[PATCH] D120223: [SLP] Fix assert from non-constant index in insertelement
Brendon Cahoon via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Sun Feb 20 16:43:53 PST 2022
bcahoon created this revision.
bcahoon added a reviewer: anton-afanasyev.
Herald added subscribers: arphaman, hiraditya.
bcahoon requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.
A call to getInsertIndex() in getTreeCost() is returning None,
which causes an assert because a non-constant index value for
insertelement was not expected. This case occurs when the
insertelement index value is defined with a PHI.
I'm not sure if this is the best way to fix this issue, but it does
fix the assert.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D120223
Files:
llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
llvm/test/Transforms/SLPVectorizer/slp-variable-insertelement.ll
Index: llvm/test/Transforms/SLPVectorizer/slp-variable-insertelement.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/SLPVectorizer/slp-variable-insertelement.ll
@@ -0,0 +1,31 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -slp-vectorizer -slp-max-vf=2 -slp-min-reg-size=32 -S < %s | FileCheck %s
+
+; It is possible to compute the tree cost for an insertelement that does not
+; have a constant index when the index is a PHI. Check if getInsertIndex
+; returns None.
+
+define void @test() local_unnamed_addr {
+; CHECK-LABEL: @test(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[FOR_BODY:%.*]]
+; CHECK: for.cond.cleanup:
+; CHECK-NEXT: unreachable
+; CHECK: for.body:
+; CHECK-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ poison, [[FOR_BODY]] ]
+; CHECK-NEXT: [[J:%.*]] = phi i32 [ poison, [[ENTRY]] ], [ 0, [[FOR_BODY]] ]
+; CHECK-NEXT: [[TMP0:%.*]] = insertelement <4 x i32> poison, i32 poison, i32 [[I]]
+; CHECK-NEXT: br i1 poison, label [[FOR_COND_CLEANUP:%.*]], label [[FOR_BODY]]
+;
+entry:
+ br label %for.body
+
+for.cond.cleanup:
+ unreachable
+
+for.body:
+ %i = phi i32 [ 0, %entry ], [ poison, %for.body ]
+ %j = phi i32 [ poison, %entry ], [ 0, %for.body ]
+ %0 = insertelement <4 x i32> poison, i32 poison, i32 %i
+ br i1 poison, label %for.cond.cleanup, label %for.body
+}
Index: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
===================================================================
--- llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -5917,7 +5917,10 @@
// to detect it as a final shuffled/identity match.
if (auto *VU = dyn_cast_or_null<InsertElementInst>(EU.User)) {
if (auto *FTy = dyn_cast<FixedVectorType>(VU->getType())) {
- unsigned InsertIdx = *getInsertIndex(VU);
+ Optional<unsigned> Idx = getInsertIndex(VU);
+ if (!Idx)
+ continue;
+ unsigned InsertIdx = *Idx;
auto *It = find_if(FirstUsers, [VU](Value *V) {
return areTwoInsertFromSameBuildVector(VU,
cast<InsertElementInst>(V));
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D120223.410193.patch
Type: text/x-patch
Size: 2253 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220221/1df6e366/attachment.bin>
More information about the llvm-commits
mailing list