Changeset 166266 in webkit

Timestamp:

Mar 25, 2014 4:28:48 PM (10 years ago)

Author:

fpizlo@apple.com

Message:

Fix 32-bit getter call alignment.

Reviewed by Mark Hahnenberg.

• jit/Repatch.cpp:

(JSC::generateGetByIdStub):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• jit/Repatch.cpp (modified) (4 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2014-03-25  Filip Pizlo  <fpizlo@apple.com>
+
+        Fix 32-bit getter call alignment.
+
+        Reviewed by Mark Hahnenberg.
+
+        * jit/Repatch.cpp:
+        (JSC::generateGetByIdStub):
+
 2014-03-25  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/jit/Repatch.cpp

@@ -341 +341 @@
             //   code.
             //
-            // Therefore, we temporary grow the stack for the purpose of the call and then
-            // degrow it after.
+            // Therefore, we temporarily grow the stack for the purpose of the call and then
+            // shrink it after.
             
             callLinkInfo = std::make_unique<CallLinkInfo>();
@@ -364 +364 @@
                 JSStack::CallFrameHeaderSize + numberOfParameters;
             
-            unsigned alignedNumberOfNeededRegs =
-                WTF::roundUpToMultipleOf(stackAlignmentRegisters(), numberOfRegsForCall);
-            
-            unsigned alignedNumberOfNeededBytes =
-                alignedNumberOfNeededRegs * sizeof(Register);
+            unsigned numberOfBytesForCall =
+                numberOfRegsForCall * sizeof(Register) - sizeof(CallerFrameAndPC);
+            
+            unsigned alignedNumberOfBytesForCall =
+                WTF::roundUpToMultipleOf(stackAlignmentBytes(), numberOfBytesForCall);
             
             stubJit.subPtr(
-                MacroAssembler::TrustedImm32(
-                    alignedNumberOfNeededBytes - sizeof(CallerFrameAndPC)),
+                MacroAssembler::TrustedImm32(alignedNumberOfBytesForCall),
                 MacroAssembler::stackPointerRegister);
             
@@ -405 +404 @@
             
             stubJit.addPtr(
-                MacroAssembler::TrustedImm32(
-                    alignedNumberOfNeededBytes - sizeof(CallerFrameAndPC)),
+                MacroAssembler::TrustedImm32(alignedNumberOfBytesForCall),
                 MacroAssembler::stackPointerRegister);
             
@@ -420 +418 @@
             
             stubJit.addPtr(
-                MacroAssembler::TrustedImm32(
-                    alignedNumberOfNeededBytes - sizeof(CallerFrameAndPC)),
+                MacroAssembler::TrustedImm32(alignedNumberOfBytesForCall),
                 MacroAssembler::stackPointerRegister);