[PATCH] Fix gcc.dg/guality/asm-1.c regressions on 4.6 branch

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

Apparently a recent change (2011-10-1[23] or so) regressed
gcc.dg/guality/asm-1.c test on x86_64-linux on the 4.6 branch.
This turned out to be a bug in loc_descriptor which has been passing wrong
mode on the recursive call, so when we had var_location note containing
SImode subreg of some DImode expression, the inner loc_descriptor would
just give up because of the mode mismatch.

Fixed thusly (here the trunk version of the patch, attached 4.6 version),
bootstrapped/regtested on x86_64-linux and i686-linux (both branches in each
case), ok for trunk/4.6?

2011-10-18  Jakub Jelinek  <jakub@redhat.com>

	* dwarf2out.c (loc_descriptor): For SUBREG pass SUBREG_REG's mode as
	second argument instead of mode.

--- gcc/dwarf2out.c.jj	2011-09-08 11:21:10.000000000 +0200
+++ gcc/dwarf2out.c	2011-10-18 14:09:46.000000000 +0200
@@ -12502,7 +12502,8 @@ loc_descriptor (rtx rtl, enum machine_mo
 	 legitimate to make the Dwarf info refer to the whole register which
 	 contains the given subreg.  */
       if (REG_P (SUBREG_REG (rtl)) && subreg_lowpart_p (rtl))
-	loc_result = loc_descriptor (SUBREG_REG (rtl), mode, initialized);
+	loc_result = loc_descriptor (SUBREG_REG (rtl),
+				     GET_MODE (SUBREG_REG (rtl)), initialized);
       else
 	goto do_default;
       break;

	Jakub

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