combine.c (make_extraction): Handle TRUNCATEd INNERs.

gcc/
	* combine.c (make_extraction): Handle TRUNCATEd INNERs.

From-SVN: r193600

gcc/ChangeLog

 2012-11-18  Richard Sandiford  <rdsandiford@googlemail.com>
 
+	* combine.c (make_extraction): Handle TRUNCATEd INNERs.
+
+2012-11-18  Richard Sandiford  <rdsandiford@googlemail.com>
+
 	* expr.c (expand_assignment): Don't set MEM_KEEP_ALIAS_SET_P here.
 	* emit-rtl.c (set_mem_attributes_minus_bitpos): Handle DECL_BIT_FIELDs,
 	using their size instead of the COMPONENT_REF's.

gcc/combine.c

@@ -7022,6 +7022,8 @@ make_extraction (enum machine_mode mode, rtx inner, HOST_WIDE_INT pos,
       if (new_rtx != 0)
 	return gen_rtx_ASHIFT (mode, new_rtx, XEXP (inner, 1));
     }
+  else if (GET_CODE (inner) == TRUNCATE)
+    inner = XEXP (inner, 0);
 
   inner_mode = GET_MODE (inner);