diff options
Diffstat (limited to 'chapter17')
3 files changed, 50 insertions, 4 deletions
diff --git a/chapter17/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter17/src/main/java/com/seaofnodes/simple/node/SubNode.java index 24499cbc..2f2a7a05 100644 --- a/chapter17/src/main/java/com/seaofnodes/simple/node/SubNode.java +++ b/chapter17/src/main/java/com/seaofnodes/simple/node/SubNode.java @@ -42,13 +42,24 @@ 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; + + // Keep invalid operands for type checking. + if( t1 instanceof TypeInteger x && t2 instanceof TypeInteger y ) { + if( y.isConstant() && y.value()==0 ) return lhs; + if( x.isConstant() && x.value()==0 ) return new MinusNode(rhs); + } + // x - (-y) is x+y - if( in(2) instanceof MinusNode minus ) - return new AddNode(in(1),minus.in(1)); + if( rhs instanceof MinusNode minus ) + return new AddNode(lhs,minus.in(1)); // (-x) - y is -(x+y) - if( in(1) instanceof MinusNode minus ) - return new MinusNode(new AddNode(minus.in(1),in(2)).peephole()); + if( lhs instanceof MinusNode minus ) + return new MinusNode(new AddNode(minus.in(1),rhs).peephole()); return null; } diff --git a/chapter17/src/test/java/com/seaofnodes/simple/Chapter04Test.java b/chapter17/src/test/java/com/seaofnodes/simple/Chapter04Test.java index 0db3afde..dfd3569f 100644 --- a/chapter17/src/test/java/com/seaofnodes/simple/Chapter04Test.java +++ b/chapter17/src/test/java/com/seaofnodes/simple/Chapter04Test.java @@ -51,6 +51,34 @@ public class Chapter04Test { } @Test + public void testSub0() { + Parser parser = new Parser("return arg-0;"); + StopNode ret = parser.parse(); + assertEquals("return arg;", ret.print()); + } + + @Test + public void test0Sub() { + Parser parser = new Parser("return 0-arg;"); + StopNode ret = parser.parse(); + assertEquals("return (-arg);", ret.print()); + } + + @Test + public void testSubNeg() { + Parser parser = new Parser("return 3--arg;"); + StopNode ret = parser.parse(); + assertEquals("return (arg+3);", ret.print()); + } + + @Test + public void testNegSub() { + Parser parser = new Parser("return -arg-3;"); + StopNode ret = parser.parse(); + assertEquals("return (-(arg+3));", ret.print()); + } + + @Test public void testVarArg() { Parser parser = new Parser("return arg; "); StopNode stop = parser.parse(); diff --git a/chapter17/src/test/java/com/seaofnodes/simple/Chapter12Test.java b/chapter17/src/test/java/com/seaofnodes/simple/Chapter12Test.java index e81f9845..f7efde96 100644 --- a/chapter17/src/test/java/com/seaofnodes/simple/Chapter12Test.java +++ b/chapter17/src/test/java/com/seaofnodes/simple/Chapter12Test.java @@ -8,6 +8,13 @@ import static org.junit.Assert.assertEquals; import static org.junit.Assert.fail; public class Chapter12Test { + @Test public void testSubZeroFloat() { + var stop = new Parser("flt x = arg; return 0-x;").parse().iterate(); + // Compare strings so +0.0 and -0.0 remain distinct. + assertEquals("0.0", Evaluator.evaluate(stop,0).toString()); + assertEquals("-1.0", Evaluator.evaluate(stop,1).toString()); + } + @Test public void testDeadNumericReturns() { for( String[] test : new String[][] { {"if(1) return 7; else return 2.5;", "7"}, |