From d59ad8a8013fd76177fb61c741562af3024d34cd Mon Sep 17 00:00:00 2001
From: Vladimir Medic <Vladimir.Medic@imgtec.com>
Date: Tue, 1 Oct 2013 09:48:56 +0000
Subject: [PATCH] This patch adds aliases for Mips sub instruction with
 immediate operands. Corresponding test cases are added.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191734 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/Mips/AsmParser/MipsAsmParser.cpp | 22 +++++++++++++++++++++
 lib/Target/Mips/MipsInstrInfo.td            | 18 +++++++++++++++--
 test/MC/Mips/mips-alu-instructions.s        |  4 ++++
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index 5b77d87350a..447e7dc6e1c 100644
--- a/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -144,6 +144,9 @@ class MipsAsmParser : public MCTargetAsmParser {
   MipsAsmParser::OperandMatchResultTy
   parseMSA128DRegs(SmallVectorImpl<MCParsedAsmOperand*> &Operands);
 
+  MipsAsmParser::OperandMatchResultTy
+  parseInvNum(SmallVectorImpl<MCParsedAsmOperand*> &Operands);
+
   bool searchSymbolAlias(SmallVectorImpl<MCParsedAsmOperand*> &Operands,
                          unsigned RegKind);
 
@@ -351,6 +354,7 @@ public:
   bool isToken() const { return Kind == k_Token; }
   bool isMem() const { return Kind == k_Memory; }
   bool isPtrReg() const { return Kind == k_PtrReg; }
+  bool isInvNum() const { return Kind == k_Immediate; }
 
   StringRef getToken() const {
     assert(Kind == k_Token && "Invalid access!");
@@ -1817,6 +1821,24 @@ MipsAsmParser::parseCCRRegs(SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
   return parseRegs(Operands, (int) MipsOperand::Kind_CCRRegs);
 }
 
+MipsAsmParser::OperandMatchResultTy
+MipsAsmParser::parseInvNum(SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
+  const MCExpr *IdVal;
+  // If the first token is '$' we may have register operand.
+  if (Parser.getTok().is(AsmToken::Dollar))
+    return MatchOperand_NoMatch;
+  SMLoc S = Parser.getTok().getLoc();
+  if (getParser().parseExpression(IdVal))
+    return MatchOperand_ParseFail;
+  const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(IdVal);
+    assert( MCE && "Unexpected MCExpr type.");
+  int64_t Val = MCE->getValue();
+  SMLoc E = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
+  Operands.push_back(MipsOperand::CreateImm(
+                     MCConstantExpr::Create(0 - Val, getContext()), S, E));
+  return MatchOperand_Success;
+}
+
 MCSymbolRefExpr::VariantKind MipsAsmParser::getVariantKind(StringRef Symbol) {
 
   MCSymbolRefExpr::VariantKind VK
diff --git a/lib/Target/Mips/MipsInstrInfo.td b/lib/Target/Mips/MipsInstrInfo.td
index 1f802891f32..f92f3336f15 100644
--- a/lib/Target/Mips/MipsInstrInfo.td
+++ b/lib/Target/Mips/MipsInstrInfo.td
@@ -282,11 +282,22 @@ def MipsMemAsmOperand : AsmOperandClass {
   let ParserMethod = "parseMemOperand";
 }
 
+def MipsInvertedImmoperand : AsmOperandClass {
+  let Name = "InvNum";
+  let RenderMethod = "addImmOperands";
+  let ParserMethod = "parseInvNum";
+}
+
 def PtrRegAsmOperand : AsmOperandClass {
   let Name = "PtrReg";
   let ParserMethod = "parsePtrReg";
 }
 
+
+def InvertedImOperand : Operand<i32> {
+  let ParserMatchClass = MipsInvertedImmoperand;
+}
+
 // Address operand
 def mem : Operand<iPTR> {
   let PrintMethod = "printMemOperand";
@@ -1120,6 +1131,11 @@ def  : InstAlias<"tgeu $rs, $rt", (TGEU GPR32Opnd:$rs, GPR32Opnd:$rt, 0), 1>;
 def  : InstAlias<"tlt $rs, $rt", (TLT GPR32Opnd:$rs, GPR32Opnd:$rt, 0), 1>;
 def  : InstAlias<"tltu $rs, $rt", (TLTU GPR32Opnd:$rs, GPR32Opnd:$rt, 0), 1>;
 def  : InstAlias<"tne $rs, $rt", (TNE GPR32Opnd:$rs, GPR32Opnd:$rt, 0), 1>;
+def : InstAlias<"sub, $rd, $rs, $imm",
+                (ADDi GPR32Opnd:$rd, GPR32Opnd:$rs, InvertedImOperand:$imm)>;
+def : InstAlias<"subu, $rd, $rs, $imm",
+                (ADDiu GPR32Opnd:$rd, GPR32Opnd:$rs, InvertedImOperand:$imm)>;
+
 //===----------------------------------------------------------------------===//
 // Assembler Pseudo Instructions
 //===----------------------------------------------------------------------===//
@@ -1139,8 +1155,6 @@ class LoadAddressImm<string instr_asm, Operand Od, RegisterOperand RO> :
                      !strconcat(instr_asm, "\t$rt, $imm32")> ;
 def LoadAddr32Imm : LoadAddressImm<"la", uimm5, GPR32Opnd>;
 
-
-
 //===----------------------------------------------------------------------===//
 //  Arbitrary patterns that map to one or more instructions
 //===----------------------------------------------------------------------===//
diff --git a/test/MC/Mips/mips-alu-instructions.s b/test/MC/Mips/mips-alu-instructions.s
index eccc2880d41..68a8da07c2b 100644
--- a/test/MC/Mips/mips-alu-instructions.s
+++ b/test/MC/Mips/mips-alu-instructions.s
@@ -86,7 +86,9 @@
 # CHECK:  mult   $3, $5          # encoding: [0x18,0x00,0x65,0x00]
 # CHECK:  multu  $3, $5          # encoding: [0x19,0x00,0x65,0x00]
 # CHECK:  sub    $9, $6, $7      # encoding: [0x22,0x48,0xc7,0x00]
+# CHECK:  addi   $sp, $sp, -56   # encoding: [0xc8,0xff,0xbd,0x23]
 # CHECK:  subu   $4, $3, $5      # encoding: [0x23,0x20,0x65,0x00]
+# CHECK:  addiu   $sp, $sp, -40  # encoding: [0xd8,0xff,0xbd,0x27]
 # CHECK:  neg     $6, $7         # encoding: [0x22,0x30,0x07,0x00]
 # CHECK:  negu    $6, $7         # encoding: [0x23,0x30,0x07,0x00]
 # CHECK:  move    $7, $8         # encoding: [0x21,0x38,0x00,0x01]
@@ -109,7 +111,9 @@
     mult   $3,$5
     multu  $3,$5
     sub    $9,$6,$7
+    sub    $sp,$sp,56
     subu   $4,$3,$5
+    subu    $sp,$sp,40
     neg    $6,$7
     negu   $6,$7
     move   $7,$8
-- 
2.34.1