From 8e8af9b74d52e494d10772b03d31d3f3238098dc Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Tue, 27 Sep 2011 17:24:03 +0000 Subject: fwprop.c (forward_propagate_and_simplify): After checking reg/subreg combinations, check whether the modes are the same. gcc/ * fwprop.c (forward_propagate_and_simplify): After checking reg/subreg combinations, check whether the modes are the same. From-SVN: r179287 --- gcc/fwprop.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) (limited to 'gcc/fwprop.c') diff --git a/gcc/fwprop.c b/gcc/fwprop.c index 236dda2..5368d18 100644 --- a/gcc/fwprop.c +++ b/gcc/fwprop.c @@ -1232,21 +1232,24 @@ forward_propagate_and_simplify (df_ref use, rtx def_insn, rtx def_set) /* If def and use are subreg, check if they match. */ reg = DF_REF_REG (use); - if (GET_CODE (reg) == SUBREG - && GET_CODE (SET_DEST (def_set)) == SUBREG - && (SUBREG_BYTE (SET_DEST (def_set)) != SUBREG_BYTE (reg) - || GET_MODE (SET_DEST (def_set)) != GET_MODE (reg))) - return false; - + if (GET_CODE (reg) == SUBREG && GET_CODE (SET_DEST (def_set)) == SUBREG) + { + if (SUBREG_BYTE (SET_DEST (def_set)) != SUBREG_BYTE (reg)) + return false; + } /* Check if the def had a subreg, but the use has the whole reg. */ - if (REG_P (reg) && GET_CODE (SET_DEST (def_set)) == SUBREG) + else if (REG_P (reg) && GET_CODE (SET_DEST (def_set)) == SUBREG) return false; - /* Check if the use has a subreg, but the def had the whole reg. Unlike the previous case, the optimization is possible and often useful indeed. */ - if (GET_CODE (reg) == SUBREG && REG_P (SET_DEST (def_set))) + else if (GET_CODE (reg) == SUBREG && REG_P (SET_DEST (def_set))) reg = SUBREG_REG (reg); + /* Make sure that we can treat REG as having the same mode as the + source of DEF_SET. */ + if (GET_MODE (SET_DEST (def_set)) != GET_MODE (reg)) + return false; + /* Check if the substitution is valid (last, because it's the most expensive check!). */ src = SET_SRC (def_set); -- cgit v1.1