arm.c (arm_output_mi_thunk): Fix offset for TARGET_THUMB1_ONLY.

2014-06-20  Julian Brown  <julian@codesourcery.com>
	    Chung-Lin Tang  <cltang@codesourcery.com>

	* config/arm/arm.c (arm_output_mi_thunk): Fix offset for
	TARGET_THUMB1_ONLY. Add comments.


Co-Authored-By: Chung-Lin Tang <cltang@codesourcery.com>

From-SVN: r211834

gcc/ChangeLog

+2014-06-20  Julian Brown  <julian@codesourcery.com>
+	    Chung-Lin Tang  <cltang@codesourcery.com>
+
+	* config/arm/arm.c (arm_output_mi_thunk): Fix offset for
+	TARGET_THUMB1_ONLY. Add comments.
+
 2014-06-19  Tom de Vries  <tom@codesourcery.com>
 
 	* config/aarch64/aarch64-protos.h (aarch64_emit_call_insn): Change

gcc/config/arm/arm.c

@@ -28455,9 +28455,13 @@ arm_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
       fputs (":\n", file);
       if (flag_pic)
 	{
-	  /* Output ".word .LTHUNKn-7-.LTHUNKPCn".  */
+	  /* Output ".word .LTHUNKn-[3,7]-.LTHUNKPCn".  */
 	  rtx tem = XEXP (DECL_RTL (function), 0);
-	  tem = plus_constant (GET_MODE (tem), tem, -7);
+	  /* For TARGET_THUMB1_ONLY the thunk is in Thumb mode, so the PC
+	     pipeline offset is four rather than eight.  Adjust the offset
+	     accordingly.  */
+	  tem = plus_constant (GET_MODE (tem), tem,
+			       TARGET_THUMB1_ONLY ? -3 : -7);
 	  tem = gen_rtx_MINUS (GET_MODE (tem),
 			       tem,
 			       gen_rtx_SYMBOL_REF (Pmode,