[clang] 1ab9327 - [TargetMachine][CodeGenModule] Delete unneeded ppc32 special case from shouldAssumeDSOLocal

[Fangrui Song via cfe-commits]

Author: Fangrui Song
Date: 2020-12-05T00:42:07-08:00
New Revision: 1ab9327d1c01645806394faa648f65e947b65177

URL: https://github.com/llvm/llvm-project/commit/1ab9327d1c01645806394faa648f65e947b65177
DIFF: https://github.com/llvm/llvm-project/commit/1ab9327d1c01645806394faa648f65e947b65177.diff

LOG: [TargetMachine][CodeGenModule] Delete unneeded ppc32 special case from shouldAssumeDSOLocal

PPCMCInstLower does not actually call shouldAssumeDSOLocal for ppc32 so this is dead.
Actually Clang ppc32 does produce a pair of absolute relocations which match GCC.

This also fixes a comment (R_PPC_COPY and R_PPC64_COPY do exist).

Added: 
    

Modified: 
    clang/lib/CodeGen/CodeGenModule.cpp
    llvm/lib/Target/TargetMachine.cpp

Removed: 
    


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diff  --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index ce5fb9434950..0bb9c91f2434 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -967,10 +967,8 @@ static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
   if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
     return false;
 
-  // PPC has no copy relocations and cannot use a plt entry as a symbol address.
-  llvm::Triple::ArchType Arch = TT.getArch();
-  if (Arch == llvm::Triple::ppc || Arch == llvm::Triple::ppc64 ||
-      Arch == llvm::Triple::ppc64le)
+  // PowerPC64 prefers TOC indirection to avoid copy relocations.
+  if (TT.isPPC64())
     return false;
 
   // If we can use copy relocations we can assume it is local.

diff  --git a/llvm/lib/Target/TargetMachine.cpp b/llvm/lib/Target/TargetMachine.cpp
index 30f588193def..e2fd4687d3c8 100644
--- a/llvm/lib/Target/TargetMachine.cpp
+++ b/llvm/lib/Target/TargetMachine.cpp
@@ -186,8 +186,8 @@ bool TargetMachine::shouldAssumeDSOLocal(const Module &M,
       return false;
     Triple::ArchType Arch = TT.getArch();
 
-    // PowerPC prefers avoiding copy relocations.
-    if (Arch == Triple::ppc || TT.isPPC64())
+    // PowerPC64 prefers TOC indirection to avoid copy relocations.
+    if (TT.isPPC64())
       return false;
 
     // dso_local is traditionally implied for Reloc::Static. Eventually we shall