[SLP][REVEC] Fix false assumption of the source for castToScalarTyElem.

[HanKuanChen]

The argument V may come from adjustExtracts, which is the vector operand of ExtractElementInst. In addition, it is not existed in getTreeEntry.

The vector operand of ExtractElementInst may have a type of <1 x Ty>, ensuring that the number of elements in ScalarTy and VecTy are equal.

reference: #99411

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Han-Kuan Chen (HanKuanChen)

Changes

The argument V may come from adjustExtracts, which is the vector operand of ExtractElementInst. In addition, it is not existed in getTreeEntry.

The vector operand of ExtractElementInst may have a type of <1 x Ty>, ensuring that the number of elements in ScalarTy and VecTy are equal.

reference: #99411

---

Full diff: https://github.com/llvm/llvm-project/pull/99424.diff

1 Files Affected:

• (modified) llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp (+1-1)

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index ccb6734d5618c..a09bb00f3419e 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -11850,7 +11850,7 @@ class BoUpSLP::ShuffleInstructionBuilder final : public BaseShuffleAnalysis {
   Value *castToScalarTyElem(Value *V,
                             std::optional<bool> IsSigned = std::nullopt) {
     auto *VecTy = cast<VectorType>(V->getType());
-    assert(getNumElements(ScalarTy) < getNumElements(VecTy) &&
+    assert(getNumElements(ScalarTy) <= getNumElements(VecTy) &&
            (getNumElements(VecTy) % getNumElements(ScalarTy) == 0));
     if (VecTy->getElementType() == ScalarTy->getScalarType())
       return V;

[dyung]

Should we add either or both of the crashing examples as tests?

[alexey-bataev]

LG

[llvm-ci]

LLVM Buildbot has detected a new failure on builder llvm-clang-aarch64-darwin running on doug-worker-4 while building llvm at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/2111

Here is the relevant piece of the build log for the reference:

Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: Transforms/SLPVectorizer/revec-fix-99411.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 2: /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/opt -mtriple x86_64-unknown-linux-gnu -passes=slp-vectorizer -S /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Transforms/SLPVectorizer/revec-fix-99411.ll | /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Transforms/SLPVectorizer/revec-fix-99411.ll
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Transforms/SLPVectorizer/revec-fix-99411.ll
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/opt -mtriple x86_64-unknown-linux-gnu -passes=slp-vectorizer -S /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Transforms/SLPVectorizer/revec-fix-99411.ll
/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/opt: warning: failed to infer data layout: unable to get target for 'x86_64-unknown-linux-gnu', see --version and --triple.
/Users/buildbot/buildbot-root/aarch64-darwin/build/bin/opt: WARNING: failed to create target machine for 'x86_64-unknown-linux-gnu': unable to get target for 'x86_64-unknown-linux-gnu', see --version and --triple.
�[1m/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Transforms/SLPVectorizer/revec-fix-99411.ll:7:15: �[0m�[0;1;31merror: �[0m�[1mCHECK-NEXT: expected string not found in input
�[0m; CHECK-NEXT: store <2 x i64> zeroinitializer, ptr null, align 8
�[0;1;32m              ^
�[0m�[1m<stdin>:6:7: �[0m�[0;1;30mnote: �[0m�[1mscanning from here
�[0mentry:
�[0;1;32m      ^
�[0m�[1m<stdin>:7:19: �[0m�[0;1;30mnote: �[0m�[1mpossible intended match here
�[0m %0 = extractelement <1 x i64> zeroinitializer, i64 0
�[0;1;32m                  ^
�[0m
Input file: <stdin>
Check file: /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Transforms/SLPVectorizer/revec-fix-99411.ll

-dump-input=help explains the following input dump.

Input was:
<<<<<<
�[1m�[0m�[0;1;30m           1: �[0m�[1m�[0;1;46m; ModuleID = '/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Transforms/SLPVectorizer/revec-fix-99411.ll' �[0m
�[0;1;30m           2: �[0m�[1m�[0;1;46msource_filename = "/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/Transforms/SLPVectorizer/revec-fix-99411.ll" �[0m
�[0;1;30m           3: �[0m�[1m�[0;1;46mtarget triple = "x86_64-unknown-linux-gnu" �[0m
�[0;1;30m           4: �[0m�[1m�[0;1;46m �[0m
�[0;1;30m           5: �[0m�[1m�[0;1;46mdefine void �[0m@e(�[0;1;46m) { �[0m
�[0;1;32mlabel:5'0                 ^~~
�[0m�[0;1;32mlabel:5'1                 ^~~
�[0m�[0;1;30m           6: �[0m�[1m�[0;1;46m�[0mentry:�[0;1;46m �[0m
�[0;1;32mnext:6        ^~~~~~
�[0m�[0;1;31mnext:7'0            X error: no match found
�[0m�[0;1;30m           7: �[0m�[1m�[0;1;46m %0 = extractelement <1 x i64> zeroinitializer, i64 0 �[0m
�[0;1;31mnext:7'0      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
�[0m�[0;1;35mnext:7'1                        ?                                    possible intended match
�[0m�[0;1;30m           8: �[0m�[1m�[0;1;46m %bf.value = and i64 %0, 0 �[0m
�[0;1;31mnext:7'0      ~~~~~~~~~~~~~~~~~~~~~~~~~~~
�[0m�[0;1;30m           9: �[0m�[1m�[0;1;46m %bf.set = or i64 0, %bf.value �[0m
�[0;1;31mnext:7'0      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
�[0m�[0;1;30m          10: �[0m�[1m�[0;1;46m store i64 %bf.set, ptr getelementptr inbounds (i8, ptr null, i64 8), align 8 �[0m
�[0;1;31mnext:7'0      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
�[0m�[0;1;30m          11: �[0m�[1m�[0;1;46m %bf.value2 = and i64 0, 0 �[0m
�[0;1;31mnext:7'0      ~~~~~~~~~~~~~~~~~~~~~~~~~~~
�[0m�[0;1;30m          12: �[0m�[1m�[0;1;46m %bf.set4 = or i64 0, %bf.value2 �[0m
�[0;1;31mnext:7'0      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...

[dyung]

@HanKuanChen the test you added is failing on at least one buildbot, see the message above (I happen to manage that build bot). Can you take a look so that I don't have to revert your change?

[amykhuang]

looks good for me, aside from the test issue