[llvm-branch-commits] [llvm] f5c1570 - Revert "[VPlan] Remove unused VPExpandSCEVRecipe before expansion (#181329)"

via llvm-branch-commits llvm-branch-commits at lists.llvm.org
Mon Mar 2 04:11:17 PST 2026


Author: Jan Patrick Lehr
Date: 2026-03-02T13:11:13+01:00
New Revision: f5c15702c28d6535fa8c947df465a917af09147c

URL: https://github.com/llvm/llvm-project/commit/f5c15702c28d6535fa8c947df465a917af09147c
DIFF: https://github.com/llvm/llvm-project/commit/f5c15702c28d6535fa8c947df465a917af09147c.diff

LOG: Revert "[VPlan] Remove unused VPExpandSCEVRecipe before expansion (#181329)"

This reverts commit c62c00c52405da2650512ab030bef30a9ccaec6a.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
    llvm/test/Transforms/LoopVectorize/cast-induction.ll
    llvm/test/Transforms/LoopVectorize/pointer-induction.ll
    llvm/test/Transforms/LoopVectorize/reuse-lcssa-phi-scev-expansion.ll
    llvm/test/Transforms/LoopVectorize/version-mem-access.ll
    llvm/test/Transforms/LoopVectorize/version-stride-with-integer-casts.ll
    llvm/test/Transforms/PhaseOrdering/AArch64/indvars-vectorization.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
index c6aabe7f1ec0f..38b4c8bbae982 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp
@@ -5130,10 +5130,6 @@ VPlanTransforms::expandSCEVs(VPlan &Plan, ScalarEvolution &SE) {
     auto *ExpSCEV = dyn_cast<VPExpandSCEVRecipe>(&R);
     if (!ExpSCEV)
       break;
-    if (ExpSCEV->getNumUsers() == 0) {
-      ExpSCEV->eraseFromParent();
-      continue;
-    }
     const SCEV *Expr = ExpSCEV->getSCEV();
     Value *Res =
         Expander.expandCodeFor(Expr, Expr->getType(), EntryBB->getTerminator());

diff  --git a/llvm/test/Transforms/LoopVectorize/cast-induction.ll b/llvm/test/Transforms/LoopVectorize/cast-induction.ll
index bcc2aea0f81ad..2764a61728fe3 100644
--- a/llvm/test/Transforms/LoopVectorize/cast-induction.ll
+++ b/llvm/test/Transforms/LoopVectorize/cast-induction.ll
@@ -322,6 +322,7 @@ define void @test_start_zext(i32 %start, ptr %dst) {
 ; VF4-SAME: i32 [[START:%.*]], ptr [[DST:%.*]]) {
 ; VF4-NEXT:  [[ENTRY:.*:]]
 ; VF4-NEXT:    [[START_EXT:%.*]] = zext i32 [[START]] to i64
+; VF4-NEXT:    [[TMP0:%.*]] = sub i64 100, [[START_EXT]]
 ; VF4-NEXT:    br label %[[VECTOR_SCEVCHECK:.*]]
 ; VF4:       [[VECTOR_SCEVCHECK]]:
 ; VF4-NEXT:    [[IDENT_CHECK:%.*]] = icmp ne i32 [[START]], 1

diff  --git a/llvm/test/Transforms/LoopVectorize/pointer-induction.ll b/llvm/test/Transforms/LoopVectorize/pointer-induction.ll
index c73f2f7c865af..d5088fe60ee9f 100644
--- a/llvm/test/Transforms/LoopVectorize/pointer-induction.ll
+++ b/llvm/test/Transforms/LoopVectorize/pointer-induction.ll
@@ -713,10 +713,12 @@ define void @strided_ptr_iv_runtime_stride(ptr %pIn, ptr %pOut, i32 %nCols, i32
 ; STRIDED-NEXT:    [[POUT1:%.*]] = ptrtoaddr ptr [[POUT:%.*]] to i64
 ; STRIDED-NEXT:    [[TMP0:%.*]] = zext i32 [[NCOLS:%.*]] to i64
 ; STRIDED-NEXT:    [[UMAX:%.*]] = call i64 @llvm.umax.i64(i64 [[TMP0]], i64 1)
+; STRIDED-NEXT:    [[TMP1:%.*]] = sext i32 [[STRIDE:%.*]] to i64
+; STRIDED-NEXT:    [[TMP2:%.*]] = shl nsw i64 [[TMP1]], 2
 ; STRIDED-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[UMAX]], 4
 ; STRIDED-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_SCEVCHECK:%.*]]
 ; STRIDED:       vector.scevcheck:
-; STRIDED-NEXT:    [[IDENT_CHECK:%.*]] = icmp ne i32 [[STRIDE:%.*]], 1
+; STRIDED-NEXT:    [[IDENT_CHECK:%.*]] = icmp ne i32 [[STRIDE]], 1
 ; STRIDED-NEXT:    br i1 [[IDENT_CHECK]], label [[SCALAR_PH]], label [[VECTOR_MEMCHECK:%.*]]
 ; STRIDED:       vector.memcheck:
 ; STRIDED-NEXT:    [[TMP3:%.*]] = sub i64 [[POUT1]], [[PIN2]]

diff  --git a/llvm/test/Transforms/LoopVectorize/reuse-lcssa-phi-scev-expansion.ll b/llvm/test/Transforms/LoopVectorize/reuse-lcssa-phi-scev-expansion.ll
index b306dac8a4334..55c73cb0928ff 100644
--- a/llvm/test/Transforms/LoopVectorize/reuse-lcssa-phi-scev-expansion.ll
+++ b/llvm/test/Transforms/LoopVectorize/reuse-lcssa-phi-scev-expansion.ll
@@ -205,10 +205,21 @@ define void @expand_
diff _scev_unknown(ptr %dst, i1 %invar.c, i32 %step) mustprog
 ; CHECK-NEXT:    br i1 [[INVAR_C]], label %[[LOOP_2_PREHEADER:.*]], label %[[LOOP_1]]
 ; CHECK:       [[LOOP_2_PREHEADER]]:
 ; CHECK-NEXT:    [[IV_1_LCSSA:%.*]] = phi i32 [ [[IV_1]], %[[LOOP_1]] ]
+; CHECK-NEXT:    [[TMP1:%.*]] = add i32 [[IV_1_LCSSA]], [[STEP]]
+; CHECK-NEXT:    [[SMAX:%.*]] = call i32 @llvm.smax.i32(i32 [[TMP1]], i32 0)
+; CHECK-NEXT:    [[TMP2:%.*]] = mul i32 [[STEP]], -2
+; CHECK-NEXT:    [[TMP3:%.*]] = mul i32 [[INDVAR]], -1
+; CHECK-NEXT:    [[TMP4:%.*]] = add i32 [[TMP3]], [[TMP2]]
+; CHECK-NEXT:    [[TMP5:%.*]] = add i32 [[SMAX]], [[TMP4]]
+; CHECK-NEXT:    [[UMIN:%.*]] = call i32 @llvm.umin.i32(i32 [[TMP5]], i32 1)
+; CHECK-NEXT:    [[TMP6:%.*]] = add i32 [[UMIN]], 1
+; CHECK-NEXT:    [[TMP7:%.*]] = sub i32 [[TMP5]], [[UMIN]]
+; CHECK-NEXT:    [[UMAX:%.*]] = call i32 @llvm.umax.i32(i32 [[STEP]], i32 1)
+; CHECK-NEXT:    [[TMP8:%.*]] = udiv i32 [[TMP7]], [[UMAX]]
+; CHECK-NEXT:    [[TMP9:%.*]] = add i32 [[TMP6]], [[TMP8]]
 ; CHECK-NEXT:    [[TMP16:%.*]] = sub i32 2, [[STEP]]
 ; CHECK-NEXT:    [[TMP12:%.*]] = add i32 [[IV_1_LCSSA]], [[TMP16]]
 ; CHECK-NEXT:    [[SMAX1:%.*]] = call i32 @llvm.smax.i32(i32 [[TMP12]], i32 0)
-; CHECK-NEXT:    [[TMP3:%.*]] = mul i32 [[INDVAR]], -1
 ; CHECK-NEXT:    [[TMP14:%.*]] = add i32 [[TMP3]], -1
 ; CHECK-NEXT:    [[TMP15:%.*]] = add i32 [[SMAX1]], [[TMP14]]
 ; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i32 [[TMP15]], 2

diff  --git a/llvm/test/Transforms/LoopVectorize/version-mem-access.ll b/llvm/test/Transforms/LoopVectorize/version-mem-access.ll
index baefa12858eb2..8b9a526899041 100644
--- a/llvm/test/Transforms/LoopVectorize/version-mem-access.ll
+++ b/llvm/test/Transforms/LoopVectorize/version-mem-access.ll
@@ -77,6 +77,7 @@ define void @fn1(ptr noalias %x, ptr noalias %c, double %a) {
 ; CHECK-NEXT:    [[CMP8:%.*]] = icmp sgt i32 [[CONV2]], 0
 ; CHECK-NEXT:    br i1 [[CMP8]], label %[[LOOP_PREHEADER:.*]], [[EXIT:label %.*]]
 ; CHECK:       [[LOOP_PREHEADER]]:
+; CHECK-NEXT:    [[TMP0:%.*]] = zext i32 [[CONV2]] to i64
 ; CHECK-NEXT:    br label %[[VECTOR_SCEVCHECK:.*]]
 ; CHECK:       [[VECTOR_SCEVCHECK]]:
 ; CHECK-NEXT:    [[IDENT_CHECK:%.*]] = icmp ne i32 [[CONV]], 1

diff  --git a/llvm/test/Transforms/LoopVectorize/version-stride-with-integer-casts.ll b/llvm/test/Transforms/LoopVectorize/version-stride-with-integer-casts.ll
index 5839b0a5e8113..6a6ae316f4e52 100644
--- a/llvm/test/Transforms/LoopVectorize/version-stride-with-integer-casts.ll
+++ b/llvm/test/Transforms/LoopVectorize/version-stride-with-integer-casts.ll
@@ -401,6 +401,8 @@ define void @zext_of_i1_stride(i1 %g, ptr %dst) mustprogress {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[G_16:%.*]] = zext i1 [[G]] to i16
 ; CHECK-NEXT:    [[G_64:%.*]] = zext i1 [[G]] to i64
+; CHECK-NEXT:    [[TMP0:%.*]] = udiv i64 15, [[G_64]]
+; CHECK-NEXT:    [[TMP1:%.*]] = add nuw nsw i64 [[TMP0]], 1
 ; CHECK-NEXT:    br label [[VECTOR_SCEVCHECK:%.*]]
 ; CHECK:       vector.scevcheck:
 ; CHECK-NEXT:    [[IDENT_CHECK:%.*]] = icmp ne i1 [[G]], true

diff  --git a/llvm/test/Transforms/PhaseOrdering/AArch64/indvars-vectorization.ll b/llvm/test/Transforms/PhaseOrdering/AArch64/indvars-vectorization.ll
index 51446cbbc51a9..8d20a3ba8ed08 100644
--- a/llvm/test/Transforms/PhaseOrdering/AArch64/indvars-vectorization.ll
+++ b/llvm/test/Transforms/PhaseOrdering/AArch64/indvars-vectorization.ll
@@ -66,7 +66,7 @@ define void @s172(i32 noundef %xa, i32 noundef %xb, ptr noundef %a, ptr noundef
 ; CHECK:       middle.block:
 ; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[TMP8]], [[N_VEC]]
 ; CHECK-NEXT:    br i1 [[CMP_N]], label [[FOR_END]], label [[FOR_BODY_PREHEADER13]]
-; CHECK:       for.body.preheader11:
+; CHECK:       for.body.preheader14:
 ; CHECK-NEXT:    [[INDVARS_IV_PH:%.*]] = phi i64 [ [[TMP0]], [[VECTOR_MEMCHECK]] ], [ [[TMP0]], [[FOR_BODY_PREHEADER]] ], [ [[IND_END]], [[MIDDLE_BLOCK]] ]
 ; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
 ; CHECK:       for.body:


        


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