diff options
| author | Richard Stallman <rms@gnu.org> | 1992-12-27 03:55:29 +0000 |
|---|---|---|
| committer | Richard Stallman <rms@gnu.org> | 1992-12-27 03:55:29 +0000 |
| commit | f5df292efc42b912b8babdd3593545fa3ec0842c (patch) | |
| tree | a470983d15aef01440ea07de263ad3c9c3f8ee32 | |
| parent | 66212c2f764860e8b40ec23c1a45b9bf754c5354 (diff) | |
| download | gcc-f5df292efc42b912b8babdd3593545fa3ec0842c.zip gcc-f5df292efc42b912b8babdd3593545fa3ec0842c.tar.gz gcc-f5df292efc42b912b8babdd3593545fa3ec0842c.tar.bz2 | |
(store_bit_field): If VALUE needs to be narrowed, do
it with gen_lowpart, not an explicit SUBREG.
From-SVN: r2920
| -rw-r--r-- | gcc/expmed.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/gcc/expmed.c b/gcc/expmed.c index 5819ce4..2c95a86 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -402,12 +402,18 @@ store_bit_field (str_rtx, bitsize, bitnum, fieldmode, value, align, total_size) if (GET_MODE_BITSIZE (GET_MODE (value)) >= bitsize) { /* Optimization: Don't bother really extending VALUE - if it has all the bits we will actually use. */ + if it has all the bits we will actually use. However, + if we must narrow it, be sure we do it correctly. */ - /* Avoid making subreg of a subreg, or of a mem. */ - if (GET_CODE (value1) != REG) + if (GET_MODE_SIZE (GET_MODE (value)) < GET_MODE_SIZE (maxmode)) + { + /* Avoid making subreg of a subreg, or of a mem. */ + if (GET_CODE (value1) != REG) value1 = copy_to_reg (value1); - value1 = gen_rtx (SUBREG, maxmode, value1, 0); + value1 = gen_rtx (SUBREG, maxmode, value1, 0); + } + else + value1 = gen_lowpart (maxmode, value1); } else if (!CONSTANT_P (value)) /* Parse phase is supposed to make VALUE's data type |