[MIPS][MSA] Invert operand order of ILVOD when lowering VECTOR_SHUFFLE (#123555)

This PR fixes operand order of `ILVOD.df` when lowering
`VECTOR_SHUFFLE`, the result was `<y[1], x[1]>` while it should be
`<x[1], y[1]>`.

* This PR is split from #123040.

Author: Cyanoxygen

Diff for: llvm/lib/Target/Mips/MipsSEISelLowering.cpp

@@ -2736,7 +2736,7 @@ static SDValue lowerVECTOR_SHUFFLE_ILVOD(SDValue Op, EVT ResTy,
   else
     return SDValue();
 
-  return DAG.getNode(MipsISD::ILVOD, SDLoc(Op), ResTy, Wt, Ws);
+  return DAG.getNode(MipsISD::ILVOD, SDLoc(Op), ResTy, Ws, Wt);
 }
 
 // Lower VECTOR_SHUFFLE into ILVR (if possible).

Diff for: llvm/test/CodeGen/Mips/msa/shuffle.ll

@@ -533,7 +533,7 @@ define void @ilvod_v16i8_0(ptr %c, ptr %a, ptr %b) nounwind {
   ; CHECK-DAG: ld.b [[R2:\$w[0-9]+]], 0($6)
   %3 = shufflevector <16 x i8> %1, <16 x i8> %2,
                      <16 x i32> <i32 1, i32 17, i32 3, i32 19, i32 5, i32 21, i32 7, i32 23, i32 9, i32 25, i32 11, i32 27, i32 13, i32 29, i32 15, i32 31>
-  ; CHECK-DAG: ilvod.b [[R3:\$w[0-9]+]], [[R1]], [[R2]]
+  ; CHECK-DAG: ilvod.b [[R3:\$w[0-9]+]], [[R2]], [[R1]]
   store <16 x i8> %3, ptr %c
   ; CHECK-DAG: st.b [[R3]], 0($4)
 
@@ -548,7 +548,7 @@ define void @ilvod_v8i16_0(ptr %c, ptr %a, ptr %b) nounwind {
   %2 = load <8 x i16>, ptr %b
   ; CHECK-DAG: ld.h [[R2:\$w[0-9]+]], 0($6)
   %3 = shufflevector <8 x i16> %1, <8 x i16> %2, <8 x i32> <i32 1, i32 9, i32 3, i32 11, i32 5, i32 13, i32 7, i32 15>
-  ; CHECK-DAG: ilvod.h [[R3:\$w[0-9]+]], [[R1]], [[R2]]
+  ; CHECK-DAG: ilvod.h [[R3:\$w[0-9]+]], [[R2]], [[R1]]
   store <8 x i16> %3, ptr %c
   ; CHECK-DAG: st.h [[R3]], 0($4)
 
@@ -563,7 +563,7 @@ define void @ilvod_v4i32_0(ptr %c, ptr %a, ptr %b) nounwind {
   %2 = load <4 x i32>, ptr %b
   ; CHECK-DAG: ld.w [[R2:\$w[0-9]+]], 0($6)
   %3 = shufflevector <4 x i32> %1, <4 x i32> %2, <4 x i32> <i32 1, i32 5, i32 3, i32 7>
-  ; CHECK-DAG: ilvod.w [[R3:\$w[0-9]+]], [[R1]], [[R2]]
+  ; CHECK-DAG: ilvod.w [[R3:\$w[0-9]+]], [[R2]], [[R1]]
   store <4 x i32> %3, ptr %c
   ; CHECK-DAG: st.w [[R3]], 0($4)
 
@@ -578,7 +578,7 @@ define void @ilvod_v2i64_0(ptr %c, ptr %a, ptr %b) nounwind {
   %2 = load <2 x i64>, ptr %b
   ; CHECK-DAG: ld.d [[R2:\$w[0-9]+]], 0($6)
   %3 = shufflevector <2 x i64> %1, <2 x i64> %2, <2 x i32> <i32 1, i32 3>
-  ; CHECK-DAG: ilvod.d [[R3:\$w[0-9]+]], [[R1]], [[R2]]
+  ; CHECK-DAG: ilvod.d [[R3:\$w[0-9]+]], [[R2]], [[R1]]
   store <2 x i64> %3, ptr %c
   ; CHECK-DAG: st.d [[R3]], 0($4)
 
@@ -934,7 +934,7 @@ define void @ilvl_v2i64_0(ptr %c, ptr %a, ptr %b) nounwind {
   ; CHECK-DAG: ld.d [[R2:\$w[0-9]+]], 0($6)
   %3 = shufflevector <2 x i64> %1, <2 x i64> %2, <2 x i32> <i32 1, i32 3>
   ; ilvl.d and ilvod.d are equivalent for v2i64
-  ; CHECK-DAG: ilvod.d [[R3:\$w[0-9]+]], [[R1]], [[R2]]
+  ; CHECK-DAG: ilvod.d [[R3:\$w[0-9]+]], [[R2]], [[R1]]
   store <2 x i64> %3, ptr %c
   ; CHECK-DAG: st.d [[R3]], 0($4)
 
@@ -1290,7 +1290,7 @@ define void @pckod_v2i64_0(ptr %c, ptr %a, ptr %b) nounwind {
   ; CHECK-DAG: ld.d [[R2:\$w[0-9]+]], 0($6)
   %3 = shufflevector <2 x i64> %1, <2 x i64> %2, <2 x i32> <i32 1, i32 3>
   ; pckod.d and ilvod.d are equivalent for v2i64
-  ; CHECK-DAG: ilvod.d [[R3:\$w[0-9]+]], [[R1]], [[R2]]
+  ; CHECK-DAG: ilvod.d [[R3:\$w[0-9]+]], [[R2]], [[R1]]
   store <2 x i64> %3, ptr %c
   ; CHECK-DAG: st.d [[R3]], 0($4)