[wasm] Save FP & PC when calling C functions (x64 only)

This change is needed for profiling of Wasm code that calls C-function
to ignore the C-stack above the Wasm stack that otherwise couldn't be
parsed otherwise.

R=clemensb@chromium.org
R=petermarshall@chromium.org
R=jgruber@chromium.org

Bug: chromium:1045860
Change-Id: Ia0788189ca666e77f1564576903c1dc4fd745b8d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2066964
Commit-Queue: Emanuel Ziegler <ecmziegler@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66408}

src/codegen/x64/macro-assembler-x64.cc

@@ -2651,26 +2651,35 @@ void TurboAssembler::CallCFunction(Register function, int num_arguments) {
 
   // Save the frame pointer and PC so that the stack layout remains iterable,
   // even without an ExitFrame which normally exists between JS and C frames.
-  if (isolate() != nullptr) {
+  if (isolate() != nullptr || root_array_available_) {
     Label get_pc;
     DCHECK(!AreAliased(kScratchRegister, function));
     leaq(kScratchRegister, Operand(&get_pc, 0));
     bind(&get_pc);
-    movq(ExternalReferenceAsOperand(
-             ExternalReference::fast_c_call_caller_pc_address(isolate())),
+    movq(isolate() != nullptr
+             ? ExternalReferenceAsOperand(
+                   ExternalReference::fast_c_call_caller_pc_address(isolate()))
+             : Operand(kRootRegister,
+                       IsolateData::fast_c_call_caller_pc_offset()),
          kScratchRegister);
-    movq(ExternalReferenceAsOperand(
-             ExternalReference::fast_c_call_caller_fp_address(isolate())),
+    movq(isolate() != nullptr
+             ? ExternalReferenceAsOperand(
+                   ExternalReference::fast_c_call_caller_fp_address(isolate()))
+             : Operand(kRootRegister,
+                       IsolateData::fast_c_call_caller_fp_offset()),
          rbp);
   }
 
   call(function);
 
+  // We don't unset the PC; the FP is the source of truth.
   if (isolate() != nullptr) {
-    // We don't unset the PC; the FP is the source of truth.
     movq(ExternalReferenceAsOperand(
              ExternalReference::fast_c_call_caller_fp_address(isolate())),
          Immediate(0));
+  } else if (root_array_available_) {
+    movq(Operand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset()),
+         Immediate(0));
   }
 
   DCHECK_NE(base::OS::ActivationFrameAlignment(), 0);

src/execution/isolate-data.h

@@ -62,6 +62,14 @@ class IsolateData final {
     return kBuiltinsTableOffset - kIsolateRootBias;
   }
 
+  static constexpr int fast_c_call_caller_fp_offset() {
+    return kFastCCallCallerFPOffset - kIsolateRootBias;
+  }
+
+  static constexpr int fast_c_call_caller_pc_offset() {
+    return kFastCCallCallerPCOffset - kIsolateRootBias;
+  }
+
   // Root-register-relative offset of the given builtin table entry.
   // TODO(ishell): remove in favour of typified id version.
   static int builtin_slot_offset(int builtin_index) {