From 349c23d0527569284a8bec67f27130c4358e056c Mon Sep 17 00:00:00 2001 From: fuhsnn <66062782+fuhsnn@users.noreply.github.com> Date: Fri, 25 Sep 2026 07:25:49 +0800 Subject: Extend and backport SubNode peephole --- .../main/java/com/seaofnodes/simple/node/SubNode.java | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'chapter06/src') diff --git a/chapter06/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter06/src/main/java/com/seaofnodes/simple/node/SubNode.java index d3fd1c7e..fa777a30 100644 --- a/chapter06/src/main/java/com/seaofnodes/simple/node/SubNode.java +++ b/chapter06/src/main/java/com/seaofnodes/simple/node/SubNode.java @@ -32,6 +32,25 @@ public class SubNode extends Node { @Override public Node idealize() { + Node lhs = in(1); + Node rhs = in(2); + Type t1 = lhs._type; + Type t2 = rhs._type; + + if( t2.isConstant() && t2 instanceof TypeInteger i && i.value()==0 ) + return lhs; + + if( t1.isConstant() && t1 instanceof TypeInteger i && i.value()==0 ) + return new MinusNode(rhs); + + // x - (-y) is x+y + if( rhs instanceof MinusNode minus ) + return new AddNode(lhs,minus.in(1)); + + // (-x) - y is -(x+y) + if( lhs instanceof MinusNode minus ) + return new MinusNode(new AddNode(minus.in(1),rhs).peephole()); + return null; } -- cgit v1.2.3