[llvm] [RISCV] Add hasREV8Like helper to RISCVSubtarget. NFC (PR #158775)

[Craig Topper via llvm-commits]

https://github.com/topperc created https://github.com/llvm/llvm-project/pull/158775

None

>From 137ec5c110a683ffefac29bf5ee83f7883649b8d Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Mon, 15 Sep 2025 21:25:02 -0700
Subject: [PATCH] [RISCV] Add hasREV8Like helper to RISCVSubtarget. NFC

---
 llvm/lib/Target/RISCV/RISCVISelLowering.cpp | 7 +------
 llvm/lib/Target/RISCV/RISCVSubtarget.h      | 3 +++
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 5485b916c2031..f5bb70b8a93e0 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -378,13 +378,8 @@ RISCVTargetLowering::RISCVTargetLowering(const TargetMachine &TM,
     setOperationAction({ISD::ROTL, ISD::ROTR}, XLenVT, Expand);
   }
 
-  // With Zbb we have an XLen rev8 instruction, but not GREVI. So we'll
-  // pattern match it directly in isel.
   setOperationAction(ISD::BSWAP, XLenVT,
-                     (Subtarget.hasStdExtZbb() || Subtarget.hasStdExtZbkb() ||
-                      Subtarget.hasVendorXTHeadBb())
-                         ? Legal
-                         : Expand);
+                     Subtarget.hasREV8Like() ? Legal : Expand);
 
   if ((Subtarget.hasVendorXCVbitmanip() || Subtarget.hasVendorXqcibm()) &&
       !Subtarget.is64Bit()) {
diff --git a/llvm/lib/Target/RISCV/RISCVSubtarget.h b/llvm/lib/Target/RISCV/RISCVSubtarget.h
index 0d9cd16a77937..d4aca90816d81 100644
--- a/llvm/lib/Target/RISCV/RISCVSubtarget.h
+++ b/llvm/lib/Target/RISCV/RISCVSubtarget.h
@@ -196,6 +196,9 @@ class RISCVSubtarget : public RISCVGenSubtargetInfo {
   bool hasCPOPLike() const {
     return HasStdExtZbb || (HasVendorXCVbitmanip && !IsRV64);
   }
+  bool hasREV8Like() const {
+    return HasStdExtZbb | HasStdExtZbkb || HasVendorXTHeadBb;
+  }
 
   bool hasBEXTILike() const { return HasStdExtZbs || HasVendorXTHeadBs; }