re PR target/61578 (Code size increase for ARM thumb compared to 4.8.x when compiling with -Os)

2015-09-25  Vladimir Makarov  <vmakarov@redhat.com>

	PR target/61578
	* lra-constarints.c (match_reload): Check presence of the input pseudo
	in the output pseudo.

From-SVN: r228153

gcc/ChangeLog

+2015-09-25  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR target/61578
+	* lra-constarints.c (match_reload): Check presence of the input pseudo
+	in the output pseudo.
+
 2015-09-25  Tobias Burnus  <burnus@net-b.de>
 
 	* doc/invoke.texi (-fsanitize): Minor wording tweak.

gcc/lra-constraints.c

@@ -945,6 +945,12 @@ match_reload (signed char out, signed char *ins, enum reg_class goal_class,
 	= (ins[1] < 0 && REG_P (in_rtx)
 	   && (int) REGNO (in_rtx) < lra_new_regno_start
 	   && find_regno_note (curr_insn, REG_DEAD, REGNO (in_rtx))
+	   /* We can not use the same value if the pseudo is mentioned
+	      in the output, e.g. as an address part in memory,
+	      becuase output reload will actually extend the pseudo
+	      liveness.  We don't care about eliminable hard regs here
+	      as we are interesting only in pseudos.  */
+	   && (out < 0 || regno_use_in (REGNO (in_rtx), out_rtx) == NULL_RTX)
 	   ? lra_create_new_reg (inmode, in_rtx, goal_class, "")
 	   : lra_create_new_reg_with_unique_value (outmode, out_rtx,
 						   goal_class, ""));