From 3272aa3f0858604b8a43298ea79b33a675d33049 Mon Sep 17 00:00:00 2001
From: LC <mai.iam2048@gmail.com>
Date: Wed, 17 Jun 2026 00:36:33 -0400
Subject: [PATCH] [SVE256] Handle SSE insertions for ROUNDPD/ROUNDPS

See #3799
---
 .../Core/OpcodeDispatcher/Vector.cpp          |  2 +-
 unittests/ASM/SSELanePreservation/roundpd.asm | 25 +++++++++++++++++++
 unittests/ASM/SSELanePreservation/roundps.asm | 25 +++++++++++++++++++
 3 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 unittests/ASM/SSELanePreservation/roundpd.asm
 create mode 100644 unittests/ASM/SSELanePreservation/roundps.asm

diff --git a/FEXCore/Source/Interface/Core/OpcodeDispatcher/Vector.cpp b/FEXCore/Source/Interface/Core/OpcodeDispatcher/Vector.cpp
index 3b2d19e37..ee84ad248 100644
--- a/FEXCore/Source/Interface/Core/OpcodeDispatcher/Vector.cpp
+++ b/FEXCore/Source/Interface/Core/OpcodeDispatcher/Vector.cpp
@@ -4019,7 +4019,7 @@ void OpDispatchBuilder::VectorRound(OpcodeArgs, IR::OpSize ElementSize) {
   const uint64_t Mode = Op->Src[1].Literal();
   Src = VectorRoundImpl(OpSizeFromDst(Op), ElementSize, Src, Mode);
 
-  StoreResultFPR(Op, Src);
+  StoreResult_WithAVXInsert(VectorOpType::SSE, RegClass::FPR, Op, Src);
 }
 
 void OpDispatchBuilder::AVXVectorRound(OpcodeArgs, IR::OpSize ElementSize) {
diff --git a/unittests/ASM/SSELanePreservation/roundpd.asm b/unittests/ASM/SSELanePreservation/roundpd.asm
new file mode 100644
index 000000000..808b2b9d9
--- /dev/null
+++ b/unittests/ASM/SSELanePreservation/roundpd.asm
@@ -0,0 +1,25 @@
+%ifdef CONFIG
+{
+  "HostFeatures": ["AVX"],
+  "RegData": {
+    "XMM0": ["0x43cc1ad6970b4549", "0x8000000000000000", "0xccdbcfc31f3ff0f3", "0x108390defebac4be"],
+    "XMM1": ["0xc4be43cc1ad6970b", "0x4549bd7eb46a1278", "0", "0"],
+    "XMM2": ["0xc4be43cc1ad6970b", "0x4549bd7eb46a1278", "0xf793ef673dac6e4c", "0xbb7b5b3d85d34271"]
+  }
+}
+%endif
+
+vmovaps ymm0, [rel .data]
+vmovaps ymm1, [rel .data + (1 * 32)]
+vmovaps ymm2, [rel .data + (2 * 32)]
+
+roundpd xmm0, xmm1, 0b00
+vroundpd xmm1, xmm2, 0b00
+
+hlt
+
+align 32
+.data:
+dq 0xfdecd28fab3fa4a5, 0x7d7ccd8836d09fc2, 0xccdbcfc31f3ff0f3, 0x108390defebac4be
+dq 0x43cc1ad6970b4549, 0xbd7eb46a1278f793, 0xef673dac6e4cbb7b, 0x5b3d85d342718be9
+dq 0xc4be43cc1ad6970b, 0x4549bd7eb46a1278, 0xf793ef673dac6e4c, 0xbb7b5b3d85d34271
diff --git a/unittests/ASM/SSELanePreservation/roundps.asm b/unittests/ASM/SSELanePreservation/roundps.asm
new file mode 100644
index 000000000..125d2d524
--- /dev/null
+++ b/unittests/ASM/SSELanePreservation/roundps.asm
@@ -0,0 +1,25 @@
+%ifdef CONFIG
+{
+  "HostFeatures": ["AVX"],
+  "RegData": {
+    "XMM0": ["0x43cc000080000000", "0x8000000000000000", "0xccdbcfc31f3ff0f3", "0x108390defebac4be"],
+    "XMM1": ["0xc4be400000000000", "0x4549c00080000000", "0", "0"],
+    "XMM2": ["0xc4be43cc1ad6970b", "0x4549bd7eb46a1278", "0xf793ef673dac6e4c", "0xbb7b5b3d85d34271"]
+  }
+}
+%endif
+
+vmovaps ymm0, [rel .data]
+vmovaps ymm1, [rel .data + (1 * 32)]
+vmovaps ymm2, [rel .data + (2 * 32)]
+
+roundps xmm0, xmm1, 0b00
+vroundps xmm1, xmm2, 0b00
+
+hlt
+
+align 32
+.data:
+dq 0xfdecd28fab3fa4a5, 0x7d7ccd8836d09fc2, 0xccdbcfc31f3ff0f3, 0x108390defebac4be
+dq 0x43cc1ad6970b4549, 0xbd7eb46a1278f793, 0xef673dac6e4cbb7b, 0x5b3d85d342718be9
+dq 0xc4be43cc1ad6970b, 0x4549bd7eb46a1278, 0xf793ef673dac6e4c, 0xbb7b5b3d85d34271