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| author | Geoffrey Keating <geoffk@redhat.com> | 2001-11-20 04:12:11 +0000 |
|---|---|---|
| committer | Geoffrey Keating <geoffk@gcc.gnu.org> | 2001-11-20 04:12:11 +0000 |
| commit | e98f90d363be3496fbd8917c69df761e5a47cbf7 (patch) | |
| tree | 1ccd724b6adc95dce984fa68fefd6b1a126ab750 /gcc/expmed.c | |
| parent | 34806eda305c2da75ef89f0c88f9003ebc50a272 (diff) | |
| download | gcc-e98f90d363be3496fbd8917c69df761e5a47cbf7.tar.gz | |
* expmed.c (extract_bit_field): Don't create invalid SUBREGs.
From-SVN: r47196
Diffstat (limited to 'gcc/expmed.c')
| -rw-r--r-- | gcc/expmed.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/gcc/expmed.c b/gcc/expmed.c index 3879725487d..cb21cf5d277 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -998,6 +998,8 @@ extract_bit_field (str_rtx, bitsize, bitnum, unsignedp, enum machine_mode int_mode; enum machine_mode extv_mode = mode_for_extraction (EP_extv, 0); enum machine_mode extzv_mode = mode_for_extraction (EP_extzv, 0); + enum machine_mode mode1; + int byte_offset; /* Discount the part of the structure before the desired byte. We need to know how many bytes are safe to reference after it. */ @@ -1071,9 +1073,18 @@ extract_bit_field (str_rtx, bitsize, bitnum, unsignedp, So too extracting a subword value in the least significant part of the register. */ + byte_offset = (bitnum % BITS_PER_WORD) / BITS_PER_UNIT + + (offset * UNITS_PER_WORD); + + mode1 = (VECTOR_MODE_P (tmode) + ? mode + : mode_for_size (bitsize, GET_MODE_CLASS (tmode), 0)); + if (((GET_CODE (op0) != MEM && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode), - GET_MODE_BITSIZE (GET_MODE (op0)))) + GET_MODE_BITSIZE (GET_MODE (op0))) + && GET_MODE_SIZE (mode1) != 0 + && byte_offset % GET_MODE_SIZE (mode1) == 0) || (GET_CODE (op0) == MEM && (! SLOW_UNALIGNED_ACCESS (mode, MEM_ALIGN (op0)) || (offset * BITS_PER_UNIT % bitsize == 0 @@ -1089,10 +1100,6 @@ extract_bit_field (str_rtx, bitsize, bitnum, unsignedp, ? bitpos + bitsize == BITS_PER_WORD : bitpos == 0)))) { - enum machine_mode mode1 - = (VECTOR_MODE_P (tmode) ? mode - : mode_for_size (bitsize, GET_MODE_CLASS (tmode), 0)); - if (mode1 != GET_MODE (op0)) { if (GET_CODE (op0) == SUBREG) @@ -1108,9 +1115,7 @@ extract_bit_field (str_rtx, bitsize, bitnum, unsignedp, abort (); } if (GET_CODE (op0) == REG) - op0 = gen_rtx_SUBREG (mode1, op0, - (bitnum % BITS_PER_WORD) / BITS_PER_UNIT - + (offset * UNITS_PER_WORD)); + op0 = gen_rtx_SUBREG (mode1, op0, byte_offset); else op0 = adjust_address (op0, mode1, offset); } |