Changeset 44356 in webkit for trunk/JavaScriptCore/jit/JITArithmetic.cpp

Timestamp:

Jun 2, 2009, 2:34:28 AM (16 years ago)

Author:

[email protected]

Message:

2009-06-02 Gavin Barraclough <​[email protected]>

Reviewed by Oliver ">>" Hunt.

emitSlow_op_rshift is linking the wrong number of slow cases, if !supportsFloatingPoint().
Fixerate, and refactor/comment the code a little to make it clearer what is going on.

• jit/JITArithmetic.cpp: (JSC::JIT::emit_op_rshift): (JSC::JIT::emitSlow_op_rshift):

File:

• trunk/JavaScriptCore/jit/JITArithmetic.cpp (modified) (4 diffs)

trunk/JavaScriptCore/jit/JITArithmetic.cpp

@@ -106 +106 @@
 
     if (isOperandConstantImmediateInt(op2)) {
+        // isOperandConstantImmediateInt(op2) => 1 SlowCase
         emitGetVirtualRegister(op1, regT0);
         emitJumpSlowCaseIfNotImmediateInteger(regT0);
@@ -119 +120 @@
             Jump lhsIsInt = emitJumpIfImmediateInteger(regT0);
 #if USE(ALTERNATE_JSIMMEDIATE)
+            // supportsFloatingPoint() && USE(ALTERNATE_JSIMMEDIATE) => 3 SlowCases
             addSlowCase(emitJumpIfNotImmediateNumber(regT0));
             movePtrToDouble(regT0, fpRegT0);
-#else
+            addSlowCase(branchTruncateDoubleToInt32(fpRegT0, regT0));
+#else
+            // supportsFloatingPoint() && !USE(ALTERNATE_JSIMMEDIATE) => 5 SlowCases (of which 1 IfNotJSCell)
             emitJumpSlowCaseIfNotJSCell(regT0, op1);
             addSlowCase(checkStructure(regT0, m_globalData->numberStructure.get()));
             loadDouble(Address(regT0, FIELD_OFFSET(JSNumberCell, m_value)), fpRegT0);
-#endif
             addSlowCase(branchTruncateDoubleToInt32(fpRegT0, regT0));
-#if !USE(ALTERNATE_JSIMMEDIATE)
             addSlowCase(branchAdd32(Overflow, regT0, regT0));
 #endif
             lhsIsInt.link(this);
-        } else
+            emitJumpSlowCaseIfNotImmediateInteger(regT2);
+        } else {
+            // !supportsFloatingPoint() => 2 SlowCases
             emitJumpSlowCaseIfNotImmediateInteger(regT0);
-        emitJumpSlowCaseIfNotImmediateInteger(regT2);
+            emitJumpSlowCaseIfNotImmediateInteger(regT2);
+        }
         emitFastArithImmToInt(regT2);
 #if !PLATFORM(X86)
@@ -160 +165 @@
     unsigned op2 = currentInstruction[3].u.operand;
 
-    linkSlowCase(iter);
     JITStubCall stubCall(this, JITStubs::cti_op_rshift);
 
     if (isOperandConstantImmediateInt(op2)) {
+        linkSlowCase(iter);
         stubCall.addArgument(regT0);
         stubCall.addArgument(op2, regT2);
@@ -170 +175 @@
 #if USE(ALTERNATE_JSIMMEDIATE)
             linkSlowCase(iter);
+            linkSlowCase(iter);
+            linkSlowCase(iter);
 #else
             linkSlowCaseIfNotJSCell(iter, op1);
             linkSlowCase(iter);
             linkSlowCase(iter);
-#endif
             linkSlowCase(iter);
+            linkSlowCase(iter);
+#endif
             // We're reloading op1 to regT0 as we can no longer guarantee that
             // we have not munged the operand.  It may have already been shifted