emit-rtl.c (gen_lowpart): Don't force MEMs into a register unless the register lowpart is a...

	* emit-rtl.c (gen_lowpart): Don't force MEMs into a register unless
	the register lowpart is a TRULY_NOOP_TRUNCATION.

From-SVN: r73731

gcc/ChangeLog

+2003-11-19  Richard SAndiford  <rsandifo@redhat.com>
+
+	* emit-rtl.c (gen_lowpart): Don't force MEMs into a register unless
+	the register lowpart is a TRULY_NOOP_TRUNCATION.
+
 2003-11-19  Richard Henderson  <rth@redhat.com>
 
 	* config/i386/i386.c (print_reg): Handle QI and HI modes for

gcc/emit-rtl.c

@@ -1356,6 +1356,8 @@ gen_lowpart (enum machine_mode mode, rtx x)
       /* The following exposes the use of "x" to CSE.  */
       if (GET_MODE_SIZE (GET_MODE (x)) <= UNITS_PER_WORD
 	  && SCALAR_INT_MODE_P (GET_MODE (x))
+	  && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
+				    GET_MODE_BITSIZE (GET_MODE (x)))
 	  && ! no_new_pseudos)
 	return gen_lowpart (mode, force_reg (GET_MODE (x), x));