[llvm] [M68k] allow 16-bit registers for MOVE to/from CCR (PR #107591)

[Janis Heims via llvm-commits]

https://github.com/TechnoElf updated https://github.com/llvm/llvm-project/pull/107591

>From 5356e6c775ad4b030525a4ce344279b71936acb4 Mon Sep 17 00:00:00 2001
From: TechnoElf <technoelf at undertheprinter.com>
Date: Fri, 6 Sep 2024 16:04:22 +0200
Subject: [PATCH] [M68k] allow 16-bit registers for MOVE to/from CCR

---
 llvm/lib/Target/M68k/M68kInstrInfo.cpp | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Target/M68k/M68kInstrInfo.cpp b/llvm/lib/Target/M68k/M68kInstrInfo.cpp
index 23c5c76a47479b..dac0663f2fa67e 100644
--- a/llvm/lib/Target/M68k/M68kInstrInfo.cpp
+++ b/llvm/lib/Target/M68k/M68kInstrInfo.cpp
@@ -709,13 +709,27 @@ void M68kInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
   bool ToSR = DstReg == M68k::SR;
 
   if (FromCCR) {
-    assert(M68k::DR8RegClass.contains(DstReg) &&
-           "Need DR8 register to copy CCR");
-    Opc = M68k::MOV8dc;
+    if (M68k::DR8RegClass.contains(DstReg))
+      Opc = M68k::MOV8dc;
+    else if (M68k::DR16RegClass.contains(DstReg))
+      Opc = M68k::MOV16dc;
+    else if (M68k::DR32RegClass.contains(DstReg))
+      Opc = M68k::MOV16dc;
+    else {
+      LLVM_DEBUG(dbgs() << "Cannot copy CCR to " << RI.getName(DstReg) << '\n');
+      llvm_unreachable("Invalid register for MOVE from CCR");
+    }
   } else if (ToCCR) {
-    assert(M68k::DR8RegClass.contains(SrcReg) &&
-           "Need DR8 register to copy CCR");
-    Opc = M68k::MOV8cd;
+    if (M68k::DR8RegClass.contains(SrcReg))
+      Opc = M68k::MOV8cd;
+    else if (M68k::DR16RegClass.contains(SrcReg))
+      Opc = M68k::MOV16cd;
+    else if (M68k::DR32RegClass.contains(SrcReg))
+      Opc = M68k::MOV16cd;
+    else {
+      LLVM_DEBUG(dbgs() << "Cannot copy " << RI.getName(SrcReg) << " to CCR\n");
+      llvm_unreachable("Invalid register for MOVE to CCR");
+    }
   } else if (FromSR || ToSR)
     llvm_unreachable("Cannot emit SR copy instruction");