diff options
Diffstat (limited to 'gcc/rtlanal.c')
| -rw-r--r-- | gcc/rtlanal.c | 39 |
1 files changed, 25 insertions, 14 deletions
diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c index 44a6c6c..4dda178 100644 --- a/gcc/rtlanal.c +++ b/gcc/rtlanal.c @@ -3187,48 +3187,59 @@ loc_mentioned_in_p (rtx *loc, rtx in) return 0; } -/* Given a subreg X, return the bit offset where the subreg begins - (counting from the least significant bit of the reg). */ +/* Helper function for subreg_lsb. Given a subreg's OUTER_MODE, INNER_MODE, + and SUBREG_BYTE, return the bit offset where the subreg begins + (counting from the least significant bit of the operand). */ unsigned int -subreg_lsb (rtx x) +subreg_lsb_1 (enum machine_mode outer_mode, + enum machine_mode inner_mode, + unsigned int subreg_byte) { - enum machine_mode inner_mode = GET_MODE (SUBREG_REG (x)); - enum machine_mode mode = GET_MODE (x); unsigned int bitpos; unsigned int byte; unsigned int word; /* A paradoxical subreg begins at bit position 0. */ - if (GET_MODE_BITSIZE (mode) > GET_MODE_BITSIZE (inner_mode)) + if (GET_MODE_BITSIZE (outer_mode) > GET_MODE_BITSIZE (inner_mode)) return 0; if (WORDS_BIG_ENDIAN != BYTES_BIG_ENDIAN) /* If the subreg crosses a word boundary ensure that it also begins and ends on a word boundary. */ - if ((SUBREG_BYTE (x) % UNITS_PER_WORD - + GET_MODE_SIZE (mode)) > UNITS_PER_WORD - && (SUBREG_BYTE (x) % UNITS_PER_WORD - || GET_MODE_SIZE (mode) % UNITS_PER_WORD)) + if ((subreg_byte % UNITS_PER_WORD + + GET_MODE_SIZE (outer_mode)) > UNITS_PER_WORD + && (subreg_byte % UNITS_PER_WORD + || GET_MODE_SIZE (outer_mode) % UNITS_PER_WORD)) abort (); if (WORDS_BIG_ENDIAN) word = (GET_MODE_SIZE (inner_mode) - - (SUBREG_BYTE (x) + GET_MODE_SIZE (mode))) / UNITS_PER_WORD; + - (subreg_byte + GET_MODE_SIZE (outer_mode))) / UNITS_PER_WORD; else - word = SUBREG_BYTE (x) / UNITS_PER_WORD; + word = subreg_byte / UNITS_PER_WORD; bitpos = word * BITS_PER_WORD; if (BYTES_BIG_ENDIAN) byte = (GET_MODE_SIZE (inner_mode) - - (SUBREG_BYTE (x) + GET_MODE_SIZE (mode))) % UNITS_PER_WORD; + - (subreg_byte + GET_MODE_SIZE (outer_mode))) % UNITS_PER_WORD; else - byte = SUBREG_BYTE (x) % UNITS_PER_WORD; + byte = subreg_byte % UNITS_PER_WORD; bitpos += byte * BITS_PER_UNIT; return bitpos; } +/* Given a subreg X, return the bit offset where the subreg begins + (counting from the least significant bit of the reg). */ + +unsigned int +subreg_lsb (rtx x) +{ + return subreg_lsb_1 (GET_MODE (x), GET_MODE (SUBREG_REG (x)), + SUBREG_BYTE (x)); +} + /* This function returns the regno offset of a subreg expression. xregno - A regno of an inner hard subreg_reg (or what will become one). xmode - The mode of xregno. |