[cleanup] Delete MacroAssembler::CopyBytes, it is dead code

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 0a739dacfb0c472ee72de508b5c4552852cc4086..08117b2c218e73d7ff7b53c8bed829cd08cdc6f0 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -5174,93 +5174,6 @@ void MacroAssembler::AllocateJSValue(Register result, Register constructor,
   STATIC_ASSERT(JSValue::kSize == 4 * kPointerSize);
 }
 
-
-// Copy memory, byte-by-byte, from source to destination.  Not optimized for
-// long or aligned copies.  The contents of scratch and length are destroyed.
-// Destination is incremented by length, source, length and scratch are
-// clobbered.
-// A simpler loop is faster on small copies, but slower on large ones.
-// The cld() instruction must have been emitted, to set the direction flag(),
-// before calling this function.
-void MacroAssembler::CopyBytes(Register destination,
-                               Register source,
-                               Register length,
-                               int min_length,
-                               Register scratch) {
-  DCHECK(min_length >= 0);
-  if (emit_debug_code()) {
-    cmpl(length, Immediate(min_length));
-    Assert(greater_equal, kInvalidMinLength);
-  }
-  Label short_loop, len8, len16, len24, done, short_string;
-
-  const int kLongStringLimit = 4 * kPointerSize;
-  if (min_length <= kLongStringLimit) {
-    cmpl(length, Immediate(kPointerSize));
-    j(below, &short_string, Label::kNear);
-  }
-
-  DCHECK(source.is(rsi));
-  DCHECK(destination.is(rdi));
-  DCHECK(length.is(rcx));
-
-  if (min_length <= kLongStringLimit) {
-    cmpl(length, Immediate(2 * kPointerSize));
-    j(below_equal, &len8, Label::kNear);
-    cmpl(length, Immediate(3 * kPointerSize));
-    j(below_equal, &len16, Label::kNear);
-    cmpl(length, Immediate(4 * kPointerSize));
-    j(below_equal, &len24, Label::kNear);
-  }
-
-  // Because source is 8-byte aligned in our uses of this function,
-  // we keep source aligned for the rep movs operation by copying the odd bytes
-  // at the end of the ranges.
-  movp(scratch, length);
-  shrl(length, Immediate(kPointerSizeLog2));
-  repmovsp();
-  // Move remaining bytes of length.
-  andl(scratch, Immediate(kPointerSize - 1));
-  movp(length, Operand(source, scratch, times_1, -kPointerSize));
-  movp(Operand(destination, scratch, times_1, -kPointerSize), length);
-  addp(destination, scratch);
-
-  if (min_length <= kLongStringLimit) {
-    jmp(&done, Label::kNear);
-    bind(&len24);
-    movp(scratch, Operand(source, 2 * kPointerSize));
-    movp(Operand(destination, 2 * kPointerSize), scratch);
-    bind(&len16);
-    movp(scratch, Operand(source, kPointerSize));
-    movp(Operand(destination, kPointerSize), scratch);
-    bind(&len8);
-    movp(scratch, Operand(source, 0));
-    movp(Operand(destination, 0), scratch);
-    // Move remaining bytes of length.
-    movp(scratch, Operand(source, length, times_1, -kPointerSize));
-    movp(Operand(destination, length, times_1, -kPointerSize), scratch);
-    addp(destination, length);
-    jmp(&done, Label::kNear);
-
-    bind(&short_string);
-    if (min_length == 0) {
-      testl(length, length);
-      j(zero, &done, Label::kNear);
-    }
-
-    bind(&short_loop);
-    movb(scratch, Operand(source, 0));
-    movb(Operand(destination, 0), scratch);
-    incp(source);
-    incp(destination);
-    decl(length);
-    j(not_zero, &short_loop, Label::kNear);
-  }
-
-  bind(&done);
-}
-
-
 void MacroAssembler::InitializeFieldsWithFiller(Register current_address,
                                                 Register end_address,
                                                 Register filler) {