Modified: trunk/Source/WebCore/ChangeLog (235828 => 235829)
--- trunk/Source/WebCore/ChangeLog 2018-09-08 17:59:43 UTC (rev 235828)
+++ trunk/Source/WebCore/ChangeLog 2018-09-08 19:25:10 UTC (rev 235829)
@@ -1,3 +1,18 @@
+2018-09-08 Yusuke Suzuki <[email protected]>
+
+ [CSSJIT] Use lshiftPtr instead of mul32
+ https://bugs.webkit.org/show_bug.cgi?id=189451
+
+ Reviewed by Sam Weinig.
+
+ Use `value << 4` instead of `value * 16`. In 64bit environment, sizeof(Style::Relation) is 16,
+ so that we can use `value << 4` in CSS JIT.
+
+ No behavior change.
+
+ * cssjit/SelectorCompiler.cpp:
+ (WebCore::SelectorCompiler::SelectorCodeGenerator::generateAddStyleRelation):
+
2018-09-07 Fujii Hironori <[email protected]>
[Win][Clang] exceptionShouldTerminateProgram of StructuredExceptionHandlerSuppressor.cpp should take DWORD
Modified: trunk/Source/WebCore/cssjit/SelectorCompiler.cpp (235828 => 235829)
--- trunk/Source/WebCore/cssjit/SelectorCompiler.cpp 2018-09-08 17:59:43 UTC (rev 235828)
+++ trunk/Source/WebCore/cssjit/SelectorCompiler.cpp 2018-09-08 19:25:10 UTC (rev 235829)
@@ -2211,6 +2211,18 @@
auto dataAddress = vectorAddress.withOffset(Style::Relations::dataMemoryOffset());
auto sizeAddress = vectorAddress.withOffset(Style::Relations::sizeMemoryOffset());
+ auto getLastRelationPointer = [&] (Assembler::RegisterID sizeAndTarget) {
+ m_assembler.sub32(Assembler::TrustedImm32(1), sizeAndTarget);
+#if CPU(ADDRESS64)
+ static_assert(sizeof(Style::Relation) == 16, "");
+ static_assert(1 << 4 == 16, "");
+ m_assembler.lshiftPtr(Assembler::TrustedImm32(4), sizeAndTarget);
+#else
+ m_assembler.mul32(TrustedImm32(sizeof(Style::Relation)), sizeAndTarget, sizeAndTarget);
+#endif
+ m_assembler.addPtr(dataAddress, sizeAndTarget);
+ };
+
// For AffectsNextSibling we just increment the count if the previous added relation was in the same sibling chain.
Assembler::JumpList mergeSuccess;
if (relationType == Style::Relation::AffectsNextSibling) {
@@ -2223,9 +2235,7 @@
mergeFailure.append(m_assembler.branchTest32(Assembler::Zero, lastRelation));
// Style::Relation& lastRelation = checkingContext.styleRelations.last();
- m_assembler.sub32(Assembler::TrustedImm32(1), lastRelation);
- m_assembler.mul32(Assembler::TrustedImm32(sizeof(Style::Relation)), lastRelation, lastRelation);
- m_assembler.addPtr(dataAddress, lastRelation);
+ getLastRelationPointer(lastRelation);
// if (lastRelation.type == Style::Relation::AffectsNextSibling)
Assembler::Address typeAddress(lastRelation, OBJECT_OFFSETOF(Style::Relation, type));
@@ -2259,9 +2269,7 @@
LocalRegister relationPointer(m_registerAllocator);
m_assembler.load32(sizeAddress, relationPointer);
- m_assembler.sub32(Assembler::TrustedImm32(1), relationPointer);
- m_assembler.mul32(Assembler::TrustedImm32(sizeof(Style::Relation)), relationPointer, relationPointer);
- m_assembler.addPtr(dataAddress, relationPointer);
+ getLastRelationPointer(relationPointer);
Assembler::Address typeAddress(relationPointer, OBJECT_OFFSETOF(Style::Relation, type));
m_assembler.store32(Assembler::TrustedImm32(relationType), typeAddress);
