[llvm] [SCEVExp] Fix early exit in ComputeEndCheck. (PR #156910)
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 5 07:42:03 PDT 2025
https://github.com/fhahn updated https://github.com/llvm/llvm-project/pull/156910
>From 545ce94f6dc9c58c41274916e7ca729e018a653f Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Thu, 4 Sep 2025 15:45:46 +0100
Subject: [PATCH 1/2] [SCEVExp] Fix early exit in ComputeEndCheck.
ComputeEndCheck incorrectly returned false for unsigned predicates
starting at zero and a positive step.
The AddRec could still wrap if Step * trunc ExitCount wraps or trunc
ExitCount strips leading 1s.
Fixes https://github.com/llvm/llvm-project/issues/156849.
---
.../Utils/ScalarEvolutionExpander.cpp | 11 ++++-
.../LoopVectorize/X86/cost-model.ll | 49 ++++++++++---------
...aved-accesses-requiring-scev-predicates.ll | 17 +++++--
.../runtime-check-small-clamped-bounds.ll | 3 ++
4 files changed, 50 insertions(+), 30 deletions(-)
diff --git a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
index 3e3d51bffff33..7c12dac73f3d1 100644
--- a/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
@@ -2187,8 +2187,15 @@ Value *SCEVExpander::generateOverflowCheck(const SCEVAddRecExpr *AR,
// negative. If Step is known to be positive or negative, only create
// either 1. or 2.
auto ComputeEndCheck = [&]() -> Value * {
- // Checking <u 0 is always false.
- if (!Signed && Start->isZero() && SE.isKnownPositive(Step))
+ // Checking <u 0 is always false, if (Step * trunc ExitCount) does not wrap.
+ // TODO: Predicates that can be proven true/false should be discarded when
+ // the predicates are created, not late during expansion.
+ if (!Signed && Start->isZero() && SE.isKnownPositive(Step) &&
+ DstBits < SrcBits &&
+ ExitCount == SE.getZeroExtendExpr(SE.getTruncateExpr(ExitCount, ARTy),
+ ExitCount->getType()) &&
+ SE.willNotOverflow(Instruction::Mul, Signed, Step,
+ SE.getTruncateExpr(ExitCount, ARTy)))
return ConstantInt::getFalse(Loc->getContext());
// Get the backedge taken count and truncate or extended to the AR type.
diff --git a/llvm/test/Transforms/LoopVectorize/X86/cost-model.ll b/llvm/test/Transforms/LoopVectorize/X86/cost-model.ll
index b4c33aa7a50bc..2a2f82bfe4b3a 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/cost-model.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/cost-model.ll
@@ -224,7 +224,7 @@ define float @PR27826(ptr nocapture readonly %a, ptr nocapture readonly %b, i32
; CHECK-NEXT: [[IND_END9:%.*]] = mul i64 [[N_VEC]], 32
; CHECK-NEXT: [[N_VEC_REMAINING:%.*]] = sub i64 [[TMP2]], [[N_VEC]]
; CHECK-NEXT: [[MIN_EPILOG_ITERS_CHECK:%.*]] = icmp ult i64 [[N_VEC_REMAINING]], 4
-; CHECK-NEXT: br i1 [[MIN_EPILOG_ITERS_CHECK]], label [[VEC_EPILOG_SCALAR_PH]], label [[VEC_EPILOG_PH]]
+; CHECK-NEXT: br i1 [[MIN_EPILOG_ITERS_CHECK]], label [[VEC_EPILOG_SCALAR_PH]], label [[VEC_EPILOG_PH]], !prof [[PROF3:![0-9]+]]
; CHECK: vec.epilog.ph:
; CHECK-NEXT: [[VEC_EPILOG_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[VEC_EPILOG_ITER_CHECK]] ], [ 0, [[VECTOR_MAIN_LOOP_ITER_CHECK]] ]
; CHECK-NEXT: [[BC_MERGE_RDX:%.*]] = phi float [ [[TMP124]], [[VEC_EPILOG_ITER_CHECK]] ], [ 0.000000e+00, [[VECTOR_MAIN_LOOP_ITER_CHECK]] ]
@@ -269,7 +269,7 @@ define float @PR27826(ptr nocapture readonly %a, ptr nocapture readonly %b, i32
; CHECK-NEXT: [[TMP155]] = fadd fast <4 x float> [[TMP154]], [[TMP153]]
; CHECK-NEXT: [[INDEX_NEXT13]] = add nuw i64 [[INDEX10]], 4
; CHECK-NEXT: [[TMP156:%.*]] = icmp eq i64 [[INDEX_NEXT13]], [[N_VEC8]]
-; CHECK-NEXT: br i1 [[TMP156]], label [[VEC_EPILOG_MIDDLE_BLOCK:%.*]], label [[VEC_EPILOG_VECTOR_BODY]], !llvm.loop [[LOOP3:![0-9]+]]
+; CHECK-NEXT: br i1 [[TMP156]], label [[VEC_EPILOG_MIDDLE_BLOCK:%.*]], label [[VEC_EPILOG_VECTOR_BODY]], !llvm.loop [[LOOP4:![0-9]+]]
; CHECK: vec.epilog.middle.block:
; CHECK-NEXT: [[TMP157:%.*]] = call fast float @llvm.vector.reduce.fadd.v4f32(float 0.000000e+00, <4 x float> [[TMP155]])
; CHECK-NEXT: [[CMP_N14:%.*]] = icmp eq i64 [[TMP2]], [[N_VEC8]]
@@ -289,7 +289,7 @@ define float @PR27826(ptr nocapture readonly %a, ptr nocapture readonly %b, i32
; CHECK-NEXT: [[ADD4]] = fadd fast float [[ADD]], [[T2]]
; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 32
; CHECK-NEXT: [[CMP1:%.*]] = icmp slt i64 [[INDVARS_IV_NEXT]], [[T0]]
-; CHECK-NEXT: br i1 [[CMP1]], label [[FOR]], label [[LOOPEXIT]], !llvm.loop [[LOOP4:![0-9]+]]
+; CHECK-NEXT: br i1 [[CMP1]], label [[FOR]], label [[LOOPEXIT]], !llvm.loop [[LOOP5:![0-9]+]]
; CHECK: loopexit:
; CHECK-NEXT: [[ADD4_LCSSA:%.*]] = phi float [ [[ADD4]], [[FOR]] ], [ [[TMP124]], [[MIDDLE_BLOCK]] ], [ [[TMP157]], [[VEC_EPILOG_MIDDLE_BLOCK]] ]
; CHECK-NEXT: br label [[FOR_END]]
@@ -369,10 +369,10 @@ define void @multi_exit(ptr %dst, ptr %src.1, ptr %src.2, i64 %A, i64 %B) #0 {
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT: [[TMP13:%.*]] = load i64, ptr [[SRC_1]], align 8, !alias.scope [[META5:![0-9]+]]
+; CHECK-NEXT: [[TMP13:%.*]] = load i64, ptr [[SRC_1]], align 8, !alias.scope [[META6:![0-9]+]]
; CHECK-NEXT: [[BROADCAST_SPLATINSERT:%.*]] = insertelement <2 x i64> poison, i64 [[TMP13]], i64 0
; CHECK-NEXT: [[BROADCAST_SPLAT:%.*]] = shufflevector <2 x i64> [[BROADCAST_SPLATINSERT]], <2 x i64> poison, <2 x i32> zeroinitializer
-; CHECK-NEXT: [[TMP14:%.*]] = load i64, ptr [[SRC_2]], align 8, !alias.scope [[META8:![0-9]+]]
+; CHECK-NEXT: [[TMP14:%.*]] = load i64, ptr [[SRC_2]], align 8, !alias.scope [[META9:![0-9]+]]
; CHECK-NEXT: [[BROADCAST_SPLATINSERT9:%.*]] = insertelement <2 x i64> poison, i64 [[TMP14]], i64 0
; CHECK-NEXT: [[BROADCAST_SPLAT10:%.*]] = shufflevector <2 x i64> [[BROADCAST_SPLATINSERT9]], <2 x i64> poison, <2 x i32> zeroinitializer
; CHECK-NEXT: [[TMP15:%.*]] = icmp eq <2 x i64> [[BROADCAST_SPLAT]], zeroinitializer
@@ -380,10 +380,10 @@ define void @multi_exit(ptr %dst, ptr %src.1, ptr %src.2, i64 %A, i64 %B) #0 {
; CHECK-NEXT: [[TMP17:%.*]] = and <2 x i1> [[TMP16]], [[TMP15]]
; CHECK-NEXT: [[TMP18:%.*]] = zext <2 x i1> [[TMP17]] to <2 x i8>
; CHECK-NEXT: [[TMP19:%.*]] = extractelement <2 x i8> [[TMP18]], i32 1
-; CHECK-NEXT: store i8 [[TMP19]], ptr [[DST]], align 1, !alias.scope [[META10:![0-9]+]], !noalias [[META12:![0-9]+]]
+; CHECK-NEXT: store i8 [[TMP19]], ptr [[DST]], align 1, !alias.scope [[META11:![0-9]+]], !noalias [[META13:![0-9]+]]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
; CHECK-NEXT: [[TMP20:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
-; CHECK-NEXT: br i1 [[TMP20]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP13:![0-9]+]]
+; CHECK-NEXT: br i1 [[TMP20]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP14:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: br label [[SCALAR_PH]]
; CHECK: scalar.ph:
@@ -406,7 +406,7 @@ define void @multi_exit(ptr %dst, ptr %src.1, ptr %src.2, i64 %A, i64 %B) #0 {
; CHECK-NEXT: [[IV_1_NEXT]] = add i32 [[IV_1]], 1
; CHECK-NEXT: [[IV_1_NEXT_WIDE]] = zext i32 [[IV_1_NEXT]] to i64
; CHECK-NEXT: [[EC_2:%.*]] = icmp ult i64 [[IV_1_NEXT_WIDE]], [[B]]
-; CHECK-NEXT: br i1 [[EC_2]], label [[LOOP]], label [[EXIT]], !llvm.loop [[LOOP14:![0-9]+]]
+; CHECK-NEXT: br i1 [[EC_2]], label [[LOOP]], label [[EXIT]], !llvm.loop [[LOOP15:![0-9]+]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
@@ -485,7 +485,7 @@ define i1 @any_of_cost(ptr %start, ptr %end) #0 {
; CHECK-NEXT: [[TMP27]] = or <2 x i1> [[VEC_PHI3]], [[TMP25]]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
; CHECK-NEXT: [[TMP28:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
-; CHECK-NEXT: br i1 [[TMP28]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP15:![0-9]+]]
+; CHECK-NEXT: br i1 [[TMP28]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP16:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[BIN_RDX:%.*]] = or <2 x i1> [[TMP27]], [[TMP26]]
; CHECK-NEXT: [[TMP29:%.*]] = call i1 @llvm.vector.reduce.or.v2i1(<2 x i1> [[BIN_RDX]])
@@ -505,7 +505,7 @@ define i1 @any_of_cost(ptr %start, ptr %end) #0 {
; CHECK-NEXT: [[ANY_OF_NEXT]] = select i1 [[CMP13_NOT_NOT]], i1 [[ANY_OF]], i1 false
; CHECK-NEXT: [[PTR_IV_NEXT]] = getelementptr inbounds i8, ptr [[PTR_IV]], i64 40
; CHECK-NEXT: [[CMP_NOT:%.*]] = icmp eq ptr [[PTR_IV]], [[END]]
-; CHECK-NEXT: br i1 [[CMP_NOT]], label [[EXIT:%.*]], label [[LOOP]], !llvm.loop [[LOOP16:![0-9]+]]
+; CHECK-NEXT: br i1 [[CMP_NOT]], label [[EXIT:%.*]], label [[LOOP]], !llvm.loop [[LOOP17:![0-9]+]]
; CHECK: exit:
; CHECK-NEXT: [[ANY_OF_NEXT_LCSSA:%.*]] = phi i1 [ [[ANY_OF_NEXT]], [[LOOP]] ]
; CHECK-NEXT: ret i1 [[ANY_OF_NEXT_LCSSA]]
@@ -562,7 +562,7 @@ define i64 @cost_assume(ptr %end, i64 %N) {
; CHECK-NEXT: tail call void @llvm.assume(i1 [[TMP11]])
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 8
; CHECK-NEXT: [[TMP13:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
-; CHECK-NEXT: br i1 [[TMP13]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP20:![0-9]+]]
+; CHECK-NEXT: br i1 [[TMP13]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP18:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[BIN_RDX:%.*]] = add <2 x i64> [[TMP8]], [[TMP7]]
; CHECK-NEXT: [[BIN_RDX5:%.*]] = add <2 x i64> [[TMP9]], [[BIN_RDX]]
@@ -583,7 +583,7 @@ define i64 @cost_assume(ptr %end, i64 %N) {
; CHECK-NEXT: tail call void @llvm.assume(i1 [[C]])
; CHECK-NEXT: [[GEP:%.*]] = getelementptr nusw [9 x i8], ptr null, i64 [[IV_NEXT]]
; CHECK-NEXT: [[EC:%.*]] = icmp eq ptr [[GEP]], [[END]]
-; CHECK-NEXT: br i1 [[EC]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP21:![0-9]+]]
+; CHECK-NEXT: br i1 [[EC]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP19:![0-9]+]]
; CHECK: exit:
; CHECK-NEXT: [[DOTLCSSA:%.*]] = phi i64 [ [[TMP12]], [[LOOP]] ], [ [[TMP14]], [[MIDDLE_BLOCK]] ]
; CHECK-NEXT: ret i64 [[DOTLCSSA]]
@@ -627,7 +627,7 @@ define void @reduction_store(ptr noalias %src, ptr %dst, i1 %x) #2 {
; CHECK-NEXT: [[TMP12]] = and <4 x i32> [[VEC_PHI1]], [[TMP2]]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i32 [[INDEX]], 8
; CHECK-NEXT: [[TMP9:%.*]] = icmp eq i32 [[INDEX_NEXT]], 24
-; CHECK-NEXT: br i1 [[TMP9]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP22:![0-9]+]]
+; CHECK-NEXT: br i1 [[TMP9]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP20:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[BIN_RDX:%.*]] = and <4 x i32> [[TMP12]], [[TMP11]]
; CHECK-NEXT: [[TMP10:%.*]] = call i32 @llvm.vector.reduce.and.v4i32(<4 x i32> [[BIN_RDX]])
@@ -651,7 +651,7 @@ define void @reduction_store(ptr noalias %src, ptr %dst, i1 %x) #2 {
; CHECK-NEXT: store i32 [[RED_NEXT]], ptr [[DST]], align 4
; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 1
; CHECK-NEXT: [[EC:%.*]] = icmp eq i32 [[IV]], 29
-; CHECK-NEXT: br i1 [[EC]], label [[EXIT:%.*]], label [[LOOP]], !llvm.loop [[LOOP23:![0-9]+]]
+; CHECK-NEXT: br i1 [[EC]], label [[EXIT:%.*]], label [[LOOP]], !llvm.loop [[LOOP21:![0-9]+]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
@@ -696,7 +696,7 @@ define i64 @live_in_known_1_via_scev() {
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi <4 x i64> [ <i64 3, i64 1, i64 1, i64 1>, [[VECTOR_PH]] ], [ [[VEC_PHI]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i32 [[INDEX]], 4
; CHECK-NEXT: [[TMP0:%.*]] = icmp eq i32 [[INDEX_NEXT]], 8
-; CHECK-NEXT: br i1 [[TMP0]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP24:![0-9]+]]
+; CHECK-NEXT: br i1 [[TMP0]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP22:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[TMP3:%.*]] = call i64 @llvm.vector.reduce.mul.v4i64(<4 x i64> [[VEC_PHI]])
; CHECK-NEXT: br label [[EXIT:%.*]]
@@ -708,7 +708,7 @@ define i64 @live_in_known_1_via_scev() {
; CHECK-NEXT: [[RED_MUL]] = mul nsw i64 [[RED]], [[P_EXT]]
; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
; CHECK-NEXT: [[EC:%.*]] = icmp eq i32 [[IV_NEXT]], [[N]]
-; CHECK-NEXT: br i1 [[EC]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP25:![0-9]+]]
+; CHECK-NEXT: br i1 [[EC]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP23:![0-9]+]]
; CHECK: exit:
; CHECK-NEXT: [[RES:%.*]] = phi i64 [ [[RED_MUL]], [[LOOP]] ], [ [[TMP3]], [[MIDDLE_BLOCK]] ]
; CHECK-NEXT: ret i64 [[RES]]
@@ -753,7 +753,7 @@ define i64 @cost_loop_invariant_recipes(i1 %x, i64 %y) {
; CHECK: vector.body:
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi <2 x i64> [ splat (i64 1), [[VECTOR_PH]] ], [ [[TMP3:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP3]] = mul <2 x i64> [[TMP2]], [[VEC_PHI]]
-; CHECK-NEXT: br i1 true, label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP26:![0-9]+]]
+; CHECK-NEXT: br i1 true, label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP24:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[TMP4:%.*]] = call i64 @llvm.vector.reduce.mul.v2i64(<2 x i64> [[TMP3]])
; CHECK-NEXT: br label [[EXIT:%.*]]
@@ -768,7 +768,7 @@ define i64 @cost_loop_invariant_recipes(i1 %x, i64 %y) {
; CHECK-NEXT: [[RED_MUL]] = mul i64 [[SHL]], [[RED]]
; CHECK-NEXT: [[IV_NEXT_I_I_I]] = add i64 [[IV]], 1
; CHECK-NEXT: [[EC:%.*]] = icmp eq i64 [[IV]], 1
-; CHECK-NEXT: br i1 [[EC]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP27:![0-9]+]]
+; CHECK-NEXT: br i1 [[EC]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP25:![0-9]+]]
; CHECK: exit:
; CHECK-NEXT: [[RED_MUL_LCSSA:%.*]] = phi i64 [ [[RED_MUL]], [[LOOP]] ], [ [[TMP4]], [[MIDDLE_BLOCK]] ]
; CHECK-NEXT: ret i64 [[RED_MUL_LCSSA]]
@@ -807,7 +807,7 @@ define i32 @narrowed_reduction(ptr %a, i1 %cmp) #0 {
; CHECK-NEXT: [[TMP3:%.*]] = or <16 x i32> [[TMP1]], [[BROADCAST_SPLAT]]
; CHECK-NEXT: [[TMP5:%.*]] = trunc <16 x i32> [[TMP3]] to <16 x i1>
; CHECK-NEXT: [[TMP7]] = zext <16 x i1> [[TMP5]] to <16 x i32>
-; CHECK-NEXT: br i1 true, label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP28:![0-9]+]]
+; CHECK-NEXT: br i1 true, label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP26:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[TMP20:%.*]] = call i1 @llvm.vector.reduce.or.v16i1(<16 x i1> [[TMP5]])
; CHECK-NEXT: [[TMP21:%.*]] = zext i1 [[TMP20]] to i32
@@ -821,7 +821,7 @@ define i32 @narrowed_reduction(ptr %a, i1 %cmp) #0 {
; CHECK-NEXT: [[OR]] = or i32 [[AND]], [[CONV]]
; CHECK-NEXT: [[INC]] = add i32 [[IV]], 1
; CHECK-NEXT: [[EC:%.*]] = icmp eq i32 [[IV]], 16
-; CHECK-NEXT: br i1 [[EC]], label [[EXIT]], label [[LOOP1]], !llvm.loop [[LOOP29:![0-9]+]]
+; CHECK-NEXT: br i1 [[EC]], label [[EXIT]], label [[LOOP1]], !llvm.loop [[LOOP27:![0-9]+]]
; CHECK: exit:
; CHECK-NEXT: [[OR_LCSSA:%.*]] = phi i32 [ [[OR]], [[LOOP1]] ], [ [[TMP21]], [[MIDDLE_BLOCK]] ]
; CHECK-NEXT: ret i32 [[OR_LCSSA]]
@@ -853,6 +853,7 @@ define i32 @g(i64 %n) {
; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i32 [[TMP1]], 4
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[VEC_EPILOG_SCALAR_PH:%.*]], label [[VECTOR_SCEVCHECK:%.*]]
; CHECK: vector.scevcheck:
+; CHECK-NEXT: [[TMP28:%.*]] = trunc i64 [[N]] to i32
; CHECK-NEXT: [[TMP2:%.*]] = icmp ugt i64 [[N]], 4294967295
; CHECK-NEXT: br i1 [[TMP2]], label [[VEC_EPILOG_SCALAR_PH]], label [[VECTOR_MAIN_LOOP_ITER_CHECK:%.*]]
; CHECK: vector.main.loop.iter.check:
@@ -893,7 +894,7 @@ define i32 @g(i64 %n) {
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i32 [[INDEX]], 16
; CHECK-NEXT: [[VEC_IND_NEXT]] = add <4 x i32> [[STEP_ADD_3]], splat (i32 4)
; CHECK-NEXT: [[TMP19:%.*]] = icmp eq i32 [[INDEX_NEXT]], [[N_VEC]]
-; CHECK-NEXT: br i1 [[TMP19]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP30:![0-9]+]]
+; CHECK-NEXT: br i1 [[TMP19]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP28:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[BIN_RDX:%.*]] = or <4 x i32> [[TMP16]], [[TMP15]]
; CHECK-NEXT: [[BIN_RDX5:%.*]] = or <4 x i32> [[TMP17]], [[BIN_RDX]]
@@ -904,7 +905,7 @@ define i32 @g(i64 %n) {
; CHECK: vec.epilog.iter.check:
; CHECK-NEXT: [[N_VEC_REMAINING:%.*]] = sub i32 [[TMP1]], [[N_VEC]]
; CHECK-NEXT: [[MIN_EPILOG_ITERS_CHECK:%.*]] = icmp ult i32 [[N_VEC_REMAINING]], 4
-; CHECK-NEXT: br i1 [[MIN_EPILOG_ITERS_CHECK]], label [[VEC_EPILOG_SCALAR_PH]], label [[VEC_EPILOG_PH]]
+; CHECK-NEXT: br i1 [[MIN_EPILOG_ITERS_CHECK]], label [[VEC_EPILOG_SCALAR_PH]], label [[VEC_EPILOG_PH]], !prof [[PROF3]]
; CHECK: vec.epilog.ph:
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ [[N_VEC]], [[VEC_EPILOG_ITER_CHECK]] ], [ 0, [[VECTOR_MAIN_LOOP_ITER_CHECK]] ]
; CHECK-NEXT: [[BC_MERGE_RDX:%.*]] = phi i32 [ [[TMP20]], [[VEC_EPILOG_ITER_CHECK]] ], [ 0, [[VECTOR_MAIN_LOOP_ITER_CHECK]] ]
@@ -928,7 +929,7 @@ define i32 @g(i64 %n) {
; CHECK-NEXT: [[INDEX_NEXT15]] = add nuw i32 [[INDEX9]], 4
; CHECK-NEXT: [[VEC_IND_NEXT11]] = add <4 x i32> [[VEC_IND10]], splat (i32 4)
; CHECK-NEXT: [[TMP26:%.*]] = icmp eq i32 [[INDEX_NEXT15]], [[N_VEC8]]
-; CHECK-NEXT: br i1 [[TMP26]], label [[VEC_EPILOG_MIDDLE_BLOCK:%.*]], label [[VEC_EPILOG_VECTOR_BODY]], !llvm.loop [[LOOP31:![0-9]+]]
+; CHECK-NEXT: br i1 [[TMP26]], label [[VEC_EPILOG_MIDDLE_BLOCK:%.*]], label [[VEC_EPILOG_VECTOR_BODY]], !llvm.loop [[LOOP29:![0-9]+]]
; CHECK: vec.epilog.middle.block:
; CHECK-NEXT: [[TMP27:%.*]] = call i32 @llvm.vector.reduce.or.v4i32(<4 x i32> [[TMP25]])
; CHECK-NEXT: [[CMP_N16:%.*]] = icmp eq i32 [[TMP1]], [[N_VEC8]]
@@ -945,7 +946,7 @@ define i32 @g(i64 %n) {
; CHECK-NEXT: [[SELECT_I:%.*]] = select i1 [[EXITCOND]], i32 0, i32 2
; CHECK-NEXT: [[SELECT_NEXT]] = or i32 [[SELECT_I]], [[SELECT]]
; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 1
-; CHECK-NEXT: br i1 [[EXITCOND]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP32:![0-9]+]]
+; CHECK-NEXT: br i1 [[EXITCOND]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP30:![0-9]+]]
; CHECK: exit:
; CHECK-NEXT: [[SELECT_NEXT_LCSSA:%.*]] = phi i32 [ [[SELECT_NEXT]], [[LOOP]] ], [ [[TMP20]], [[MIDDLE_BLOCK]] ], [ [[TMP27]], [[VEC_EPILOG_MIDDLE_BLOCK]] ]
; CHECK-NEXT: ret i32 [[SELECT_NEXT_LCSSA]]
diff --git a/llvm/test/Transforms/LoopVectorize/interleaved-accesses-requiring-scev-predicates.ll b/llvm/test/Transforms/LoopVectorize/interleaved-accesses-requiring-scev-predicates.ll
index bb6c47b195e0b..9bf3c448e2cce 100644
--- a/llvm/test/Transforms/LoopVectorize/interleaved-accesses-requiring-scev-predicates.ll
+++ b/llvm/test/Transforms/LoopVectorize/interleaved-accesses-requiring-scev-predicates.ll
@@ -119,12 +119,16 @@ exit:
; For %gep, we have the following SCEV: ((4 * (zext i4 {0,+,5}<%loop> to i64))<nuw><nsw> + %x).
; Note the i4 bit wide AddRec {0,+,5}. It is known to wrap in the loop with trip count 16.
-; FIXME: Currently we incorrectly assume the widened AddRec does not wrap.
define void @wrap_predicate_for_interleave_group_wraps_for_known_trip_count(ptr noalias %x, ptr noalias %out) {
; CHECK-LABEL: define void @wrap_predicate_for_interleave_group_wraps_for_known_trip_count(
; CHECK-SAME: ptr noalias [[X:%.*]], ptr noalias [[OUT:%.*]]) {
; CHECK-NEXT: [[START:.*]]:
-; CHECK-NEXT: br i1 false, label %[[SCALAR_PH:.*]], label %[[VECTOR_PH:.*]]
+; CHECK-NEXT: br i1 false, label %[[SCALAR_PH:.*]], label %[[VECTOR_SCEVCHECK:.*]]
+; CHECK: [[VECTOR_SCEVCHECK]]:
+; CHECK-NEXT: [[MUL:%.*]] = call { i4, i1 } @llvm.umul.with.overflow.i4(i4 5, i4 -1)
+; CHECK-NEXT: [[MUL_RESULT:%.*]] = extractvalue { i4, i1 } [[MUL]], 0
+; CHECK-NEXT: [[MUL_OVERFLOW:%.*]] = extractvalue { i4, i1 } [[MUL]], 1
+; CHECK-NEXT: br i1 [[MUL_OVERFLOW]], label %[[SCALAR_PH]], label %[[VECTOR_PH:.*]]
; CHECK: [[VECTOR_PH]]:
; CHECK-NEXT: br label %[[VECTOR_BODY:.*]]
; CHECK: [[VECTOR_BODY]]:
@@ -142,7 +146,7 @@ define void @wrap_predicate_for_interleave_group_wraps_for_known_trip_count(ptr
; CHECK: [[MIDDLE_BLOCK]]:
; CHECK-NEXT: br label %[[SCALAR_PH]]
; CHECK: [[SCALAR_PH]]:
-; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 12, %[[MIDDLE_BLOCK]] ], [ 0, %[[START]] ]
+; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 12, %[[MIDDLE_BLOCK]] ], [ 0, %[[START]] ], [ 0, %[[VECTOR_SCEVCHECK]] ]
; CHECK-NEXT: br label %[[LOOP:.*]]
; CHECK: [[LOOP]]:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], %[[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
@@ -187,8 +191,13 @@ define void @wrap_predicate_for_interleave_group_unknown_trip_count(ptr noalias
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label %[[SCALAR_PH:.*]], label %[[VECTOR_SCEVCHECK:.*]]
; CHECK: [[VECTOR_SCEVCHECK]]:
; CHECK-NEXT: [[TMP0:%.*]] = add i64 [[N]], -1
+; CHECK-NEXT: [[TMP9:%.*]] = trunc i64 [[TMP0]] to i4
+; CHECK-NEXT: [[MUL:%.*]] = call { i4, i1 } @llvm.umul.with.overflow.i4(i4 3, i4 [[TMP9]])
+; CHECK-NEXT: [[MUL_RESULT:%.*]] = extractvalue { i4, i1 } [[MUL]], 0
+; CHECK-NEXT: [[MUL_OVERFLOW:%.*]] = extractvalue { i4, i1 } [[MUL]], 1
; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i64 [[TMP0]], 15
-; CHECK-NEXT: br i1 [[TMP1]], label %[[SCALAR_PH]], label %[[VECTOR_PH:.*]]
+; CHECK-NEXT: [[TMP10:%.*]] = or i1 [[MUL_OVERFLOW]], [[TMP1]]
+; CHECK-NEXT: br i1 [[TMP10]], label %[[SCALAR_PH]], label %[[VECTOR_PH:.*]]
; CHECK: [[VECTOR_PH]]:
; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i64 [[N]], 4
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i64 [[N_MOD_VF]], 0
diff --git a/llvm/test/Transforms/LoopVectorize/runtime-check-small-clamped-bounds.ll b/llvm/test/Transforms/LoopVectorize/runtime-check-small-clamped-bounds.ll
index 1035642dd78e0..04dd6dfbf780d 100644
--- a/llvm/test/Transforms/LoopVectorize/runtime-check-small-clamped-bounds.ll
+++ b/llvm/test/Transforms/LoopVectorize/runtime-check-small-clamped-bounds.ll
@@ -19,6 +19,7 @@ define void @load_clamped_index(ptr %A, ptr %B, i32 %N) {
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_SCEVCHECK:%.*]]
; CHECK: vector.scevcheck:
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[N]], -1
+; CHECK-NEXT: [[TMP3:%.*]] = trunc i32 [[TMP0]] to i2
; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i32 [[TMP0]], 3
; CHECK-NEXT: br i1 [[TMP1]], label [[SCALAR_PH]], label [[VECTOR_MEMCHECK:%.*]]
; CHECK: vector.memcheck:
@@ -89,6 +90,7 @@ define void @store_clamped_index(ptr %A, ptr %B, i32 %N) {
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_SCEVCHECK:%.*]]
; CHECK: vector.scevcheck:
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[N]], -1
+; CHECK-NEXT: [[TMP3:%.*]] = trunc i32 [[TMP0]] to i2
; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i32 [[TMP0]], 3
; CHECK-NEXT: br i1 [[TMP1]], label [[SCALAR_PH]], label [[VECTOR_MEMCHECK:%.*]]
; CHECK: vector.memcheck:
@@ -353,6 +355,7 @@ define void @clamped_index_equal_dependence(ptr %A, ptr %B, i32 %N) {
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_SCEVCHECK:%.*]]
; CHECK: vector.scevcheck:
; CHECK-NEXT: [[TMP0:%.*]] = add i32 [[N]], -1
+; CHECK-NEXT: [[TMP2:%.*]] = trunc i32 [[TMP0]] to i2
; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i32 [[TMP0]], 3
; CHECK-NEXT: br i1 [[TMP1]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
>From f3d00de6978d54e0d4b8570c1aa152ae2b837379 Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Thu, 4 Sep 2025 16:27:14 +0100
Subject: [PATCH 2/2] !fixup update additional tests
---
.../scev-inserted-runtime-check.ll | 18 ++++++++++++++----
.../wrapping-pointer-versioning.ll | 9 +++++++--
2 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/llvm/test/Transforms/LoopDistribute/scev-inserted-runtime-check.ll b/llvm/test/Transforms/LoopDistribute/scev-inserted-runtime-check.ll
index dd23a1121ebcb..bfd0ec0340fbb 100644
--- a/llvm/test/Transforms/LoopDistribute/scev-inserted-runtime-check.ll
+++ b/llvm/test/Transforms/LoopDistribute/scev-inserted-runtime-check.ll
@@ -10,8 +10,13 @@ define void @f(ptr noalias %a, ptr noalias %b, ptr noalias %c, ptr noalias %d, p
; CHECK-NEXT: br label [[FOR_BODY_LVER_CHECK:%.*]]
; CHECK: for.body.lver.check:
; CHECK-NEXT: [[TMP0:%.*]] = add i64 [[N:%.*]], -1
+; CHECK-NEXT: [[TMP2:%.*]] = trunc i64 [[TMP0]] to i32
+; CHECK-NEXT: [[MUL1:%.*]] = call { i32, i1 } @llvm.umul.with.overflow.i32(i32 2, i32 [[TMP2]])
+; CHECK-NEXT: [[MUL_RESULT:%.*]] = extractvalue { i32, i1 } [[MUL1]], 0
+; CHECK-NEXT: [[MUL_OVERFLOW:%.*]] = extractvalue { i32, i1 } [[MUL1]], 1
; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i64 [[TMP0]], 4294967295
-; CHECK-NEXT: br i1 [[TMP1]], label [[FOR_BODY_PH_LVER_ORIG:%.*]], label [[FOR_BODY_PH_LDIST1:%.*]]
+; CHECK-NEXT: [[TMP3:%.*]] = or i1 [[MUL_OVERFLOW]], [[TMP1]]
+; CHECK-NEXT: br i1 [[TMP3]], label [[FOR_BODY_PH_LVER_ORIG:%.*]], label [[FOR_BODY_PH_LDIST1:%.*]]
; CHECK: for.body.ph.lver.orig:
; CHECK-NEXT: br label [[FOR_BODY_LVER_ORIG:%.*]]
; CHECK: for.body.lver.orig:
@@ -75,7 +80,7 @@ define void @f(ptr noalias %a, ptr noalias %b, ptr noalias %c, ptr noalias %d, p
; CHECK-NEXT: br i1 [[EXITCOND]], label [[FOR_END_LOOPEXIT2:%.*]], label [[FOR_BODY]]
; CHECK: for.end.loopexit:
; CHECK-NEXT: br label [[FOR_END:%.*]]
-; CHECK: for.end.loopexit1:
+; CHECK: for.end.loopexit2:
; CHECK-NEXT: br label [[FOR_END]]
; CHECK: for.end:
; CHECK-NEXT: ret void
@@ -135,8 +140,13 @@ define void @f_with_offset(ptr noalias %b, ptr noalias %c, ptr noalias %d, ptr n
; CHECK-NEXT: br label [[FOR_BODY_LVER_CHECK:%.*]]
; CHECK: for.body.lver.check:
; CHECK-NEXT: [[TMP0:%.*]] = add i64 [[N:%.*]], -1
+; CHECK-NEXT: [[TMP2:%.*]] = trunc i64 [[TMP0]] to i32
+; CHECK-NEXT: [[MUL1:%.*]] = call { i32, i1 } @llvm.umul.with.overflow.i32(i32 2, i32 [[TMP2]])
+; CHECK-NEXT: [[MUL_RESULT:%.*]] = extractvalue { i32, i1 } [[MUL1]], 0
+; CHECK-NEXT: [[MUL_OVERFLOW:%.*]] = extractvalue { i32, i1 } [[MUL1]], 1
; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i64 [[TMP0]], 4294967295
-; CHECK-NEXT: br i1 [[TMP1]], label [[FOR_BODY_PH_LVER_ORIG:%.*]], label [[FOR_BODY_PH_LDIST1:%.*]]
+; CHECK-NEXT: [[TMP3:%.*]] = or i1 [[MUL_OVERFLOW]], [[TMP1]]
+; CHECK-NEXT: br i1 [[TMP3]], label [[FOR_BODY_PH_LVER_ORIG:%.*]], label [[FOR_BODY_PH_LDIST1:%.*]]
; CHECK: for.body.ph.lver.orig:
; CHECK-NEXT: br label [[FOR_BODY_LVER_ORIG:%.*]]
; CHECK: for.body.lver.orig:
@@ -200,7 +210,7 @@ define void @f_with_offset(ptr noalias %b, ptr noalias %c, ptr noalias %d, ptr n
; CHECK-NEXT: br i1 [[EXITCOND]], label [[FOR_END_LOOPEXIT2:%.*]], label [[FOR_BODY]]
; CHECK: for.end.loopexit:
; CHECK-NEXT: br label [[FOR_END:%.*]]
-; CHECK: for.end.loopexit1:
+; CHECK: for.end.loopexit2:
; CHECK-NEXT: br label [[FOR_END]]
; CHECK: for.end:
; CHECK-NEXT: ret void
diff --git a/llvm/test/Transforms/LoopVersioning/wrapping-pointer-versioning.ll b/llvm/test/Transforms/LoopVersioning/wrapping-pointer-versioning.ll
index 6e5eeaf9f1218..3e25695304854 100644
--- a/llvm/test/Transforms/LoopVersioning/wrapping-pointer-versioning.ll
+++ b/llvm/test/Transforms/LoopVersioning/wrapping-pointer-versioning.ll
@@ -29,7 +29,12 @@ define void @f1(ptr noalias %a,
; LV-LABEL: @f1(
; LV-NEXT: for.body.lver.check:
; LV-NEXT: [[TMP0:%.*]] = add i64 [[N:%.*]], -1
+; LV-NEXT: [[TMP5:%.*]] = trunc i64 [[TMP0]] to i32
+; LV-NEXT: [[MUL2:%.*]] = call { i32, i1 } @llvm.umul.with.overflow.i32(i32 2, i32 [[TMP5]])
+; LV-NEXT: [[MUL_RESULT1:%.*]] = extractvalue { i32, i1 } [[MUL2]], 0
+; LV-NEXT: [[MUL_OVERFLOW1:%.*]] = extractvalue { i32, i1 } [[MUL2]], 1
; LV-NEXT: [[TMP1:%.*]] = icmp ugt i64 [[TMP0]], 4294967295
+; LV-NEXT: [[TMP8:%.*]] = or i1 [[MUL_OVERFLOW1]], [[TMP1]]
; LV-NEXT: [[MUL1:%.*]] = call { i64, i1 } @llvm.umul.with.overflow.i64(i64 4, i64 [[TMP0]])
; LV-NEXT: [[MUL_RESULT:%.*]] = extractvalue { i64, i1 } [[MUL1]], 0
; LV-NEXT: [[MUL_OVERFLOW:%.*]] = extractvalue { i64, i1 } [[MUL1]], 1
@@ -37,7 +42,7 @@ define void @f1(ptr noalias %a,
; LV-NEXT: [[TMP3:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 [[MUL_RESULT]]
; LV-NEXT: [[TMP4:%.*]] = icmp ult ptr [[TMP3]], [[A]]
; LV-NEXT: [[TMP6:%.*]] = or i1 [[TMP4]], [[MUL_OVERFLOW]]
-; LV-NEXT: [[TMP7:%.*]] = or i1 [[TMP1]], [[TMP6]]
+; LV-NEXT: [[TMP7:%.*]] = or i1 [[TMP8]], [[TMP6]]
; LV-NEXT: br i1 [[TMP7]], label [[FOR_BODY_PH_LVER_ORIG:%.*]], label [[FOR_BODY_PH:%.*]]
; LV: for.body.ph.lver.orig:
; LV-NEXT: br label [[FOR_BODY_LVER_ORIG:%.*]]
@@ -75,7 +80,7 @@ define void @f1(ptr noalias %a,
; LV-NEXT: br i1 [[EXITCOND]], label [[FOR_END_LOOPEXIT2:%.*]], label [[FOR_BODY]]
; LV: for.end.loopexit:
; LV-NEXT: br label [[FOR_END:%.*]]
-; LV: for.end.loopexit2:
+; LV: for.end.loopexit5:
; LV-NEXT: br label [[FOR_END]]
; LV: for.end:
; LV-NEXT: ret void
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