Date: Fri, 15 Feb 2013 23:12:58 +0000 (UTC) From: Dimitry Andric <dim@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r246858 - head/contrib/llvm/lib/Target/X86 Message-ID: <201302152312.r1FNCw4D038809@svn.freebsd.org>
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Author: dim Date: Fri Feb 15 23:12:58 2013 New Revision: 246858 URL: http://svnweb.freebsd.org/changeset/base/246858 Log: Pull in r175057 from upstream llvm trunk: X86: Disable generation of rep;movsl when %esi is used as a base pointer. This happens when there is both stack realignment and a dynamic alloca in the function. If we overwrite %esi (rep;movsl uses fixed registers) we'll lose the base pointer and the next register spill will write into oblivion. Fixes PR15249 and unbreaks firefox on i386/freebsd. Mozilla uses dynamic allocas and freebsd a 4 byte stack alignment. MFC after: 1 week Modified: head/contrib/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp Modified: head/contrib/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp ============================================================================== --- head/contrib/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp Fri Feb 15 23:12:35 2013 (r246857) +++ head/contrib/llvm/lib/Target/X86/X86SelectionDAGInfo.cpp Fri Feb 15 23:12:58 2013 (r246858) @@ -202,6 +202,14 @@ X86SelectionDAGInfo::EmitTargetCodeForMe SrcPtrInfo.getAddrSpace() >= 256) return SDValue(); + // ESI might be used as a base pointer, in that case we can't simply overwrite + // the register. Fall back to generic code. + const X86RegisterInfo *TRI = + static_cast<const X86RegisterInfo *>(DAG.getTarget().getRegisterInfo()); + if (TRI->hasBasePointer(DAG.getMachineFunction()) && + TRI->getBaseRegister() == X86::ESI) + return SDValue(); + MVT AVT; if (Align & 1) AVT = MVT::i8;
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