svn commit: r344639 - in stable: 11/contrib/llvm/lib/Target/X86 12/contrib/llvm/lib/Target/X86

[Dimitry Andric]

Author: dim
Date: Wed Feb 27 22:02:46 2019
New Revision: 344639
URL: https://svnweb.freebsd.org/changeset/base/344639

Log:
  MFC r344503:
  
  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

Modified:
  stable/11/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
Directory Properties:
  stable/11/   (props changed)

Changes in other areas also in this revision:
Modified:
  stable/12/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
Directory Properties:
  stable/12/   (props changed)

Modified: stable/11/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
==============================================================================
--- stable/11/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp	Wed Feb 27 22:01:39 2019	(r344638)
+++ stable/11/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp	Wed Feb 27 22:02:46 2019	(r344639)
@@ -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.