rs6000.c (rs6000_legitimize_tls_address): Explain peculiarity of GOT/TOC section usage.

	* config/rs6000/rs6000.c (rs6000_legitimize_tls_address): Explain
	peculiarity of GOT/TOC section usage.

From-SVN: r105836

gcc/ChangeLog

+2005-10-24  Alan Modra  <amodra@bigpond.net.au>
+
+	* config/rs6000/rs6000.c (rs6000_legitimize_tls_address): Explain
+	peculiarity of GOT/TOC section usage.
+
 2005-10-23  Andrew Pinski  <pinskia@physics.uc.edu>
 
 	PR objc/24435

gcc/config/rs6000/rs6000.c

@@ -2978,6 +2978,11 @@ rs6000_legitimize_tls_address (rtx addr, enum tls_model model)
     {
       rtx r3, got, tga, tmp1, tmp2, eqv;
 
+      /* We currently use relocations like @got@tlsgd for tls, which
+	 means the linker will handle allocation of tls entries, placing
+	 them in the .got section.  So use a pointer to the .got section,
+	 not one to secondary TOC sections used by 64-bit -mminimal-toc,
+	 or to secondary GOT sections used by 32-bit -fPIC.  */
       if (TARGET_64BIT)
 	got = gen_rtx_REG (Pmode, 2);
       else