From 16101049f3511b5ccb3b24dd383f8d8e498b0270 Mon Sep 17 00:00:00 2001
From: Liam <byteslice@airmail.cc>
Date: Wed, 16 Nov 2022 16:10:39 -0500
Subject: [PATCH] Fix EXTR (flipped rgister order)

---
 .../arm64/emit_arm64_data_processing.cpp        |  4 ++--
 tests/A64/a64.cpp                               | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/dynarmic/backend/arm64/emit_arm64_data_processing.cpp b/src/dynarmic/backend/arm64/emit_arm64_data_processing.cpp
index 790873c2..a1e618fb 100644
--- a/src/dynarmic/backend/arm64/emit_arm64_data_processing.cpp
+++ b/src/dynarmic/backend/arm64/emit_arm64_data_processing.cpp
@@ -1408,7 +1408,7 @@ void EmitIR<IR::Opcode::ExtractRegister32>(oaknut::CodeGenerator& code, EmitCont
     RegAlloc::Realize(Wresult, Wop1, Wop2);
     const u8 lsb = args[2].GetImmediateU8();
 
-    code.EXTR(Wresult, Wop1, Wop2, lsb);
+    code.EXTR(Wresult, Wop2, Wop1, lsb);  // NB: flipped
 }
 
 template<>
@@ -1422,7 +1422,7 @@ void EmitIR<IR::Opcode::ExtractRegister64>(oaknut::CodeGenerator& code, EmitCont
     RegAlloc::Realize(Xresult, Xop1, Xop2);
     const u8 lsb = args[2].GetImmediateU8();
 
-    code.EXTR(Xresult, Xop1, Xop2, lsb);
+    code.EXTR(Xresult, Xop2, Xop1, lsb);  // NB: flipped
 }
 
 template<>
diff --git a/tests/A64/a64.cpp b/tests/A64/a64.cpp
index 067da6bb..6190ae14 100644
--- a/tests/A64/a64.cpp
+++ b/tests/A64/a64.cpp
@@ -1024,6 +1024,23 @@ TEST_CASE("A64: This is an infinite loop if fast dispatch is enabled", "[a64]")
     jit.Run();
 }
 
+TEST_CASE("A64: EXTR", "[a64]") {
+    A64TestEnv env;
+    A64::Jit jit{A64::UserConfig{&env}};
+
+    env.code_mem.emplace_back(0x93d8fef7);  // EXTR X23, X23, X24, #63
+    env.code_mem.emplace_back(0x14000000);  // B .
+
+    jit.SetPC(0);
+    jit.SetRegister(23, 0);
+    jit.SetRegister(24, 1);
+
+    env.ticks_left = 2;
+    jit.Run();
+
+    REQUIRE(jit.GetRegister(23) == 0);
+}
+
 TEST_CASE("A64: Optimization failure when folding ADD", "[a64]") {
     A64TestEnv env;
     A64::Jit jit{A64::UserConfig{&env}};