From 3242ff3354890da733159163afcd3b0c910d454c Mon Sep 17 00:00:00 2001
From: cdkersey <chad.d.kersey@gmail.com>
Date: Mon, 6 Jul 2015 22:20:05 -0600
Subject: [PATCH] %ra, %sp, %fp are now valid register identifiers.

---
 src/include/asm-tokens.h |  4 ++--
 src/include/obj.h        |  5 +++--
 src/obj.cpp              | 14 ++++++++++++++
 src/scanner.lex          |  4 ++++
 4 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/include/asm-tokens.h b/src/include/asm-tokens.h
index 5f014817..2550d44b 100644
--- a/src/include/asm-tokens.h
+++ b/src/include/asm-tokens.h
@@ -5,7 +5,7 @@ namespace HarpTools {
     ASM_T_DIR_GLOBAL,  ASM_T_DIR_ARG_NUM, ASM_T_DIR_ARG_STRING,
     ASM_T_DIR_ARG_SYM, ASM_T_DIR_ARG_R,   ASM_T_DIR_ARG_W, ASM_T_DIR_ARG_X,
     ASM_T_DIR_END,     ASM_T_LABEL,       ASM_T_PRED,      ASM_T_INST,
-    ASM_T_PREG,        ASM_T_REG,         ASM_T_LIT,       ASM_T_SYM,
-    ASM_T_PEXP
+    ASM_T_PREG,        ASM_T_REG,         ASM_T_REG_RA,    ASM_T_REG_SP,
+    ASM_T_REG_FP,      ASM_T_LIT,         ASM_T_SYM,       ASM_T_PEXP
   };
 };
diff --git a/src/include/obj.h b/src/include/obj.h
index ea5732d0..5cb9741c 100644
--- a/src/include/obj.h
+++ b/src/include/obj.h
@@ -169,10 +169,11 @@ namespace Harp {
 
   class AsmReader : public ObjReader {
   public:
-    AsmReader(ArchDef arch) : wordSize(arch.getWordSize()) {}
+    AsmReader(ArchDef arch) :
+      wordSize(arch.getWordSize()), nRegs(arch.getNRegs()) {}
     virtual Obj *read(std::istream &input);
   private:
-    Size wordSize;
+    Size wordSize, nRegs;
   };
    
   class HOFReader : public ObjReader {
diff --git a/src/obj.cpp b/src/obj.cpp
index a30ffb6b..435ec1eb 100644
--- a/src/obj.cpp
+++ b/src/obj.cpp
@@ -363,7 +363,21 @@ Obj *AsmReader::read(std::istream &input) {
           default: asmReaderError(yyline, "Unexpected predicate register");
         }
         break;
+
+      case ASM_T_REG_RA:
+        yylval.u = nRegs - 1;
+        goto continue_reg;
+
+      case ASM_T_REG_FP:
+        yylval.u = nRegs - 3;
+        goto continue_reg;
+
+      case ASM_T_REG_SP:
+        yylval.u = nRegs - 2;
+        goto continue_reg;
+
       case ASM_T_REG:
+      continue_reg:
         switch (state) {
           case ST_INST1: curInst->setDestReg(yylval.u);
                          state = ST_INST2;
diff --git a/src/scanner.lex b/src/scanner.lex
index b76205e1..ad00c25b 100644
--- a/src/scanner.lex
+++ b/src/scanner.lex
@@ -91,6 +91,10 @@ to
                                 return ASM_T_PREG; }
 <INSTARGS>%r{num}{space}[,;]? { yylval.u = read_number(YYText());
                                 return ASM_T_REG; }
+<INSTARGS>%ra { return ASM_T_REG_RA; }
+<INSTARGS>%sp { return ASM_T_REG_FP; }
+<INSTARGS>%fp { return ASM_T_REG_SP; }
+
 <INSTARGS>#{num}{space}[,;]? { yylval.u = read_number(YYText());
                                return ASM_T_LIT; }
 <INSTARGS>{sym} { yylval.s = std::string(YYText()); return ASM_T_SYM; }