Add F_POINTED_AT fact for IrField (#298)

titzer · Nov 19, 2024 · ed7f584 · ed7f584
1 parent d8d95a1
commit ed7f584
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Showing 5 changed files with 26 additions and 3 deletions.
diff --git a/aeneas/src/core/Opcode.v3 b/aeneas/src/core/Opcode.v3
@@ -182,7 +182,8 @@ component Opcodes {
 		var F = Fact.O_FOLDABLE;
 		var P = Fact.O_PURE | Fact.O_FOLDABLE; // pure => foldable
 		var C = Fact.O_COMMUTATIVE;
-		var A = Fact.O_ASSOCIATIVE;
+		// var A = Fact.O_ASSOCIATIVE;	// not exploited
+		var A = Facts.NONE;	// for now, since needed the bit
 		var NZ   = Fact.V_NON_ZERO;
 		var NNEG = Fact.V_NON_NEGATIVE;
 		var NNC = Fact.O_NO_NULL_CHECK;

diff --git a/aeneas/src/ir/Facts.v3 b/aeneas/src/ir/Facts.v3
@@ -6,6 +6,7 @@ enum Fact {
 	// facts for fields
 	F_VALUE,		// field is read-only
 	F_NORM,			// the field is an element of a normalized field
+	F_POINTED_AT,		// subject of a Pointer.atField
 	// facts for methods
 	M_EQUALS,		// method is an equality comparator
 	M_OVERRIDDEN,		// method has been overridden in a subclass
@@ -29,7 +30,10 @@ enum Fact {
 	O_PURE,			// no side-effects + deterministic
 	O_FOLDABLE,		// can be constant folded
 	O_COMMUTATIVE,		// f(x, y) == f(y, x)
-	O_ASSOCIATIVE,		// f(f(x, y), z) == f(x, f(y, z))
+	// associative is not exploited at present, and we needed the bit
+	// in order to add F_POINTED_AT (until compiler fixed to use u64
+	// for the enum set)
+	// O_ASSOCIATIVE,		// f(f(x, y), z) == f(x, f(y, z))
 	O_NO_SHIFT_CHECK,	// 31 >= y >= 0
 	O_NO_NULL_CHECK,	// x != null, x != NaN for floats
 	O_NO_BOUNDS_CHECK,	// no bounds check required

diff --git a/aeneas/src/ir/Normalization.v3 b/aeneas/src/ir/Normalization.v3
@@ -329,7 +329,8 @@ class ReachabilityNormalizer(config: NormalizerConfig, ra: ReachabilityAnalyzer)
 				// add normalized field(s) to the vector
 				var tn = rf.typeNorm;
 				var facts = if(tn.size > 1, Fact.F_NORM, Facts.NONE);
-				if (!rf.raFacts.RF_WRITTEN) facts |= (Fact.F_VALUE | Fact.O_FOLDABLE);
+				if (!rf.raFacts.RF_WRITTEN && !rf.orig.facts.F_POINTED_AT) facts |= (Fact.F_VALUE | Fact.O_FOLDABLE);
+				if (rf.orig.facts.F_POINTED_AT) facts |= Fact.F_POINTED_AT;
 				for (i < tn.size) {
 					var ft = if(tn.sub == null, tn.newType, tn.sub[i]);
 					var nf = IrField.new(rc.oldType, ft);

diff --git a/aeneas/src/ssa/SsaOptimizer.v3 b/aeneas/src/ssa/SsaOptimizer.v3
@@ -1955,6 +1955,10 @@ class SsaLoadOptimizer(context: SsaContext) {
 			}
 			ClassSetField(field) => return store(apply.input0(), field, apply, apply.input1());
 			ComponentSetField(field) => return store(null, field, apply, apply.input1());
+			PtrStore => {
+				pure.killPointedAt();
+				impure.killPointedAt();
+			}
 			Init,
 			CallMethod,
 			CallClassMethod,
@@ -2022,4 +2026,13 @@ class SsaLoadedFields {
 		}
 		length = i;
 	}
+	def killPointedAt() {
+		var i = 0;
+		for (j < length) {
+			var t = array[j];
+			if ((!t.1.facts.F_POINTED_AT) && i != j)
+				array[i++] = t;
+		}
+		length = i;
+	}
 }
diff --git a/aeneas/src/ssa/VstSsaGen.v3 b/aeneas/src/ssa/VstSsaGen.v3
@@ -880,10 +880,14 @@ class VstSsaGen extends VstVisitor<VstSsaEnv, SsaInstr> {
 			}
 			PtrAtComponentField(receiver, field, ptrType) => {
 				var spec = specOf(receiver, field, null);
+				var irFld = spec.asField();
+				irFld.facts |= Fact.F_POINTED_AT;
 				return env.addApply(env.source, V3Op.newPtrAtComponentField(spec, ptrType), Ssa.NO_INSTRS);
 			}
 			PtrAtObjectField(receiver, field, ptrType) => {
 				var spec = specOf(receiver, field, null);
+				var irFld = spec.asField();
+				irFld.facts |= Fact.F_POINTED_AT;
 				return env.addApply(env.source, V3Op.newPtrAtObjectField(spec, ptrType), [target]);
 			}
 			PtrAtRefLayoutField(receiver, field, ptrType) => {