[llvm] 965a090 - Revert "[IVDescriptors] Add pointer InductionDescriptors with non-constant strides"
David Green via llvm-commits
llvm-commits at lists.llvm.org
Fri Mar 31 03:08:57 PDT 2023
Author: David Green
Date: 2023-03-31T11:08:50+01:00
New Revision: 965a090f02cbab2dc08b78e274ce9d65e4d1221f
URL: https://github.com/llvm/llvm-project/commit/965a090f02cbab2dc08b78e274ce9d65e4d1221f
DIFF: https://github.com/llvm/llvm-project/commit/965a090f02cbab2dc08b78e274ce9d65e4d1221f.diff
LOG: Revert "[IVDescriptors] Add pointer InductionDescriptors with non-constant strides"
Multiple errors have being reported on
https://reviews.llvm.org/rG498aa534f472d28db893aa9a8627d0b46e17f312
Reverting until the correctness issues can be resolved.
We are also seeing a lot of performance differences from the patch. Some are
looking good, but some are looking pretty bad.
Added:
Modified:
llvm/lib/Analysis/IVDescriptors.cpp
llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
llvm/test/Transforms/LoopVectorize/RISCV/strided-accesses.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/IVDescriptors.cpp b/llvm/lib/Analysis/IVDescriptors.cpp
index 22b9f64ef88d8..156d141c461ed 100644
--- a/llvm/lib/Analysis/IVDescriptors.cpp
+++ b/llvm/lib/Analysis/IVDescriptors.cpp
@@ -1288,6 +1288,8 @@ InductionDescriptor::InductionDescriptor(Value *Start, InductionKind K,
assert((!getConstIntStepValue() || !getConstIntStepValue()->isZero()) &&
"Step value is zero");
+ assert((IK != IK_PtrInduction || getConstIntStepValue()) &&
+ "Step value should be constant for pointer induction");
assert((IK == IK_FpInduction || Step->getType()->isIntegerTy()) &&
"StepValue is not an integer");
@@ -1568,25 +1570,15 @@ bool InductionDescriptor::isInductionPHI(
}
assert(PhiTy->isPointerTy() && "The PHI must be a pointer");
- PointerType *PtrTy = cast<PointerType>(PhiTy);
-
- // Always use i8 element type for opaque pointer inductions.
- // This allows induction variables w/non-constant steps.
- if (PtrTy->isOpaque()) {
- D = InductionDescriptor(StartValue, IK_PtrInduction, Step,
- /* BinOp */ nullptr,
- Type::getInt8Ty(PtrTy->getContext()));
- return true;
- }
-
// Pointer induction should be a constant.
- // TODO: This could be generalized, but should probably just
- // be dropped instead once the migration to opaque ptrs is
- // complete.
if (!ConstStep)
return false;
- Type *ElementType = PtrTy->getNonOpaquePointerElementType();
+ // Always use i8 element type for opaque pointer inductions.
+ PointerType *PtrTy = cast<PointerType>(PhiTy);
+ Type *ElementType = PtrTy->isOpaque()
+ ? Type::getInt8Ty(PtrTy->getContext())
+ : PtrTy->getNonOpaquePointerElementType();
if (!ElementType->isSized())
return false;
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index df7c430d326af..21858cc1705b6 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -2492,6 +2492,8 @@ static Value *emitTransformedIndex(IRBuilderBase &B, Value *Index,
return CreateAdd(StartValue, Offset);
}
case InductionDescriptor::IK_PtrInduction: {
+ assert(isa<Constant>(Step) &&
+ "Expected constant step for pointer induction");
return B.CreateGEP(ID.getElementType(), StartValue, CreateMul(Index, Step));
}
case InductionDescriptor::IK_FpInduction: {
@@ -8269,6 +8271,7 @@ VPRecipeBase *VPRecipeBuilder::tryToOptimizeInductionPHI(
if (auto *II = Legal->getPointerInductionDescriptor(Phi)) {
VPValue *Step = vputils::getOrCreateVPValueForSCEVExpr(Plan, II->getStep(),
*PSE.getSE());
+ assert(isa<SCEVConstant>(II->getStep()));
return new VPWidenPointerInductionRecipe(
Phi, Operands[0], Step, *II,
LoopVectorizationPlanner::getDecisionAndClampRange(
@@ -9374,6 +9377,8 @@ void VPWidenPointerInductionRecipe::execute(VPTransformState &State) {
return;
}
+ assert(isa<SCEVConstant>(IndDesc.getStep()) &&
+ "Induction step not a SCEV constant!");
Type *PhiType = IndDesc.getStep()->getType();
// Build a pointer phi
diff --git a/llvm/test/Transforms/LoopVectorize/RISCV/strided-accesses.ll b/llvm/test/Transforms/LoopVectorize/RISCV/strided-accesses.ll
index 0ba05c1d621ae..a108e9b0129ce 100644
--- a/llvm/test/Transforms/LoopVectorize/RISCV/strided-accesses.ll
+++ b/llvm/test/Transforms/LoopVectorize/RISCV/strided-accesses.ll
@@ -539,89 +539,19 @@ exit:
define void @double_stride_ptr_iv(ptr %p, ptr %p2, i64 %stride) {
; CHECK-LABEL: @double_stride_ptr_iv(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[TMP0:%.*]] = call i64 @llvm.vscale.i64()
-; CHECK-NEXT: [[TMP1:%.*]] = mul i64 [[TMP0]], 4
-; CHECK-NEXT: [[TMP2:%.*]] = call i64 @llvm.umax.i64(i64 8, i64 [[TMP1]])
-; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 1024, [[TMP2]]
-; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_SCEVCHECK:%.*]]
-; CHECK: vector.scevcheck:
-; CHECK-NEXT: [[IDENT_CHECK:%.*]] = icmp ne i64 [[STRIDE:%.*]], 1
-; CHECK-NEXT: br i1 [[IDENT_CHECK]], label [[SCALAR_PH]], label [[VECTOR_MEMCHECK:%.*]]
-; CHECK: vector.memcheck:
-; CHECK-NEXT: [[SCEVGEP:%.*]] = getelementptr i8, ptr [[P2:%.*]], i64 1027
-; CHECK-NEXT: [[SCEVGEP1:%.*]] = getelementptr i8, ptr [[P:%.*]], i64 1027
-; CHECK-NEXT: [[BOUND0:%.*]] = icmp ult ptr [[P2]], [[SCEVGEP1]]
-; CHECK-NEXT: [[BOUND1:%.*]] = icmp ult ptr [[P]], [[SCEVGEP]]
-; CHECK-NEXT: [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
-; CHECK-NEXT: br i1 [[FOUND_CONFLICT]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
-; CHECK: vector.ph:
-; CHECK-NEXT: [[TMP3:%.*]] = call i64 @llvm.vscale.i64()
-; CHECK-NEXT: [[TMP4:%.*]] = mul i64 [[TMP3]], 4
-; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i64 1024, [[TMP4]]
-; CHECK-NEXT: [[N_VEC:%.*]] = sub i64 1024, [[N_MOD_VF]]
-; CHECK-NEXT: [[TMP5:%.*]] = mul i64 [[N_VEC]], [[STRIDE]]
-; CHECK-NEXT: [[IND_END:%.*]] = getelementptr i8, ptr [[P]], i64 [[TMP5]]
-; CHECK-NEXT: [[TMP6:%.*]] = mul i64 [[N_VEC]], [[STRIDE]]
-; CHECK-NEXT: [[IND_END3:%.*]] = getelementptr i8, ptr [[P2]], i64 [[TMP6]]
-; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
-; CHECK: vector.body:
-; CHECK-NEXT: [[POINTER_PHI:%.*]] = phi ptr [ [[P]], [[VECTOR_PH]] ], [ [[PTR_IND:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT: [[POINTER_PHI7:%.*]] = phi ptr [ [[P2]], [[VECTOR_PH]] ], [ [[PTR_IND8:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT: [[TMP7:%.*]] = call i64 @llvm.vscale.i64()
-; CHECK-NEXT: [[TMP8:%.*]] = mul i64 [[TMP7]], 4
-; CHECK-NEXT: [[TMP9:%.*]] = mul i64 [[TMP8]], 1
-; CHECK-NEXT: [[TMP10:%.*]] = mul i64 [[STRIDE]], [[TMP9]]
-; CHECK-NEXT: [[TMP11:%.*]] = mul i64 [[TMP8]], 0
-; CHECK-NEXT: [[DOTSPLATINSERT:%.*]] = insertelement <vscale x 4 x i64> poison, i64 [[TMP11]], i64 0
-; CHECK-NEXT: [[DOTSPLAT:%.*]] = shufflevector <vscale x 4 x i64> [[DOTSPLATINSERT]], <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer
-; CHECK-NEXT: [[TMP12:%.*]] = call <vscale x 4 x i64> @llvm.experimental.stepvector.nxv4i64()
-; CHECK-NEXT: [[TMP13:%.*]] = add <vscale x 4 x i64> [[DOTSPLAT]], [[TMP12]]
-; CHECK-NEXT: [[DOTSPLATINSERT5:%.*]] = insertelement <vscale x 4 x i64> poison, i64 [[STRIDE]], i64 0
-; CHECK-NEXT: [[DOTSPLAT6:%.*]] = shufflevector <vscale x 4 x i64> [[DOTSPLATINSERT5]], <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer
-; CHECK-NEXT: [[VECTOR_GEP:%.*]] = mul <vscale x 4 x i64> [[TMP13]], [[DOTSPLAT6]]
-; CHECK-NEXT: [[TMP14:%.*]] = getelementptr i8, ptr [[POINTER_PHI]], <vscale x 4 x i64> [[VECTOR_GEP]]
-; CHECK-NEXT: [[TMP15:%.*]] = call i64 @llvm.vscale.i64()
-; CHECK-NEXT: [[TMP16:%.*]] = mul i64 [[TMP15]], 4
-; CHECK-NEXT: [[TMP17:%.*]] = mul i64 [[TMP16]], 1
-; CHECK-NEXT: [[TMP18:%.*]] = mul i64 [[STRIDE]], [[TMP17]]
-; CHECK-NEXT: [[TMP19:%.*]] = mul i64 [[TMP16]], 0
-; CHECK-NEXT: [[DOTSPLATINSERT9:%.*]] = insertelement <vscale x 4 x i64> poison, i64 [[TMP19]], i64 0
-; CHECK-NEXT: [[DOTSPLAT10:%.*]] = shufflevector <vscale x 4 x i64> [[DOTSPLATINSERT9]], <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer
-; CHECK-NEXT: [[TMP20:%.*]] = call <vscale x 4 x i64> @llvm.experimental.stepvector.nxv4i64()
-; CHECK-NEXT: [[TMP21:%.*]] = add <vscale x 4 x i64> [[DOTSPLAT10]], [[TMP20]]
-; CHECK-NEXT: [[VECTOR_GEP13:%.*]] = mul <vscale x 4 x i64> [[TMP21]], [[DOTSPLAT6]]
-; CHECK-NEXT: [[TMP22:%.*]] = getelementptr i8, ptr [[POINTER_PHI7]], <vscale x 4 x i64> [[VECTOR_GEP13]]
-; CHECK-NEXT: [[WIDE_MASKED_GATHER:%.*]] = call <vscale x 4 x i32> @llvm.masked.gather.nxv4i32.nxv4p0(<vscale x 4 x ptr> [[TMP14]], i32 4, <vscale x 4 x i1> shufflevector (<vscale x 4 x i1> insertelement (<vscale x 4 x i1> poison, i1 true, i64 0), <vscale x 4 x i1> poison, <vscale x 4 x i32> zeroinitializer), <vscale x 4 x i32> poison), !alias.scope !16
-; CHECK-NEXT: [[TMP23:%.*]] = add <vscale x 4 x i32> [[WIDE_MASKED_GATHER]], shufflevector (<vscale x 4 x i32> insertelement (<vscale x 4 x i32> poison, i32 1, i64 0), <vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer)
-; CHECK-NEXT: call void @llvm.masked.scatter.nxv4i32.nxv4p0(<vscale x 4 x i32> [[TMP23]], <vscale x 4 x ptr> [[TMP22]], i32 4, <vscale x 4 x i1> shufflevector (<vscale x 4 x i1> insertelement (<vscale x 4 x i1> poison, i1 true, i64 0), <vscale x 4 x i1> poison, <vscale x 4 x i32> zeroinitializer)), !alias.scope !19, !noalias !16
-; CHECK-NEXT: [[TMP24:%.*]] = call i64 @llvm.vscale.i64()
-; CHECK-NEXT: [[TMP25:%.*]] = mul i64 [[TMP24]], 4
-; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], [[TMP25]]
-; CHECK-NEXT: [[PTR_IND]] = getelementptr i8, ptr [[POINTER_PHI]], i64 [[TMP10]]
-; CHECK-NEXT: [[PTR_IND8]] = getelementptr i8, ptr [[POINTER_PHI7]], i64 [[TMP18]]
-; CHECK-NEXT: [[TMP26:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
-; CHECK-NEXT: br i1 [[TMP26]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP21:![0-9]+]]
-; CHECK: middle.block:
-; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 1024, [[N_VEC]]
-; CHECK-NEXT: br i1 [[CMP_N]], label [[EXIT:%.*]], label [[SCALAR_PH]]
-; CHECK: scalar.ph:
-; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ], [ 0, [[VECTOR_SCEVCHECK]] ], [ 0, [[VECTOR_MEMCHECK]] ]
-; CHECK-NEXT: [[BC_RESUME_VAL2:%.*]] = phi ptr [ [[IND_END]], [[MIDDLE_BLOCK]] ], [ [[P]], [[ENTRY]] ], [ [[P]], [[VECTOR_SCEVCHECK]] ], [ [[P]], [[VECTOR_MEMCHECK]] ]
-; CHECK-NEXT: [[BC_RESUME_VAL4:%.*]] = phi ptr [ [[IND_END3]], [[MIDDLE_BLOCK]] ], [ [[P2]], [[ENTRY]] ], [ [[P2]], [[VECTOR_SCEVCHECK]] ], [ [[P2]], [[VECTOR_MEMCHECK]] ]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
-; CHECK-NEXT: [[I:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[NEXTI:%.*]], [[LOOP]] ]
-; CHECK-NEXT: [[PTR:%.*]] = phi ptr [ [[BC_RESUME_VAL2]], [[SCALAR_PH]] ], [ [[PTR_NEXT:%.*]], [[LOOP]] ]
-; CHECK-NEXT: [[PTR2:%.*]] = phi ptr [ [[BC_RESUME_VAL4]], [[SCALAR_PH]] ], [ [[PTR2_NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT: [[I:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[NEXTI:%.*]], [[LOOP]] ]
+; CHECK-NEXT: [[PTR:%.*]] = phi ptr [ [[P:%.*]], [[ENTRY]] ], [ [[PTR_NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT: [[PTR2:%.*]] = phi ptr [ [[P2:%.*]], [[ENTRY]] ], [ [[PTR2_NEXT:%.*]], [[LOOP]] ]
; CHECK-NEXT: [[X0:%.*]] = load i32, ptr [[PTR]], align 4
; CHECK-NEXT: [[Y0:%.*]] = add i32 [[X0]], 1
; CHECK-NEXT: store i32 [[Y0]], ptr [[PTR2]], align 4
-; CHECK-NEXT: [[PTR_NEXT]] = getelementptr inbounds i8, ptr [[PTR]], i64 [[STRIDE]]
+; CHECK-NEXT: [[PTR_NEXT]] = getelementptr inbounds i8, ptr [[PTR]], i64 [[STRIDE:%.*]]
; CHECK-NEXT: [[PTR2_NEXT]] = getelementptr inbounds i8, ptr [[PTR2]], i64 [[STRIDE]]
; CHECK-NEXT: [[NEXTI]] = add i64 [[I]], 1
; CHECK-NEXT: [[DONE:%.*]] = icmp eq i64 [[NEXTI]], 1024
-; CHECK-NEXT: br i1 [[DONE]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP22:![0-9]+]]
+; CHECK-NEXT: br i1 [[DONE]], label [[EXIT:%.*]], label [[LOOP]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
More information about the llvm-commits
mailing list