[packing] [WIP] Implementation of #packing annotations

aeneas/src/ir/Ir.v3

@@ -25,6 +25,7 @@ class IrClass extends IrItem {
 	var machSize: int = -1;
 	var boxing: Boxing;
 	var packed: bool;
+	var packingExpr: List<VstPackingExpr>;
 
 	new(ctype, typeArgs, parent, fields, methods) { }
 	def inherits(m: IrMember) -> bool {

aeneas/src/ir/Normalization.v3

@@ -18,6 +18,7 @@ class NormalizerConfig {
 	var GetScalar: (Compiler, Program, Type) -> Scalar.set = defaultGetScalar;
 	var GetBitWidth: (Compiler, Program, Type) -> byte = defaultGetBitWidth;
 	var MaxScalarWidth: byte = 64;
+	var UsedScalars: Scalar.set = Scalar.B32 | Scalar.B64 | Scalar.F32 | Scalar.F64 | Scalar.Ref;
 
 	def setSignatureLimits(maxp: int, maxr: int) {
 		if (maxp < MaxParams) MaxParams = maxp;

aeneas/src/ir/PackingSolver.v3

@@ -29,6 +29,7 @@ def COLOR = false;
 // An interval from {start}, inclusive, to {end}, exclusive.
 type Interval(start: byte, end: byte) #unboxed {
 	def render(buf: StringBuilder) -> StringBuilder { return buf.put2("%d...%d", start, end); }
+	def shl(n: byte) -> Interval { return Interval(start + n, end + n); }
 	def size() -> byte { return end - start; }
 }
 
@@ -62,7 +63,10 @@ class ScalarPattern(bits: Array<PackingBit>) {
 		var start = 0;
 		for (end < size) {
 			if (bits[end] != PackingBit.Unassigned) start = end + 1;
-			else if (end + 1 - start >= s) intervals.put(Interval(byte.view(end + 1 - s), byte.view(end + 1)));
+			else if (end + 1 - start >= s) {
+				intervals.put(Interval(byte.view(end + 1 - s), byte.view(end + 1)));
+				start = end; // don't try all intervals
+			}
 		}
 		return intervals.extract();
 	}
@@ -81,6 +85,12 @@ class ScalarPattern(bits: Array<PackingBit>) {
 		for (j = i.start; j < i.end; j++) bits[j] = PackingBit.Unassigned;
 	}
 	def copy() -> ScalarPattern { return ScalarPattern.new(Arrays.dup(bits)); }
+	def padTo(n: byte) -> ScalarPattern { return ScalarPattern.new(Arrays.grow(bits, n)); }
+	def extractFixed() -> u64 {
+		var result: u64;
+		for (i < size) if (bits[i] == PackingBit.Fixed(1)) result |= 1ul << byte.view(i);
+		return result;
+	}
 }
 
 type PackingField #unboxed {

aeneas/src/ir/SsaNormalizer.v3

@@ -1384,11 +1384,19 @@ class SsaRaNormalizer extends SsaRebuilder {
 
 		var result = Array<SsaInstr>.new(vn.size);
 		for (i < result.length) result[i] = newGraph.nullConst(vn.at(i));
-
+		for (i < vn.pattern.scalars.length) {
+			if (IntRepType.?(vn.at(i))) {
+				var irt = IntRepType.!(vn.at(i));
+				var fixed = vn.pattern.scalars[i].extractFixed();
+				if (irt.width == 64) result[i] = newGraph.valConst(irt, irt.boxL(long.view(fixed)));
+				else result[i] = newGraph.valConst(irt, irt.box(int.view(fixed)));
+			}
+		}
 		if (vn.hasExplicitTag()) {
 			var tagIdx = vn.tag.indexes[0];
-			if (IntRepType.?(vn.at(tagIdx))) result[tagIdx] = genSetInterval(result[tagIdx], newGraph.intConst(vn.tagValue), vn.tag.intervals[0], vn.tag.tn.newType, IntRepType.!(vn.at(tagIdx)));
-			else result[tagIdx] = newGraph.intConst(vn.tagValue);
+			if (!IntRepType.?(vn.at(tagIdx))) {
+				result[tagIdx] = newGraph.intConst(vn.tagValue); // explicit tag scalar (not packed)
+			}
 		}
 
 		for (i < vn.fields.length) {