Move Negate slow path out of line

Summary: In the interest of keeping the interpreter simple, and for consistency with other operations, move the slow path of Negate into `Interpreter-slowpaths.cpp`. Reviewed By: tmikov Differential Revision: D41384542 fbshipit-source-id: 4a5ea79d83908e9871e36ccb295895b0700073b6
r-barnes · Nov 18, 2022 · 003e9db · 003e9db
1 parent 5a8745f
commit 003e9db
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Showing 3 changed files with 24 additions and 17 deletions.
diff --git a/lib/VM/Interpreter-internal.h b/lib/VM/Interpreter-internal.h
@@ -141,6 +141,8 @@ CallResult<HermesValue> doIncDecOperSlowPath(Runtime &runtime, Handle<> src);
 
 CallResult<HermesValue> doBitNotSlowPath(Runtime &runtime, Handle<> src);
 
+CallResult<HermesValue> doNegateSlowPath(Runtime &runtime, Handle<> src);
+
 } // namespace vm
 } // namespace hermes
 #endif // HERMES_VM_INTERPRETER_INTERNAL_H
diff --git a/lib/VM/Interpreter-slowpaths.cpp b/lib/VM/Interpreter-slowpaths.cpp
@@ -568,6 +568,21 @@ CallResult<HermesValue> doBitNotSlowPath(Runtime &runtime, Handle<> src) {
   return BigIntPrimitive::unaryNOT(runtime, bigint);
 }
 
+CallResult<HermesValue> doNegateSlowPath(Runtime &runtime, Handle<> src) {
+  // Try converting src to a numeric.
+  auto numRes = toNumeric_RJS(runtime, src);
+  if (LLVM_UNLIKELY(numRes == ExecutionStatus::EXCEPTION))
+    return ExecutionStatus::EXCEPTION;
+  // Test for BigInt since it is cheaper than testing for number. If it is a
+  // number, negate it and return.
+  if (LLVM_LIKELY(!numRes->isBigInt()))
+    return HermesValue::encodeDoubleValue(-numRes->getNumber());
+
+  // The result is a BigInt, perform a BigInt bitwise not.
+  auto bigint = runtime.makeHandle(numRes->getBigInt());
+  return BigIntPrimitive::unaryMinus(runtime, bigint);
+}
+
 } // namespace vm
 } // namespace hermes
 

diff --git a/lib/VM/Interpreter.cpp b/lib/VM/Interpreter.cpp
@@ -3054,24 +3054,14 @@ CallResult<HermesValue> Interpreter::interpretFunction(
         if (LLVM_LIKELY(O2REG(Negate).isNumber())) {
           O1REG(Negate) =
               HermesValue::encodeDoubleValue(-O2REG(Negate).getNumber());
-        } else {
-          CAPTURE_IP(res = toNumeric_RJS(runtime, Handle<>(&O2REG(Negate))));
-          if (res == ExecutionStatus::EXCEPTION)
-            goto exception;
-          if (res->isNumber()) {
-            O1REG(Negate) = HermesValue::encodeDoubleValue(-res->getNumber());
-          } else {
-            assert(res->isBigInt() && "should be bigint");
-            CAPTURE_IP_ASSIGN(
-                auto bigint, runtime.makeHandle(res->getBigInt()));
-            CAPTURE_IP(res = BigIntPrimitive::unaryMinus(runtime, bigint));
-            if (res == ExecutionStatus::EXCEPTION) {
-              goto exception;
-            }
-            O1REG(Negate) = HermesValue::encodeBigIntValue(res->getBigInt());
-          }
-          gcScope.flushToSmallCount(KEEP_HANDLES);
+          ip = NEXTINST(Negate);
+          DISPATCH;
         }
+        CAPTURE_IP(res = doNegateSlowPath(runtime, Handle<>(&O2REG(Negate))));
+        if (res == ExecutionStatus::EXCEPTION)
+          goto exception;
+        O1REG(Negate) = *res;
+        gcScope.flushToSmallCount(KEEP_HANDLES);
         ip = NEXTINST(Negate);
         DISPATCH;
       }