[turbofan][ppc] Fix CallDescriptor::NoFunctionDescriptor.

R=miladfar@ca.ibm.com

Change-Id: I42963b089243c45a3d065fb00e2864500bd33afb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1879934Reviewed-by: Milad Farazmand <miladfar@ca.ibm.com>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64563}

src/compiler/backend/instruction-selector.cc

@@ -2830,8 +2830,9 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
 #if defined(_AIX)
       // Highest misc_field bit is used on AIX to indicate if a CFunction call
       // has function descriptor or not.
-      misc_field |= call_descriptor->HasFunctionDescriptor()
-                    << kHasFunctionDescriptorBitShift;
+      if (!call_descriptor->NoFunctionDescriptor()) {
+        misc_field |= 1 << kHasFunctionDescriptorBitShift;
+      }
 #endif
       opcode = kArchCallCFunction | MiscField::encode(misc_field);
       break;

src/compiler/linkage.h

@@ -215,9 +215,9 @@ class V8_EXPORT_PRIVATE CallDescriptor final
     // The kCallerSavedFPRegisters only matters (and set) when the more general
     // flag for kCallerSavedRegisters above is also set.
     kCallerSavedFPRegisters = 1u << 10,
-    // AIX has a function descriptor which we will set to true by default
-    // for all CFunction calls (only used for Kind::kCallAddress).
-    kHasFunctionDescriptor = 1u << 11,
+    // AIX has a function descriptor by default but it can be disabled for a
+    // certain CFunction call (only used for Kind::kCallAddress).
+    kNoFunctionDescriptor = 1u << 11,
   };
   using Flags = base::Flags<Flag>;
 
@@ -302,9 +302,7 @@ class V8_EXPORT_PRIVATE CallDescriptor final
   bool NeedsCallerSavedFPRegisters() const {
     return flags() & kCallerSavedFPRegisters;
   }
-  bool HasFunctionDescriptor() const {
-    return flags() & kHasFunctionDescriptor;
-  }
+  bool NoFunctionDescriptor() const { return flags() & kNoFunctionDescriptor; }
 
   LinkageLocation GetReturnLocation(size_t index) const {
     return location_sig_->GetReturn(index);

src/compiler/raw-machine-assembler.cc

@@ -702,13 +702,13 @@ void RawMachineAssembler::TailCallN(CallDescriptor* call_descriptor,
 
 namespace {
 
-enum FunctionDescriptorMode { kNoFunctionDescriptor, kHasFunctionDescriptor };
+enum FunctionDescriptorMode { kHasFunctionDescriptor, kNoFunctionDescriptor };
 
 Node* CallCFunctionImpl(
     RawMachineAssembler* rasm, Node* function, MachineType return_type,
     std::initializer_list<RawMachineAssembler::CFunctionArg> args,
     bool caller_saved_regs, SaveFPRegsMode mode,
-    FunctionDescriptorMode has_function_descriptor) {
+    FunctionDescriptorMode no_function_descriptor) {
   static constexpr std::size_t kNumCArgs = 10;
 
   MachineSignature::Builder builder(rasm->zone(), 1, args.size());
@@ -719,7 +719,7 @@ Node* CallCFunctionImpl(
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   if (caller_saved_regs) flags |= CallDescriptor::kCallerSavedRegisters;
   if (caller_saved_fp_regs) flags |= CallDescriptor::kCallerSavedFPRegisters;
-  if (has_function_descriptor) flags |= CallDescriptor::kHasFunctionDescriptor;
+  if (no_function_descriptor) flags |= CallDescriptor::kNoFunctionDescriptor;
   auto call_descriptor =
       Linkage::GetSimplifiedCDescriptor(rasm->zone(), builder.Build(), flags);