Bug 1811264 - Part 3: Handle remaining BigInt comparisons. r=jandem

This adds support for BigInt x {Null, Undefined} relational comparisons. Depends on D167265 Differential Revision: https://phabricator.services.mozilla.com/D167266
dothq · Jan 20, 2023 · b8bcbef · b8bcbef
1 parent 24efc8f
commit b8bcbef
Show file tree

Hide file tree

Showing 2 changed files with 98 additions and 18 deletions.
diff --git a/js/src/jit-test/tests/cacheir/bigint-compare-null-or-undef.js b/js/src/jit-test/tests/cacheir/bigint-compare-null-or-undef.js
@@ -0,0 +1,82 @@
+// Test relational comparison when one operand is null or undefined.
+
+function test(xs) {
+  for (let i = 0; i < 200; ++i) {
+    let x = xs[i % xs.length];
+
+    // The result is equal when compared to the result with explicit ToNumber conversions.
+
+    // Test when null-or-undefined is on the right-hand side.
+    assertEq(x < nullOrUndef, x < (+nullOrUndef));
+    assertEq(x <= nullOrUndef, x <= (+nullOrUndef));
+    assertEq(x >= nullOrUndef, x >= (+nullOrUndef));
+    assertEq(x > nullOrUndef, x > (+nullOrUndef));
+
+    // Test when null-or-undefined is on the left-hand side.
+    assertEq(nullOrUndef < x, (+nullOrUndef) < x);
+    assertEq(nullOrUndef <= x, (+nullOrUndef) <= x);
+    assertEq(nullOrUndef >= x, (+nullOrUndef) >= x);
+    assertEq(nullOrUndef > x, (+nullOrUndef) > x);
+  }
+}
+
+function runTest(inputs) {
+  let fNull = Function(`return ${test}`.replaceAll("nullOrUndef", "null"))();
+  fNull(inputs);
+
+  let fUndefined = Function(`return ${test}`.replaceAll("nullOrUndef", "undefined"))();
+  fUndefined(inputs);
+}
+
+// BigInt inputs
+runTest([
+  // Definitely heap digits.
+  -(2n ** 1000n),
+
+  // -(2n**64n)
+  -18446744073709551617n,
+  -18446744073709551616n,
+  -18446744073709551615n,
+
+  // -(2n**63n)
+  -9223372036854775809n,
+  -9223372036854775808n,
+  -9223372036854775807n,
+
+  // -(2**32)
+  -4294967297n,
+  -4294967296n,
+  -4294967295n,
+
+  // -(2**31)
+  -2147483649n,
+  -2147483648n,
+  -2147483647n,
+
+  -1n,
+  0n,
+  1n,
+
+  // 2**31
+  2147483647n,
+  2147483648n,
+  2147483649n,
+
+  // 2**32
+  4294967295n,
+  4294967296n,
+  4294967297n,
+
+  // 2n**63n
+  9223372036854775807n,
+  9223372036854775808n,
+  9223372036854775809n,
+
+  // 2n**64n
+  18446744073709551615n,
+  18446744073709551616n,
+  18446744073709551617n,
+
+  // Definitely heap digits.
+  2n ** 1000n,
+]);
diff --git a/js/src/jit/CacheIR.cpp b/js/src/jit/CacheIR.cpp
@@ -11284,30 +11284,22 @@ AttachDecision CompareIRGenerator::tryAttachPrimitiveSymbol(
 
 AttachDecision CompareIRGenerator::tryAttachBigIntInt32(ValOperandId lhsId,
                                                         ValOperandId rhsId) {
-  // Ensure BigInt x {Int32, Boolean}.
-  if (!(lhsVal_.isBigInt() && (rhsVal_.isInt32() || rhsVal_.isBoolean())) &&
-      !(rhsVal_.isBigInt() && (lhsVal_.isInt32() || lhsVal_.isBoolean()))) {
+  // Ensure BigInt x {Int32, Boolean, Null}.
+  if (!(lhsVal_.isBigInt() && CanConvertToInt32ForToNumber(rhsVal_)) &&
+      !(rhsVal_.isBigInt() && CanConvertToInt32ForToNumber(lhsVal_))) {
     return AttachDecision::NoAction;
   }
 
   // Case should have been handled by tryAttachStrictDifferentTypes
   MOZ_ASSERT(op_ != JSOp::StrictEq && op_ != JSOp::StrictNe);
 
-  auto createGuards = [&](const Value& v, ValOperandId vId) {
-    if (v.isBoolean()) {
-      return writer.guardBooleanToInt32(vId);
-    }
-    MOZ_ASSERT(v.isInt32());
-    return writer.guardToInt32(vId);
-  };
-
   if (lhsVal_.isBigInt()) {
     BigIntOperandId bigIntId = writer.guardToBigInt(lhsId);
-    Int32OperandId intId = createGuards(rhsVal_, rhsId);
+    Int32OperandId intId = EmitGuardToInt32ForToNumber(writer, rhsId, rhsVal_);
 
     writer.compareBigIntInt32Result(op_, bigIntId, intId);
   } else {
-    Int32OperandId intId = createGuards(lhsVal_, lhsId);
+    Int32OperandId intId = EmitGuardToInt32ForToNumber(writer, lhsId, lhsVal_);
     BigIntOperandId bigIntId = writer.guardToBigInt(rhsId);
 
     writer.compareBigIntInt32Result(ReverseCompareOp(op_), bigIntId, intId);
@@ -11320,22 +11312,28 @@ AttachDecision CompareIRGenerator::tryAttachBigIntInt32(ValOperandId lhsId,
 
 AttachDecision CompareIRGenerator::tryAttachBigIntNumber(ValOperandId lhsId,
                                                          ValOperandId rhsId) {
-  // Ensure BigInt x Number.
-  if (!(lhsVal_.isBigInt() && rhsVal_.isNumber()) &&
-      !(rhsVal_.isBigInt() && lhsVal_.isNumber())) {
+  // Ensure BigInt x {Number, Undefined}.
+  if (!(lhsVal_.isBigInt() && CanConvertToDoubleForToNumber(rhsVal_)) &&
+      !(rhsVal_.isBigInt() && CanConvertToDoubleForToNumber(lhsVal_))) {
     return AttachDecision::NoAction;
   }
 
   // Case should have been handled by tryAttachStrictDifferentTypes
   MOZ_ASSERT(op_ != JSOp::StrictEq && op_ != JSOp::StrictNe);
 
+  // Case should have been handled by tryAttachBigIntInt32.
+  MOZ_ASSERT(!CanConvertToInt32ForToNumber(lhsVal_));
+  MOZ_ASSERT(!CanConvertToInt32ForToNumber(rhsVal_));
+
   if (lhsVal_.isBigInt()) {
     BigIntOperandId bigIntId = writer.guardToBigInt(lhsId);
-    NumberOperandId numId = writer.guardIsNumber(rhsId);
+    NumberOperandId numId =
+        EmitGuardToDoubleForToNumber(writer, rhsId, rhsVal_);
 
     writer.compareBigIntNumberResult(op_, bigIntId, numId);
   } else {
-    NumberOperandId numId = writer.guardIsNumber(lhsId);
+    NumberOperandId numId =
+        EmitGuardToDoubleForToNumber(writer, lhsId, lhsVal_);
     BigIntOperandId bigIntId = writer.guardToBigInt(rhsId);
 
     writer.compareBigIntNumberResult(ReverseCompareOp(op_), bigIntId, numId);