Changeset 38928 in webkit for trunk/JavaScriptCore/jit/JIT.cpp

Timestamp:

Dec 2, 2008, 6:10:54 PM (16 years ago)

Author:

[email protected]

Message:

2008-12-02 Gavin Barraclough <​[email protected]>

Reviewed by Geoffrey Garen.

Plant shift right immediate instructions, which are awesome.
​https://bugs.webkit.org/show_bug.cgi?id=22610
~5% on the v8-crypto test.

• jit/JIT.cpp: (JSC::JIT::privateCompileMainPass): (JSC::JIT::privateCompileSlowCases):

File:

• trunk/JavaScriptCore/jit/JIT.cpp (modified) (2 diffs)

trunk/JavaScriptCore/jit/JIT.cpp

@@ -1813 +1813 @@
         }
         case op_rshift: {
-            emitGetVirtualRegisters(instruction[i + 2].u.operand, X86::eax, instruction[i + 3].u.operand, X86::ecx, i);
-            emitJumpSlowCaseIfNotImmNum(X86::eax, i);
-            emitJumpSlowCaseIfNotImmNum(X86::ecx, i);
-            emitFastArithImmToInt(X86::ecx);
-            __ sarl_CLr(X86::eax);
+            unsigned src1 = instruction[i + 2].u.operand;
+            unsigned src2 = instruction[i + 3].u.operand;
+            if (JSValue* value = getConstantImmediateNumericArg(src2)) {
+                emitGetVirtualRegister(src1, X86::eax, i);
+                emitJumpSlowCaseIfNotImmNum(X86::eax, i);
+                // Mask with 0x1f as per ecma-262 11.7.2 step 7.
+                __ sarl_i8r(JSImmediate::getTruncatedUInt32(value) & 0x1f, X86::eax);
+            } else {
+                emitGetVirtualRegisters(src1, X86::eax, src2, X86::ecx, i);
+                emitJumpSlowCaseIfNotImmNum(X86::eax, i);
+                emitJumpSlowCaseIfNotImmNum(X86::ecx, i);
+                emitFastArithImmToInt(X86::ecx);
+                __ sarl_CLr(X86::eax);
+            }
             emitFastArithPotentiallyReTagImmediate(X86::eax);
             emitPutVirtualRegister(instruction[i + 1].u.operand);
@@ -2415 +2424 @@
         }
         case op_rshift: {
+            unsigned src2 = instruction[i + 3].u.operand;
             __ link(iter->from, __ label());
-            __ link((++iter)->from, __ label());
+            if (getConstantImmediateNumericArg(src2))
+                emitPutCTIArgFromVirtualRegister(src2, 4, X86::ecx);
+            else {
+                __ link((++iter)->from, __ label());
+                emitPutCTIArg(X86::ecx, 4);
+            }
+
             emitPutCTIArg(X86::eax, 0);
-            emitPutCTIArg(X86::ecx, 4);
             emitCTICall(i, Interpreter::cti_op_rshift);
             emitPutVirtualRegister(instruction[i + 1].u.operand);