Produce a relocation for pcrel absolute values. Based on a patch by David Meyer.

llvm-svn: 120006

2 files changed, 28 insertions, 8 deletions

diff --git a/llvm/lib/Target/X86/X86MCCodeEmitter.cpp b/llvm/lib/Target/X86/X86MCCodeEmitter.cpp
index fea37f85a74..586216d774b 100644
--- a/llvm/lib/Target/X86/X86MCCodeEmitter.cpp
+++ b/llvm/lib/Target/X86/X86MCCodeEmitter.cpp
@@ -218,18 +218,22 @@ void X86MCCodeEmitter::
 EmitImmediate(const MCOperand &DispOp, unsigned Size, MCFixupKind FixupKind,
               unsigned &CurByte, raw_ostream &OS,
               SmallVectorImpl<MCFixup> &Fixups, int ImmOffset) const {
-  // If this is a simple integer displacement that doesn't require a relocation,
-  // emit it now.
+  const MCExpr *Expr = NULL;
   if (DispOp.isImm()) {
-    // FIXME: is this right for pc-rel encoding??  Probably need to emit this as
-    // a fixup if so.
-    EmitConstant(DispOp.getImm()+ImmOffset, Size, CurByte, OS);
-    return;
+    // If this is a simple integer displacement that doesn't require a relocation,
+    // emit it now.
+    if (FixupKind != MCFixupKind(X86::reloc_pcrel_1byte) &&
+	FixupKind != MCFixupKind(X86::reloc_pcrel_2byte) &&
+	FixupKind != MCFixupKind(X86::reloc_pcrel_4byte)) {
+      EmitConstant(DispOp.getImm()+ImmOffset, Size, CurByte, OS);
+      return;
+    }
+    Expr = MCConstantExpr::Create(DispOp.getImm(), Ctx);
+  } else {
+    Expr = DispOp.getExpr();
   }
 
   // If we have an immoffset, add it to the expression.
-  const MCExpr *Expr = DispOp.getExpr();
-
   if (FixupKind == FK_Data_4 && StartsWithGlobalOffsetTable(Expr)) {
     assert(ImmOffset == 0);
 
diff --git a/llvm/test/MC/ELF/call-abs.ll b/llvm/test/MC/ELF/call-abs.ll
new file mode 100644
index 00000000000..6ebd17f30cf
--- /dev/null
+++ b/llvm/test/MC/ELF/call-abs.ll
@@ -0,0 +1,16 @@
+; RUN: llc -filetype=obj -mtriple i686-pc-linux-gnu %s -o - | elf-dump | FileCheck %s
+
+define i32 @f() nounwind optsize ssp {
+entry:
+  %call = tail call i32 inttoptr (i64 42 to i32 ()*)() nounwind optsize
+  %add = add nsw i32 %call, 1
+  ret i32 %add
+}
+
+; CHECK:      ('_relocations', [
+; CHECK-NEXT:  # Relocation 0x00000000
+; CHECK-NEXT:  (('r_offset', 0x00000004)
+; CHECK-NEXT:   ('r_sym', 0x00000000)
+; CHECK-NEXT:   ('r_type', 0x00000002)
+; CHECK-NEXT:  ),
+; CHECK-NEXT: ])