diff options
| author | Richard Sandiford <richard.sandiford@arm.com> | 2016-05-09 15:30:32 +0000 |
|---|---|---|
| committer | Richard Sandiford <richard.sandiford@arm.com> | 2016-05-09 15:30:32 +0000 |
| commit | b8065b0d71545c8d7802c400231937a00134991d (patch) | |
| tree | 17ca09172235f42f9b155a4381183327145e72ef | |
| parent | 9f0d00a4263289606e55641297e2d5897d92a1e0 (diff) | |
Fix handling of negative bitpos in expand_debug_expr
expand_debug_expr handled negative bit positions using:
else if (bitpos < 0)
{
HOST_WIDE_INT units
= (-bitpos + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
op0 = adjust_address_nv (op0, mode1, units);
bitpos += units * BITS_PER_UNIT;
}
Here "units" is the negative of the (negative) byte offset, so I think
we should be offsetting OP0 by -units instead. E.g. a bitpos of -17
would give units==3, so this code would move OP0 up by 3 bytes and set
bitpos to 7, giving a total bitpos of 31.
Just noticed by inspection. An assert triggered for:
gcc.target/i386/mpx/bitfields-1-lbv.c
gcc.target/i386/mpx/field-addr-7-lbv.c
gcc.target/i386/mpx/reference-3-lbv.cpp
gcc.target/i386/mpx/reference-4-lbv.cpp
at -m32 but otherwise this case doesn't seem to trigger during a
bootstrap and regtest.
Tested on x86_64-linux-gnu.
gcc/
* cfgexpand.c (expand_debug_expr): Fix address offset for negative
bitpos.
git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@236041 138bc75d-0d04-0410-961f-82ee72b054a4
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/cfgexpand.c | 2 |
2 files changed, 6 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 85f0e6738f6..314f5f6d67f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2016-05-09 Richard Sandiford <richard.sandiford@arm.com> + * cfgexpand.c (expand_debug_expr): Fix address offset for negative + bitpos. + +2016-05-09 Richard Sandiford <richard.sandiford@arm.com> + * tree-affine.c (wide_int_constant_multiple_p): Add missing pointer dereference. diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c index 21f21c97502..77a1964d4c0 100644 --- a/gcc/cfgexpand.c +++ b/gcc/cfgexpand.c @@ -4473,7 +4473,7 @@ expand_debug_expr (tree exp) { HOST_WIDE_INT units = (-bitpos + BITS_PER_UNIT - 1) / BITS_PER_UNIT; - op0 = adjust_address_nv (op0, mode1, units); + op0 = adjust_address_nv (op0, mode1, -units); bitpos += units * BITS_PER_UNIT; } else if (bitpos == 0 && bitsize == GET_MODE_BITSIZE (mode)) |