From: Korey Sewell <ksewell@umich.edu>
Date: Mon, 20 Feb 2006 06:49:16 +0000 (-0500)
Subject: Support for All Jump Instructions ...
X-Git-Tag: m5_2.0_beta1~87^2~87
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=38ce95db3b7cf471dcd3c12b784877c4dc238d6f;p=gem5.git

Support for All Jump Instructions ...
Redo format for Branches and Jumps ( Must update NNPC not NPC )

Now all branches and jumps look like they auto-generate correctly from isa_parser.py!!!

arch/mips/isa/decoder.isa:
    Support for All Jump Instructions ..
arch/mips/isa/formats/branch.isa:
    Redo format for Branches and Jumps ( Must update NNPC not NPC )
arch/mips/isa/formats/util.isa:
    define clear_exe_inst_hazards for later use

--HG--
extra : convert_revision : 63618ed12ee6ed94c47d29619cc1cab2cbaf5cda
---

diff --git a/arch/mips/isa/decoder.isa b/arch/mips/isa/decoder.isa
index f46024f15..e3889ef7a 100644
--- a/arch/mips/isa/decoder.isa
+++ b/arch/mips/isa/decoder.isa
@@ -58,15 +58,17 @@ decode OPCODE_HI default Unknown::unknown() {
 
                 //Table A-3 Note: "Specific encodings of the hint field are used
                 //to distinguish JR from JR.HB and JALR from JALR.HB"
-                format Unconditional {
+                format Jump {
                     0x0: decode HINT {
-                        0:jr({{ }},IsReturn,IsLink);
-                        1:jr_hb({{ }},IsReturn,IsLink);
+                        0:jr({{ NNPC = Rs; }},IsReturn);
+
+                        1:jr_hb({{ NNPC = Rs; clear_exe_inst_hazards(); }},IsReturn);
                     }
 
                     0x1: decode HINT {
-                        0: jalr({{ }},'IsCall','IsReturn','IsLink');
-                        1: jalr_hb({{ }},IsCall,IsReturn,IsLink);
+                        0: jalr({{ NNPC = Rs; }},IsCall,IsReturn);
+
+                        1: jalr_hb({{ NNPC = Rs; clear_exe_inst_hazards();}},IsCall,IsReturn);
                     }
                 }
 
@@ -75,7 +77,6 @@ decode OPCODE_HI default Unknown::unknown() {
                     0x3: movn({{ if (Rt != 0) Rd = Rs; }});
                 }
 
-
                 format WarnUnimpl {
                     0x4: syscall();//{{ xc->syscall()}},IsNonSpeculative
                     0x5: break();
@@ -196,9 +197,10 @@ decode OPCODE_HI default Unknown::unknown() {
             }
         }
 
-        format Unconditional {
-            0x2: j({{ }});
-            0x3: jal({{ }},IsCall,IsLink);
+        format Jump {
+            0x2: j({{ NNPC = (NPC & 0xF0000000) & (0x00000000 & JMPTARG << 2);}});
+
+            0x3: jal({{ NNPC = (NPC & 0xF0000000) & (0x00000000 & JMPTARG << 2);}},IsCall,IsLink);
         }
 
         format Branch {
diff --git a/arch/mips/isa/formats/branch.isa b/arch/mips/isa/formats/branch.isa
index 1f7a6f330..fc207fd3f 100644
--- a/arch/mips/isa/formats/branch.isa
+++ b/arch/mips/isa/formats/branch.isa
@@ -250,20 +250,22 @@ output decoder {{
 }};
 
 def format Branch(code,*flags) {{
-    code = 'bool cond;\n\t' + code + '\n'
-
     #Add Link Code if Link instruction
     strlen = len(name)
     if name[strlen-2:] == 'al':
-        code += 'R31 = NPC + 4;\n'
+        code += 'R31 = NNPC;\n'
 
-    # condition code
-    code += 'if (cond) {'
-    code += '  NPC = NPC + disp;\n'
-    code += '  NNPC = NNPC + disp;\n } \n'
+    #Condition code
+    code = 'bool cond;\n' + code
+    code += 'if (cond) {\n'
+    #code += '//NPC=NPC: just placeholder to force parser to writeback NPC\n'
+    #code += '  NPC = NPC; \n'
+    code += '  NNPC = NPC + disp;\n'
+    code += '} \n'
 
     iop = InstObjParams(name, Name, 'Branch', CodeBlock(code),
                         ('IsDirectControl', 'IsCondControl'))
+
     header_output = BasicDeclare.subst(iop)
     decoder_output = BasicConstructor.subst(iop)
     decode_block = BasicDecode.subst(iop)
@@ -272,30 +274,38 @@ def format Branch(code,*flags) {{
 
 
 def format BranchLikely(code,*flags) {{
-    code = 'bool cond;\n\t\t\t' + code
-
     #Add Link Code if Link instruction
     strlen = len(name)
     if name[strlen-3:] == 'all':
-        code += 'R31 = NPC + 4;\n'
+        code += 'R31 = NNPC;\n'
 
-    #condition code
+    #Condition code
+    code = 'bool cond;\n' + code
     code += 'if (cond) {'
-    code += '  NPC = NPC + disp;\n'
-    code += '  NNPC = NNPC + disp;\n } \n'
+    #code += '//NPC=NPC: just placeholder to force parser to writeback NPC\n'
+    #code += 'NPC = NPC; \n'
+    code += 'NNPC = NPC + disp;\n'
+    code += '} \n'
 
 
     iop = InstObjParams(name, Name, 'Branch', CodeBlock(code),
                         ('IsDirectControl', 'IsCondControl','IsCondDelaySlot'))
+
     header_output = BasicDeclare.subst(iop)
     decoder_output = BasicConstructor.subst(iop)
     decode_block = BasicDecode.subst(iop)
     exec_output = BasicExecute.subst(iop)
 }};
 
-def format Unconditional(code,*flags) {{
-    iop = InstObjParams(name, Name, 'Jump', CodeBlock(code),
+def format Jump(code,*flags) {{
+    #Add Link Code if Link instruction
+    strlen = len(name)
+    if strlen >= 3 and name[2:3] == 'al':
+            code = 'R31 = NNPC;\n' + code
+
+    iop = InstObjParams(name, Name, 'Jump', CodeBlock(code),\
                         ('IsIndirectControl', 'IsUncondControl'))
+
     header_output = BasicDeclare.subst(iop)
     decoder_output = BasicConstructor.subst(iop)
     decode_block = BasicDecode.subst(iop)
diff --git a/arch/mips/isa/formats/util.isa b/arch/mips/isa/formats/util.isa
index c6dae6783..1eff92269 100644
--- a/arch/mips/isa/formats/util.isa
+++ b/arch/mips/isa/formats/util.isa
@@ -24,3 +24,13 @@ def UncondCtrlBase(name, Name, base_class, npc_expr, flags):
     return (header_output, decoder_output,
             JumpOrBranchDecode.subst(nolink_iop), exec_output)
 }};
+
+output exec {{
+
+    /// CLEAR ALL CPU INST/EXE HAZARDS
+    inline void
+    clear_exe_inst_hazards()
+    {
+        //CODE HERE
+    }
+}