[llvm] 1f3f987 - [VPlan] Fix crash when narrowing interleave-groups with reuse.

Florian Hahn via llvm-commits llvm-commits at lists.llvm.org
Fri Jul 4 13:32:35 PDT 2025


Author: Florian Hahn
Date: 2025-07-04T21:32:24+01:00
New Revision: 1f3f9874b025057add56bfe27e792bcb04bde43e

URL: https://github.com/llvm/llvm-project/commit/1f3f9874b025057add56bfe27e792bcb04bde43e
DIFF: https://github.com/llvm/llvm-project/commit/1f3f9874b025057add56bfe27e792bcb04bde43e.diff

LOG: [VPlan] Fix crash when narrowing interleave-groups with reuse.

If a wide load is used multiple times in an expression, it will be
narrowed the first time. Re-use the already narrowed op in that case to
fix crash.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
    llvm/test/Transforms/LoopVectorize/AArch64/transform-narrow-interleave-to-widen-memory-cost.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index 8e05b0138eeed..75c7b20250846 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -3251,6 +3251,12 @@ void VPlanTransforms::narrowInterleaveGroups(VPlan &Plan, ElementCount VF,
       return L;
     }
 
+    if (auto *RepR = dyn_cast<VPReplicateRecipe>(R)) {
+      assert(RepR->isSingleScalar() &&
+             isa<LoadInst>(RepR->getUnderlyingInstr()) &&
+             "must be a single scalar load");
+      return RepR;
+    }
     auto *WideLoad = cast<VPWidenLoadRecipe>(R);
 
     // Narrow wide load to uniform scalar load, as transformed VPlan will only

diff  --git a/llvm/test/Transforms/LoopVectorize/AArch64/transform-narrow-interleave-to-widen-memory-cost.ll b/llvm/test/Transforms/LoopVectorize/AArch64/transform-narrow-interleave-to-widen-memory-cost.ll
index 1ca118572d54f..173766cc0a656 100644
--- a/llvm/test/Transforms/LoopVectorize/AArch64/transform-narrow-interleave-to-widen-memory-cost.ll
+++ b/llvm/test/Transforms/LoopVectorize/AArch64/transform-narrow-interleave-to-widen-memory-cost.ll
@@ -277,4 +277,174 @@ exit:
   ret void
 }
 
+define void @single_fmul_used_by_each_member(ptr noalias %A, ptr noalias %B, ptr noalias %C, i64 %n) #0 {
+; CHECK-LABEL: define void @single_fmul_used_by_each_member(
+; CHECK-SAME: ptr noalias [[A:%.*]], ptr noalias [[B:%.*]], ptr noalias [[C:%.*]], i64 [[N:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:  [[ITER_CHECK:.*]]:
+; CHECK-NEXT:    [[TMP0:%.*]] = add i64 [[N]], 1
+; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP0]], 2
+; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label %[[VEC_EPILOG_SCALAR_PH:.*]], label %[[VECTOR_SCEVCHECK:.*]]
+; CHECK:       [[VECTOR_SCEVCHECK]]:
+; CHECK-NEXT:    [[SCEVGEP:%.*]] = getelementptr i8, ptr [[B]], i64 8
+; CHECK-NEXT:    [[MUL:%.*]] = call { i64, i1 } @llvm.umul.with.overflow.i64(i64 16, i64 [[N]])
+; CHECK-NEXT:    [[MUL_RESULT:%.*]] = extractvalue { i64, i1 } [[MUL]], 0
+; CHECK-NEXT:    [[MUL_OVERFLOW:%.*]] = extractvalue { i64, i1 } [[MUL]], 1
+; CHECK-NEXT:    [[TMP1:%.*]] = sub i64 0, [[MUL_RESULT]]
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr i8, ptr [[SCEVGEP]], i64 [[MUL_RESULT]]
+; CHECK-NEXT:    [[TMP3:%.*]] = icmp ult ptr [[TMP2]], [[SCEVGEP]]
+; CHECK-NEXT:    [[TMP4:%.*]] = or i1 [[TMP3]], [[MUL_OVERFLOW]]
+; CHECK-NEXT:    [[MUL1:%.*]] = call { i64, i1 } @llvm.umul.with.overflow.i64(i64 16, i64 [[N]])
+; CHECK-NEXT:    [[MUL_RESULT2:%.*]] = extractvalue { i64, i1 } [[MUL1]], 0
+; CHECK-NEXT:    [[MUL_OVERFLOW3:%.*]] = extractvalue { i64, i1 } [[MUL1]], 1
+; CHECK-NEXT:    [[TMP5:%.*]] = sub i64 0, [[MUL_RESULT2]]
+; CHECK-NEXT:    [[TMP6:%.*]] = getelementptr i8, ptr [[B]], i64 [[MUL_RESULT2]]
+; CHECK-NEXT:    [[TMP7:%.*]] = icmp ult ptr [[TMP6]], [[B]]
+; CHECK-NEXT:    [[TMP8:%.*]] = or i1 [[TMP7]], [[MUL_OVERFLOW3]]
+; CHECK-NEXT:    [[SCEVGEP4:%.*]] = getelementptr i8, ptr [[C]], i64 8
+; CHECK-NEXT:    [[MUL5:%.*]] = call { i64, i1 } @llvm.umul.with.overflow.i64(i64 16, i64 [[N]])
+; CHECK-NEXT:    [[MUL_RESULT6:%.*]] = extractvalue { i64, i1 } [[MUL5]], 0
+; CHECK-NEXT:    [[MUL_OVERFLOW7:%.*]] = extractvalue { i64, i1 } [[MUL5]], 1
+; CHECK-NEXT:    [[TMP9:%.*]] = sub i64 0, [[MUL_RESULT6]]
+; CHECK-NEXT:    [[TMP10:%.*]] = getelementptr i8, ptr [[SCEVGEP4]], i64 [[MUL_RESULT6]]
+; CHECK-NEXT:    [[TMP11:%.*]] = icmp ult ptr [[TMP10]], [[SCEVGEP4]]
+; CHECK-NEXT:    [[TMP12:%.*]] = or i1 [[TMP11]], [[MUL_OVERFLOW7]]
+; CHECK-NEXT:    [[MUL8:%.*]] = call { i64, i1 } @llvm.umul.with.overflow.i64(i64 16, i64 [[N]])
+; CHECK-NEXT:    [[MUL_RESULT9:%.*]] = extractvalue { i64, i1 } [[MUL8]], 0
+; CHECK-NEXT:    [[MUL_OVERFLOW10:%.*]] = extractvalue { i64, i1 } [[MUL8]], 1
+; CHECK-NEXT:    [[TMP13:%.*]] = sub i64 0, [[MUL_RESULT9]]
+; CHECK-NEXT:    [[TMP14:%.*]] = getelementptr i8, ptr [[C]], i64 [[MUL_RESULT9]]
+; CHECK-NEXT:    [[TMP15:%.*]] = icmp ult ptr [[TMP14]], [[C]]
+; CHECK-NEXT:    [[TMP16:%.*]] = or i1 [[TMP15]], [[MUL_OVERFLOW10]]
+; CHECK-NEXT:    [[TMP17:%.*]] = or i1 [[TMP4]], [[TMP8]]
+; CHECK-NEXT:    [[TMP18:%.*]] = or i1 [[TMP17]], [[TMP12]]
+; CHECK-NEXT:    [[TMP19:%.*]] = or i1 [[TMP18]], [[TMP16]]
+; CHECK-NEXT:    br i1 [[TMP19]], label %[[VEC_EPILOG_SCALAR_PH]], label %[[VECTOR_MAIN_LOOP_ITER_CHECK:.*]]
+; CHECK:       [[VECTOR_MAIN_LOOP_ITER_CHECK]]:
+; CHECK-NEXT:    [[MIN_ITERS_CHECK11:%.*]] = icmp ult i64 [[TMP0]], 8
+; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK11]], label %[[VEC_EPILOG_PH:.*]], label %[[VECTOR_PH:.*]]
+; CHECK:       [[VECTOR_PH]]:
+; CHECK-NEXT:    [[N_MOD_VF:%.*]] = urem i64 [[TMP0]], 8
+; CHECK-NEXT:    [[N_VEC:%.*]] = sub i64 [[TMP0]], [[N_MOD_VF]]
+; CHECK-NEXT:    br label %[[VECTOR_BODY:.*]]
+; CHECK:       [[VECTOR_BODY]]:
+; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[TMP20:%.*]] = add i64 [[INDEX]], 2
+; CHECK-NEXT:    [[TMP21:%.*]] = add i64 [[INDEX]], 4
+; CHECK-NEXT:    [[TMP22:%.*]] = add i64 [[INDEX]], 6
+; CHECK-NEXT:    [[TMP23:%.*]] = getelementptr double, ptr [[A]], i64 [[INDEX]]
+; CHECK-NEXT:    [[TMP24:%.*]] = getelementptr double, ptr [[TMP23]], i32 0
+; CHECK-NEXT:    [[TMP25:%.*]] = getelementptr double, ptr [[TMP23]], i32 2
+; CHECK-NEXT:    [[TMP26:%.*]] = getelementptr double, ptr [[TMP23]], i32 4
+; CHECK-NEXT:    [[TMP27:%.*]] = getelementptr double, ptr [[TMP23]], i32 6
+; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <2 x double>, ptr [[TMP24]], align 8
+; CHECK-NEXT:    [[WIDE_LOAD12:%.*]] = load <2 x double>, ptr [[TMP25]], align 8
+; CHECK-NEXT:    [[WIDE_LOAD13:%.*]] = load <2 x double>, ptr [[TMP26]], align 8
+; CHECK-NEXT:    [[WIDE_LOAD14:%.*]] = load <2 x double>, ptr [[TMP27]], align 8
+; CHECK-NEXT:    [[TMP28:%.*]] = fmul <2 x double> [[WIDE_LOAD]], splat (double 5.000000e+00)
+; CHECK-NEXT:    [[TMP29:%.*]] = fmul <2 x double> [[WIDE_LOAD12]], splat (double 5.000000e+00)
+; CHECK-NEXT:    [[TMP30:%.*]] = fmul <2 x double> [[WIDE_LOAD13]], splat (double 5.000000e+00)
+; CHECK-NEXT:    [[TMP31:%.*]] = fmul <2 x double> [[WIDE_LOAD14]], splat (double 5.000000e+00)
+; CHECK-NEXT:    [[TMP32:%.*]] = getelementptr { double, double }, ptr [[B]], i64 [[INDEX]]
+; CHECK-NEXT:    [[TMP33:%.*]] = getelementptr { double, double }, ptr [[B]], i64 [[TMP20]]
+; CHECK-NEXT:    [[TMP34:%.*]] = getelementptr { double, double }, ptr [[B]], i64 [[TMP21]]
+; CHECK-NEXT:    [[TMP35:%.*]] = getelementptr { double, double }, ptr [[B]], i64 [[TMP22]]
+; CHECK-NEXT:    [[TMP36:%.*]] = shufflevector <2 x double> [[TMP28]], <2 x double> [[TMP28]], <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    [[INTERLEAVED_VEC:%.*]] = shufflevector <4 x double> [[TMP36]], <4 x double> poison, <4 x i32> <i32 0, i32 2, i32 1, i32 3>
+; CHECK-NEXT:    store <4 x double> [[INTERLEAVED_VEC]], ptr [[TMP32]], align 8
+; CHECK-NEXT:    [[TMP37:%.*]] = shufflevector <2 x double> [[TMP29]], <2 x double> [[TMP29]], <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    [[INTERLEAVED_VEC15:%.*]] = shufflevector <4 x double> [[TMP37]], <4 x double> poison, <4 x i32> <i32 0, i32 2, i32 1, i32 3>
+; CHECK-NEXT:    store <4 x double> [[INTERLEAVED_VEC15]], ptr [[TMP33]], align 8
+; CHECK-NEXT:    [[TMP38:%.*]] = shufflevector <2 x double> [[TMP30]], <2 x double> [[TMP30]], <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    [[INTERLEAVED_VEC16:%.*]] = shufflevector <4 x double> [[TMP38]], <4 x double> poison, <4 x i32> <i32 0, i32 2, i32 1, i32 3>
+; CHECK-NEXT:    store <4 x double> [[INTERLEAVED_VEC16]], ptr [[TMP34]], align 8
+; CHECK-NEXT:    [[TMP39:%.*]] = shufflevector <2 x double> [[TMP31]], <2 x double> [[TMP31]], <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    [[INTERLEAVED_VEC17:%.*]] = shufflevector <4 x double> [[TMP39]], <4 x double> poison, <4 x i32> <i32 0, i32 2, i32 1, i32 3>
+; CHECK-NEXT:    store <4 x double> [[INTERLEAVED_VEC17]], ptr [[TMP35]], align 8
+; CHECK-NEXT:    [[TMP40:%.*]] = getelementptr { double, double }, ptr [[C]], i64 [[INDEX]]
+; CHECK-NEXT:    [[TMP41:%.*]] = getelementptr { double, double }, ptr [[C]], i64 [[TMP20]]
+; CHECK-NEXT:    [[TMP42:%.*]] = getelementptr { double, double }, ptr [[C]], i64 [[TMP21]]
+; CHECK-NEXT:    [[TMP43:%.*]] = getelementptr { double, double }, ptr [[C]], i64 [[TMP22]]
+; CHECK-NEXT:    store <4 x double> [[INTERLEAVED_VEC]], ptr [[TMP40]], align 8
+; CHECK-NEXT:    store <4 x double> [[INTERLEAVED_VEC15]], ptr [[TMP41]], align 8
+; CHECK-NEXT:    store <4 x double> [[INTERLEAVED_VEC16]], ptr [[TMP42]], align 8
+; CHECK-NEXT:    store <4 x double> [[INTERLEAVED_VEC17]], ptr [[TMP43]], align 8
+; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 8
+; CHECK-NEXT:    [[TMP44:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
+; CHECK-NEXT:    br i1 [[TMP44]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP9:![0-9]+]]
+; CHECK:       [[MIDDLE_BLOCK]]:
+; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[TMP0]], [[N_VEC]]
+; CHECK-NEXT:    br i1 [[CMP_N]], label %[[EXIT:.*]], label %[[VEC_EPILOG_ITER_CHECK:.*]]
+; CHECK:       [[VEC_EPILOG_ITER_CHECK]]:
+; CHECK-NEXT:    [[N_VEC_REMAINING:%.*]] = sub i64 [[TMP0]], [[N_VEC]]
+; CHECK-NEXT:    [[MIN_EPILOG_ITERS_CHECK:%.*]] = icmp ult i64 [[N_VEC_REMAINING]], 2
+; CHECK-NEXT:    br i1 [[MIN_EPILOG_ITERS_CHECK]], label %[[VEC_EPILOG_SCALAR_PH]], label %[[VEC_EPILOG_PH]]
+; 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:    [[N_MOD_VF22:%.*]] = urem i64 [[TMP0]], 2
+; CHECK-NEXT:    [[N_VEC23:%.*]] = sub i64 [[TMP0]], [[N_MOD_VF22]]
+; CHECK-NEXT:    br label %[[VEC_EPILOG_VECTOR_BODY:.*]]
+; CHECK:       [[VEC_EPILOG_VECTOR_BODY]]:
+; CHECK-NEXT:    [[INDEX24:%.*]] = phi i64 [ [[VEC_EPILOG_RESUME_VAL]], %[[VEC_EPILOG_PH]] ], [ [[INDEX_NEXT25:%.*]], %[[VEC_EPILOG_VECTOR_BODY]] ]
+; CHECK-NEXT:    [[TMP45:%.*]] = getelementptr double, ptr [[A]], i64 [[INDEX24]]
+; CHECK-NEXT:    [[TMP46:%.*]] = getelementptr double, ptr [[TMP45]], i32 0
+; CHECK-NEXT:    [[TMP47:%.*]] = load double, ptr [[TMP46]], align 8
+; CHECK-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <2 x double> poison, double [[TMP47]], i64 0
+; CHECK-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <2 x double> [[BROADCAST_SPLATINSERT]], <2 x double> poison, <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[TMP48:%.*]] = fmul <2 x double> [[BROADCAST_SPLAT]], splat (double 5.000000e+00)
+; CHECK-NEXT:    [[TMP49:%.*]] = getelementptr { double, double }, ptr [[B]], i64 [[INDEX24]]
+; CHECK-NEXT:    store <2 x double> [[TMP48]], ptr [[TMP49]], align 8
+; CHECK-NEXT:    [[TMP50:%.*]] = getelementptr { double, double }, ptr [[C]], i64 [[INDEX24]]
+; CHECK-NEXT:    store <2 x double> [[TMP48]], ptr [[TMP50]], align 8
+; CHECK-NEXT:    [[INDEX_NEXT25]] = add nuw i64 [[INDEX24]], 1
+; CHECK-NEXT:    [[TMP51:%.*]] = icmp eq i64 [[INDEX_NEXT25]], [[N_VEC23]]
+; CHECK-NEXT:    br i1 [[TMP51]], label %[[VEC_EPILOG_MIDDLE_BLOCK:.*]], label %[[VEC_EPILOG_VECTOR_BODY]], !llvm.loop [[LOOP10:![0-9]+]]
+; CHECK:       [[VEC_EPILOG_MIDDLE_BLOCK]]:
+; CHECK-NEXT:    [[CMP_N26:%.*]] = icmp eq i64 [[TMP0]], [[N_VEC23]]
+; CHECK-NEXT:    br i1 [[CMP_N26]], label %[[EXIT]], label %[[VEC_EPILOG_SCALAR_PH]]
+; CHECK:       [[VEC_EPILOG_SCALAR_PH]]:
+; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC23]], %[[VEC_EPILOG_MIDDLE_BLOCK]] ], [ [[N_VEC]], %[[VEC_EPILOG_ITER_CHECK]] ], [ 0, %[[VECTOR_SCEVCHECK]] ], [ 0, %[[ITER_CHECK]] ]
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], %[[VEC_EPILOG_SCALAR_PH]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
+; CHECK-NEXT:    [[GEP_A:%.*]] = getelementptr double, ptr [[A]], i64 [[IV]]
+; CHECK-NEXT:    [[L:%.*]] = load double, ptr [[GEP_A]], align 8
+; CHECK-NEXT:    [[DIV:%.*]] = fmul double [[L]], 5.000000e+00
+; CHECK-NEXT:    [[GEP_B_1:%.*]] = getelementptr { double, double }, ptr [[B]], i64 [[IV]], i32 1
+; CHECK-NEXT:    store double [[DIV]], ptr [[GEP_B_1]], align 8
+; CHECK-NEXT:    [[GEP_C_1:%.*]] = getelementptr { double, double }, ptr [[C]], i64 [[IV]], i32 1
+; CHECK-NEXT:    store double [[DIV]], ptr [[GEP_C_1]], align 8
+; CHECK-NEXT:    [[GEP_B:%.*]] = getelementptr { double, double }, ptr [[B]], i64 [[IV]]
+; CHECK-NEXT:    store double [[DIV]], ptr [[GEP_B]], align 8
+; CHECK-NEXT:    [[GEP_C:%.*]] = getelementptr { double, double }, ptr [[C]], i64 [[IV]]
+; CHECK-NEXT:    store double [[DIV]], ptr [[GEP_C]], align 8
+; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
+; CHECK-NEXT:    [[EC:%.*]] = icmp eq i64 [[IV]], [[N]]
+; CHECK-NEXT:    br i1 [[EC]], label %[[EXIT]], label %[[LOOP]], !llvm.loop [[LOOP11:![0-9]+]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+  %gep.A = getelementptr double, ptr %A, i64 %iv
+  %l = load double, ptr %gep.A, align 8
+  %div = fmul double %l, 5.000000e+00
+  %gep.B.1 = getelementptr {double, double}, ptr %B, i64 %iv, i32 1
+  store double %div, ptr %gep.B.1, align 8
+  %gep.C.1 = getelementptr {double, double}, ptr %C, i64 %iv, i32 1
+  store double %div, ptr %gep.C.1, align 8
+  %gep.B = getelementptr {double, double}, ptr %B, i64 %iv
+  store double %div, ptr %gep.B, align 8
+  %gep.C = getelementptr {double, double}, ptr %C, i64 %iv
+  store double %div, ptr %gep.C, align 8
+  %iv.next = add i64 %iv, 1
+  %ec = icmp eq i64 %iv, %n
+  br i1 %ec, label %exit, label %loop
+
+exit:
+  ret void
+}
+
 attributes #0 = { "target-cpu"="neoverse-v2" }


        


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