[llvm] [GlobalIsel] Combine G_EXTRACT_VECTOR_ELT (PR #85321)

[Amara Emerson via llvm-commits]

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@@ -0,0 +1,174 @@
+//===- CombinerHelperVectorOps.cpp-----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements CombinerHelper for G_EXTRACT_VECTOR_ELT.
+//
+//===----------------------------------------------------------------------===//
+#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
+#include "llvm/CodeGen/GlobalISel/GenericMachineInstrs.h"
+#include "llvm/CodeGen/GlobalISel/LegalizerHelper.h"
+#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
+#include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
+#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
+#include "llvm/CodeGen/GlobalISel/Utils.h"
+#include "llvm/CodeGen/LowLevelTypeUtils.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/TargetLowering.h"
+#include "llvm/CodeGen/TargetOpcodes.h"
+#include "llvm/Support/Casting.h"
+#include <optional>
+
+#define DEBUG_TYPE "gi-combiner"
+
+using namespace llvm;
+using namespace MIPatternMatch;
+
+bool CombinerHelper::matchExtractVectorElement(MachineInstr &MI,
+                                               BuildFnTy &MatchInfo) {
+
+  GExtractVectorElement *Extract = cast<GExtractVectorElement>(&MI);
+
+  Register Dst = Extract->getReg(0);
+  Register Vector = Extract->getVectorReg();
+  Register Index = Extract->getIndexReg();
+  LLT DstTy = MRI.getType(Dst);
+  LLT VectorTy = MRI.getType(Vector);
+
+  // The vector register can be def'd by various ops that
+  // have vector as its type. They can all be used for
+  // constant folding, scalarizing, canonicalization, or
+  // combining based on symmetry.
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aemerson wrote:

Can you clang-format these lines to use up the 80 cols

https://github.com/llvm/llvm-project/pull/85321