Optimize fast element conversion in arm using batch store/loads.

src/arm/macro-assembler-arm.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 302 matching lines @@
         stm(db_w, sp, src1.bit() | src2.bit(), cond);
         str(src3, MemOperand(sp, 4, NegPreIndex), cond);
       }
     } else {
       str(src1, MemOperand(sp, 4, NegPreIndex), cond);
       Push(src2, src3, cond);
     }
   }
 
   // Push four registers.  Pushes leftmost register first (to highest address).
-  void Push(Register src1, Register src2,
-            Register src3, Register src4, Condition cond = al) {
+  void Push(Register src1,
+            Register src2,
+            Register src3,
+            Register src4,
+            Condition cond = al) {
     ASSERT(!src1.is(src2));
     ASSERT(!src2.is(src3));
     ASSERT(!src1.is(src3));
     ASSERT(!src1.is(src4));
     ASSERT(!src2.is(src4));
     ASSERT(!src3.is(src4));
     if (src1.code() > src2.code()) {
       if (src2.code() > src3.code()) {
         if (src3.code() > src4.code()) {
           stm(db_w,
@@ skipping 17 matching lines @@
   // Pop two registers. Pops rightmost register first (from lower address).
   void Pop(Register src1, Register src2, Condition cond = al) {
     ASSERT(!src1.is(src2));
     if (src1.code() > src2.code()) {
       ldm(ia_w, sp, src1.bit() | src2.bit(), cond);
     } else {
       ldr(src2, MemOperand(sp, 4, PostIndex), cond);
       ldr(src1, MemOperand(sp, 4, PostIndex), cond);
     }
   }
 

[Yang, 2011/10/19 11:41:11]

Not moving the function body to macro-assembler-arm.cc because ldm is not
defined there.

+  // Pop three registers.  Pops rightmost register first (from lower address).
+  void Pop(Register src1, Register src2, Register src3, Condition cond = al) {
+    ASSERT(!src1.is(src2));
+    ASSERT(!src2.is(src3));
+    ASSERT(!src1.is(src3));
+    if (src1.code() > src2.code()) {
+      if (src2.code() > src3.code()) {
+        ldm(ia_w, sp, src1.bit() | src2.bit() | src3.bit(), cond);
+      } else {
+        ldr(src3, MemOperand(sp, 4, PostIndex), cond);
+        ldm(ia_w, sp, src1.bit() | src2.bit(), cond);
+      }
+    } else {
+      Pop(src2, src3, cond);
+      str(src1, MemOperand(sp, 4, PostIndex), cond);
+    }
+  }
+
+  // Pop four registers.  Pops rightmost register first (from lower address).
+  void Pop(Register src1,
+           Register src2,
+           Register src3,
+           Register src4,
+           Condition cond = al) {
+    ASSERT(!src1.is(src2));
+    ASSERT(!src2.is(src3));
+    ASSERT(!src1.is(src3));
+    ASSERT(!src1.is(src4));
+    ASSERT(!src2.is(src4));
+    ASSERT(!src3.is(src4));
+    if (src1.code() > src2.code()) {
+      if (src2.code() > src3.code()) {
+        if (src3.code() > src4.code()) {
+          ldm(ia_w,
+              sp,
+              src1.bit() | src2.bit() | src3.bit() | src4.bit(),
+              cond);
+        } else {
+          ldr(src4, MemOperand(sp, 4, PostIndex), cond);
+          ldm(ia_w, sp, src1.bit() | src2.bit() | src3.bit(), cond);
+        }
+      } else {
+        Pop(src3, src4, cond);
+        ldm(ia_w, sp, src1.bit() | src2.bit(), cond);
+      }
+    } else {
+      Pop(src2, src3, src4, cond);
+      ldr(src1, MemOperand(sp, 4, PostIndex), cond);
+    }
+  }
+
   // Push and pop the registers that can hold pointers, as defined by the
   // RegList constant kSafepointSavedRegisters.
   void PushSafepointRegisters();
   void PopSafepointRegisters();
   void PushSafepointRegistersAndDoubles();
   void PopSafepointRegistersAndDoubles();
   // Store value in register src in the safepoint stack slot for
   // register dst.
   void StoreToSafepointRegisterSlot(Register src, Register dst);
   void StoreToSafepointRegistersAndDoublesSlot(Register src, Register dst);
@@ skipping 905 matching lines @@
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_MACRO_ASSEMBLER_ARM_H_