[llvm] Move gfni for bitreverse check out of SSSE3. (PR #88938)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-x86

Author: None (shamithoke)

<details>
<summary>Changes</summary>

For lowering bitreverse using GFNI, the check is put under SSSE3. This can be pulled out of SSSE3. 

---
Full diff: https://github.com/llvm/llvm-project/pull/88938.diff


1 Files Affected:

- (modified) llvm/lib/Target/X86/X86ISelLowering.cpp (+7-7) 


``````````diff
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index f16a751a166d69..27107f554fccf1 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -1276,6 +1276,13 @@ X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
     setOperationAction(ISD::STRICT_FDIV,        MVT::v2f64, Legal);
   }
 
+  if (Subtarget.hasGFNI()) {
+    setOperationAction(ISD::BITREVERSE, MVT::i8, Custom);
+    setOperationAction(ISD::BITREVERSE, MVT::i16, Custom);
+    setOperationAction(ISD::BITREVERSE, MVT::i32, Custom);
+    setOperationAction(ISD::BITREVERSE, MVT::i64, Custom);
+  }
+
   if (!Subtarget.useSoftFloat() && Subtarget.hasSSSE3()) {
     setOperationAction(ISD::ABS,                MVT::v16i8, Legal);
     setOperationAction(ISD::ABS,                MVT::v8i16, Legal);
@@ -1286,13 +1293,6 @@ X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
       setOperationAction(ISD::CTLZ,             VT, Custom);
     }
 
-    if (Subtarget.hasGFNI()) {
-      setOperationAction(ISD::BITREVERSE, MVT::i8, Custom);
-      setOperationAction(ISD::BITREVERSE, MVT::i16, Custom);
-      setOperationAction(ISD::BITREVERSE, MVT::i32, Custom);
-      setOperationAction(ISD::BITREVERSE, MVT::i64, Custom);
-    }
-
     // These might be better off as horizontal vector ops.
     setOperationAction(ISD::ADD,                MVT::i16, Custom);
     setOperationAction(ISD::ADD,                MVT::i32, Custom);

``````````

</details>


https://github.com/llvm/llvm-project/pull/88938