From f09a8c39623c49161832034a4d5ebc8a25473f89 Mon Sep 17 00:00:00 2001
From: Xinhui Yang <cyan@cyano.uk>
Date: Wed, 15 Jan 2025 10:57:33 +0800
Subject: [PATCH] [MIPS][MSA] Invert operand order of ILVOD when lowering
 VECTOR_SHUFFLE

The result was <y[1], x[1]> while it should be <x[1], y[1]>.

This affects the result of vector shuffles:

    %result = shufflevector <4 x i32> %x, <4 x i32> %y,
              <4 x 132> <i32 1, i32 5, i32 3, i32 7>

The mask above matches the pattern wanted by the ILVOD lowering.
The result is <%y[1], %x[1], %y[3], %x[3]>, while it should be
<%x[1], %y[1], %x[3], %y[3]>.

* tests/CodeGen/Mips: Update MSA shuffle tests according to the change.
---
 llvm/lib/Target/Mips/MipsSEISelLowering.cpp |  2 +-
 llvm/test/CodeGen/Mips/msa/shuffle.ll       | 12 ++++++------
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/llvm/lib/Target/Mips/MipsSEISelLowering.cpp b/llvm/lib/Target/Mips/MipsSEISelLowering.cpp
index 818b1683bb867..1d1b0f9c6ae2a 100644
--- a/llvm/lib/Target/Mips/MipsSEISelLowering.cpp
+++ b/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 --git a/llvm/test/CodeGen/Mips/msa/shuffle.ll b/llvm/test/CodeGen/Mips/msa/shuffle.ll
index e93bb7cdd1128..37eefd695c2ed 100644
--- a/llvm/test/CodeGen/Mips/msa/shuffle.ll
+++ b/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)