MIPS: Minor bug fixes to macro-asm and simulator.

src/mips/macro-assembler-mips.cc

 // 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 819 matching lines @@
 
 
 void MacroAssembler::Trunc_uw_d(FPURegister fd, FPURegister fs) {
   Trunc_uw_d(fs, t4);
   mtc1(t4, fd);
 }
 
 
 void MacroAssembler::Trunc_uw_d(FPURegister fd, Register rs) {
   ASSERT(!fd.is(f22));
-  ASSERT(!rs.is(t6));
+  ASSERT(!rs.is(t8));
 
   // Load 2^31 into f22.
-  Or(t6, zero_reg, 0x80000000);
-  Cvt_d_uw(f22, t6);
+  Or(t8, zero_reg, 0x80000000);
+  Cvt_d_uw(f22, t8);
 
   // Test if f22 > fd.
   c(OLT, D, fd, f22);
 
   Label simple_convert;
   // If fd < 2^31 we can convert it normally.
   bc1t(&simple_convert);
 
   // First we subtract 2^31 from fd, then trunc it to rs
   // and add 2^31 to rs.
 
   sub_d(f22, fd, f22);
   trunc_w_d(f22, f22);
   mfc1(rs, f22);
-  or_(rs, rs, t6);
+  or_(rs, rs, t8);
 
   Label done;
   Branch(&done);
   // Simple conversion.
   bind(&simple_convert);
   trunc_w_d(f22, fd);
   mfc1(rs, f22);
 
   bind(&done);
 }
@@ skipping 1686 matching lines @@
   AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
   sw(heap_number_map, FieldMemOperand(result, HeapObject::kMapOffset));
 }
 
 
 void MacroAssembler::AllocateHeapNumberWithValue(Register result,
                                                  FPURegister value,
                                                  Register scratch1,
                                                  Register scratch2,
                                                  Label* gc_required) {
-  LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
-  AllocateHeapNumber(result, scratch1, scratch2, t6, gc_required);
+  LoadRoot(t8, Heap::kHeapNumberMapRootIndex);
+  AllocateHeapNumber(result, scratch1, scratch2, t8, gc_required);
   sdc1(value, FieldMemOperand(result, HeapNumber::kValueOffset));
 }
 
 
 // Copies a fixed number of fields of heap objects from src to dst.
 void MacroAssembler::CopyFields(Register dst,
                                 Register src,
                                 RegList temps,
                                 int field_count) {
   ASSERT((temps & dst.bit()) == 0);
@@ skipping 664 matching lines @@
                                              Register right,
                                              Register overflow_dst,
                                              Register scratch) {
   ASSERT(!dst.is(overflow_dst));
   ASSERT(!dst.is(scratch));
   ASSERT(!overflow_dst.is(scratch));
   ASSERT(!overflow_dst.is(left));
   ASSERT(!overflow_dst.is(right));
   ASSERT(!left.is(right));
 
-  // TODO(kalmard) There must be a way to optimize dst == left and dst == right
-  // cases.
-
   if (dst.is(left)) {
-    addu(overflow_dst, left, right);
-    xor_(dst, overflow_dst, left);
-    xor_(scratch, overflow_dst, right);
-    and_(scratch, scratch, dst);
-    mov(dst, overflow_dst);
-    mov(overflow_dst, scratch);
+    mov(scratch, left);  // Preserve left.
+    addu(dst, left, right);  // Left is overwritten.
+    xor_(scratch, dst, scratch);  // Original left.
+    xor_(overflow_dst, dst, right);
+    and_(overflow_dst, overflow_dst, scratch);
   } else if (dst.is(right)) {
-    addu(overflow_dst, left, right);
-    xor_(dst, overflow_dst, right);
-    xor_(scratch, overflow_dst, left);
-    and_(scratch, scratch, dst);
-    mov(dst, overflow_dst);
-    mov(overflow_dst, scratch);
+    mov(scratch, right);  // Preserve right.
+    addu(dst, left, right);  // Right is overwritten.
+    xor_(scratch, dst, scratch);  // Original right.
+    xor_(overflow_dst, dst, left);
+    and_(overflow_dst, overflow_dst, scratch);
   } else {
     addu(dst, left, right);
     xor_(overflow_dst, dst, left);
     xor_(scratch, dst, right);
     and_(overflow_dst, scratch, overflow_dst);
   }
 }
 
 
 void MacroAssembler::SubuAndCheckForOverflow(Register dst,
                                              Register left,
                                              Register right,
                                              Register overflow_dst,
                                              Register scratch) {
   ASSERT(!dst.is(overflow_dst));
   ASSERT(!dst.is(scratch));
   ASSERT(!overflow_dst.is(scratch));
   ASSERT(!overflow_dst.is(left));
   ASSERT(!overflow_dst.is(right));
   ASSERT(!left.is(right));
   ASSERT(!scratch.is(left));
   ASSERT(!scratch.is(right));
 
-  // TODO(kalmard) There must be a way to optimize dst == left and dst == right
-  // cases.
-
   if (dst.is(left)) {
-    subu(overflow_dst, left, right);
-    xor_(scratch, overflow_dst, left);
-    xor_(dst, left, right);
-    and_(scratch, scratch, dst);
-    mov(dst, overflow_dst);
-    mov(overflow_dst, scratch);
+    mov(scratch, left);  // Preserve left.
+    subu(dst, left, right);  // Left is overwritten.
+    xor_(overflow_dst, dst, scratch);  // scratch is original left.
+    xor_(scratch, scratch, right);  // scratch is original left.
+    and_(overflow_dst, scratch, overflow_dst);
   } else if (dst.is(right)) {
-    subu(overflow_dst, left, right);
-    xor_(dst, left, right);
-    xor_(scratch, overflow_dst, left);
-    and_(scratch, scratch, dst);
-    mov(dst, overflow_dst);
-    mov(overflow_dst, scratch);
+    mov(scratch, right);  // Preserve right.
+    subu(dst, left, right);  // Right is overwritten.
+    xor_(overflow_dst, dst, left);
+    xor_(scratch, left, scratch);  // Original right.
+    and_(overflow_dst, scratch, overflow_dst);
   } else {
     subu(dst, left, right);
     xor_(overflow_dst, dst, left);
     xor_(scratch, left, right);
     and_(overflow_dst, scratch, overflow_dst);
   }
 }
 
 
 void MacroAssembler::CallRuntime(const Runtime::Function* f,
@@ skipping 788 matching lines @@
        opcode == BGTZL);
   opcode = (cond == eq) ? BEQ : BNE;
   instr = (instr & ~kOpcodeMask) | opcode;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS