From 5097e9f08dacb25e4c4aca20b48aa7d523067628 Mon Sep 17 00:00:00 2001
From: Cliff Click <cliffc@acm.org>
Date: Sat, 15 Mar 2025 16:05:04 -0700
Subject: Encoding fixes

---
 .../com/seaofnodes/simple/codegen/Encoding.java    | 12 +++++++--
 .../seaofnodes/simple/node/cpus/arm/BranchARM.java |  9 ++++---
 .../seaofnodes/simple/node/cpus/arm/CallARM.java   |  2 +-
 .../seaofnodes/simple/node/cpus/arm/FloatARM.java  |  2 +-
 .../seaofnodes/simple/node/cpus/riscv/AUIPC.java   |  3 +--
 .../simple/node/cpus/riscv/BranchRISC.java         |  6 ++++-
 .../simple/node/cpus/riscv/CallRISC.java           |  5 ++--
 .../seaofnodes/simple/node/cpus/riscv/FltRISC.java | 14 ++++-------
 .../simple/node/cpus/riscv/SetFRISC.java           |  2 +-
 .../seaofnodes/simple/node/cpus/riscv/SetRISC.java |  2 +-
 .../seaofnodes/simple/node/cpus/riscv/riscv.java   | 17 +++----------
 .../simple/node/cpus/x86_64_v2/AddFX86.java        |  2 +-
 .../simple/node/cpus/x86_64_v2/DivFX86.java        |  2 +-
 .../simple/node/cpus/x86_64_v2/FltX86.java         |  4 +--
 .../simple/node/cpus/x86_64_v2/JmpX86.java         |  7 ++++--
 .../simple/node/cpus/x86_64_v2/MulFX86.java        |  2 +-
 .../simple/node/cpus/x86_64_v2/SubFX86.java        |  2 +-
 .../simple/node/cpus/x86_64_v2/x86_64_v2.java      | 21 +++-------------
 .../com/seaofnodes/simple/print/ASMPrinter.java    | 29 ++++++++++++++++------
 .../java/com/seaofnodes/simple/Chapter21Test.java  | 20 +++++++++++++++
 20 files changed, 94 insertions(+), 69 deletions(-)

(limited to 'chapter21/src')

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 413754b0..4971624d 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
@@ -45,7 +45,7 @@ public class Encoding {
         _bits = new BAOS();
     }
 
-    // Short cut to the defining register
+    // Shortcut to the defining register
     public short reg(Node n) {
         return _code._regAlloc.regnum(n);
     }
@@ -153,7 +153,15 @@ public class Encoding {
                 } // Else nothing
             } else if( tld > bld ) { // True enters a deeper loop
                 throw Utils.TODO();
-            } // Else True exits a loop, always forward and good
+            } else if( fld == bld && f.out(0) instanceof LoopNode ) { // Else True exits a loop, always forward and good
+                // if false is the loop backedge, make sure its true/taken
+                // Invert test and Proj fields
+                iff.invert();
+                t.invert();
+                f.invert();
+                CProjNode tmp=f; f=t; t=tmp; // Swap t/f
+
+            }
 
             // Always visit the False side last (so True side first), so that
             // when the False RPO visit returns, the IF is immediately next.
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 daa212f5..a7cbd1aa 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
@@ -7,7 +7,7 @@ import com.seaofnodes.simple.node.*;
 
 // Jump on flags, uses flags
 public class BranchARM extends IfNode implements MachNode{
-    final String _bop;
+    String _bop;
     BranchARM(IfNode iff, String bop ) {
         super(iff);
         _bop = bop;
@@ -27,9 +27,11 @@ public class BranchARM extends IfNode implements MachNode{
 
     @Override public RegMask regmap(int i) { assert i==1; return arm.FLAGS_MASK; }
     @Override public RegMask outregmap() { return null; }
+    @Override public void invert() { _bop = invert(_bop);  }
 
     // Encoding is appended into the byte array; size is returned
     @Override public void encoding( Encoding enc ) {
+        enc.jump(this,cproj(0));
         // Assuming that condition flags are already set.  These flags are set
         // by comparison (or sub).  No need for regs because it uses flags
         arm.COND cond = switch (_bop) {
@@ -47,9 +49,10 @@ public class BranchARM extends IfNode implements MachNode{
     @Override public void asm(CodeGen code, SB sb) {
         String src = code.reg(in(1));
         if( src!="flags" ) sb.p(src);
-        else sb.p(" ");
         Node prj = cproj(0);
-        sb.p(prj instanceof LoopNode ? "LOOP" : "L").p(prj._nid);
+        while( prj.nOuts() == 1 )
+            prj = prj.out(0);       // Skip empty blocks
+        sb.p(prj instanceof LoopNode ? " LOOP" : " L").p(prj._nid);
     }
     @Override public String comment() { return "L"+cproj(1)._nid+", L"+cproj(0)._nid; }
 }
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 3058e7c8..2a815f37 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
@@ -33,7 +33,7 @@ public class CallARM extends CallNode implements MachNode {
     @Override public void asm(CodeGen code, SB sb) {
         sb.p(_name);
         for( int i=0; i<nargs(); i++ )
-            sb.p(code.reg(arg(i))).p("  ");
+            sb.p(code.reg(arg(i+2))).p("  ");
         sb.unchar(2);
     }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/FloatARM.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/FloatARM.java
index 70e4b085..be837f04 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/FloatARM.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/arm/FloatARM.java
@@ -22,7 +22,7 @@ public class FloatARM extends ConstantNode implements MachNode {
 
     // Encoding is appended into the byte array; size is returned
     @Override public void encoding( Encoding enc ) {
-        short self = (short)(enc.reg(this) - arm.D_OFFSET);
+        short dst = (short)(enc.reg(this) - arm.D_OFFSET);
         double d = ((TypeFloat)_con).value();
         long x = Double.doubleToRawLongBits(d);
         // Any number that can be expressed as +/-n * 2-r,where n and r are integers, 16 <= n <= 31, 0 <= r <= 7.
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 ebae13b6..30c63d8d 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
@@ -17,8 +17,7 @@ public class AUIPC extends ConstantNode implements MachNode {
     @Override public void encoding( Encoding enc ) {
         enc.relo(this,(TypeFunPtr)_con);
         short dst = enc.reg(this);
-        int auipc = riscv.u_type(0x17, dst, 0);
-        enc.add4(auipc);
+        enc.add4(riscv.u_type(0x17, dst, 0));
     }
 
     @Override public void asm(CodeGen code, SB sb) {
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/BranchRISC.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/BranchRISC.java
index a7c0b7c7..f000a5d3 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/BranchRISC.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/BranchRISC.java
@@ -8,7 +8,7 @@ import java.util.BitSet;
 
 // Conditional branch such as: BEQ
 public class BranchRISC extends IfNode implements MachNode {
-    final String _bop;
+    String _bop;
     // label is obtained implicitly
     BranchRISC( IfNode iff, String bop, Node n1, Node n2 ) {
         super(iff);
@@ -22,6 +22,7 @@ public class BranchRISC extends IfNode implements MachNode {
     @Override public String comment() { return "L"+cproj(1)._nid+", L"+cproj(0)._nid; }
     @Override public RegMask regmap(int i) { return riscv.RMASK; }
     @Override public RegMask outregmap() { return null; }
+    @Override public void invert() { _bop = invert(_bop);  }
 
     @Override public StringBuilder _print1(StringBuilder sb, BitSet visited) {
         in(1)._print0(sb.append("if( "),visited).append(_bop);
@@ -32,6 +33,7 @@ public class BranchRISC extends IfNode implements MachNode {
 
     // Encoding is appended into the byte array; size is returned
     @Override public void encoding( Encoding enc ) {
+        enc.jump(this,cproj(0));
         // Todo: relocs (for offset - immf)
         short src1 = enc.reg(in(1));
         short src2 = in(2)==null ? (short)riscv.ZERO : enc.reg(in(2));
@@ -41,6 +43,8 @@ public class BranchRISC extends IfNode implements MachNode {
     @Override public void asm(CodeGen code, SB sb) {
         sb.p(code.reg(in(1))).p(" ").p(_bop).p(" ").p(in(2)==null ? "#0" : code.reg(in(2))).p(" ");
         Node prj = cproj(0);
+        while( prj.nOuts() == 1 )
+            prj = prj.out(0);       // Skip empty blocks
         sb.p(prj instanceof LoopNode ? "LOOP" : "L").p(prj._nid);
     }
 }
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 e93852da..d0309829 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
@@ -40,7 +40,8 @@ public class CallRISC extends CallNode implements MachNode {
     @Override public void asm(CodeGen code, SB sb) {
         sb.p(_name).p("  ");
         for( int i=0; i<nargs(); i++ )
-            sb.p(code.reg(arg(i))).p("  ");
-        sb.unchar(2);
+            sb.p(code.reg(arg(i+2))).p(", ");
+        sb.unchar(2).p("  ").p(code.reg(fptr()));
+
     }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/FltRISC.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/FltRISC.java
index 0242d333..7ce82ec7 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/FltRISC.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/FltRISC.java
@@ -16,16 +16,12 @@ public class FltRISC extends ConstantNode implements MachNode{
     @Override public FltRISC copy() { return new FltRISC(this); }
     // Encoding is appended into the byte array; size is returned
     @Override public void encoding( Encoding enc ) {
+        enc.largeConstant(this,_con);
         short dst = (short)(enc.reg(this) - riscv.F_OFFSET);
-        double d = ((TypeFloat)_con).value();
-        long x = Double.doubleToRawLongBits(d);
-
-        // Encode as either a memory slot and load, or stuff into an integer
-        // register (probably 2 int ops), then a fmv.w.x so 3 ops.
-
-        //int body = riscv.i_type(0x07, dst, 0X03, fpr_reg - riscv.F_OFFSET, x);
-        //enc.push_add4(body);
-        throw Utils.TODO();
+        // AUIPC dst,#hi20_constant_pool
+        enc.add4(riscv.u_type(0x17, dst, 0));
+        // Load dst,[dst+#low12_constant_pool]
+        enc.add4(riscv.i_type(0x07, dst, 0x03, dst, 0));
     }
 
     @Override public void asm(CodeGen code, SB sb) {
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SetFRISC.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SetFRISC.java
index 52a3c24d..99345f51 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SetFRISC.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SetFRISC.java
@@ -28,6 +28,6 @@ public class SetFRISC extends MachConcreteNode implements MachNode {
     }
 
     @Override public void asm(CodeGen code, SB sb) {
-        sb.p(code.reg(in(1))).p(" ").p(_bop).p(" ").p(code.reg(in(2)));
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" ").p(_bop).p(" ").p(code.reg(in(2)));
     }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SetRISC.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SetRISC.java
index cae450c5..e81e363e 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SetRISC.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SetRISC.java
@@ -12,6 +12,6 @@ public class SetRISC extends MachConcreteNode implements MachNode {
     @Override public RegMask outregmap() { return riscv.WMASK; }
     @Override public void encoding( Encoding enc ) { riscv.r_type(enc,this,2,0); }
     @Override public void asm(CodeGen code, SB sb) {
-        sb.p(code.reg(in(1))).p(" < ").p(code.reg(in(2)));
+        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" < ").p(code.reg(in(2)));
     }
 }
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 fcea5e28..8d44fe34 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
@@ -170,24 +170,15 @@ public class riscv extends Machine {
         DYN,       // In instruction’s rm field, selects dynamic rounding mode; In Rounding Mode register, reserved
     }
 
-    // seqz ( sltiu rd, rs, 1 ) - 0001 0011
-    static public int setop(String op) {
-        return switch(op) {
-        case "<"  -> 0x33;
-        case "<=" -> 0x13;
-        case "==" -> 0x33;
-        default   -> throw Utils.TODO();
-        };
-    }
     // Since opcode is the same just return back func3
-    // BEQ: 01100011
-    // BLT: 01100011
-    // BLE: bge rt, rs, offset:
     static public int jumpop(String op) {
         return switch(op) {
+        case "=="  -> 0x0;
+        case "!="  -> 0x1;
         case "<"   -> 0x4;
         case "<="  -> 0x5;
-        case "=="  -> 0;
+        case "u<"  -> 0x6;
+        case "u<=" -> 0x7;
         default  ->  throw Utils.TODO();
         };
     }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFX86.java
index 86b3b365..839b147c 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/AddFX86.java
@@ -27,6 +27,6 @@ public class AddFX86 extends MachConcreteNode implements MachNode {
 
     // General form: "addf  dst += src"
     @Override public void asm(CodeGen code, SB sb) {
-        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" + ").p(code.reg(in(2)));
+        sb.p(code.reg(this)).p(" += ").p(code.reg(in(2)));
     }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivFX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivFX86.java
index bfd57b34..52988d13 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivFX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/DivFX86.java
@@ -29,6 +29,6 @@ public class DivFX86 extends MachConcreteNode implements MachNode {
 
     // General form: "divf  dst /= src"
     @Override public void asm(CodeGen code, SB sb) {
-        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" / ").p(code.reg(in(2)));
+        sb.p(code.reg(this)).p(" /= ").p(code.reg(in(2)));
     }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FltX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FltX86.java
index 5c4002e1..2d332764 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FltX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/FltX86.java
@@ -15,7 +15,7 @@ public class FltX86 extends ConstantNode implements MachNode {
     // Encoding is appended into the byte array; size is returned
     @Override public void encoding( Encoding enc ) {
         enc.largeConstant(this,_con);
-        // Simply move the constant into a FPR
+        // Load the constant into a FPR
         // movsd xmm, [rip + 0]
         // F2 0F 10 /r MOVSD xmm1, m64
         short dst = (short)(enc.reg(this ) - x86_64_v2.XMM_OFFSET);
@@ -32,6 +32,6 @@ public class FltX86 extends ConstantNode implements MachNode {
     }
 
     @Override public void asm(CodeGen code, SB sb) {
-        _con.print(sb.p(code.reg(this)).p(" #"));
+        _con.print(sb.p(code.reg(this)).p(" = #"));
     }
 }
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 1a5a4d0a..ae5635b8 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
@@ -6,7 +6,7 @@ import com.seaofnodes.simple.node.*;
 
 // Jump on flags, uses flags
 public class JmpX86 extends IfNode implements MachNode {
-    final String _bop;
+    String _bop;
     JmpX86( IfNode iff, String bop ) {
         super(iff);
         _bop = bop;
@@ -26,6 +26,7 @@ public class JmpX86 extends IfNode implements MachNode {
     }
     @Override public RegMask regmap(int i) { assert i==1; return x86_64_v2.FLAGS_MASK; }
     @Override public RegMask outregmap() { return null; }
+    @Override public void invert() { _bop = invert(_bop);  }
 
     // Encoding is appended into the byte array; size is returned
     @Override public void encoding( Encoding enc ) {
@@ -39,7 +40,9 @@ public class JmpX86 extends IfNode implements MachNode {
     @Override public void asm(CodeGen code, SB sb) {
         String src = code.reg(in(1));
         if( src!="flags" ) sb.p(src);
-        Node prj = cproj(0);
+        Node prj = cproj(0);    // 0 is True is jump target
+        while( prj.nOuts() == 1 )
+            prj = prj.out(0);       // Skip empty blocks
         sb.p(prj instanceof LoopNode ? " LOOP" : " L").p(prj._nid);
     }
 
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulFX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulFX86.java
index bac84140..cb18e708 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulFX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MulFX86.java
@@ -29,6 +29,6 @@ public class MulFX86 extends MachConcreteNode implements MachNode {
 
     // General form: "mulf  dst *= src"
     @Override public void asm(CodeGen code, SB sb) {
-        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" * ").p(code.reg(in(2)));
+        sb.p(code.reg(this)).p(" *= ").p(code.reg(in(2)));
     }
 }
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubFX86.java b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubFX86.java
index d727d429..0c952ddc 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubFX86.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SubFX86.java
@@ -26,6 +26,6 @@ public class SubFX86 extends MachConcreteNode implements MachNode {
 
     // General form: "subf  dst -= src"
     @Override public void asm(CodeGen code, SB sb) {
-        sb.p(code.reg(this)).p(" = ").p(code.reg(in(1))).p(" - ").p(code.reg(in(2)));
+        sb.p(code.reg(this)).p(" -= ").p(code.reg(in(2)));
     }
 }
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 9263616e..8cd7128d 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
@@ -62,18 +62,6 @@ public class x86_64_v2 extends Machine {
         DIRECT,          // mem
     };
 
-    // Inverting IfNode
-    static public String invert(String op) {
-        return switch (op) {
-        case "==" -> "!=";
-        case "!=" -> "==";
-        case ">"  -> "<=";
-        case "<"  -> ">=";
-        case ">=" -> "<" ;
-        case "<=" -> ">" ;
-        default -> throw new IllegalStateException("Unexpected value: " + op);
-        };
-    }
     // opcode included here
     // 0F 84 cd	JE rel32
     // 0F 85 cd	JNE rel32
@@ -81,8 +69,6 @@ public class x86_64_v2 extends Machine {
     // 0F 8C cd	JL rel32
     // 0F 8E cd	JLE rel32
     // 0F 8D cd	JGE rel32
-
-
     static public int jumpop(String op) {
         return switch (op) {
         case "==" -> 0x84;
@@ -512,9 +498,10 @@ public class x86_64_v2 extends Machine {
         // If/Bool combos will match to a Cmp/Set which sets flags.
         // Most general arith ops will also set flags, which the Jmp needs directly.
         // Loads do not set the flags, and will need an explicit TEST
-        if(!(iff.in(1) instanceof BoolNode))
-            iff.setDef(1, new BoolNode.EQ(iff.in(1), new ConstantNode(TypeInteger.ZERO)));
-        return new JmpX86(iff, invert(((BoolNode) iff.in(1)).op()));
+        BoolNode bool;
+        if( iff.in(1) instanceof BoolNode bool0 ) bool = bool0;
+        else iff.setDef(1, bool=new BoolNode.EQ(iff.in(1), new ConstantNode(TypeInteger.ZERO)));
+        return new JmpX86(iff, bool.op());
     }
 
     private Node ld(LoadNode ld) {
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java b/chapter21/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java
index 55a45a32..d511d8ad 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java
@@ -38,7 +38,7 @@ public abstract class ASMPrinter {
         return iadr;
     }
 
-    static private final int encWidth = 8;
+    static private final int encWidth = 10;
     static private final int opWidth = 5;
     static private final int argWidth = 30;
     static int doBlock(int iadr, SB sb, CodeGen code, FunNode fun, int cfgidx) {
@@ -47,6 +47,7 @@ public abstract class ASMPrinter {
             sb.p(label(bb)).p(":").nl();
         if( bb instanceof CallNode ) return iadr;
         final boolean postAlloc = code._phase.ordinal() > CodeGen.Phase.RegAlloc.ordinal();
+        final boolean postEncode= code._phase.ordinal() >=CodeGen.Phase.Encoding.ordinal();
 
         boolean once=false;
         for( Node n : bb.outs() ) {
@@ -73,20 +74,22 @@ public abstract class ASMPrinter {
         // All the non-phis
         for( int i=0; i<bb.nOuts(); i++ )
             if( !(bb.out(i) instanceof PhiNode) )
-                iadr = doInst(iadr, sb,code, cfgidx, bb.out(i),postAlloc );
+                iadr = doInst(iadr, sb,code, cfgidx, bb.out(i),postAlloc, postEncode );
 
         return iadr;
     }
 
-    static int doInst( int iadr, SB sb, CodeGen code, int cfgidx, Node n, boolean postAlloc ) {
+    static int doInst( int iadr, SB sb, CodeGen code, int cfgidx, Node n, boolean postAlloc, boolean postEncode ) {
         if( n instanceof CProjNode ) return iadr;
-        if( n instanceof CalleeSaveNode && postAlloc ) return iadr;
+        if( postAlloc && n instanceof CalleeSaveNode ) return iadr;
+        if( postEncode && n instanceof ProjNode ) return iadr;
         if( n instanceof MemMergeNode ) return iadr;
 
         // All blocks ending in a Region will need to either fall into or jump
         // to this block.  Until the post-reg-alloc block layout cleanup, we
         // need to assume a jump.  There's no real hardware op here, yet.
         if( n instanceof RegionNode cfg && !(n instanceof FunNode) ) {
+            if( postEncode ) return iadr; // All jumps inserted already
             while( cfgidx < code._cfg._len-1 ) {
                 CFGNode next = code._cfg.at(++cfgidx);
                 if( next == n ) return iadr; // Fall-through, no branch
@@ -108,16 +111,17 @@ public abstract class ASMPrinter {
 
         // ADDR ENCODING  Op--- dst = src op src       // Comment
         // 1234 abcdefgh  ld4   RAX = [Rbase + off]    // Comment
-        sb.hex2(iadr);
-        sb.p(" ");
+        sb.hex2(iadr).p(" ");
 
         // Encoding
+        int fatEncoding = 0;
         if( code._encoding != null ) {
             int size = code._encoding._opLen[n._nid];
-            for( int i=0; i<size; i++ )
+            for( int i=0; i<Math.min(size,encWidth>>1); i++ )
                 sb.hex1(code._encoding._bits.buf()[iadr++]);
             for( int i=size*2; i<encWidth; i++ )
                 sb.p(" ");
+            fatEncoding = size - (encWidth>>1); // Not-printed parts of encoding
         } else
             sb.fix(encWidth,"");
         sb.p("  ");
@@ -151,11 +155,20 @@ public abstract class ASMPrinter {
 
         sb.nl();
 
+
+        if( fatEncoding > 0 ) {
+            sb.hex2(iadr).p(" ");
+            for( int i=0; i<fatEncoding; i++ )
+                sb.hex1(code._encoding._bits.buf()[iadr++]);
+            sb.nl();
+        }
+
+
         // MultiNodes are immediately followed by projection(s)
         if( !(n instanceof CFGNode) && n instanceof MultiNode ) {
             for( Node proj : n._outputs ) {
                 assert proj instanceof ProjNode;
-                doInst(iadr,sb,code, cfgidx, proj,postAlloc);
+                doInst(iadr,sb,code, cfgidx, proj,postAlloc,postEncode);
             }
         }
 
diff --git a/chapter21/src/test/java/com/seaofnodes/simple/Chapter21Test.java b/chapter21/src/test/java/com/seaofnodes/simple/Chapter21Test.java
index 770c7165..e2a79b8f 100644
--- a/chapter21/src/test/java/com/seaofnodes/simple/Chapter21Test.java
+++ b/chapter21/src/test/java/com/seaofnodes/simple/Chapter21Test.java
@@ -42,4 +42,24 @@ public class Chapter21Test {
         testCPU(src,"arm"      , "SystemV",0,"return (or,arg,2);");
     }
 
+    @Test
+    public void testNewtonFloat() {
+        String src =
+"""
+// Newtons approximation to the square root
+val sqrt = { flt x ->
+    flt guess = x;
+    while( 1 ) {
+        flt next = (x/guess + guess)/2;
+        if( next == guess ) return guess;
+        guess = next;
+    }
+};
+flt farg = arg;
+return sqrt(farg) + sqrt(farg+2.0);
+""";
+        testCPU(src,"x86_64_v2", "SystemV",25,null);
+        testCPU(src,"riscv"    , "SystemV",17,null);
+        testCPU(src,"arm"      , "SystemV",18,null);
+    }
 }
-- 
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