From: Nirav Dave <niravd@google.com>
Date: Mon, 4 Mar 2019 19:12:56 +0000 (+0000)
Subject: [MC] Teach ELFObjectWriter that parse-time variables do not appear in
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1e15b24cc4f3b3b3fba54879cf3625bdec4eae09;p=llvm

[MC] Teach ELFObjectWriter that parse-time variables do not appear in
symbol table.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355325 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index aec2bdeded3..4e0a4f45431 100644
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -577,6 +577,10 @@ bool ELFWriter::isInSymtab(const MCAsmLayout &Layout, const MCSymbolELF &Symbol,
                            bool Used, bool Renamed) {
   if (Symbol.isVariable()) {
     const MCExpr *Expr = Symbol.getVariableValue();
+    // Target Expressions that are always inlined do not appear in the symtab
+    if (const auto *T = dyn_cast<MCTargetExpr>(Expr))
+      if (T->inlineAssignedExpr())
+        return false;
     if (const MCSymbolRefExpr *Ref = dyn_cast<MCSymbolRefExpr>(Expr)) {
       if (Ref->getKind() == MCSymbolRefExpr::VK_WEAKREF)
         return false;
diff --git a/test/MC/X86/unused_reg_var_assign.s b/test/MC/X86/unused_reg_var_assign.s
new file mode 100644
index 00000000000..53e5cd6a274
--- /dev/null
+++ b/test/MC/X86/unused_reg_var_assign.s
@@ -0,0 +1,3 @@
+# RUN: llvm-mc -triple x86_64-unknown-linux-gnu -filetype obj %s -o %t
+	
+reg_i = %xmm0