From: Richard Sandiford Date: Wed, 30 Aug 2017 11:18:29 +0000 (+0000) Subject: [58/77] Use scalar_int_mode in a try_combine optimisation X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=2123a9a50fb35109af6c2ba3bcfd71a1d5432954;p=gcc.git [58/77] Use scalar_int_mode in a try_combine optimisation This patch uses scalar_int_modes for: /* If I2 is setting a pseudo to a constant and I3 is setting some sub-part of it to another constant, merge them by making a new constant. */ This was already implicit, but the danger with checking only CONST_SCALAR_INT_P is that it can include CC values too. 2017-08-30 Richard Sandiford Alan Hayward David Sherwood gcc/ * combine.c (try_combine): Use is_a when trying to combine a full-register integer set with a subreg integer set. Co-Authored-By: Alan Hayward Co-Authored-By: David Sherwood From-SVN: r251510 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 51f6f374546..3fb54e6c82f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2017-08-30 Richard Sandiford + Alan Hayward + David Sherwood + + * combine.c (try_combine): Use is_a when + trying to combine a full-register integer set with a subreg + integer set. + 2017-08-30 Richard Sandiford Alan Hayward David Sherwood diff --git a/gcc/combine.c b/gcc/combine.c index 85a2f50bca6..022a5b5f15c 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -2645,6 +2645,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, rtx other_pat = 0; rtx new_other_notes; int i; + scalar_int_mode dest_mode, temp_mode; /* Immediately return if any of I0,I1,I2 are the same insn (I3 can never be). */ @@ -2847,33 +2848,40 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, constant. */ if (i1 == 0 && (temp_expr = single_set (i2)) != 0 + && is_a (GET_MODE (SET_DEST (temp_expr)), &temp_mode) && CONST_SCALAR_INT_P (SET_SRC (temp_expr)) && GET_CODE (PATTERN (i3)) == SET && CONST_SCALAR_INT_P (SET_SRC (PATTERN (i3))) && reg_subword_p (SET_DEST (PATTERN (i3)), SET_DEST (temp_expr))) { rtx dest = SET_DEST (PATTERN (i3)); + rtx temp_dest = SET_DEST (temp_expr); int offset = -1; int width = 0; - + if (GET_CODE (dest) == ZERO_EXTRACT) { if (CONST_INT_P (XEXP (dest, 1)) - && CONST_INT_P (XEXP (dest, 2))) + && CONST_INT_P (XEXP (dest, 2)) + && is_a (GET_MODE (XEXP (dest, 0)), + &dest_mode)) { width = INTVAL (XEXP (dest, 1)); offset = INTVAL (XEXP (dest, 2)); dest = XEXP (dest, 0); if (BITS_BIG_ENDIAN) - offset = GET_MODE_PRECISION (GET_MODE (dest)) - width - offset; + offset = GET_MODE_PRECISION (dest_mode) - width - offset; } } else { if (GET_CODE (dest) == STRICT_LOW_PART) dest = XEXP (dest, 0); - width = GET_MODE_PRECISION (GET_MODE (dest)); - offset = 0; + if (is_a (GET_MODE (dest), &dest_mode)) + { + width = GET_MODE_PRECISION (dest_mode); + offset = 0; + } } if (offset >= 0) @@ -2882,9 +2890,9 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, if (subreg_lowpart_p (dest)) ; /* Handle the case where inner is twice the size of outer. */ - else if (GET_MODE_PRECISION (GET_MODE (SET_DEST (temp_expr))) - == 2 * GET_MODE_PRECISION (GET_MODE (dest))) - offset += GET_MODE_PRECISION (GET_MODE (dest)); + else if (GET_MODE_PRECISION (temp_mode) + == 2 * GET_MODE_PRECISION (dest_mode)) + offset += GET_MODE_PRECISION (dest_mode); /* Otherwise give up for now. */ else offset = -1; @@ -2895,23 +2903,22 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, rtx inner = SET_SRC (PATTERN (i3)); rtx outer = SET_SRC (temp_expr); - wide_int o - = wi::insert (rtx_mode_t (outer, GET_MODE (SET_DEST (temp_expr))), - rtx_mode_t (inner, GET_MODE (dest)), - offset, width); + wide_int o = wi::insert (rtx_mode_t (outer, temp_mode), + rtx_mode_t (inner, dest_mode), + offset, width); combine_merges++; subst_insn = i3; subst_low_luid = DF_INSN_LUID (i2); added_sets_2 = added_sets_1 = added_sets_0 = 0; - i2dest = SET_DEST (temp_expr); + i2dest = temp_dest; i2dest_killed = dead_or_set_p (i2, i2dest); /* Replace the source in I2 with the new constant and make the resulting insn the new pattern for I3. Then skip to where we validate the pattern. Everything was set up above. */ SUBST (SET_SRC (temp_expr), - immed_wide_int_const (o, GET_MODE (SET_DEST (temp_expr)))); + immed_wide_int_const (o, temp_mode)); newpat = PATTERN (i2);