MIPS: Change CmpWeakValue to a more MIPS like GetWeakValue.

This approach saves one instruction by eliminating the use of Subu as a
pseudo-comparison.

BUG=

Review URL: https://codereview.chromium.org/779793004

Cr-Commit-Position: refs/heads/master@{#25662}

diff --git a/src/ic/mips/handler-compiler-mips.cc b/src/ic/mips/handler-compiler-mips.cc
index 6bfc5d7fbc940e277015a508b8049fc5b9a83450..3167dea9d326a134bf029946d306fbbfdd737f50 100644 (file)
--- a/src/ic/mips/handler-compiler-mips.cc
+++ b/src/ic/mips/handler-compiler-mips.cc
@@ -419,8 +419,8 @@ Register PropertyHandlerCompiler::CheckPrototypes(
       __ lw(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
       if (depth != 1 || check == CHECK_ALL_MAPS) {
         Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
-        __ CmpWeakValue(scratch2, map_reg, cell);
-        __ Branch(miss, ne, scratch2, Operand(zero_reg));
+        __ GetWeakValue(scratch2, cell);
+        __ Branch(miss, ne, scratch2, Operand(map_reg));
       }
 
       // Check access rights to the global object.  This has to happen after
@@ -453,8 +453,8 @@ Register PropertyHandlerCompiler::CheckPrototypes(
     // Check the holder map.
     __ lw(scratch1, FieldMemOperand(reg, HeapObject::kMapOffset));
     Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
-    __ CmpWeakValue(scratch2, scratch1, cell);
-    __ Branch(miss, ne, scratch2, Operand(zero_reg));
+    __ GetWeakValue(scratch2, cell);
+    __ Branch(miss, ne, scratch2, Operand(scratch1));
   }
 
   // Perform security check for access to the global object.

diff --git a/src/ic/mips64/handler-compiler-mips64.cc b/src/ic/mips64/handler-compiler-mips64.cc
index 9d63460154ec76c4c169b37f09b9e506fa75f889..6a35d6c17475ba66d4a0a7579e241f1e220208ee 100644 (file)
--- a/src/ic/mips64/handler-compiler-mips64.cc
+++ b/src/ic/mips64/handler-compiler-mips64.cc
@@ -420,8 +420,8 @@ Register PropertyHandlerCompiler::CheckPrototypes(
       __ ld(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
       if (depth != 1 || check == CHECK_ALL_MAPS) {
         Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
-        __ CmpWeakValue(scratch2, map_reg, cell);
-        __ Branch(miss, ne, scratch2, Operand(zero_reg));
+        __ GetWeakValue(scratch2, cell);
+        __ Branch(miss, ne, scratch2, Operand(map_reg));
       }
 
       // Check access rights to the global object.  This has to happen after
@@ -454,8 +454,8 @@ Register PropertyHandlerCompiler::CheckPrototypes(
     // Check the holder map.
     __ ld(scratch1, FieldMemOperand(reg, HeapObject::kMapOffset));
     Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
-    __ CmpWeakValue(scratch2, scratch1, cell);
-    __ Branch(miss, ne, scratch2, Operand(zero_reg));
+    __ GetWeakValue(scratch2, cell);
+    __ Branch(miss, ne, scratch2, Operand(scratch1));
   }
 
   // Perform security check for access to the global object.

diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 9cd9afa71a9ab86506ae7b78bd50c1f6ef9c59b8..78a583f5b0e1e9d8bad7a9583b82d584d7df55f4 100644 (file)
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -4027,18 +4027,15 @@ void MacroAssembler::CheckMap(Register obj,
 }
 
 
-void MacroAssembler::CmpWeakValue(Register match, Register value,
-                                  Handle<WeakCell> cell) {
-  li(match, Operand(cell));
-  lw(match, FieldMemOperand(match, WeakCell::kValueOffset));
-  Subu(match, value, match);
+void MacroAssembler::GetWeakValue(Register value, Handle<WeakCell> cell) {
+  li(value, Operand(cell));
+  lw(value, FieldMemOperand(value, WeakCell::kValueOffset));
 }
 
 
 void MacroAssembler::LoadWeakValue(Register value, Handle<WeakCell> cell,
                                    Label* miss) {
-  li(value, Operand(cell));
-  lw(value, FieldMemOperand(value, WeakCell::kValueOffset));
+  GetWeakValue(value, cell);
   JumpIfSmi(value, miss);
 }
 

diff --git a/src/mips/macro-assembler-mips.h b/src/mips/macro-assembler-mips.h
index a712dbd1500c8410ecf04b3b66be3b880c30cc33..7a2c209514c90e240ef6a8186c4d7a32e9a57cf3 100644 (file)
--- a/src/mips/macro-assembler-mips.h
+++ b/src/mips/macro-assembler-mips.h
@@ -1089,9 +1089,8 @@ class MacroAssembler: public Assembler {
                    Handle<Code> success,
                    SmiCheckType smi_check_type);
 
-  // Compare the given value and the value of the weak cell. Write the result
-  // to the match register.
-  void CmpWeakValue(Register match, Register value, Handle<WeakCell> cell);
+  // Get value of the weak cell.
+  void GetWeakValue(Register value, Handle<WeakCell> cell);
 
   // Load the value of the weak cell in the value register. Branch to the
   // given miss label is the weak cell was cleared.

diff --git a/src/mips64/macro-assembler-mips64.cc b/src/mips64/macro-assembler-mips64.cc
index c68f3e5a7819f69ab1d8d0d52fce913c45c4900e..f04331d0e2fb88559643ef3baf37f5926c9722a0 100644 (file)
--- a/src/mips64/macro-assembler-mips64.cc
+++ b/src/mips64/macro-assembler-mips64.cc
@@ -3994,18 +3994,15 @@ void MacroAssembler::CheckMap(Register obj,
 }
 
 
-void MacroAssembler::CmpWeakValue(Register match, Register value,
-                                  Handle<WeakCell> cell) {
-  li(match, Operand(cell));
-  ld(match, FieldMemOperand(match, WeakCell::kValueOffset));
-  Dsubu(match, value, match);
+void MacroAssembler::GetWeakValue(Register value, Handle<WeakCell> cell) {
+  li(value, Operand(cell));
+  ld(value, FieldMemOperand(value, WeakCell::kValueOffset));
 }
 
 
 void MacroAssembler::LoadWeakValue(Register value, Handle<WeakCell> cell,
                                    Label* miss) {
-  li(value, Operand(cell));
-  ld(value, FieldMemOperand(value, WeakCell::kValueOffset));
+  GetWeakValue(value, cell);
   JumpIfSmi(value, miss);
 }
 

diff --git a/src/mips64/macro-assembler-mips64.h b/src/mips64/macro-assembler-mips64.h
index b0316d1fb0f1f6bad72eb18590f5c7979c8f51cb..1cc3f9589d61d7590dc893013daba2dd9e59a083 100644 (file)
--- a/src/mips64/macro-assembler-mips64.h
+++ b/src/mips64/macro-assembler-mips64.h
@@ -1119,9 +1119,8 @@ class MacroAssembler: public Assembler {
                    Handle<Code> success,
                    SmiCheckType smi_check_type);
 
-  // Compare the given value and the value of the weak cell. Write the result
-  // to the match register.
-  void CmpWeakValue(Register match, Register value, Handle<WeakCell> cell);
+  // Get value of the weak cell.
+  void GetWeakValue(Register value, Handle<WeakCell> cell);
 
   // Load the value of the weak cell in the value register. Branch to the
   // given miss label is the weak cell was cleared.