Changeset 154158 in webkit for trunk/Source/JavaScriptCore/assembler/X86Assembler.h

Timestamp:

Aug 15, 2013, 7:35:31 PM (12 years ago)

Author:

[email protected]

Message:

[JSC] x86: Use inc and dec when possible
​https://bugs.webkit.org/show_bug.cgi?id=119831

Reviewed by Geoffrey Garen.

When incrementing or decrementing by an immediate of 1, use the insctructions
inc and dec instead of add and sub.
The instructions have good timing and their encoding is smaller.

• assembler/MacroAssemblerX86Common.h:

(JSC::MacroAssemblerX86_64::add32):
(JSC::MacroAssemblerX86_64::sub32):

• assembler/MacroAssemblerX86_64.h:

(JSC::MacroAssemblerX86_64::add64):
(JSC::MacroAssemblerX86_64::sub64):

• assembler/X86Assembler.h:

(JSC::X86Assembler::dec_r):
(JSC::X86Assembler::decq_r):
(JSC::X86Assembler::inc_r):
(JSC::X86Assembler::incq_r):

File:

• trunk/Source/JavaScriptCore/assembler/X86Assembler.h (modified) (1 diff)

trunk/Source/JavaScriptCore/assembler/X86Assembler.h

@@ -501 +501 @@
 #endif
 
+    void dec_r(RegisterID dst)
+    {
+        m_formatter.oneByteOp(OP_GROUP5_Ev, GROUP1_OP_OR, dst);
+    }
+
+    void decq_r(RegisterID dst)
+    {
+        m_formatter.oneByteOp64(OP_GROUP5_Ev, GROUP1_OP_OR, dst);
+    }
+
+    void inc_r(RegisterID dst)
+    {
+        m_formatter.oneByteOp(OP_GROUP5_Ev, GROUP1_OP_ADD, dst);
+    }
+
+    void incq_r(RegisterID dst)
+    {
+        m_formatter.oneByteOp64(OP_GROUP5_Ev, GROUP1_OP_ADD, dst);
+    }
+
     void negl_r(RegisterID dst)
     {