Date: Sun, 24 Feb 2019 21:22:17 +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: r344503 - head/contrib/llvm/lib/Target/X86 Message-ID: <201902242122.x1OLMHJu051734@repo.freebsd.org>
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Author: dim Date: Sun Feb 24 21:22:16 2019 New Revision: 344503 URL: https://svnweb.freebsd.org/changeset/base/344503 Log: Pull in r354756 from upstream llvm trunk (by Craig Topper): [X86] Fix tls variable lowering issue with large code model Summary: The problem here is the lowering for tls variable. Below is the DAG for the code. SelectionDAG has 11 nodes: t0: ch = EntryToken t8: i64,ch = load<(load 8 from `i8 addrspace(257)* null`, addrspace 257)> t0, Constant:i64<0>, undef:i64 t10: i64 = X86ISD::WrapperRIP TargetGlobalTLSAddress:i64<i32* @x> 0 [TF=10] t11: i64,ch = load<(load 8 from got)> t0, t10, undef:i64 t12: i64 = add t8, t11 t4: i32,ch = load<(dereferenceable load 4 from @x)> t0, t12, undef:i64 t6: ch = CopyToReg t0, Register:i32 %0, t4 And when mcmodel is large, below instruction can NOT be folded. t10: i64 = X86ISD::WrapperRIP TargetGlobalTLSAddress:i64<i32* @x> 0 [TF=10] t11: i64,ch = load<(load 8 from got)> t0, t10, undef:i64 So "t11: i64,ch = load<(load 8 from got)> t0, t10, undef:i64" is lowered to " Morphed node: t11: i64,ch = MOV64rm<Mem:(load 8 from got)> t10, TargetConstant:i8<1>, Register:i64 $noreg, TargetConstant:i32<0>, Register:i32 $noreg, t0" When llvm start to lower "t10: i64 = X86ISD::WrapperRIP TargetGlobalTLSAddress:i64<i32* @x> 0 [TF=10]", it fails. The patch is to fold the load and X86ISD::WrapperRIP. Fixes PR26906 Patch by LuoYuanke Reviewers: craig.topper, rnk, annita.zhang, wxiao3 Reviewed By: rnk Subscribers: llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D58336 This should fix "fatal error: error in backend: Cannot select" messages when compiling <ctype.h> functions using -mcmodel=large. Reported by: phk PR: 233143 MFC after: 3 days Modified: head/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp Modified: head/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp ============================================================================== --- head/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp Sun Feb 24 21:05:13 2019 (r344502) +++ head/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp Sun Feb 24 21:22:16 2019 (r344503) @@ -989,15 +989,23 @@ bool X86DAGToDAGISel::matchWrapper(SDValue N, X86ISelA if (AM.hasSymbolicDisplacement()) return true; + bool IsRIPRelTLS = false; bool IsRIPRel = N.getOpcode() == X86ISD::WrapperRIP; + if (IsRIPRel) { + SDValue Val = N.getOperand(0); + if (Val.getOpcode() == ISD::TargetGlobalTLSAddress) + IsRIPRelTLS = true; + } - // We can't use an addressing mode in the 64-bit large code model. In the - // medium code model, we use can use an mode when RIP wrappers are present. - // That signifies access to globals that are known to be "near", such as the - // GOT itself. + // We can't use an addressing mode in the 64-bit large code model. + // Global TLS addressing is an exception. In the medium code model, + // we use can use a mode when RIP wrappers are present. + // That signifies access to globals that are known to be "near", + // such as the GOT itself. CodeModel::Model M = TM.getCodeModel(); if (Subtarget->is64Bit() && - (M == CodeModel::Large || (M == CodeModel::Medium && !IsRIPRel))) + ((M == CodeModel::Large && !IsRIPRelTLS) || + (M == CodeModel::Medium && !IsRIPRel))) return true; // Base and index reg must be 0 in order to use %rip as base.
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