progress on patching calls

23 files changed, 159 insertions, 112 deletions

diff --git a/chapter21/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java b/chapter21/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java
index a2c836a8..c6ac68c4 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java
@@ -230,7 +230,7 @@ public class CodeGen {
         for( int i=0; i < x.nIns(); i++ )
             x._inputs.set(i, _instSelect(x.in(i),map) );
         if( x instanceof MachNode mach )
-            mach.postSelect();  // Post selection action
+            mach.postSelect(this);  // Post selection action
 
         // Updates forward edges only.
         n._outputs.clear();
@@ -297,45 +297,6 @@ public class CodeGen {
         return this;
     }
 
-    public CodeGen exportELF() {
-        assert _phase == Phase.Encoding;
-        _phase = Phase.Export;
-        ElfFile obj = new ElfFile(this);
-        obj.export();
-        return this;
-    }
-
-    public static void print_as_hex(Encoding enc) {
-        for (byte b : enc._bits.toByteArray()) {
-            System.out.print(String.format("%02X", b));
-        }
-        System.out.println();
-    }
-
-    public void print_as_hex() {
-        for (byte b : _encoding._bits.toByteArray()) {
-            System.out.print(String.format("%02X", b));
-        }
-        System.out.println();
-    }
-
-    //// Debug purposes for now
-//    public CodeGen printENCODING() {
-//        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
-//
-//        for(Node bb : CodeGen.CODE._cfg) {
-//            for(Node n: bb.outs()) {
-//                if(n instanceof MachNode) {
-//                    ((MachNode) n).encoding(E);
-//                }
-//            }
-//        }
-//
-//        print_as_hex(outputStream);
-//        // Get the raw bytes from the output stream
-//        return this;
-//    }
-
     public String reg(Node n) {
         if( _phase.ordinal() >= Phase.RegAlloc.ordinal() ) {
             String s = _regAlloc.reg(n);
@@ -361,6 +322,16 @@ public class CodeGen {
     public byte[] binary() { throw Utils.TODO(); }
 
     // ---------------------------
+    // Exporting to external formats
+    public CodeGen exportELF() {
+        assert _phase == Phase.Encoding;
+        _phase = Phase.Export;
+        ElfFile obj = new ElfFile(this);
+        obj.export();
+        return this;
+    }
+
+    // ---------------------------
     SB asm(SB sb) { return ASMPrinter.print(sb,this); }
     public String asm() { return asm(new SB()).toString(); }
 
@@ -379,4 +350,35 @@ public class CodeGen {
 
     // Debugging helper
     public Node f(int idx) { return _stop.find(idx); }
+
+    public static void print_as_hex(Encoding enc) {
+        for (byte b : enc._bits.toByteArray()) {
+            System.out.print(String.format("%02X", b));
+        }
+        System.out.println();
+    }
+
+    public void print_as_hex() {
+        for (byte b : _encoding._bits.toByteArray()) {
+            System.out.print(String.format("%02X", b));
+        }
+        System.out.println();
+    }
+
+    //// Debug purposes for now
+//    public CodeGen printENCODING() {
+//        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+//
+//        for(Node bb : CodeGen.CODE._cfg) {
+//            for(Node n: bb.outs()) {
+//                if(n instanceof MachNode) {
+//                    ((MachNode) n).encoding(E);
+//                }
+//            }
+//        }
+//
+//        print_as_hex(outputStream);
+//        // Get the raw bytes from the output stream
+//        return this;
+//    }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/codegen/ElfFile.java b/chapter21/src/main/java/com/seaofnodes/simple/codegen/ElfFile.java
index b263ea6b..c01eadd1 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/codegen/ElfFile.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/codegen/ElfFile.java
@@ -284,9 +284,10 @@ public class ElfFile {
 
         // create .text relocations
         DataSection text_rela = new DataSection(".rela.text", 4 /* SHT_RELA */);
-        for (Map.Entry<Node,TypeFunPtr> e : _code._encoding._funcRelos.entrySet()) {
-            int nid    = e.getKey()._nid;
-            int sym_id = _funcs.get(e.getValue())._index;
+        for( Node n : _code._encoding._externals) {
+            int nid    = n._nid;
+            TypeFunPtr tfp = n instanceof CallNode call ? call.tfp() : (TypeFunPtr)n._type;
+            int sym_id = _funcs.get(tfp)._index;
             int offset = _code._encoding._opStart[nid] + _code._encoding._opLen[nid] - 4;
 
             // u64 offset
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/codegen/Encoding.java b/chapter21/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
index 6ddaa1f4..7cdbf1c8 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
@@ -42,18 +42,12 @@ public class Encoding {
         public byte[] buf() { return buf; }
         void set( byte[] buf0, int count0 ) { buf=buf0; count=count0; }
     };
-    final public BAOS _bits;
+    final public BAOS _bits = new BAOS();
 
     public int [] _opStart;     // Start  of opcodes, by _nid
     public byte[] _opLen;       // Length of opcodes, by _nid
 
-    Encoding( CodeGen code ) {
-        _code = code;
-        _bits = new BAOS();
-        _bigCons = new HashMap<>();
-        _jmps = new HashMap<>();
-        _funcRelos = new HashMap<>();
-    }
+    Encoding( CodeGen code ) { _code = code; }
 
     // Shortcut to the defining register
     public short reg(Node n) {
@@ -87,31 +81,30 @@ public class Encoding {
     }
 
 
-    // Relocation thinking:
-    // `encoding()` calls back with info (TFP needed, branch target needed).
-    // Record start of op & TFP/target info.
-
-    // During some future RELO phase, after TFP layout/targets known
-    // call back with `ReloNode.patch(byte[],src_offset,TFP,dst_offset)`
-    // X86 gets a special pass for expanding short jumps.
-
-    public final HashMap<Node,TypeFunPtr> _funcRelos;
-    public void relo( Node relo, TypeFunPtr t ) {
-        _funcRelos.put(relo, t);
+    // Nodes need "relocation" patching; things done after code is placed.
+    private final Ary<Node> _internals = new Ary<>(Node.class);
+    public  final Ary<Node> _externals = new Ary<>(Node.class);
+    public Encoding relo( CallNode call ) {
+        (call.external() ? _externals : _internals).add(call);
+        return this;
     }
+    public Encoding reloTFP( ConstantNode con ) { _internals.add(con); return this; }
+
     public void relo( NewNode nnn ) {
         // TODO: record alloc relocation info
     }
     // Store t as a 32/64 bit constant in the code space; generate RIP-relative
     // addressing to load it
 
-    public final HashMap<Node,Type> _bigCons;
+    public final HashMap<Node,Type> _bigCons = new HashMap<>();
     public void largeConstant( Node relo, Type t ) {
         assert t.isConstant();
         _bigCons.put(relo,t);
         // TODO:
     }
-    private final HashMap<CFGNode,CFGNode> _jmps;
+
+    // Local relocation info for patching local jumps, once targets are known.
+    private final HashMap<CFGNode,CFGNode> _jmps = new HashMap<>();
     public void jump( CFGNode jmp, CFGNode target ) { _jmps.put(jmp,target); }
 
     void encode() {
@@ -222,9 +215,10 @@ public class Encoding {
         _opStart= new int [_code.UID()];
         _opLen  = new byte[_code.UID()];
         for( CFGNode bb : _code._cfg ) {
-            if( !(bb instanceof MachNode) ) _opStart[bb._nid] = _bits.size();
+            if( !(bb instanceof MachNode) || bb instanceof FunNode )
+                _opStart[bb._nid] = _bits.size();
             for( Node n : bb._outputs ) {
-                if( n instanceof MachNode mach ) {
+                if( n instanceof MachNode mach && !(n instanceof FunNode) ) {
                     _opStart[n._nid] = _bits.size();
                     mach.encoding( this );
                     _opLen[n._nid] = (byte) (_bits.size() - _opStart[n._nid]);
@@ -300,6 +294,20 @@ public class Encoding {
             int start = _opStart[jmp._nid];
             ((RIPRelSize)jmp).patch(this, start, _opLen[jmp._nid], _opStart[target._nid] - start);
         }
+
+
+        // Walk the local code-address relocations
+        for( Node n : _internals ) {
+            TypeFunPtr tfp = n instanceof CallNode call ? call.tfp() : (TypeFunPtr)n._type;
+            FunNode fun = _code.link(tfp);
+            int start = _opStart[n._nid];
+            ((RIPRelSize)n).patch(this, start, _opLen[n._nid], _opStart[fun._nid] - start);
+        }
+
+        // Walk the external call relocations
+        for( Node call : _externals ) {
+          throw Utils.TODO();
+        }
     }
 
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/CallNode.java b/chapter21/src/main/java/com/seaofnodes/simple/node/CallNode.java
index f8f34422..484a613e 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/CallNode.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/CallNode.java
@@ -50,6 +50,10 @@ public class CallNode extends CFGNode {
     // Error if not a TFP
     public TypeFunPtr tfp() { return (TypeFunPtr)fptr()._type; }
 
+    // Call is to an externally supplied code
+    public boolean external() { return false; }
+
+
     // Find the Call End from the Call
     public CallEndNode cend() {
         // Always in use slot 0
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/MachNode.java b/chapter21/src/main/java/com/seaofnodes/simple/node/MachNode.java
index 2c67ff2d..5486b1c1 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/MachNode.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/MachNode.java
@@ -9,7 +9,7 @@ public interface MachNode {
     default Machine machine() { return CodeGen.CODE._mach; }
 
     // Run a post-instruction-selection action
-    default void postSelect() { }
+    default void postSelect( CodeGen code ) { }
 
     // Register mask allowed on input i.  0 for no register.
     RegMask regmap( int i );
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/BranchARM.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/BranchARM.java
index e3c63ccc..b3384f21 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/BranchARM.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/BranchARM.java
@@ -14,7 +14,7 @@ public class BranchARM extends IfNode implements MachNode, RIPRelSize {
     @Override public String op() { return "j"+_bop; }
     @Override public String label() { return op(); }
 
-    @Override public void postSelect() {
+    @Override public void postSelect(CodeGen code) {
         Node set = in(1);
         Node cmp = set.in(1);
         // Bypass an expected Set and just reference the cmp directly
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/CallARM.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/CallARM.java
index 1d3d4d3d..ed22da06 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/CallARM.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/CallARM.java
@@ -5,7 +5,7 @@ import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.node.*;
 import com.seaofnodes.simple.type.TypeFunPtr;
 
-public class CallARM extends CallNode implements MachNode {
+public class CallARM extends CallNode implements MachNode, RIPRelSize {
     final TypeFunPtr _tfp;
     final String _name;
 
@@ -25,9 +25,17 @@ public class CallARM extends CallNode implements MachNode {
     @Override public RegMask outregmap() { return null; }
 
     @Override public void encoding( Encoding enc ) {
-        enc.relo(this,_tfp);    // Record relo info
+        enc.relo(this);
         // BL
-        enc.add4(arm.b(0B100101,0)); // Target patched at link time
+        enc.add4(arm.b(0b100101,0)); // Target patched at link time
+    }
+
+    // Delta is from opcode start, but X86 measures from the end of the 5-byte encoding
+    @Override public byte encSize(int delta) { return 4; }
+
+    // Delta is from opcode start
+    @Override public void patch( Encoding enc, int opStart, int opLen, int delta ) {
+        enc.patch4(opStart,arm.b(0b100101,delta));
     }
 
     @Override public void asm(CodeGen code, SB sb) {
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/FunARM.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/FunARM.java
index 736bca47..2e8bf6ad 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/FunARM.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/FunARM.java
@@ -1,7 +1,6 @@
 package com.seaofnodes.simple.node.cpus.arm;
 
-import com.seaofnodes.simple.codegen.Encoding;
-import com.seaofnodes.simple.codegen.RegMask;
+import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.node.FunNode;
 import com.seaofnodes.simple.node.MachNode;
 
@@ -10,4 +9,5 @@ public class FunARM  extends FunNode implements MachNode {
     @Override public RegMask regmap(int i) { return null; }
     @Override public RegMask outregmap() { return null; }
     @Override public void encoding( Encoding enc ) { }
+    @Override public void postSelect(CodeGen code) { code.link(this);  }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/RetARM.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/RetARM.java
index 2a702247..290421aa 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/RetARM.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/RetARM.java
@@ -8,7 +8,7 @@ public class RetARM extends ReturnNode implements MachNode {
     RetARM(ReturnNode ret, FunNode fun) { super(ret, fun); fun.setRet(this); }
     @Override public String op() { return "ret"; }
     // Correct Nodes outside the normal edges
-    @Override public void postSelect() {
+    @Override public void postSelect(CodeGen code) {
         FunNode fun = (FunNode)rpc().in(0);
         _fun = fun;
         fun.setRet(this);
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/TFPARM.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/TFPARM.java
index eb06a4e0..429148d2 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/TFPARM.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/TFPARM.java
@@ -14,7 +14,7 @@ public class TFPARM extends ConstantNode implements MachNode {
     @Override public boolean isClone() { return true; }
     @Override public TFPARM copy() { return new TFPARM(this); }
     @Override public void encoding( Encoding enc ) {
-        enc.relo(this,(TypeFunPtr)_con);
+        enc.reloTFP(this);
         short self = enc.reg(this);
         // adrp    x0, 0
         int adrp = arm.adrp(1,0, 0b10000, 0,self);
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java
index 6b3faa4e..a3f08730 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java
@@ -542,9 +542,9 @@ public class arm extends Machine {
     }
 
     private Node call(CallNode call){
-        if(call.fptr() instanceof ConstantNode con && con._con instanceof TypeFunPtr tfp)
-            return new CallARM(call, tfp);
-        return new CallRRARM(call);
+        return call.fptr() instanceof ConstantNode con && con._con instanceof TypeFunPtr tfp
+            ? new CallARM(call, tfp)
+            : new CallRRARM(call);
     }
 
     private Node or(OrNode or) {
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/AUIPC.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/AUIPC.java
index 30c63d8d..244e0456 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/AUIPC.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/AUIPC.java
@@ -7,7 +7,7 @@ import com.seaofnodes.simple.node.MachNode;
 import com.seaofnodes.simple.type.TypeFunPtr;
 
 // Add upper 20bits to PC.  Immediate comes from the relocation info.
-public class AUIPC extends ConstantNode implements MachNode {
+public class AUIPC extends ConstantNode implements MachNode, RIPRelSize {
     AUIPC( TypeFunPtr tfp ) { super(tfp); }
     @Override public RegMask regmap(int i) { return null; }
     @Override public RegMask outregmap() { return riscv.WMASK; }
@@ -15,11 +15,23 @@ public class AUIPC extends ConstantNode implements MachNode {
     @Override public AUIPC copy() { return new AUIPC((TypeFunPtr)_con); }
     @Override public String op() { return "auipc"; }
     @Override public void encoding( Encoding enc ) {
-        enc.relo(this,(TypeFunPtr)_con);
+        enc.reloTFP(this);
         short dst = enc.reg(this);
         enc.add4(riscv.u_type(0x17, dst, 0));
     }
 
+    // Delta is from opcode start, but X86 measures from the end of the 5-byte encoding
+    @Override public byte encSize(int delta) { return 4; }
+
+    // Delta is from opcode start
+    @Override public void patch( Encoding enc, int opStart, int opLen, int delta ) {
+        //short rpc = enc.reg(this);
+        //// High half is where the TFP constant used to be, the last input
+        //short auipc = enc.reg(in(_inputs._len-1));
+        //enc.patch4(opStart,riscv.i_type(0x67, rpc, 0, auipc, delta));
+        throw Utils.TODO();
+    }
+
     @Override public void asm(CodeGen code, SB sb) {
         String reg = code.reg(this);
         sb.p(reg).p(" = PC+#");
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/CallRISC.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/CallRISC.java
index d0309829..538a68be 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/CallRISC.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/CallRISC.java
@@ -5,14 +5,13 @@ import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.node.*;
 import com.seaofnodes.simple.type.TypeFunPtr;
 
-public class CallRISC extends CallNode implements MachNode {
+public class CallRISC extends CallNode implements MachNode, RIPRelSize {
     final TypeFunPtr _tfp;
     final String _name;
-    CallRISC( CallNode call, TypeFunPtr tfp, AUIPC auipc ) {
+    CallRISC( CallNode call, TypeFunPtr tfp ) {
         super(call);
         assert tfp.isConstant();
         _inputs.pop(); // Pop constant target
-        _inputs.add(auipc);     // Add high-half address
         _tfp = tfp;
         _name = CodeGen.CODE.link(tfp)._name;
     }
@@ -29,12 +28,24 @@ public class CallRISC extends CallNode implements MachNode {
     @Override public TypeFunPtr tfp() { return _tfp; }
 
     @Override public void encoding( Encoding enc ) {
-        enc.relo(this,_tfp);
+        enc.relo(this);
+        short rpc = enc.reg(this);
+        //// High half is where the TFP constant used to be, the last input
+        //short auipc = enc.reg(in(_inputs._len-1));
+        //enc.add4(riscv.i_type(0x67, rpc, 0, auipc, 0));
+        // TODO: JAL for range
+        throw Utils.TODO();
+    }
+
+    // Delta is from opcode start, but X86 measures from the end of the 5-byte encoding
+    @Override public byte encSize(int delta) { return 4; }
+
+    // Delta is from opcode start
+    @Override public void patch( Encoding enc, int opStart, int opLen, int delta ) {
         short rpc = enc.reg(this);
         // High half is where the TFP constant used to be, the last input
         short auipc = enc.reg(in(_inputs._len-1));
-        int body = riscv.i_type(0x67, rpc, 0/*JALR.C*/, auipc, 0);
-        enc.add4(body);
+        enc.patch4(opStart,riscv.i_type(0x67, rpc, 0, auipc, delta&0xFFF));
     }
 
     @Override public void asm(CodeGen code, SB sb) {
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/FunRISC.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/FunRISC.java
index 0e931e02..6f1e4b6c 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/FunRISC.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/FunRISC.java
@@ -1,7 +1,6 @@
 package com.seaofnodes.simple.node.cpus.riscv;
 
-import com.seaofnodes.simple.codegen.Encoding;
-import com.seaofnodes.simple.codegen.RegMask;
+import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.node.FunNode;
 import com.seaofnodes.simple.node.MachNode;
 
@@ -10,4 +9,5 @@ public class FunRISC extends FunNode implements MachNode {
     @Override public RegMask regmap(int i) { return null; }
     @Override public RegMask outregmap() { return null; }
     @Override public void encoding( Encoding enc ) { }
+    @Override public void postSelect(CodeGen code) { code.link(this);  }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/RetRISC.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/RetRISC.java
index 9f89f983..181e9ac0 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/RetRISC.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/RetRISC.java
@@ -12,7 +12,7 @@ public class RetRISC extends ReturnNode implements MachNode{
     RetRISC(ReturnNode ret, FunNode fun) { super(ret, fun); fun.setRet(this); }
     @Override public String op() { return "ret"; }
     // Correct Nodes outside the normal edges
-    @Override public void postSelect() {
+    @Override public void postSelect(CodeGen code) {
         FunNode fun = (FunNode)rpc().in(0);
         _fun = fun;
         fun.setRet(this);
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/TFPRISC.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/TFPRISC.java
index d2bdcb8a..4b096e7b 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/TFPRISC.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/TFPRISC.java
@@ -14,7 +14,7 @@ public class TFPRISC extends ConstantNode implements MachNode {
     @Override public boolean isClone() { return true; }
     @Override public TFPRISC copy() { return new TFPRISC(this); }
     @Override public void encoding( Encoding enc ) {
-        enc.relo(this,(TypeFunPtr)_con);
+        enc.reloTFP(this);
         short dst = enc.reg(this);
         TypeFunPtr tfp = (TypeFunPtr)_con;
         // auipc  t0,0
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/riscv.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/riscv.java
index 8e048c0a..e3cc8724 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/riscv.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/riscv.java
@@ -378,13 +378,9 @@ public class riscv extends Machine {
     }
 
     private Node call(CallNode call) {
-        // Options here are:
-        // 4G range in 2ops and either PC-relative or absolute
-        // 4K range in 1op absolute
-        // Since 4K is too small, we're going with 4G PC-relative in 2 ops
-        if( call.fptr() instanceof ConstantNode con && con._con instanceof TypeFunPtr tfp )
-            return new CallRISC(call, tfp, new AUIPC(tfp));
-        return new CallRRISC(call);
+        return call.fptr() instanceof ConstantNode con && con._con instanceof TypeFunPtr tfp
+            ? new CallRISC(call, tfp)
+            : new CallRRISC(call);
     }
     private Node nnn(NewNode nnn) {
         // TODO: pass in the TFP for alloc
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallX86.java
index bb5cf7bb..fc1da246 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/CallX86.java
@@ -1,14 +1,12 @@
 package com.seaofnodes.simple.node.cpus.x86_64_v2;
 
 import com.seaofnodes.simple.SB;
-import com.seaofnodes.simple.codegen.CodeGen;
-import com.seaofnodes.simple.codegen.Encoding;
-import com.seaofnodes.simple.codegen.RegMask;
+import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.node.CallNode;
 import com.seaofnodes.simple.node.MachNode;
 import com.seaofnodes.simple.type.TypeFunPtr;
 
-public class CallX86 extends CallNode implements MachNode {
+public class CallX86 extends CallNode implements MachNode, RIPRelSize {
     final TypeFunPtr _tfp;
     final String _name;
     CallX86( CallNode call, TypeFunPtr tfp ) {
@@ -28,11 +26,18 @@ public class CallX86 extends CallNode implements MachNode {
 
     // Encoding is appended into the byte array; size is returned
     @Override public void encoding( Encoding enc ) {
-        enc.relo(this,_tfp);
-        enc.add1(0xe8);
-        enc.add4(0);            // Target patched at link time
+        enc.relo(this).add1(0xe8).add4(0);
     }
 
+    // Delta is from opcode start, but X86 measures from the end of the 5-byte encoding
+    @Override public byte encSize(int delta) { return 5; }
+
+    // Delta is from opcode start
+    @Override public void patch( Encoding enc, int opStart, int opLen, int delta ) {
+        enc.patch4(opStart+1, delta-5);
+    }
+
+
     @Override public void asm(CodeGen code, SB sb) {
         sb.p(_name).p("  ");
         for( int i=0; i<nargs(); i++ )
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FunX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FunX86.java
index 120053fa..22cb8698 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FunX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FunX86.java
@@ -1,7 +1,6 @@
 package com.seaofnodes.simple.node.cpus.x86_64_v2;
 
-import com.seaofnodes.simple.codegen.Encoding;
-import com.seaofnodes.simple.codegen.RegMask;
+import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.node.FunNode;
 import com.seaofnodes.simple.node.MachNode;
 
@@ -10,4 +9,5 @@ public class FunX86 extends FunNode implements MachNode {
     @Override public RegMask regmap(int i) { return null; }
     @Override public RegMask outregmap() { return null; }
     @Override public void encoding( Encoding enc ) { }
+    @Override public void postSelect(CodeGen code) { code.link(this);  }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java
index 667ab012..2d27e5c7 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java
@@ -13,7 +13,7 @@ public class JmpX86 extends IfNode implements MachNode, RIPRelSize {
     }
     @Override public String op() { return "j"+_bop; }
     @Override public String label() { return op(); }
-    @Override public void postSelect() {
+    @Override public void postSelect(CodeGen code) {
         Node set = in(1);
         Node cmp = set.in(1);
         // Bypass an expected Set and just reference the cmp directly
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/RetX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/RetX86.java
index 1a08bb4c..34458e8f 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/RetX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/RetX86.java
@@ -8,7 +8,7 @@ public class RetX86 extends ReturnNode implements MachNode {
     RetX86( ReturnNode ret, FunNode fun ) { super(ret, fun); fun.setRet(this); }
     @Override public String op() { return "ret"; }
     // Correct Nodes outside the normal edges
-    @Override public void postSelect() {
+    @Override public void postSelect(CodeGen code) {
         FunNode fun = (FunNode)rpc().in(0);
         _fun = fun;
         fun.setRet(this);
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/TFPX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/TFPX86.java
index a80531b6..6131fea6 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/TFPX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/TFPX86.java
@@ -35,7 +35,7 @@ public class TFPX86 extends ConstantNode implements MachNode {
 
         // lea to load function pointer address
         // lea rax, [rip+disp32]
-        enc.relo(this,(TypeFunPtr)_con);
+        enc.reloTFP(this);
         enc.add1(x86_64_v2.rex(dst, 0, 0));
         enc.add1(0x8D); // opcode
         enc.add1(x86_64_v2.modrm(x86_64_v2.MOD.INDIRECT, dst, 0b101));
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
index af5dbff4..ee0f89d6 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
@@ -453,9 +453,9 @@ public class x86_64_v2 extends Machine {
     }
 
     private Node call(CallNode call) {
-        if( call.fptr() instanceof ConstantNode con && con._con instanceof TypeFunPtr tfp )
-            return new CallX86(call, tfp);
-        return new CallRX86(call);
+        return call.fptr() instanceof ConstantNode con && con._con instanceof TypeFunPtr tfp
+            ? new CallX86(call, tfp)
+            : new CallRX86(call);
     }
 
     // Because X86 flags, a normal ideal Bool is 2 X86 ops: a "cmp" and at "setz".