Implement byte swapping instructions on MIPS32 and MIPS64.

src/mips/macro-assembler-mips.cc

 // Copyright 2012 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 <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_MIPS
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ skipping 12 matching lines @@
     : Assembler(arg_isolate, buffer, size),
       generating_stub_(false),
       has_frame_(false),
       has_double_zero_reg_set_(false) {
   if (create_code_object == CodeObjectRequired::kYes) {
     code_object_ =
         Handle<Object>::New(isolate()->heap()->undefined_value(), isolate());
   }
 }
 
-
 void MacroAssembler::Load(Register dst,
                           const MemOperand& src,
                           Representation r) {
   DCHECK(!r.IsDouble());
   if (r.IsInteger8()) {
     lb(dst, src);
   } else if (r.IsUInteger8()) {
     lbu(dst, src);
   } else if (r.IsInteger16()) {
     lh(dst, src);
@@ skipping 16 matching lines @@
   } else {
     if (r.IsHeapObject()) {
       AssertNotSmi(src);
     } else if (r.IsSmi()) {
       AssertSmi(src);
     }
     sw(src, dst);
   }
 }
 
-
 void MacroAssembler::LoadRoot(Register destination,
                               Heap::RootListIndex index) {
   lw(destination, MemOperand(s6, index << kPointerSizeLog2));
 }
 
 
 void MacroAssembler::LoadRoot(Register destination,
                               Heap::RootListIndex index,
                               Condition cond,
                               Register src1, const Operand& src2) {
@@ skipping 1103 matching lines @@
     Register tmp = rd.is(rt) ? scratch : rd;
     DCHECK(!tmp.is(rt));
     sll(tmp, rs, sa);
     Addu(rd, rt, tmp);
   }
 }
 
 
 // ------------Pseudo-instructions-------------
 
+// Word Swap Byte
+void MacroAssembler::ByteSwapSigned(Register reg, int operand_size) {
+  DCHECK(operand_size == 1 || operand_size == 2 || operand_size == 4);
+  if (IsMipsArchVariant(kMips32r2) || IsMipsArchVariant(kMips32r6)) {

[balazs.kilvady, 2016/06/21 10:24:58]

Please use { and } in the below if instructions.

+    if (operand_size == 2)
+      seh(reg, reg);
+    else if (operand_size == 1)
+      seb(reg, reg);
+    // No need to do any preparation if operand_size is 4
+
+    wsbh(reg, reg);
+    rotr(reg, reg, 16);
+  } else if (IsMipsArchVariant(kMips32r1) || IsMipsArchVariant(kLoongson)) {
+    if (operand_size == 1) {
+      sll(reg, reg, 24);
+      sra(reg, reg, 24);
+    } else if (operand_size == 2) {
+      sll(reg, reg, 16);
+      sra(reg, reg, 16);
+    }
+    // No need to do any preparation if operand_size is 4
+
+    Register tmp = t0;
+    Register tmp2 = t1;
+
+    andi(tmp2, reg, 0xFF);
+    sll(tmp2, tmp2, 24);
+    or_(tmp, zero_reg, tmp2);
+
+    andi(tmp2, reg, 0xFF00);
+    sll(tmp2, tmp2, 8);
+    or_(tmp, tmp, tmp2);
+
+    srl(reg, reg, 8);
+    andi(tmp2, reg, 0xFF00);
+    or_(tmp, tmp, tmp2);
+
+    srl(reg, reg, 16);
+    andi(tmp2, reg, 0xFF);
+    or_(tmp, tmp, tmp2);
+
+    or_(reg, tmp, zero_reg);
+  }
+}
+
+void MacroAssembler::ByteSwapUnsigned(Register reg, int operand_size) {
+  DCHECK(operand_size == 1 || operand_size == 2);
+
+  if (IsMipsArchVariant(kMips32r2) || IsMipsArchVariant(kMips32r6)) {

[balazs.kilvady, 2016/06/21 10:24:58]

{}

+    if (operand_size == 1)
+      andi(reg, reg, 0xFF);
+    else
+      andi(reg, reg, 0xFFFF);
+    // No need to do any preparation if operand_size is 4
+
+    wsbh(reg, reg);
+    rotr(reg, reg, 16);
+  } else if (IsMipsArchVariant(kMips32r1) || IsMipsArchVariant(kLoongson)) {
+    if (operand_size == 1) {
+      sll(reg, reg, 24);
+    } else {
+      Register tmp = t0;
+
+      andi(tmp, reg, 0xFF00);
+      sll(reg, reg, 24);
+      sll(tmp, tmp, 8);
+      or_(reg, tmp, reg);
+    }
+  }
+}
+
 void MacroAssembler::Ulw(Register rd, const MemOperand& rs) {
   DCHECK(!rd.is(at));
   DCHECK(!rs.rm().is(at));
   if (IsMipsArchVariant(kMips32r6)) {
     lw(rd, rs);
   } else {
     DCHECK(IsMipsArchVariant(kMips32r2) || IsMipsArchVariant(kMips32r1) ||
            IsMipsArchVariant(kLoongson));
     if (is_int16(rs.offset() + kMipsLwrOffset) &&
         is_int16(rs.offset() + kMipsLwlOffset)) {
@@ skipping 5591 matching lines @@
   if (mag.shift > 0) sra(result, result, mag.shift);
   srl(at, dividend, 31);
   Addu(result, result, Operand(at));
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS