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author | rth <rth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2004-11-08 19:18:16 +0000 |
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committer | rth <rth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2004-11-08 19:18:16 +0000 |
commit | c974df900ed8b9cb62019330efcab6ad1b3128e5 (patch) | |
tree | 05875fc07773a13ef841f991578d7e0b84c9a533 /gcc/expmed.c | |
parent | 2749f8088f0de9ad87faef3584e4e4cdc9f40ed5 (diff) | |
download | ppe42-gcc-c974df900ed8b9cb62019330efcab6ad1b3128e5.tar.gz ppe42-gcc-c974df900ed8b9cb62019330efcab6ad1b3128e5.zip |
* expmed.c (extract_force_align_mem_bit_field): Correct handling at
the end of a page.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@90288 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/expmed.c')
-rw-r--r-- | gcc/expmed.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/gcc/expmed.c b/gcc/expmed.c index a108efaa4ee..191df725476 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -1891,11 +1891,16 @@ extract_force_align_mem_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize, if (STRICT_ALIGNMENT) { base = plus_constant (XEXP (op0, 0), bitpos / BITS_PER_UNIT); - base = force_operand (base, NULL); bitpos %= BITS_PER_UNIT; - /* Force alignment of the address; load two sequential values. */ - a1 = expand_simple_binop (Pmode, AND, base, + /* We load two values to be concatenate. There's an edge condition + that bears notice -- an aligned value at the end of a page can + only load one value lest we segfault. So the two values we load + are at "base & -size" and "(base + size - 1) & -size". If base + is unaligned, the addresses will be aligned and sequential; if + base is aligned, the addresses will both be equal to base. */ + + a1 = expand_simple_binop (Pmode, AND, force_operand (base, NULL), GEN_INT (-(HOST_WIDE_INT)m_size), NULL, true, OPTAB_LIB_WIDEN); mark_reg_pointer (a1, m_bitsize); @@ -1903,7 +1908,10 @@ extract_force_align_mem_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize, set_mem_align (v1, m_bitsize); v1 = force_reg (mode, validize_mem (v1)); - a2 = plus_constant (a1, GET_MODE_SIZE (mode)); + a2 = plus_constant (base, GET_MODE_SIZE (mode) - 1); + a2 = expand_simple_binop (Pmode, AND, force_operand (a2, NULL), + GEN_INT (-(HOST_WIDE_INT)m_size), + NULL, true, OPTAB_LIB_WIDEN); v2 = gen_rtx_MEM (mode, a2); set_mem_align (v2, m_bitsize); v2 = force_reg (mode, validize_mem (v2)); |