[llvm] Bug fixes for ISelLowering for HVX (PR #164416)
Fateme Hosseini via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 21 06:14:28 PDT 2025
https://github.com/fhossein-quic created https://github.com/llvm/llvm-project/pull/164416
1. createHvxPrefixPred was computing an invalid byte count for small predicate types, leading to a crash during instruction selection.
2. HexagonTargetLowering::SplitHvxMemOp assumed the memory vector type is always simple. This patch adds a guard to avoid processing non-simple vector types, which can lead to failure.
Patch By:
Fateme Hosseini
>From 50e149dcaaefad35cc7a78f7b20dd7488be70721 Mon Sep 17 00:00:00 2001
From: pavani karveti <quic_pkarveti at quicinc.com>
Date: Thu, 3 Jul 2025 06:19:40 -0700
Subject: [PATCH] Bug fixes for ISelLowering for HVX
1. createHvxPrefixPred was computing an invalid byte count for small
predicate types, leading to a crash during instruction selection.
2. HexagonTargetLowering::SplitHvxMemOp assumed the memory vector type
is always simple. This patch adds a guard to avoid processing
non-simple vector types, which can lead to failure.
Patch By:
Fateme Hosseini
Co-authored-by: Sergei Larin <slarin at quicinc.com>
Co-authored-by: Pavani Karveti <pkarveti at qti.qualcomm.com>
---
.../Target/Hexagon/HexagonISelLoweringHVX.cpp | 29 +++++-
.../CodeGen/Hexagon/inst_masked_store_bug1.ll | 89 +++++++++++++++++++
2 files changed, 116 insertions(+), 2 deletions(-)
create mode 100644 llvm/test/CodeGen/Hexagon/inst_masked_store_bug1.ll
diff --git a/llvm/lib/Target/Hexagon/HexagonISelLoweringHVX.cpp b/llvm/lib/Target/Hexagon/HexagonISelLoweringHVX.cpp
index a94e131dd7214..2b630aa8a819d 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelLoweringHVX.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelLoweringHVX.cpp
@@ -1059,8 +1059,11 @@ HexagonTargetLowering::createHvxPrefixPred(SDValue PredV, const SDLoc &dl,
SDValue W0 = isUndef(PredV)
? DAG.getUNDEF(MVT::i64)
: DAG.getNode(HexagonISD::P2D, dl, MVT::i64, PredV);
- Words[IdxW].push_back(HiHalf(W0, DAG));
- Words[IdxW].push_back(LoHalf(W0, DAG));
+ if (Bytes < BitBytes) {
+ Words[IdxW].push_back(HiHalf(W0, DAG));
+ Words[IdxW].push_back(LoHalf(W0, DAG));
+ } else
+ Words[IdxW].push_back(W0);
while (Bytes < BitBytes) {
IdxW ^= 1;
@@ -1081,7 +1084,26 @@ HexagonTargetLowering::createHvxPrefixPred(SDValue PredV, const SDLoc &dl,
Bytes *= 2;
}
+ while (Bytes > BitBytes) {
+ IdxW ^= 1;
+ Words[IdxW].clear();
+
+ if (Bytes <= 4) {
+ for (const SDValue &W : Words[IdxW ^ 1]) {
+ SDValue T = contractPredicate(W, dl, DAG);
+ Words[IdxW].push_back(T);
+ }
+ } else {
+ for (const SDValue &W : Words[IdxW ^ 1]) {
+ Words[IdxW].push_back(W);
+ }
+ }
+ Bytes /= 2;
+ }
+
assert(Bytes == BitBytes);
+ if (BitBytes == 1 && PredTy == MVT::v2i1)
+ ByteTy = MVT::getVectorVT(MVT::i16, HwLen);
SDValue Vec = ZeroFill ? getZero(dl, ByteTy, DAG) : DAG.getUNDEF(ByteTy);
SDValue S4 = DAG.getConstant(HwLen-4, dl, MVT::i32);
@@ -3135,6 +3157,9 @@ SDValue
HexagonTargetLowering::SplitHvxMemOp(SDValue Op, SelectionDAG &DAG) const {
auto *MemN = cast<MemSDNode>(Op.getNode());
+ if (!MemN->getMemoryVT().isSimple())
+ return Op;
+
MVT MemTy = MemN->getMemoryVT().getSimpleVT();
if (!isHvxPairTy(MemTy))
return Op;
diff --git a/llvm/test/CodeGen/Hexagon/inst_masked_store_bug1.ll b/llvm/test/CodeGen/Hexagon/inst_masked_store_bug1.ll
new file mode 100644
index 0000000000000..858e0a9b8eab7
--- /dev/null
+++ b/llvm/test/CodeGen/Hexagon/inst_masked_store_bug1.ll
@@ -0,0 +1,89 @@
+;; RUN: llc --mtriple=hexagon -mattr=+hvxv79,+hvx-length128b %s -o - | FileCheck %s
+;; Sanity check for lowering masked scatter without assertion errors.
+
+define void @outer_product(ptr %aptr, ptr %bptr, ptr %cptr, i32 %T, i32 %W) {
+entry:
+ %W.ripple.bcast.splatinsert = insertelement <8 x i32> poison, i32 %W, i64 0
+ %W.ripple.bcast.splat = shufflevector <8 x i32> %W.ripple.bcast.splatinsert, <8 x i32> poison, <8 x i32> zeroinitializer
+ %div1194 = lshr i32 %T, 3
+ %cmp84.not = icmp ult i32 %T, 8
+ br i1 %cmp84.not, label %for.end49, label %for.body.preheader
+
+for.body.preheader: ; preds = %entry
+ %div10195 = lshr i32 %W, 3
+ %cmp1782.not = icmp ult i32 %W, 8
+ %arrayidx27.ripple.LS.dim.slope = mul <8 x i32> %W.ripple.bcast.splat, <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+ %arrayidx27.ripple.LS.dim.slope.ripple.bcast = shufflevector <8 x i32> %arrayidx27.ripple.LS.dim.slope, <8 x i32> poison, <64 x i32> <i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 4, i32 4, i32 4, i32 4, i32 4, i32 4, i32 4, i32 4, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 6, i32 6, i32 6, i32 6, i32 6, i32 6, i32 6, i32 6, i32 7, i32 7, i32 7, i32 7, i32 7, i32 7, i32 7, i32 7>
+ %arrayidx27.ripple.LS.slope = add <64 x i32> %arrayidx27.ripple.LS.dim.slope.ripple.bcast, <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+ %invariant.gep196 = getelementptr i8, ptr %cptr, <64 x i32> %arrayidx27.ripple.LS.slope
+ br label %for.body
+
+for.body: ; preds = %for.end, %for.body.preheader
+ %ripple.par.iv.085 = phi i32 [ %add48, %for.end ], [ 0, %for.body.preheader ]
+ %mul2 = shl i32 %ripple.par.iv.085, 3
+ br i1 %cmp1782.not, label %for.end, label %for.body18.lr.ph
+
+for.body18.lr.ph: ; preds = %for.body
+ %arrayidx = getelementptr inbounds nuw i8, ptr %aptr, i32 %mul2
+ %mul25 = mul i32 %mul2, %W
+ %gep197 = getelementptr i8, <64 x ptr> %invariant.gep196, i32 %mul25
+ br label %for.body18
+
+for.body18: ; preds = %for.body18, %for.body18.lr.ph
+ %ripple.par.iv15.083 = phi i32 [ 0, %for.body18.lr.ph ], [ %add28, %for.body18 ]
+ %mul19 = shl i32 %ripple.par.iv15.083, 3
+ %.ripple.LS.instance184 = load <8 x i8>, ptr %arrayidx, align 1
+ %.ripple.LS.instance184.ripple.bcast = shufflevector <8 x i8> %.ripple.LS.instance184, <8 x i8> poison, <64 x i32> <i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 4, i32 4, i32 4, i32 4, i32 4, i32 4, i32 4, i32 4, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 6, i32 6, i32 6, i32 6, i32 6, i32 6, i32 6, i32 6, i32 7, i32 7, i32 7, i32 7, i32 7, i32 7, i32 7, i32 7>
+ %arrayidx21 = getelementptr inbounds nuw i8, ptr %bptr, i32 %mul19
+ %.ripple.LS.instance = load <8 x i8>, ptr %arrayidx21, align 1
+ %.ripple.LS.instance.ripple.bcast = shufflevector <8 x i8> %.ripple.LS.instance, <8 x i8> poison, <64 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+ %mul23.ripple.LS.instance = mul <64 x i8> %.ripple.LS.instance.ripple.bcast, %.ripple.LS.instance184.ripple.bcast
+ %gep = getelementptr i8, <64 x ptr> %gep197, i32 %mul19
+ tail call void @llvm.masked.scatter.v64i8.v64p0(<64 x i8> %mul23.ripple.LS.instance, <64 x ptr> %gep, i32 1, <64 x i1> splat (i1 true))
+ %add28 = add nuw i32 %ripple.par.iv15.083, 1
+ %cmp17 = icmp ult i32 %add28, %div10195
+ br i1 %cmp17, label %for.body18, label %for.end.loopexit
+
+for.end.loopexit: ; preds = %for.body18
+ %0 = shl i32 %add28, 3
+ br label %for.end
+
+for.end: ; preds = %for.end.loopexit, %for.body
+ %ripple.par.iv15.0.lcssa = phi i32 [ 0, %for.body ], [ %0, %for.end.loopexit ]
+ %add30.ripple.bcast.splatinsert = insertelement <8 x i32> poison, i32 %ripple.par.iv15.0.lcssa, i64 0
+ %add30.ripple.bcast.splat = shufflevector <8 x i32> %add30.ripple.bcast.splatinsert, <8 x i32> poison, <8 x i32> zeroinitializer
+ %add30.ripple.LS.instance = or disjoint <8 x i32> %add30.ripple.bcast.splat, <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+ %cmp32.ripple.LS.instance = icmp ne i32 %ripple.par.iv15.0.lcssa, %W
+ %cmp32.ripple.LS.instance.ripple.bcast.splatinsert = insertelement <8 x i1> poison, i1 %cmp32.ripple.LS.instance, i64 0
+ %cmp32.ripple.LS.instance.ripple.bcast.splat = shufflevector <8 x i1> %cmp32.ripple.LS.instance.ripple.bcast.splatinsert, <8 x i1> poison, <8 x i32> zeroinitializer
+ %cmp33.ripple.vectorized = icmp ult <8 x i32> %add30.ripple.LS.instance, %W.ripple.bcast.splat
+ %or.cond.ripple.LS.instance = select <8 x i1> %cmp32.ripple.LS.instance.ripple.bcast.splat, <8 x i1> %cmp33.ripple.vectorized, <8 x i1> zeroinitializer
+ %or.cond.ripple.LS.instance.ripple.bcast = shufflevector <8 x i1> %or.cond.ripple.LS.instance, <8 x i1> poison, <64 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+ %or.cond.ripple.LS.instance.ripple.reducelog2.shuffle = shufflevector <8 x i1> %or.cond.ripple.LS.instance, <8 x i1> <i1 poison, i1 poison, i1 poison, i1 poison, i1 poison, i1 poison, i1 poison, i1 false>, <8 x i32> <i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 15>
+ %or.cond.ripple.LS.instance.ripple.reducelog2.operator = or <8 x i1> %or.cond.ripple.LS.instance, %or.cond.ripple.LS.instance.ripple.reducelog2.shuffle
+ %or.cond.ripple.LS.instance.ripple.reducelog2.shuffle189 = shufflevector <8 x i1> %or.cond.ripple.LS.instance.ripple.reducelog2.operator, <8 x i1> <i1 poison, i1 poison, i1 poison, i1 poison, i1 poison, i1 poison, i1 false, i1 false>, <8 x i32> <i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 14, i32 15>
+ %or.cond.ripple.LS.instance.ripple.reducelog2.operator190 = or <8 x i1> %or.cond.ripple.LS.instance.ripple.reducelog2.operator, %or.cond.ripple.LS.instance.ripple.reducelog2.shuffle189
+ %or.cond.ripple.LS.instance.ripple.reducelog2.shuffle191 = shufflevector <8 x i1> %or.cond.ripple.LS.instance.ripple.reducelog2.operator190, <8 x i1> poison, <8 x i32> <i32 4, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison>
+ %or.cond.ripple.LS.instance.ripple.reducelog2.operator192 = or <8 x i1> %or.cond.ripple.LS.instance.ripple.reducelog2.operator190, %or.cond.ripple.LS.instance.ripple.reducelog2.shuffle191
+ %ripple.red.extract.ripple.bcast.splat = shufflevector <8 x i1> %or.cond.ripple.LS.instance.ripple.reducelog2.operator192, <8 x i1> poison, <8 x i32> zeroinitializer
+ %arrayidx34.ripple.branch.clone = getelementptr inbounds nuw i8, ptr %aptr, i32 %mul2
+ %.ripple.LS.instance188.ripple.branch.clone.ripple.masked.load = tail call <8 x i8> @llvm.masked.load.v8i8.p0(ptr %arrayidx34.ripple.branch.clone, i32 1, <8 x i1> %ripple.red.extract.ripple.bcast.splat, <8 x i8> poison)
+ %.ripple.LS.instance188.ripple.bcast.ripple.branch.clone = shufflevector <8 x i8> %.ripple.LS.instance188.ripple.branch.clone.ripple.masked.load, <8 x i8> poison, <64 x i32> <i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 4, i32 4, i32 4, i32 4, i32 4, i32 4, i32 4, i32 4, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 6, i32 6, i32 6, i32 6, i32 6, i32 6, i32 6, i32 6, i32 7, i32 7, i32 7, i32 7, i32 7, i32 7, i32 7, i32 7>
+ %arrayidx36.ripple.branch.clone = getelementptr inbounds nuw i8, ptr %bptr, i32 %ripple.par.iv15.0.lcssa
+ %.ripple.LS.instance187.ripple.branch.clone.ripple.masked.load = tail call <8 x i8> @llvm.masked.load.v8i8.p0(ptr %arrayidx36.ripple.branch.clone, i32 1, <8 x i1> %or.cond.ripple.LS.instance, <8 x i8> poison)
+ %.ripple.LS.instance187.ripple.bcast.ripple.branch.clone = shufflevector <8 x i8> %.ripple.LS.instance187.ripple.branch.clone.ripple.masked.load, <8 x i8> poison, <64 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+ %mul38.ripple.LS.instance.ripple.branch.clone = mul <64 x i8> %.ripple.LS.instance187.ripple.bcast.ripple.branch.clone, %.ripple.LS.instance188.ripple.bcast.ripple.branch.clone
+ %mul40.ripple.branch.clone = mul i32 %mul2, %W
+ %1 = getelementptr i8, ptr %cptr, i32 %mul40.ripple.branch.clone
+ %arrayidx42.ripple.branch.clone = getelementptr i8, ptr %1, i32 %ripple.par.iv15.0.lcssa
+ %arrayidx42.ripple.LS.instance.ripple.branch.clone = getelementptr i8, ptr %arrayidx42.ripple.branch.clone, <64 x i32> %arrayidx27.ripple.LS.slope
+ tail call void @llvm.masked.scatter.v64i8.v64p0(<64 x i8> %mul38.ripple.LS.instance.ripple.branch.clone, <64 x ptr> %arrayidx42.ripple.LS.instance.ripple.branch.clone, i32 1, <64 x i1> %or.cond.ripple.LS.instance.ripple.bcast)
+ %add48 = add nuw i32 %ripple.par.iv.085, 1
+ %cmp = icmp ult i32 %add48, %div1194
+ br i1 %cmp, label %for.body, label %for.end49
+
+for.end49: ; preds = %for.end, %entry
+ ret void
+}
+
+;; CHECK: outer_product
More information about the llvm-commits
mailing list