diff options
Diffstat (limited to 'chapter21/src/main/java')
3 files changed, 79 insertions, 12 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 a1294890..4215233e 100644 --- a/chapter21/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java +++ b/chapter21/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java @@ -303,14 +303,14 @@ public class CodeGen { // --------------------------- // Encoding int _tEncode; + public Encoding _encoding; public CodeGen encode() { assert _phase == Phase.RegAlloc; _phase = Phase.Encoding; long t0 = System.currentTimeMillis(); - - - //_tEncode = (int)(System.currentTimeMillis() - t0); - //throw Utils.TODO(); + _encoding = new Encoding(this); + _encoding.encode(); + _tEncode = (int)(System.currentTimeMillis() - t0); return this; } // Encoded binary, no relocation info diff --git a/chapter21/src/main/java/com/seaofnodes/simple/codegen/Encoding.java b/chapter21/src/main/java/com/seaofnodes/simple/codegen/Encoding.java new file mode 100644 index 00000000..d7a19e2a --- /dev/null +++ b/chapter21/src/main/java/com/seaofnodes/simple/codegen/Encoding.java @@ -0,0 +1,60 @@ +package com.seaofnodes.simple.codegen; + +import com.seaofnodes.simple.Utils; +import com.seaofnodes.simple.node.*; +import java.io.ByteArrayOutputStream; + + +/** + * Instruction encodings + * + * This class holds the encoding bits, plus the relocation information needed + * to move the code to a non-zero offset, or write to an external file (ELF). + * + * There are also a bunch of generic utilities for managing bits and bytes + * common in all encodings. + */ +public class Encoding { + + // Top-level program graph structure + final CodeGen _code; + + // Instruction bytes. The registers are encoded already. Relocatable data + // is in a fixed format depending on the kind of relocation. + + // - RIP-relative offsets into the same chunk are just encoded with their + // check relative offsets; no relocation info is required. + + // - Fixed address targets in the same encoding will be correct for a zero + // base; moving the entire encoding requires adding the new base address. + + // - RIP-relative to external chunks have a zero offset; the matching + // relocation info will be used to patch the correct value. + + final ByteArrayOutputStream _bits; + + + Encoding( CodeGen code ) { + _code = code; + _bits = new ByteArrayOutputStream(); + } + + + void encode() { + // Basic block layout. Now that RegAlloc is finished, no more spill + // code will appear. We can change our BB layout from RPO to something + // that minimizes actual branches, takes advantage of fall-through + // edges, and tries to help simple branch predictions: back branches + // are predicted taken, forward not-taken. + + + + + // Write bits in order + for( CFGNode bb : _code._cfg ) + for( Node n : bb._outputs ) + if( n instanceof MachNode mach ) + throw Utils.TODO(); + } + +} 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 1a233aa2..72da53bf 100644 --- a/chapter21/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java +++ b/chapter21/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java @@ -3,7 +3,6 @@ package com.seaofnodes.simple.print; import com.seaofnodes.simple.codegen.CodeGen; import com.seaofnodes.simple.SB; import com.seaofnodes.simple.node.*; -import com.seaofnodes.simple.type.TypeFunPtr; import com.seaofnodes.simple.type.TypeMem; import com.seaofnodes.simple.type.TypeRPC; @@ -45,7 +44,7 @@ public abstract class ASMPrinter { static int doBlock(int iadr, SB sb, CodeGen code, FunNode fun, int cfgidx) { CFGNode bb = code._cfg.at(cfgidx); if( bb != fun && !(bb instanceof IfNode) && !(bb instanceof CallEndNode) && !(bb instanceof CallNode) && !(bb instanceof CProjNode && bb.in(0) instanceof CallEndNode )) - sb.p(bb instanceof LoopNode ? "LOOP" : "L").p(bb._nid).p(":").nl(); + sb.p(label(bb)).p(":").nl(); if( bb instanceof CallNode ) return iadr; final boolean postAlloc = code._phase.ordinal() > CodeGen.Phase.RegAlloc.ordinal(); @@ -56,7 +55,7 @@ public abstract class ASMPrinter { break; if( nPhi>0 ) { - // Post-alloc phi prints all on one line + // Post- RegAlloc phi prints all on one line if( postAlloc ) { sb.fix(4," ").p(" ").fix(encWidth,"").p(" "); for( int i=0; i<nPhi; i++ ) { @@ -67,6 +66,7 @@ public abstract class ASMPrinter { sb.unchar().nl(); } else { + // Pre- RegAlloc phi prints one line per for( int j=0; j<nPhi; j++ ) { PhiNode phi = (PhiNode)bb.out(j); if( phi._type instanceof TypeMem || phi._type instanceof TypeRPC ) continue; // Nothing for the hidden ones @@ -85,20 +85,22 @@ public abstract class ASMPrinter { // All the non-phis for( int i=nPhi; i<bb.nOuts(); i++ ) - iadr = doInst(iadr, sb,code,fun,bb,bb.out(i),postAlloc ); + iadr = doInst(iadr, sb,code, cfgidx, bb.out(i),postAlloc ); return iadr; } - static int doInst(int iadr, SB sb, CodeGen code, FunNode fun, CFGNode bb, Node n, boolean postAlloc ) { + static int doInst( int iadr, SB sb, CodeGen code, int cfgidx, Node n, boolean postAlloc ) { if( n instanceof CProjNode ) return iadr; if( n instanceof CalleeSaveNode && postAlloc ) 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 && !(n instanceof FunNode) ) { - sb.hex4(iadr++).p(" ").fix(encWidth,"??").p(" ").fix(opWidth,"JMP").p(" ").fix(argWidth,"L"+n._nid).nl(); + if( n instanceof RegionNode cfg && !(n instanceof FunNode) ) { + if( code._cfg.at(cfgidx+1) == n ) return iadr; // Fall-through, no branch + sb.hex4(iadr++).p(" ").fix(encWidth,"??").p(" ").fix(opWidth,"JMP").p(" ").fix(argWidth,label(cfg)).nl(); return iadr; } @@ -154,10 +156,15 @@ public abstract class ASMPrinter { if( !(n instanceof CFGNode) && n instanceof MultiNode ) { for( Node proj : n._outputs ) { assert proj instanceof ProjNode; - doInst(iadr,sb,code,fun,bb,proj,postAlloc); + doInst(iadr,sb,code, cfgidx, proj,postAlloc); } } return iadr; } + + private static String label( CFGNode bb ) { + return (bb instanceof LoopNode ? "LOOP" : "L")+bb._nid; + } + } |