Changeset 251951 in webkit

Timestamp:

Nov 1, 2019 4:07:34 PM (4 years ago)

Author:

sbarati@apple.com

Message:

Refactor uses of StructureStubInfo 'thisGPR' to a union for thisGPR and prototypeGPR
​https://bugs.webkit.org/show_bug.cgi?id=203693

Reviewed by Mark Lam and Yusuke Suzuki.

I'm going to be adding a third overload for this field when making
GetByVal inline caching part of StructureStubInfo. It's nicer for
each use case of this field to use it by the proper name.

• bytecode/AccessCase.cpp:

(JSC::AccessCase::generateWithGuard):
(JSC::AccessCase::generateImpl):

• bytecode/PolymorphicAccess.cpp:

(JSC::PolymorphicAccess::regenerate):

• bytecode/PolymorphicAccess.h:

(JSC::AccessGenerationState::AccessGenerationState):

• bytecode/StructureStubInfo.h:
• jit/JITInlineCacheGenerator.cpp:

(JSC::JITByIdGenerator::JITByIdGenerator):
(JSC::JITGetByIdWithThisGenerator::JITGetByIdWithThisGenerator):
(JSC::JITInstanceOfGenerator::JITInstanceOfGenerator):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• bytecode/AccessCase.cpp (modified) (6 diffs)
• bytecode/PolymorphicAccess.cpp (modified) (2 diffs)
• bytecode/PolymorphicAccess.h (modified) (2 diffs)
• bytecode/StructureStubInfo.h (modified) (1 diff)
• jit/JITInlineCacheGenerator.cpp (modified) (3 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2019-11-01  Saam Barati  <sbarati@apple.com>
+
+        Refactor uses of StructureStubInfo 'thisGPR' to a union for thisGPR and prototypeGPR
+        https://bugs.webkit.org/show_bug.cgi?id=203693
+
+        Reviewed by Mark Lam and Yusuke Suzuki.
+
+        I'm going to be adding a third overload for this field when making
+        GetByVal inline caching part of StructureStubInfo. It's nicer for
+        each use case of this field to use it by the proper name.
+
+        * bytecode/AccessCase.cpp:
+        (JSC::AccessCase::generateWithGuard):
+        (JSC::AccessCase::generateImpl):
+        * bytecode/PolymorphicAccess.cpp:
+        (JSC::PolymorphicAccess::regenerate):
+        * bytecode/PolymorphicAccess.h:
+        (JSC::AccessGenerationState::AccessGenerationState):
+        * bytecode/StructureStubInfo.h:
+        * jit/JITInlineCacheGenerator.cpp:
+        (JSC::JITByIdGenerator::JITByIdGenerator):
+        (JSC::JITGetByIdWithThisGenerator::JITGetByIdWithThisGenerator):
+        (JSC::JITInstanceOfGenerator::JITInstanceOfGenerator):
+
 2019-11-01  Alexey Shvayka  <shvaikalesh@gmail.com>
 

trunk/Source/JavaScriptCore/bytecode/AccessCase.cpp

@@ -466 +466 @@
     JSValueRegs valueRegs = state.valueRegs;
     GPRReg baseGPR = state.baseGPR;
-    GPRReg thisGPR = state.thisGPR != InvalidGPRReg ? state.thisGPR : baseGPR;
     GPRReg scratchGPR = state.scratchGPR;
 
@@ -604 +603 @@
         fallThrough.append(
             jit.branchPtr(
-                CCallHelpers::NotEqual, thisGPR,
+                CCallHelpers::NotEqual, state.u.prototypeGPR,
                 CCallHelpers::TrustedImmPtr(as<InstanceOfAccessCase>().prototype())));
         break;
         
     case InstanceOfGeneric: {
-        // Legend: value = `base instanceof this`.
+        GPRReg prototypeGPR = state.u.prototypeGPR;
+        // Legend: value = `base instanceof prototypeGPR`.
         
         GPRReg valueGPR = valueRegs.payloadGPR();
@@ -616 +616 @@
         allocator.lock(baseGPR);
         allocator.lock(valueGPR);
-        allocator.lock(thisGPR);
+        allocator.lock(prototypeGPR);
         allocator.lock(scratchGPR);
         
@@ -622 +622 @@
         
         if (!state.stubInfo->prototypeIsKnownObject)
-            state.failAndIgnore.append(jit.branchIfNotObject(thisGPR));
+            state.failAndIgnore.append(jit.branchIfNotObject(prototypeGPR));
         
         ScratchRegisterAllocator::PreservedState preservedState =
@@ -660 +660 @@
         jit.move(scratch2GPR, valueGPR);
         
-        CCallHelpers::Jump isInstance = jit.branchPtr(CCallHelpers::Equal, valueGPR, thisGPR);
+        CCallHelpers::Jump isInstance = jit.branchPtr(CCallHelpers::Equal, valueGPR, prototypeGPR);
 
 #if USE(JSVALUE64)
@@ -717 +717 @@
     JSValueRegs valueRegs = state.valueRegs;
     GPRReg baseGPR = state.baseGPR;
-    GPRReg thisGPR = state.thisGPR != InvalidGPRReg ? state.thisGPR : baseGPR;
+    GPRReg thisGPR = state.u.thisGPR != InvalidGPRReg ? state.u.thisGPR : baseGPR;
     GPRReg scratchGPR = state.scratchGPR;
 

trunk/Source/JavaScriptCore/bytecode/PolymorphicAccess.cpp

@@ -396 +396 @@
     
     state.baseGPR = stubInfo.baseGPR();
-    state.thisGPR = stubInfo.patch.thisGPR;
+    state.u.thisGPR = stubInfo.patch.u.thisGPR;
     state.valueRegs = stubInfo.valueRegs();
 
@@ -402 +402 @@
     state.allocator = &allocator;
     allocator.lock(state.baseGPR);
-    if (state.thisGPR != InvalidGPRReg)
-        allocator.lock(state.thisGPR);
+    if (state.u.thisGPR != InvalidGPRReg)
+        allocator.lock(state.u.thisGPR);
     allocator.lock(state.valueRegs);
 #if USE(JSVALUE32_64)

trunk/Source/JavaScriptCore/bytecode/PolymorphicAccess.h

@@ -194 +194 @@
         , m_calculatedCallSiteIndex(false)
     {
+        u.thisGPR = InvalidGPRReg;
     }
     VM& m_vm;
@@ -206 +207 @@
     MacroAssembler::JumpList failAndIgnore;
     GPRReg baseGPR { InvalidGPRReg };
-    GPRReg thisGPR { InvalidGPRReg };
+    union {
+        GPRReg thisGPR;
+        GPRReg prototypeGPR;
+    } u;
     JSValueRegs valueRegs;
     GPRReg scratchGPR { InvalidGPRReg };

trunk/Source/JavaScriptCore/bytecode/StructureStubInfo.h

@@ -202 +202 @@
         GPRReg baseGPR;
         GPRReg valueGPR;
-        GPRReg thisGPR;
+        union {
+            GPRReg thisGPR;
+            GPRReg prototypeGPR;
+        } u;
 #if USE(JSVALUE32_64)
         GPRReg valueTagGPR;

trunk/Source/JavaScriptCore/jit/JITInlineCacheGenerator.cpp

@@ -75 +75 @@
     m_stubInfo->patch.baseGPR = base.payloadGPR();
     m_stubInfo->patch.valueGPR = value.payloadGPR();
-    m_stubInfo->patch.thisGPR = InvalidGPRReg;
+    m_stubInfo->patch.u.thisGPR = InvalidGPRReg;
 #if USE(JSVALUE32_64)
     m_stubInfo->patch.baseTagGPR = base.tagGPR();
@@ -123 +123 @@
     RELEASE_ASSERT(thisRegs.payloadGPR() != thisRegs.tagGPR());
 
-    m_stubInfo->patch.thisGPR = thisRegs.payloadGPR();
+    m_stubInfo->patch.u.thisGPR = thisRegs.payloadGPR();
 #if USE(JSVALUE32_64)
     m_stubInfo->patch.thisTagGPR = thisRegs.tagGPR();
@@ -187 +187 @@
     m_stubInfo->patch.baseGPR = value;
     m_stubInfo->patch.valueGPR = result;
-    m_stubInfo->patch.thisGPR = prototype;
+    m_stubInfo->patch.u.prototypeGPR = prototype;
 #if USE(JSVALUE32_64)
     m_stubInfo->patch.baseTagGPR = InvalidGPRReg;