[llvm] Revert "[llvm][LoongArch] Improve loongarch_lasx_xvpermi_q instrinsic" (PR #84708)

[Lu Weining via llvm-commits]

https://github.com/SixWeining created https://github.com/llvm/llvm-project/pull/84708

Reverts llvm/llvm-project#82984

See the discussion in https://github.com/llvm/llvm-project/pull/83540.

>From c8a99293cb41576acb1cdd6e90ff2a04059b0075 Mon Sep 17 00:00:00 2001
From: Lu Weining <luweining at loongson.cn>
Date: Mon, 11 Mar 2024 10:31:16 +0800
Subject: [PATCH] Revert "[llvm][LoongArch] Improve loongarch_lasx_xvpermi_q
 instrinsic (#82984)"

This reverts commit d7c80bba698bded48c1df4b4bb7424a181aa6195.
---
 .../LoongArch/LoongArchISelLowering.cpp       | 25 +---------------
 .../CodeGen/LoongArch/lasx/intrinsic-permi.ll | 30 -------------------
 2 files changed, 1 insertion(+), 54 deletions(-)

diff --git a/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp b/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
index 2d71423d6dd593..907aae13d6de0c 100644
--- a/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
+++ b/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
@@ -968,28 +968,6 @@ static SDValue checkIntrinsicImmArg(SDValue Op, unsigned ImmOp,
   return SDValue();
 }
 
-static SDValue checkAndModifyXVPERMI_QIntrinsicImmArg(SDValue Op,
-                                                      SelectionDAG &DAG) {
-  SDValue Op3 = Op->getOperand(3);
-  uint64_t Imm = Op3->getAsZExtVal();
-  // Check the range of ImmArg.
-  if (!isUInt<8>(Imm)) {
-    DAG.getContext()->emitError(Op->getOperationName(0) +
-                                ": argument out of range.");
-    return DAG.getNode(ISD::UNDEF, SDLoc(Op), Op.getValueType());
-  }
-
-  // For instruction xvpermi.q, only [1:0] and [5:4] bits of operands[3]
-  // are used. The unused bits in operands[3] need to be set to 0 to avoid
-  // causing undefined behavior on LA464.
-  if ((Imm & 0x33) != Imm) {
-    Op3 = DAG.getTargetConstant(Imm & 0x33, SDLoc(Op), Op3.getValueType());
-    DAG.UpdateNodeOperands(Op.getNode(), Op->getOperand(0), Op->getOperand(1),
-                           Op->getOperand(2), Op3);
-  }
-  return SDValue();
-}
-
 SDValue
 LoongArchTargetLowering::lowerINTRINSIC_WO_CHAIN(SDValue Op,
                                                  SelectionDAG &DAG) const {
@@ -1247,14 +1225,13 @@ LoongArchTargetLowering::lowerINTRINSIC_WO_CHAIN(SDValue Op,
   case Intrinsic::loongarch_lsx_vextrins_d:
   case Intrinsic::loongarch_lasx_xvshuf4i_d:
   case Intrinsic::loongarch_lasx_xvpermi_w:
+  case Intrinsic::loongarch_lasx_xvpermi_q:
   case Intrinsic::loongarch_lasx_xvbitseli_b:
   case Intrinsic::loongarch_lasx_xvextrins_b:
   case Intrinsic::loongarch_lasx_xvextrins_h:
   case Intrinsic::loongarch_lasx_xvextrins_w:
   case Intrinsic::loongarch_lasx_xvextrins_d:
     return checkIntrinsicImmArg<8>(Op, 3, DAG);
-  case Intrinsic::loongarch_lasx_xvpermi_q:
-    return checkAndModifyXVPERMI_QIntrinsicImmArg(Op, DAG);
   case Intrinsic::loongarch_lsx_vrepli_b:
   case Intrinsic::loongarch_lsx_vrepli_h:
   case Intrinsic::loongarch_lsx_vrepli_w:
diff --git a/llvm/test/CodeGen/LoongArch/lasx/intrinsic-permi.ll b/llvm/test/CodeGen/LoongArch/lasx/intrinsic-permi.ll
index 92669d2e589558..0d9f9daabc4488 100644
--- a/llvm/test/CodeGen/LoongArch/lasx/intrinsic-permi.ll
+++ b/llvm/test/CodeGen/LoongArch/lasx/intrinsic-permi.ll
@@ -36,33 +36,3 @@ entry:
   %res = call <32 x i8> @llvm.loongarch.lasx.xvpermi.q(<32 x i8> %va, <32 x i8> %vb, i32 1)
   ret <32 x i8> %res
 }
-
-define <32 x i8> @lasx_xvpermi_q_204(<32 x i8> %va, <32 x i8> %vb) nounwind {
-; CHECK-LABEL: lasx_xvpermi_q_204:
-; CHECK:       # %bb.0: # %entry
-; CHECK-NEXT:    xvpermi.q $xr0, $xr1, 0
-; CHECK-NEXT:    ret
-entry:
-  %res = call <32 x i8> @llvm.loongarch.lasx.xvpermi.q(<32 x i8> %va, <32 x i8> %vb, i32 204)
-  ret <32 x i8> %res
-}
-
-define <32 x i8> @lasx_xvpermi_q_221(<32 x i8> %va, <32 x i8> %vb) nounwind {
-; CHECK-LABEL: lasx_xvpermi_q_221:
-; CHECK:       # %bb.0: # %entry
-; CHECK-NEXT:    xvpermi.q $xr0, $xr1, 17
-; CHECK-NEXT:    ret
-entry:
-  %res = call <32 x i8> @llvm.loongarch.lasx.xvpermi.q(<32 x i8> %va, <32 x i8> %vb, i32 221)
-  ret <32 x i8> %res
-}
-
-define <32 x i8> @lasx_xvpermi_q_255(<32 x i8> %va, <32 x i8> %vb) nounwind {
-; CHECK-LABEL: lasx_xvpermi_q_255:
-; CHECK:       # %bb.0: # %entry
-; CHECK-NEXT:    xvpermi.q $xr0, $xr1, 51
-; CHECK-NEXT:    ret
-entry:
-  %res = call <32 x i8> @llvm.loongarch.lasx.xvpermi.q(<32 x i8> %va, <32 x i8> %vb, i32 255)
-  ret <32 x i8> %res
-}