The goal of this series is to fix the problem present in sparse
when a bitfield in an uninitialized automatic variable is first
set then read-back.
In this case the bitfield itself is initialized but not the
remaining of the structure/word and sparse was not smart
enough to handle it.
This is for testing only as it still requires some verifications.
Dibyendu,
This should now really solve your test case with:
s3.onebit = 1;
if (s3.onebit != 1)
...
Changes since v1:
- use the hack from March to work-around the problem
with undefined vars.
- add the missing simplifications to make the
store-and-load-back of a bitfield almost a no-op
as it should be.
The series is available in the git repository at:
git://github.com/lucvoo/sparse.git fix-loading-partialy-defined-bitfields-v2
----------------------------------------------------------------
Luc Van Oostenryck (8):
Remove single-store shortcut
new helper: def_opcode()
reuse nbr_pseudo_users()
change the masking when loading bitfields
simplify ((A & M') | B ) & M when M' & M == 0
transform (A & M) >> S to (A >> S) & (M >> S)
transform (A << S) >> S into A & (-1 >> S)
fix: cast of OP_AND only valid if it's an OP_CAST
flow.c | 39 +-----------
linearize.c | 15 +++--
linearize.h | 5 ++
simplify.c | 107 ++++++++++++++++++++++++++++++---
unssa.c | 5 --
validation/bitfield-size.c | 4 +-
validation/optim/store-load-bitfield.c | 66 ++++++++++++++++++++
7 files changed, 181 insertions(+), 60 deletions(-)
create mode 100644 validation/optim/store-load-bitfield.c
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