Changeset 196045 in webkit

Timestamp:

Feb 2, 2016 9:03:38 PM (8 years ago)

Author:

benjamin@webkit.org

Message:

[JSC] Do not copy FP when lowering FramePointer
​https://bugs.webkit.org/show_bug.cgi?id=153769

Reviewed by Michael Saboff.

That extra move is just wasted time. The fewer Moves we have,
the happier IRC is.

• b3/B3LowerToAir.cpp:

(JSC::B3::Air::LowerToAir::tmp):
(JSC::B3::Air::LowerToAir::lower):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• b3/B3LowerToAir.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2016-02-02  Benjamin Poulain  <benjamin@webkit.org>
+
+        [JSC] Do not copy FP when lowering FramePointer
+        https://bugs.webkit.org/show_bug.cgi?id=153769
+
+        Reviewed by Michael Saboff.
+
+        That extra move is just wasted time. The fewer Moves we have,
+        the happier IRC is.
+
+        * b3/B3LowerToAir.cpp:
+        (JSC::B3::Air::LowerToAir::tmp):
+        (JSC::B3::Air::LowerToAir::lower):
+
 2016-02-02  Keith Miller  <keith_miller@apple.com>
 

trunk/Source/JavaScriptCore/b3/B3LowerToAir.cpp

@@ -309 +309 @@
             while (shouldCopyPropagate(value))
                 value = value->child(0);
+
+            if (value->opcode() == FramePointer)
+                return Tmp(GPRInfo::callFrameRegister);
+
             Tmp& realTmp = m_valueToTmp[value];
             if (!realTmp) {
@@ -1946 +1950 @@
 
         case FramePointer: {
-            append(Move, Tmp(GPRInfo::callFrameRegister), tmp(m_value));
+            ASSERT(tmp(m_value) == Tmp(GPRInfo::callFrameRegister));
             return;
         }