{{.*}}
204218
; CHECK: for.end.loopexit:
205219
; CHECK-NEXT: br label [[FOR_END]]
206220
; CHECK: for.end:
@@ -233,12 +247,14 @@ if.then2:
233247
for.inc:
234248
%inc = add nsw i32 %i.05, 1
235249
%cmp = icmp slt i32 %inc, %k
236-
br i1 %cmp, label %for.body, label %for.end
250+
br i1 %cmp, label %for.body, label %for.end, !llvm.loop !2
237251

238252
for.end:
239253
ret void
240254
}
241255

256+
!2 = distinct !{!2}
257+
242258
; Check that we can peel off iterations that make a condition false.
243259
define void @test3(i32 %k) {
244260
; CHECK-LABEL: @test3(
@@ -258,7 +274,9 @@ define void @test3(i32 %k) {
258274
; CHECK: for.inc.peel:
259275
; CHECK-NEXT: [[INC_PEEL:%.*]] = add nsw i32 0, 1
260276
; CHECK-NEXT: [[CMP_PEEL:%.*]] = icmp slt i32 [[INC_PEEL]], [[K:%.*]]
261-
; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%.*]]
277+
; CHECK-NEXT: br i1 [[CMP_PEEL]], label [[FOR_BODY_PEEL_NEXT:%.*]], label [[FOR_END:%[^,]*]]
278+
; Verify that MD_loop metadata is dropped.
279+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
262280
; CHECK: for.body.peel.next:
263281
; CHECK-NEXT: br label [[FOR_BODY_PEEL2:%.*]]
264282
; CHECK: for.body.peel2:
@@ -274,6 +292,8 @@ define void @test3(i32 %k) {
274292
; CHECK-NEXT: [[INC_PEEL7:%.*]] = add nsw i32 [[INC_PEEL]], 1
275293
; CHECK-NEXT: [[CMP_PEEL8:%.*]] = icmp slt i32 [[INC_PEEL7]], [[K]]
276294
; CHECK-NEXT: br i1 [[CMP_PEEL8]], label [[FOR_BODY_PEEL_NEXT1:%.*]], label [[FOR_END]]
295+
; Verify that MD_loop metadata is dropped.
296+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
277297
; CHECK: for.body.peel.next1:
278298
; CHECK-NEXT: br label [[FOR_BODY_PEEL10:%.*]]
279299
; CHECK: for.body.peel10:
@@ -289,6 +309,8 @@ define void @test3(i32 %k) {
289309
; CHECK-NEXT: [[INC_PEEL15:%.*]] = add nsw i32 [[INC_PEEL7]], 1
290310
; CHECK-NEXT: [[CMP_PEEL16:%.*]] = icmp slt i32 [[INC_PEEL15]], [[K]]
291311
; CHECK-NEXT: br i1 [[CMP_PEEL16]], label [[FOR_BODY_PEEL_NEXT9:%.*]], label [[FOR_END]]
312+
; Verify that MD_loop metadata is dropped.
313+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
292314
; CHECK: for.body.peel.next9:
293315
; CHECK-NEXT: br label [[FOR_BODY_PEEL_NEXT17:%.*]]
294316
; CHECK: for.body.peel.next17:
@@ -307,7 +329,7 @@ define void @test3(i32 %k) {
307329
; CHECK: for.inc:
308330
; CHECK-NEXT: [[INC]] = add nuw nsw i32 [[I_05]], 1
309331
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], [[K]]
310-
; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !3
332+
; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop !{{.*}}
311333
; CHECK: for.end.loopexit:
312334
; CHECK-NEXT: br label [[FOR_END]]
313335
; CHECK: for.end:
@@ -332,12 +354,14 @@ if.else:
332354
for.inc:
333355
%inc = add nsw i32 %i.05, 1
334356
%cmp = icmp slt i32 %inc, %k
335-
br i1 %cmp, label %for.body, label %for.end
357+
br i1 %cmp, label %for.body, label %for.end, !llvm.loop !3
336358

337359
for.end:
338360
ret void
339361
}
340362

363+
!3 = distinct !{!3}
364+
341365
; Test that we only peel off iterations if it simplifies a condition in the
342366
; loop body after peeling at most MaxPeelCount iterations.
343367
define void @test4(i32 %k) {

‎llvm/test/Transforms/LoopUnroll/peel-loop.ll‎

Lines changed: 24 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -8,17 +8,24 @@
88
; CHECK: [[NEXT0]]:
99
; CHECK: store i32 0, i32* %p, align 4
1010
; CHECK: %[[CMP1:.*]] = icmp eq i32 %k, 1
11-
; CHECK: br i1 %[[CMP1]], label %for.end, label %[[NEXT1:.*]]
11+
; CHECK: br i1 %[[CMP1]], label %for.end, label %[[NEXT1:[^,]*]]
12+
; Verify that MD_loop metadata is dropped.
13+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
1214
; CHECK: [[NEXT1]]:
1315
; CHECK: %[[INC1:.*]] = getelementptr inbounds i32, i32* %p, i64 1
1416
; CHECK: store i32 1, i32* %[[INC1]], align 4
1517
; CHECK: %[[CMP2:.*]] = icmp sgt i32 %k, 2
1618
; CHECK: br i1 %[[CMP2]], label %[[NEXT2:.*]], label %for.end
19+
; Verify that MD_loop metadata is dropped.
20+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
1721
; CHECK: [[NEXT2]]:
1822
; CHECK: %[[INC2:.*]] = getelementptr inbounds i32, i32* %p, i64 2
1923
; CHECK: store i32 2, i32* %[[INC2]], align 4
2024
; CHECK: %[[CMP3:.*]] = icmp eq i32 %k, 3
21-
; CHECK: br i1 %[[CMP3]], label %for.end, label %[[LOOP_PH:.*]]
25+
; CHECK: br i1 %[[CMP3]], label %for.end, label %[[LOOP_PH:[^,]*]]
26+
; Verify that MD_loop metadata is dropped.
27+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
28+
; CHECK: br i1 %[[CMP4:.*]], label %[[LOOP_PH]], label %for.end, !llvm.loop !{{.*}}
2229
; CHECK: for.end:
2330
; CHECK: ret void
2431

@@ -37,7 +44,7 @@ for.body: ; preds = %for.body.lr.ph, %fo
3744
store i32 %i.05, i32* %p.addr.04, align 4
3845
%inc = add nsw i32 %i.05, 1
3946
%cmp = icmp slt i32 %inc, %k
40-
br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge
47+
br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge, !llvm.loop !1
4148

4249
for.cond.for.end_crit_edge: ; preds = %for.body
4350
br label %for.end
@@ -46,6 +53,8 @@ for.end: ; preds = %for.cond.for.end_cr
4653
ret void
4754
}
4855

56+
!1 = distinct !{!1}
57+
4958
; Make sure peeling works correctly when a value defined in a loop is used
5059
; in later code - we need to correctly plumb the phi depending on which
5160
; iteration is actually used.
@@ -55,17 +64,24 @@ for.end: ; preds = %for.cond.for.end_cr
5564
; CHECK: [[NEXT0]]:
5665
; CHECK: store i32 0, i32* %p, align 4
5766
; CHECK: %[[CMP1:.*]] = icmp eq i32 %k, 1
58-
; CHECK: br i1 %[[CMP1]], label %for.end, label %[[NEXT1:.*]]
67+
; CHECK: br i1 %[[CMP1]], label %for.end, label %[[NEXT1:[^,]*]]
68+
; Verify that MD_loop metadata is dropped.
69+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
5970
; CHECK: [[NEXT1]]:
6071
; CHECK: %[[INC1:.*]] = getelementptr inbounds i32, i32* %p, i64 1
6172
; CHECK: store i32 1, i32* %[[INC1]], align 4
6273
; CHECK: %[[CMP2:.*]] = icmp sgt i32 %k, 2
6374
; CHECK: br i1 %[[CMP2]], label %[[NEXT2:.*]], label %for.end
75+
; Verify that MD_loop metadata is dropped.
76+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
6477
; CHECK: [[NEXT2]]:
6578
; CHECK: %[[INC2:.*]] = getelementptr inbounds i32, i32* %p, i64 2
6679
; CHECK: store i32 2, i32* %[[INC2]], align 4
6780
; CHECK: %[[CMP3:.*]] = icmp eq i32 %k, 3
68-
; CHECK: br i1 %[[CMP3]], label %for.end, label %[[LOOP_PH:.*]]
81+
; CHECK: br i1 %[[CMP3]], label %for.end, label %[[LOOP_PH:[^,]*]]
82+
; Verify that MD_loop metadata is dropped.
83+
; CHECK-NOT: , !llvm.loop !{{[0-9]*}}
84+
; CHECK: br i1 %[[CMP4:.*]], label %[[LOOP_PH]], label %for.end, !llvm.loop !{{.*}}
6985
; CHECK: for.end:
7086
; CHECK: %ret = phi i32 [ 0, %entry ], [ 1, %[[NEXT0]] ], [ 2, %[[NEXT1]] ], [ 3, %[[NEXT2]] ], [ %inc, %for.body ]
7187
; CHECK: ret i32 %ret
@@ -84,7 +100,7 @@ for.body: ; preds = %for.body.lr.ph, %fo
84100
store i32 %i.05, i32* %p.addr.04, align 4
85101
%inc = add nsw i32 %i.05, 1
86102
%cmp = icmp slt i32 %inc, %k
87-
br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge
103+
br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge, !llvm.loop !2
88104

89105
for.cond.for.end_crit_edge: ; preds = %for.body
90106
br label %for.end
@@ -93,3 +109,5 @@ for.end: ; preds = %for.cond.for.end_cr
93109
%ret = phi i32 [ 0, %entry], [ %inc, %for.cond.for.end_crit_edge ]
94110
ret i32 %ret
95111
}
112+
113+
!2 = distinct !{!2}

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