From 5cc8504fb555a5878e6aa086c9fadc10e177d963 Mon Sep 17 00:00:00 2001
From: raaller <ralerrdirsardx@gmail.com>
Date: Thu, 3 Sep 2026 22:41:06 +0300
Subject: [PATCH] x86: fix JO/JNO operand size in 64-bit mode

---
 arch/X86/X86DisassemblerDecoder.c |  2 ++
 tests/issues/issues.yaml          | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/arch/X86/X86DisassemblerDecoder.c b/arch/X86/X86DisassemblerDecoder.c
index 8d58cd410d..039303768e 100644
--- a/arch/X86/X86DisassemblerDecoder.c
+++ b/arch/X86/X86DisassemblerDecoder.c
@@ -1287,6 +1287,8 @@ static int getID(struct InternalInstruction *insn)
 				insn->displacementSize = 4;
 			}
 			break;
+		case 0x80:
+		case 0x81:
 		case 0x82:
 		case 0x83:
 		case 0x84:
diff --git a/tests/issues/issues.yaml b/tests/issues/issues.yaml
index 1d64dcd372..e6c021b87b 100644
--- a/tests/issues/issues.yaml
+++ b/tests/issues/issues.yaml
@@ -7012,3 +7012,25 @@ test_cases:
           regs_read: [ rsp, ss ]
           regs_write: [ rsp, rip ]
           groups: [ ret, mode64 ]
+  -
+    input:
+      name: "issue 3037 x86-64 JO ignores operand-size override"
+      bytes: [ 0x66,0x0f,0x80,0xce,0xfa,0xa5,0xd8 ]
+      arch: "CS_ARCH_X86"
+      options: [ CS_MODE_64, CS_OPT_DETAIL ]
+      address: 0x0
+    expected:
+      insns:
+      -
+        asm_text: "jo 0xffffffffd8a5fad5"
+  -
+    input:
+      name: "issue 3037 x86-64 JNO ignores operand-size override"
+      bytes: [ 0x66,0x0f,0x81,0xce,0xfa,0xa5,0xd8 ]
+      arch: "CS_ARCH_X86"
+      options: [ CS_MODE_64, CS_OPT_DETAIL ]
+      address: 0x0
+    expected:
+      insns:
+      -
+        asm_text: "jno 0xffffffffd8a5fad5"