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[VPlan] Add initial CFG simplification, removing BranchOnCond true.
1 parent e5f5517 commit 332205c

32 files changed

+117
-78
lines changed

‎llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -2685,6 +2685,7 @@ void InnerLoopVectorizer::createVectorLoopSkeleton(StringRef Prefix) {
26852685
SplitBlock(LoopVectorPreHeader, LoopVectorPreHeader->getTerminator(), DT,
26862686
LI, nullptr, Twine(Prefix) + "scalar.ph");
26872687
replaceVPBBWithIRVPBB(Plan.getScalarPreheader(), LoopScalarPreHeader);
2688+
26882689
}
26892690

26902691
/// Return the expanded step for \p ID using \p ExpandedSCEVs to look up SCEV

‎llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

Lines changed: 39 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1437,6 +1437,44 @@ void VPlanTransforms::truncateToMinimalBitwidths(
14371437
"some entries in MinBWs haven't been processed");
14381438
}
14391439

1440+
/// Remove BranchOnCond recipes with constant conditions together with removing
1441+
/// dead edges to their successors. Remove blocks that become dead (no remaining
1442+
/// predecessors())
1443+
static void simplifyCFG(VPlan &Plan) {
1444+
using namespace llvm::VPlanPatternMatch;
1445+
// Start by collecting successor blocks known to not be taken from
1446+
// branch-on-cond terminator in their predecessor.
1447+
SmallVector<VPBlockBase *> WorkList;
1448+
for (VPBasicBlock *VPBB : VPBlockUtils::blocksOnly<VPBasicBlock>(
1449+
vp_depth_first_deep(Plan.getEntry()))) {
1450+
VPRecipeBase *Term = VPBB->getTerminator();
1451+
if (!Term || !match(Term, m_BranchOnCond(m_True())))
1452+
continue;
1453+
VPBasicBlock *DeadSucc = cast<VPBasicBlock>(VPBB->getSuccessors()[1]);
1454+
VPBlockUtils::disconnectBlocks(VPBB, DeadSucc);
1455+
Term->eraseFromParent();
1456+
WorkList.push_back(DeadSucc);
1457+
}
1458+
1459+
VPValue Tmp;
1460+
// Remove any block in the worklist if it doesn't have any predecessors left.
1461+
// Disconnect the block from all successors and queue them for removal.
1462+
while (!WorkList.empty()) {
1463+
VPBlockBase *VPBB = WorkList.pop_back_val();
1464+
if (VPBB->getNumPredecessors() != 0)
1465+
continue;
1466+
for (VPBlockBase *Succ : to_vector(VPBB->getSuccessors())) {
1467+
VPBlockUtils::disconnectBlocks(VPBB, Succ);
1468+
WorkList.push_back(Succ);
1469+
}
1470+
// Replace all uses of values defined in VPB with a dummy VPValue to
1471+
// facilitate removal. All blocks with remaining uses of the dummy value
1472+
// must be removed by subsequent operation.
1473+
VPBB->dropAllReferences(&Tmp);
1474+
delete VPBB;
1475+
}
1476+
}
1477+
14401478
void VPlanTransforms::optimize(VPlan &Plan) {
14411479
runPass(removeRedundantCanonicalIVs, Plan);
14421480
runPass(removeRedundantInductionCasts, Plan);
@@ -1450,6 +1488,7 @@ void VPlanTransforms::optimize(VPlan &Plan) {
14501488

14511489
runPass(createAndOptimizeReplicateRegions, Plan);
14521490
runPass(mergeBlocksIntoPredecessors, Plan);
1491+
runPass(simplifyCFG,Plan);
14531492
runPass(licm, Plan);
14541493
}
14551494

‎llvm/test/Transforms/LoopVectorize/AArch64/first-order-recurrence-fold-tail.ll

Lines changed: 3 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -71,14 +71,13 @@ define i32 @test_phi_iterator_invalidation(ptr %A, ptr noalias %B) {
7171
; CHECK-NEXT: br i1 [[TMP31]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
7272
; CHECK: middle.block:
7373
; CHECK-NEXT: [[VECTOR_RECUR_EXTRACT:%.*]] = extractelement <4 x i16> [[TMP24]], i32 3
74-
; CHECK-NEXT: br i1 true, label [[EXIT:%.*]], label [[SCALAR_PH]]
74+
; CHECK-NEXT: br label [[EXIT:%.*]]
7575
; CHECK: scalar.ph:
76-
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 1004, [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
77-
; CHECK-NEXT: [[SCALAR_RECUR_INIT:%.*]] = phi i16 [ [[VECTOR_RECUR_EXTRACT]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY]] ]
76+
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ]
7877
; CHECK-NEXT: br label [[LOOP:%.*]]
7978
; CHECK: loop:
8079
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], [[LOOP]] ]
81-
; CHECK-NEXT: [[SCALAR_RECUR:%.*]] = phi i16 [ [[SCALAR_RECUR_INIT]], [[SCALAR_PH]] ], [ [[FOR_NEXT:%.*]], [[LOOP]] ]
80+
; CHECK-NEXT: [[SCALAR_RECUR:%.*]] = phi i16 [ 0, [[SCALAR_PH]] ], [ [[FOR_NEXT:%.*]], [[LOOP]] ]
8281
; CHECK-NEXT: [[SEXT:%.*]] = sext i16 [[SCALAR_RECUR]] to i32
8382
; CHECK-NEXT: [[IV_NEXT]] = add i64 [[IV]], 1
8483
; CHECK-NEXT: [[GEP_A:%.*]] = getelementptr i32, ptr [[A]], i64 [[IV_NEXT]]

‎llvm/test/Transforms/LoopVectorize/AArch64/pr73894.ll

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -54,10 +54,10 @@ define i32 @pr70988(ptr %src, i32 %n) {
5454
; CHECK-NEXT: br i1 [[TMP20]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
5555
; CHECK: middle.block:
5656
; CHECK-NEXT: [[RDX_MINMAX:%.*]] = call i32 @llvm.smax.i32(i32 [[TMP17]], i32 [[TMP18]])
57-
; CHECK-NEXT: br i1 true, label [[EXIT:%.*]], label [[SCALAR_PH]]
57+
; CHECK-NEXT: br label [[EXIT:%.*]]
5858
; CHECK: scalar.ph:
59-
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
60-
; CHECK-NEXT: [[BC_MERGE_RDX:%.*]] = phi i32 [ [[RDX_MINMAX]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY]] ]
59+
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ]
60+
; CHECK-NEXT: [[BC_MERGE_RDX:%.*]] = phi i32 [ 0, [[ENTRY]] ]
6161
; CHECK-NEXT: br label [[LOOP:%.*]]
6262
; CHECK: loop:
6363
; CHECK-NEXT: [[INDUC:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[INDUC_NEXT:%.*]], [[LOOP]] ]

‎llvm/test/Transforms/LoopVectorize/AArch64/sve-tail-folding-optsize.ll

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -37,9 +37,9 @@ define void @trip1025_i64(ptr noalias nocapture noundef %dst, ptr noalias nocapt
3737
; CHECK-NEXT: [[TMP15:%.*]] = extractelement <vscale x 2 x i1> [[TMP14]], i32 0
3838
; CHECK-NEXT: br i1 [[TMP15]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
3939
; CHECK: middle.block:
40-
; CHECK-NEXT: br i1 true, label [[FOR_END:%.*]], label [[SCALAR_PH]]
40+
; CHECK-NEXT: br label [[FOR_END:%.*]]
4141
; CHECK: scalar.ph:
42-
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
42+
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ]
4343
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
4444
; CHECK: for.body:
4545
; CHECK-NEXT: [[I_06:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[INC:%.*]], [[FOR_BODY]] ]

‎llvm/test/Transforms/LoopVectorize/RISCV/pr88802.ll

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -58,9 +58,9 @@ define void @test(ptr %p, i64 %a, i8 %b) {
5858
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i32 [[INDEX]], 4
5959
; CHECK-NEXT: br i1 true, label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY1]], !llvm.loop [[LOOP0:![0-9]+]]
6060
; CHECK: middle.block:
61-
; CHECK-NEXT: br i1 true, label [[EXIT:%.*]], label [[SCALAR_PH]]
61+
; CHECK-NEXT: br label [[EXIT:%.*]]
6262
; CHECK: scalar.ph:
63-
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ 4, [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
63+
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ]
6464
; CHECK-NEXT: br label [[FOR_COND:%.*]]
6565
; CHECK: for.cond:
6666
; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[ADD:%.*]], [[FOR_BODY:%.*]] ]

‎llvm/test/Transforms/LoopVectorize/RISCV/short-trip-count.ll

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -23,9 +23,9 @@ define void @small_trip_count_min_vlen_128(ptr nocapture %a) nounwind vscale_ran
2323
; CHECK-NEXT: call void @llvm.masked.store.nxv1i32.p0(<vscale x 1 x i32> [[TMP6]], ptr [[TMP8]], i32 4, <vscale x 1 x i1> [[ACTIVE_LANE_MASK]])
2424
; CHECK-NEXT: br label [[MIDDLE_BLOCK:%.*]]
2525
; CHECK: middle.block:
26-
; CHECK-NEXT: br i1 true, label [[EXIT:%.*]], label [[SCALAR_PH]]
26+
; CHECK-NEXT: br label [[EXIT:%.*]]
2727
; CHECK: scalar.ph:
28-
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
28+
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ]
2929
; CHECK-NEXT: br label [[LOOP:%.*]]
3030
; CHECK: loop:
3131
; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[LOOP]] ], [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ]
@@ -80,9 +80,9 @@ define void @small_trip_count_min_vlen_32(ptr nocapture %a) nounwind vscale_rang
8080
; CHECK-NEXT: call void @llvm.masked.store.nxv4i32.p0(<vscale x 4 x i32> [[TMP8]], ptr [[TMP10]], i32 4, <vscale x 4 x i1> [[ACTIVE_LANE_MASK]])
8181
; CHECK-NEXT: br label [[MIDDLE_BLOCK:%.*]]
8282
; CHECK: middle.block:
83-
; CHECK-NEXT: br i1 true, label [[EXIT:%.*]], label [[SCALAR_PH]]
83+
; CHECK-NEXT: br label [[EXIT:%.*]]
8484
; CHECK: scalar.ph:
85-
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
85+
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ]
8686
; CHECK-NEXT: br label [[LOOP:%.*]]
8787
; CHECK: loop:
8888
; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[LOOP]] ], [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ]

‎llvm/test/Transforms/LoopVectorize/RISCV/vectorize-force-tail-with-evl-interleave.ll

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -66,9 +66,9 @@ define void @interleave(ptr noalias %a, ptr noalias %b, i64 %N) {
6666
; IF-EVL-NEXT: [[TMP33:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
6767
; IF-EVL-NEXT: br i1 [[TMP33]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
6868
; IF-EVL: middle.block:
69-
; IF-EVL-NEXT: br i1 true, label [[FOR_COND_CLEANUP:%.*]], label [[SCALAR_PH]]
69+
; IF-EVL-NEXT: br label [[FOR_COND_CLEANUP:%.*]]
7070
; IF-EVL: scalar.ph:
71-
; IF-EVL-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
71+
; IF-EVL-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ]
7272
; IF-EVL-NEXT: br label [[FOR_BODY:%.*]]
7373
; IF-EVL: for.body:
7474
; IF-EVL-NEXT: [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], [[FOR_BODY]] ]

‎llvm/test/Transforms/LoopVectorize/RISCV/vectorize-force-tail-with-evl-iv32.ll

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -44,9 +44,9 @@ define void @iv32(ptr noalias %a, ptr noalias %b, i32 %N) {
4444
; IF-EVL-NEXT: [[TMP18:%.*]] = icmp eq i32 [[IV_NEXT]], [[N_VEC]]
4545
; IF-EVL-NEXT: br i1 [[TMP18]], label [[MIDDLE_BLOCK:%.*]], label [[FOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
4646
; IF-EVL: middle.block:
47-
; IF-EVL-NEXT: br i1 true, label [[FOR_COND_CLEANUP:%.*]], label [[SCALAR_PH]]
47+
; IF-EVL-NEXT: br label [[FOR_COND_CLEANUP:%.*]]
4848
; IF-EVL: scalar.ph:
49-
; IF-EVL-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY1:%.*]] ]
49+
; IF-EVL-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ 0, [[ENTRY1:%.*]] ]
5050
; IF-EVL-NEXT: br label [[FOR_BODY1:%.*]]
5151
; IF-EVL: for.body:
5252
; IF-EVL-NEXT: [[IV1:%.*]] = phi i32 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[IV_NEXT1:%.*]], [[FOR_BODY1]] ]

‎llvm/test/Transforms/LoopVectorize/RISCV/vectorize-force-tail-with-evl-masked-loadstore.ll

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -58,9 +58,9 @@ define void @masked_loadstore(ptr noalias %a, ptr noalias %b, i64 %n) {
5858
; IF-EVL-NEXT: [[TMP22:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
5959
; IF-EVL-NEXT: br i1 [[TMP22]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
6060
; IF-EVL: middle.block:
61-
; IF-EVL-NEXT: br i1 true, label [[EXIT:%.*]], label [[SCALAR_PH]]
61+
; IF-EVL-NEXT: br label [[EXIT:%.*]]
6262
; IF-EVL: scalar.ph:
63-
; IF-EVL-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
63+
; IF-EVL-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ]
6464
; IF-EVL-NEXT: br label [[FOR_BODY:%.*]]
6565
; IF-EVL: for.body:
6666
; IF-EVL-NEXT: [[I_011:%.*]] = phi i64 [ [[INC:%.*]], [[FOR_INC:%.*]] ], [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ]

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