[llvm-branch-commits] [llvm] release/21.x: [Hexagon] Add missing operand when disassembling Y4_crswap10 (#153849) (PR #153926)

[via llvm-branch-commits]

https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/153926

Backport 76d993bd25ff462d915f69772454e7b1ca42fdb8

Requested by: @androm3da

>From 27a00648607f22b4b2d1de4adb72fe6364a7ef88 Mon Sep 17 00:00:00 2001
From: Sergei Barannikov <barannikov88 at gmail.com>
Date: Sat, 16 Aug 2025 05:13:43 +0300
Subject: [PATCH] [Hexagon] Add missing operand when disassembling Y4_crswap10
 (#153849)

Auto-generated decoder fails to add the $sgp10 operand because it has no
encoding bits.
Work around this by adding the missing operand after decoding is
complete.

Fixes #153829.

(cherry picked from commit 76d993bd25ff462d915f69772454e7b1ca42fdb8)
---
 llvm/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp | 3 +++
 llvm/test/MC/Hexagon/system-inst.s                           | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/llvm/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp b/llvm/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp
index 22cff7c80fa01..bcddb540d35dc 100644
--- a/llvm/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp
+++ b/llvm/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp
@@ -526,6 +526,9 @@ DecodeStatus HexagonDisassembler::getSingleInstruction(MCInst &MI, MCInst &MCB,
     MI.insert(MI.begin() + 1,
               MCOperand::createExpr(MCConstantExpr::create(-1, getContext())));
     break;
+  case Hexagon::Y4_crswap10:
+    MI.addOperand(MCOperand::createReg(Hexagon::SGP1_0));
+    break;
   default:
     break;
   }
diff --git a/llvm/test/MC/Hexagon/system-inst.s b/llvm/test/MC/Hexagon/system-inst.s
index 7bc1533598532..07f7ca0acb2dc 100644
--- a/llvm/test/MC/Hexagon/system-inst.s
+++ b/llvm/test/MC/Hexagon/system-inst.s
@@ -89,6 +89,9 @@ crswap(r12,sgp0)
 #CHECK: 652dc000 { crswap(r13,sgp1) }
 crswap(r13,sgp1)
 
+#CHECK: 6d8ec000 { crswap(r15:14,s1:0) }
+crswap(r15:14,sgp1:0)
+
 #CHECK: 660fc00e { r14 = getimask(r15) }
 r14=getimask(r15)