Fix bugs x86 storing only 32bits of a large constant

Missed field narrowing in a few cases

2 files changed, 35 insertions, 1 deletions

diff --git a/chapter19/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java b/chapter19/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
index e7e0b874..1b14bcf1 100644
--- a/chapter19/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
+++ b/chapter19/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
@@ -430,7 +430,7 @@ public class x86_64_v2 extends Machine {
     }
     private int imm( Node xval ) {
         assert val==null && imm==0;
-        if( xval instanceof ConstantNode con && con._con instanceof TypeInteger ti ) {
+        if( xval instanceof ConstantNode con && con._con instanceof TypeInteger ti && ti.isConstant() && (int)ti.value()==ti.value() ) {
             val = null;
             imm = (int)ti.value();
             assert imm == ti.value(); // In 32-bit range
diff --git a/chapter19/src/test/java/com/seaofnodes/simple/X86StoreTest.java b/chapter19/src/test/java/com/seaofnodes/simple/X86StoreTest.java
new file mode 100644
index 00000000..c32a69c3
--- /dev/null
+++ b/chapter19/src/test/java/com/seaofnodes/simple/X86StoreTest.java
@@ -0,0 +1,34 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.node.cpus.x86_64_v2.StoreX86;
+import com.seaofnodes.simple.type.TypeInteger;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class X86StoreTest {
+    @Test public void testConstantStores() {
+        check("u8",255,false);
+        check("u16",65535,false);
+        check("u32",Integer.MAX_VALUE,false);
+        check("u32",2147483648L,true);
+        check("u32",4294967295L,true);
+        check("int",Integer.MIN_VALUE,false);
+        check("int",Integer.MAX_VALUE,false);
+        for( long value : new long[]{2147483648L,4294967295L,-2147483649L,
+                                    0x123456789abcdefL,Long.MIN_VALUE,Long.MAX_VALUE} )
+            check("int",value,true);
+    }
+
+    private static void check(String type, long value, boolean register) {
+        // Returning the object keeps the Store; returning its field could fold.
+        String literal = value==Long.MIN_VALUE ? "(-9223372036854775807-1)" : Long.toString(value);
+        String src = "struct S { "+type+" x="+literal+"; }; return new S;";
+        CodeGen code = new CodeGen(src).driver(CodeGen.Phase.InstructionSelection,"x86_64_v2","SystemV");
+        StoreX86 store = code._stop.walk(n -> n instanceof StoreX86 st && st._name.equals("x") ? st : null);
+        assertNotNull(src,store);
+        if( register ) {
+            assertNotNull(src,store.in(4));
+            assertEquals(src,value,((TypeInteger)store.in(4)._type).value());
+        } else assertNull(src,store.in(4));
+    }
+}