poly_int: subreg_get_info

This patch makes subreg_get_info handle polynomial sizes.

2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* rtlanal.c (subreg_get_info): Handle polynomial mode sizes.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r256150

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5cb1c23a070f0009a5318064d426bfa9e07285c7..e7901e52116e6a0f95cf9eca0f6cdde6cc02ac0f 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
+           Alan Hayward  <alan.hayward@arm.com>
+           David Sherwood  <david.sherwood@arm.com>
+
+       * rtlanal.c (subreg_get_info): Handle polynomial mode sizes.
+
 2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
            Alan Hayward  <alan.hayward@arm.com>
            David Sherwood  <david.sherwood@arm.com>

diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index 78836edfc85db71f1aab84acbf681bb09f87e23a..89c8816fbb913b91acacd92a1ca1ec4d263daa6a 100644 (file)
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -3694,8 +3694,9 @@ subreg_get_info (unsigned int xregno, machine_mode xmode,
 
   gcc_assert (xregno < FIRST_PSEUDO_REGISTER);
 
-  unsigned int xsize = GET_MODE_SIZE (xmode);
-  unsigned int ysize = GET_MODE_SIZE (ymode);
+  poly_uint64 xsize = GET_MODE_SIZE (xmode);
+  poly_uint64 ysize = GET_MODE_SIZE (ymode);
+
   bool rknown = false;
 
   /* If the register representation of a non-scalar mode has holes in it,
@@ -3707,6 +3708,7 @@ subreg_get_info (unsigned int xregno, machine_mode xmode,
       /* As a consequence, we must be dealing with a constant number of
         scalars, and thus a constant offset.  */
       HOST_WIDE_INT coffset = offset.to_constant ();
+      HOST_WIDE_INT cysize = ysize.to_constant ();
       nregs_xmode = HARD_REGNO_NREGS_WITH_PADDING (xregno, xmode);
       unsigned int nunits = GET_MODE_NUNITS (xmode);
       scalar_mode xmode_unit = GET_MODE_INNER (xmode);
@@ -3727,7 +3729,7 @@ subreg_get_info (unsigned int xregno, machine_mode xmode,
         of each unit.  */
       if ((coffset / GET_MODE_SIZE (xmode_unit) + 1 < nunits)
          && (coffset / GET_MODE_SIZE (xmode_unit)
-             != ((coffset + ysize - 1) / GET_MODE_SIZE (xmode_unit))))
+             != ((coffset + cysize - 1) / GET_MODE_SIZE (xmode_unit))))
        {
          info->representable_p = false;
          rknown = true;
@@ -3738,8 +3740,12 @@ subreg_get_info (unsigned int xregno, machine_mode xmode,
 
   nregs_ymode = hard_regno_nregs (xregno, ymode);
 
+  /* Subreg sizes must be ordered, so that we can tell whether they are
+     partial, paradoxical or complete.  */
+  gcc_checking_assert (ordered_p (xsize, ysize));
+
   /* Paradoxical subregs are otherwise valid.  */
-  if (!rknown && known_eq (offset, 0U) && ysize > xsize)
+  if (!rknown && known_eq (offset, 0U) && maybe_gt (ysize, xsize))
     {
       info->representable_p = true;
       /* If this is a big endian paradoxical subreg, which uses more
@@ -3761,20 +3767,19 @@ subreg_get_info (unsigned int xregno, machine_mode xmode,
 
   /* If registers store different numbers of bits in the different
      modes, we cannot generally form this subreg.  */
+  poly_uint64 regsize_xmode, regsize_ymode;
   if (!HARD_REGNO_NREGS_HAS_PADDING (xregno, xmode)
       && !HARD_REGNO_NREGS_HAS_PADDING (xregno, ymode)
-      && (xsize % nregs_xmode) == 0
-      && (ysize % nregs_ymode) == 0)
+      && multiple_p (xsize, nregs_xmode, &regsize_xmode)
+      && multiple_p (ysize, nregs_ymode, &regsize_ymode))
     {
-      int regsize_xmode = xsize / nregs_xmode;
-      int regsize_ymode = ysize / nregs_ymode;
       if (!rknown
-         && ((nregs_ymode > 1 && regsize_xmode > regsize_ymode)
-             || (nregs_xmode > 1 && regsize_ymode > regsize_xmode)))
+         && ((nregs_ymode > 1 && maybe_gt (regsize_xmode, regsize_ymode))
+             || (nregs_xmode > 1 && maybe_gt (regsize_ymode, regsize_xmode))))
        {
          info->representable_p = false;
-         info->nregs = CEIL (ysize, regsize_xmode);
-         if (!can_div_trunc_p (offset, regsize_xmode, &info->offset))
+         if (!can_div_away_from_zero_p (ysize, regsize_xmode, &info->nregs)
+             || !can_div_trunc_p (offset, regsize_xmode, &info->offset))
            /* Checked by validate_subreg.  We must know at compile time
               which inner registers are being accessed.  */
            gcc_unreachable ();
@@ -3800,7 +3805,7 @@ subreg_get_info (unsigned int xregno, machine_mode xmode,
       HOST_WIDE_INT count;
       if (!rknown
          && WORDS_BIG_ENDIAN == REG_WORDS_BIG_ENDIAN
-         && regsize_xmode == regsize_ymode
+         && known_eq (regsize_xmode, regsize_ymode)
          && constant_multiple_p (offset, regsize_ymode, &count))
        {
          info->representable_p = true;
@@ -3837,8 +3842,7 @@ subreg_get_info (unsigned int xregno, machine_mode xmode,
      be exact, otherwise we don't know how to verify the constraint.
      These conditions may be relaxed but subreg_regno_offset would
      need to be redesigned.  */
-  gcc_assert ((xsize % num_blocks) == 0);
-  poly_uint64 bytes_per_block = xsize / num_blocks;
+  poly_uint64 bytes_per_block = exact_div (xsize, num_blocks);
 
   /* Get the number of the first block that contains the subreg and the byte
      offset of the subreg from the start of that block.  */