Branch: refs/heads/main Home: https://github.com/WebKit/WebKit Commit: cbff45e59253712319ac26cab74d8c76557d91ca https://github.com/WebKit/WebKit/commit/cbff45e59253712319ac26cab74d8c76557d91ca Author: Joseph Griego <jgri...@igalia.com> Date: 2022-12-22 (Thu, 22 Dec 2022)
Changed paths: M Source/JavaScriptCore/b3/B3StackmapGenerationParams.cpp M Source/JavaScriptCore/b3/air/AirAllocateRegistersAndStackAndGenerateCode.cpp M Source/JavaScriptCore/b3/air/AirCode.cpp M Source/JavaScriptCore/b3/air/AirHandleCalleeSaves.cpp M Source/JavaScriptCore/b3/air/AirLowerAfterRegAlloc.cpp M Source/JavaScriptCore/b3/air/testair.cpp M Source/JavaScriptCore/interpreter/Interpreter.cpp Log Message: ----------- [JSC] B3/Air should use the system register convention https://bugs.webkit.org/show_bug.cgi?id=249776 Reviewed by Yusuke Suzuki. A previous patch (189dce5799e8) changed several of these locations to use the `vmCalleeSaveRegisters` over the `calleeSaveRegisters`--change them back. Though on most platforms with Air support, these two register sets are identical, on ARMv7, which is new to the Air club, fewer registers are included in the VM register calee-save set than in the system's callee-save set, which caused problems with unwinding. This patch also addresses the ARMv7-only issue with unwinding: if an Air callee in a VM stack being unwound saves registers other than VM callee-saves, they simply won't be restored--this is OK for the time being as VM callers will only expect the VM callee-saves to be preserved. Eventually we may want to enable code generation on ARMv7 to select the VM convention over the system one to avoid unnecessary save/restores in ARM-generated code. (The alternative, making vmCalleeSaveRegisters use all of the available platform callee-saves, isn't appealing, as we want more temporary registers available to the assembler and lower tiers) Note that the usage in `B3StackGenerationParams.cpp` was actually more-or-less original to that file. Still, it seems correct to use `calleeSaveRegisters` there. (And again, on platforms other than ARMv7, the change is a no-op; the sets are identical) * Source/JavaScriptCore/b3/B3StackmapGenerationParams.cpp: (JSC::B3::StackmapGenerationParams::unavailableRegisters const): * Source/JavaScriptCore/b3/air/AirAllocateRegistersAndStackAndGenerateCode.cpp: (JSC::B3::Air::GenerateAndAllocateRegisters::prepareForGeneration): * Source/JavaScriptCore/b3/air/AirCode.cpp: (JSC::B3::Air::Code::Code): * Source/JavaScriptCore/b3/air/AirHandleCalleeSaves.cpp: (JSC::B3::Air::handleCalleeSaves): * Source/JavaScriptCore/b3/air/AirLowerAfterRegAlloc.cpp: (JSC::B3::Air::lowerAfterRegAlloc): * Source/JavaScriptCore/b3/air/testair.cpp: * Source/JavaScriptCore/interpreter/Interpreter.cpp: (JSC::UnwindFunctor::copyCalleeSavesToEntryFrameCalleeSavesBuffer const): Canonical link: https://commits.webkit.org/258261@main _______________________________________________ webkit-changes mailing list webkit-changes@lists.webkit.org https://lists.webkit.org/mailman/listinfo/webkit-changes