[llvm-branch-commits] [SPARC][IAS] Add support for `setsw` pseudoinstruction (PR #125150)

[Sergei Barannikov via llvm-branch-commits]

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@@ -734,6 +737,69 @@ bool SparcAsmParser::expandSET(MCInst &Inst, SMLoc IDLoc,
   return false;
 }
 
+bool SparcAsmParser::expandSETSW(MCInst &Inst, SMLoc IDLoc,
+                                 SmallVectorImpl<MCInst> &Instructions) {
+  MCOperand MCRegOp = Inst.getOperand(0);
+  MCOperand MCValOp = Inst.getOperand(1);
+  assert(MCRegOp.isReg());
+  assert(MCValOp.isImm() || MCValOp.isExpr());
+
+  // the imm operand can be either an expression or an immediate.
+  bool IsImm = Inst.getOperand(1).isImm();
+  int64_t ImmValue = IsImm ? MCValOp.getImm() : 0;
+  const MCExpr *ValExpr = IsImm ? MCConstantExpr::create(ImmValue, getContext())
+                                : MCValOp.getExpr();
+
+  bool IsSmallImm = IsImm && isInt<13>(ImmValue);
+  bool NoLowBitsImm = IsImm && ((ImmValue & 0x3FF) == 0);
+
+  MCOperand PrevReg = MCOperand::createReg(Sparc::G0);
+
+  if (!isInt<32>(ImmValue)) {
+    return Error(IDLoc,
+                 "set: argument must be between -2147483648 and 2147483647");
+  }
+
+  // Very small immediates can be expressed without emitting a sethi.
+  if (!IsSmallImm) {
+    // sethi %hi(val), rd
+    Instructions.push_back(
+        MCInstBuilder(SP::SETHIi)
+            .addReg(MCRegOp.getReg())
+            .addExpr(adjustPICRelocation(SparcMCExpr::VK_Sparc_HI, ValExpr)));
+
+    PrevReg = MCRegOp;
+  }
+
+  // If the immediate has the lower bits set or is small, we need to emit an or.
+  if (!NoLowBitsImm || IsSmallImm) {
+    const MCExpr *Expr =
+        IsSmallImm ? ValExpr
+                   : adjustPICRelocation(SparcMCExpr::VK_Sparc_LO, ValExpr);
+
+    // or    rd, %lo(val), rd
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s-barannikov wrote:

(very minor nit) extra spaces here and in the snippet below

https://github.com/llvm/llvm-project/pull/125150