[llvm] r293180 - Use shouldAssumeDSOLocal in classifyGlobalReference.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Thu Jan 26 09:02:31 2017
New Revision: 293180

URL: http://llvm.org/viewvc/llvm-project?rev=293180&view=rev
Log:
Use shouldAssumeDSOLocal in classifyGlobalReference.

And teach shouldAssumeDSOLocal that ppc has no copy relocations.

The resulting code handle a few more case than before. For example, it
knows that a weak symbol can be resolved to another .o file, but it
will still be in the main executable.

Modified:
    llvm/trunk/lib/Target/PowerPC/PPCSubtarget.cpp
    llvm/trunk/lib/Target/TargetMachine.cpp
    llvm/trunk/test/CodeGen/PowerPC/fast-isel-load-store.ll
    llvm/trunk/test/CodeGen/PowerPC/mcm-obj.ll

Modified: llvm/trunk/lib/Target/PowerPC/PPCSubtarget.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCSubtarget.cpp?rev=293180&r1=293179&r2=293180&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCSubtarget.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCSubtarget.cpp Thu Jan 26 09:02:31 2017
@@ -220,8 +220,8 @@ bool PPCSubtarget::enableSubRegLiveness(
   return UseSubRegLiveness;
 }
 
-unsigned char PPCSubtarget::classifyGlobalReference(
-    const GlobalValue *GV) const {
+unsigned char
+PPCSubtarget::classifyGlobalReference(const GlobalValue *GV) const {
   // Note that currently we don't generate non-pic references.
   // If a caller wants that, this will have to be updated.
 
@@ -229,23 +229,9 @@ unsigned char PPCSubtarget::classifyGlob
   if (TM.getCodeModel() == CodeModel::Large)
     return PPCII::MO_PIC_FLAG | PPCII::MO_NLP_FLAG;
 
-  unsigned char flags = PPCII::MO_PIC_FLAG;
-
-  // Only if the relocation mode is PIC do we have to worry about
-  // interposition. In all other cases we can use a slightly looser standard to
-  // decide how to access the symbol.
-  if (TM.getRelocationModel() == Reloc::PIC_) {
-    // If it's local, or it's non-default, it can't be interposed.
-    if (!GV->hasLocalLinkage() &&
-        GV->hasDefaultVisibility()) {
-      flags |= PPCII::MO_NLP_FLAG;
-    }
-    return flags;
-  }
-
-  if (GV->isStrongDefinitionForLinker())
-    return flags;
-  return flags | PPCII::MO_NLP_FLAG;
+  if (TM.shouldAssumeDSOLocal(*GV->getParent(), GV))
+    return PPCII::MO_PIC_FLAG;
+  return PPCII::MO_PIC_FLAG | PPCII::MO_NLP_FLAG;
 }
 
 bool PPCSubtarget::isELFv2ABI() const { return TM.isELFv2ABI(); }

Modified: llvm/trunk/lib/Target/TargetMachine.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/TargetMachine.cpp?rev=293180&r1=293179&r2=293180&view=diff
==============================================================================
--- llvm/trunk/lib/Target/TargetMachine.cpp (original)
+++ llvm/trunk/lib/Target/TargetMachine.cpp Thu Jan 26 09:02:31 2017
@@ -163,8 +163,11 @@ bool TargetMachine::shouldAssumeDSOLocal
     bool IsTLS = GV && GV->isThreadLocal();
     bool IsAccessViaCopyRelocs =
         Options.MCOptions.MCPIECopyRelocations && GV && isa<GlobalVariable>(GV);
-    // Check if we can use copy relocations.
-    if (!IsTLS && (RM == Reloc::Static || IsAccessViaCopyRelocs))
+    Triple::ArchType Arch = TT.getArch();
+    bool IsPPC =
+        Arch == Triple::ppc || Arch == Triple::ppc64 || Arch == Triple::ppc64le;
+    // Check if we can use copy relocations. PowerPC has no copy relocations.
+    if (!IsTLS && !IsPPC && (RM == Reloc::Static || IsAccessViaCopyRelocs))
       return true;
   }
 

Modified: llvm/trunk/test/CodeGen/PowerPC/fast-isel-load-store.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/fast-isel-load-store.ll?rev=293180&r1=293179&r2=293180&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/fast-isel-load-store.ll (original)
+++ llvm/trunk/test/CodeGen/PowerPC/fast-isel-load-store.ll Thu Jan 26 09:02:31 2017
@@ -196,7 +196,7 @@ define void @t17(i64 %v) nounwind {
   %1 = add nsw i64 %v, 1
   store i64 %1, i64* getelementptr inbounds ([8192 x i64], [8192 x i64]* @i, i32 0, i64 5000), align 8
 ; ELF64: addis
-; ELF64: ld
+; ELF64: addi
 ; ELF64: addi
 ; ELF64: lis
 ; ELF64: ori

Modified: llvm/trunk/test/CodeGen/PowerPC/mcm-obj.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/mcm-obj.ll?rev=293180&r1=293179&r2=293180&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/mcm-obj.ll (original)
+++ llvm/trunk/test/CodeGen/PowerPC/mcm-obj.ll Thu Jan 26 09:02:31 2017
@@ -108,11 +108,10 @@ entry:
   ret i32 %0
 }
 
-; Verify generation of R_PPC64_TOC16_HA and R_PPC64_TOC16_LO_DS for
-; accessing tentatively declared variable ti.
+; Verify generation of relocations foraccessing variable ti.
 ;
 ; MEDIUM-NEXT:     0x{{[0-9,A-F]+}} R_PPC64_TOC16_HA [[SYM6:[^ ]+]]
-; MEDIUM-NEXT:     0x{{[0-9,A-F]+}} R_PPC64_TOC16_LO_DS [[SYM6]]
+; MEDIUM-NEXT:     0x{{[0-9,A-F]+}} R_PPC64_TOC16_LO [[SYM6]]
 ;
 ; LARGE-NEXT:      0x{{[0-9,A-F]+}} R_PPC64_TOC16_HA [[SYM6:[^ ]+]]
 ; LARGE-NEXT:      0x{{[0-9,A-F]+}} R_PPC64_TOC16_LO_DS [[SYM6]]