(simplify_rtx, case SUBREG): Fix direction of test when calling

operand_subword; use inline code intead of subreg_lowpart_p.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@13698 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/combine.c b/gcc/combine.c
index 2300ce9..89f6525 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -3383,7 +3383,7 @@ simplify_rtx (x, op0_mode, last, in_dest)
 
       if (CONSTANT_P (SUBREG_REG (x)) && op0_mode != VOIDmode
          && GET_MODE_SIZE (mode) == UNITS_PER_WORD
-         && GET_MODE_SIZE (op0_mode) < UNITS_PER_WORD
+         && GET_MODE_SIZE (op0_mode) > UNITS_PER_WORD
          && GET_MODE_CLASS (mode) == MODE_INT)
        {
          temp = operand_subword (SUBREG_REG (x), SUBREG_WORD (x),
@@ -3395,8 +3395,16 @@ simplify_rtx (x, op0_mode, last, in_dest)
       /* If we want a subreg of a constant, at offset 0,
         take the low bits.  On a little-endian machine, that's
         always valid.  On a big-endian machine, it's valid
-        only if the constant's mode fits in one word.  */
-      if (CONSTANT_P (SUBREG_REG (x)) && subreg_lowpart_p (x)
+        only if the constant's mode fits in one word.   Note that we
+        cannot use subreg_lowpart_p since we SUBREG_REG may be VOIDmode.  */
+      if (CONSTANT_P (SUBREG_REG (x))
+         && ((GET_MODE_SIZE (op0_mode) <= UNITS_PER_WORD
+             || ! WORDS_BIG_ENDIAN)
+             ? SUBREG_WORD (x) == 0
+             : (SUBREG_WORD (x)
+                == ((GET_MODE_SIZE (op0_mode)
+                     - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD))
+                    / UNITS_PER_WORD)))
          && GET_MODE_SIZE (mode) <= GET_MODE_SIZE (op0_mode)
          && (! WORDS_BIG_ENDIAN
              || GET_MODE_BITSIZE (op0_mode) <= BITS_PER_WORD))