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| author | Michael Meissner <meissner@linux.ibm.com> | 2023-02-01 12:30:19 -0500 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2023-05-08 14:03:42 +0200 |
| commit | e2b993db57f90fedd1bd7756f7ad4c5bfded4b8f (patch) | |
| tree | a0e4a8159e44c410a4a2f4754f83becadf6db877 | |
| parent | c93bde224c075c14d5ee54331386cbcda48c65dd (diff) | |
| download | gcc-e2b993db57f90fedd1bd7756f7ad4c5bfded4b8f.zip gcc-e2b993db57f90fedd1bd7756f7ad4c5bfded4b8f.tar.gz gcc-e2b993db57f90fedd1bd7756f7ad4c5bfded4b8f.tar.bz2 | |
Bump up precision size to 16 bits.
The new __dmr type that is being added as a possible future PowerPC instruction
set bumps into a structure field size issue. The size of the __dmr type is 1024 bits.
The precision field in tree_type_common is currently 10 bits, so if you store
1,024 into field, you get a 0 back. When you get 0 in the precision field, the
ccp pass passes this 0 to sext_hwi in hwint.h. That function in turn generates
a shift that is equal to the host wide int bit size, which is undefined as
machine dependent for shifting in C/C++.
int shift = HOST_BITS_PER_WIDE_INT - prec;
return ((HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) src << shift)) >> shift;
It turns out the x86_64 where I first did my tests returns the original input
before the two shifts, while the PowerPC always returns 0. In the ccp pass, the
original input is -1, and so it worked. When I did the runs on the PowerPC, the
result was 0, which ultimately led to the failure.
2023-02-01 Richard Biener <rguenther@suse.de>
Michael Meissner <meissner@linux.ibm.com>
PR middle-end/108623
* tree-core.h (tree_type_common): Bump up precision field to 16 bits.
Align bit fields > 1 bit to at least an 8-bit boundary.
| -rw-r--r-- | gcc/tree-core.h | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/gcc/tree-core.h b/gcc/tree-core.h index 847f0b1..a1aea13 100644 --- a/gcc/tree-core.h +++ b/gcc/tree-core.h @@ -1680,18 +1680,8 @@ struct GTY(()) tree_type_common { tree attributes; unsigned int uid; - unsigned int precision : 10; - unsigned no_force_blk_flag : 1; - unsigned needs_constructing_flag : 1; - unsigned transparent_aggr_flag : 1; - unsigned restrict_flag : 1; - unsigned contains_placeholder_bits : 2; - + unsigned int precision : 16; ENUM_BITFIELD(machine_mode) mode : 8; - - /* TYPE_STRING_FLAG for INTEGER_TYPE and ARRAY_TYPE. - TYPE_CXX_ODR_P for RECORD_TYPE and UNION_TYPE. */ - unsigned string_flag : 1; unsigned lang_flag_0 : 1; unsigned lang_flag_1 : 1; unsigned lang_flag_2 : 1; @@ -1707,12 +1697,22 @@ struct GTY(()) tree_type_common { so we need to store the value 32 (not 31, as we need the zero as well), hence six bits. */ unsigned align : 6; + /* TYPE_STRING_FLAG for INTEGER_TYPE and ARRAY_TYPE. + TYPE_CXX_ODR_P for RECORD_TYPE and UNION_TYPE. */ + unsigned string_flag : 1; + unsigned no_force_blk_flag : 1; + unsigned warn_if_not_align : 6; + unsigned needs_constructing_flag : 1; + unsigned transparent_aggr_flag : 1; + + unsigned contains_placeholder_bits : 2; + unsigned restrict_flag : 1; unsigned typeless_storage : 1; unsigned empty_flag : 1; unsigned indivisible_p : 1; unsigned no_named_args_stdarg_p : 1; - unsigned spare : 15; + unsigned spare : 9; alias_set_type alias_set; tree pointer_to; |