PPC: [strong] Function arity check should be based on required parameters

src/ppc/builtins-ppc.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_PPC
 
 #include "src/codegen.h"
 #include "src/debug.h"
@@ skipping 1747 matching lines @@
     __ subi(r3, r3, Operand(kPointerSize));
     __ bne(&copy);
 
     __ b(&invoke);
   }
 
   {  // Too few parameters: Actual < expected
     __ bind(&too_few);
 
     // If the function is strong we need to throw an error.
-    Label weak_function;
+    Label no_strong_error;
     __ LoadP(r7, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
-    __ lwz(r7, FieldMemOperand(r7, SharedFunctionInfo::kCompilerHintsOffset));
-    __ TestBit(r7,
+    __ lwz(r8, FieldMemOperand(r7, SharedFunctionInfo::kCompilerHintsOffset));
+    __ TestBit(r8,
 #if V8_TARGET_ARCH_PPC64
                SharedFunctionInfo::kStrongModeFunction,
 #else
                SharedFunctionInfo::kStrongModeFunction + kSmiTagSize,
 #endif
                r0);
-    __ beq(&weak_function, cr0);
+    __ beq(&no_strong_error, cr0);
+
+    // What we really care about is the required number of arguments.
+    __ lwa(r7, FieldMemOperand(r7, SharedFunctionInfo::kLengthOffset));
+#if V8_TARGET_ARCH_PPC64
+    // See commment near kLenghtOffset in src/objects.h
+    __ srawi(r7, r7, kSmiTagSize);
+#else
+    __ SmiUntag(r7);
+#endif
+    __ cmp(r3, r7);
+    __ bge(&no_strong_error);
 
     {
       FrameScope frame(masm, StackFrame::MANUAL);
       EnterArgumentsAdaptorFrame(masm);
       __ CallRuntime(Runtime::kThrowStrongModeTooFewArguments, 0);
     }
 
-    __ bind(&weak_function);
+    __ bind(&no_strong_error);
     EnterArgumentsAdaptorFrame(masm);
 
     // Calculate copy start address into r0 and copy end address is fp.
     // r3: actual number of arguments as a smi
     // r4: function
     // r5: expected number of arguments
     // ip: code entry to call
     __ SmiToPtrArrayOffset(r3, r3);
     __ add(r3, r3, fp);
 
@@ skipping 55 matching lines @@
     __ bkpt(0);
   }
 }
 
 
 #undef __
 }
 }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_PPC