With the inclusion of the "df" field in the union, this union is going to be at the offset 8 because of the alignment rules. The alignment bits in the middle are uninitialized and valgrind complains with errors similar to this:
==10298== Conditional jump or move depends on uninitialised value(s) ==10298== at 0x4C31D52: __memcmp_sse4_1 (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==10298== by 0xAB16663: backend_reg::equals(backend_reg const&) const (brw_shader.cpp:690) ==10298== by 0xAAB629D: fs_reg::equals(fs_reg&) const (brw_fs.cpp:456) ==10298== by 0xAAD4452: operands_match(fs_inst*, fs_inst*, bool*) (brw_fs_cse.cpp:161) ==10298== by 0xAAD46C3: instructions_match(fs_inst*, fs_inst*, bool*) (brw_fs_cse.cpp:187) ==10298== by 0xAAD4BAA: fs_visitor::opt_cse_local(bblock_t*) (brw_fs_cse.cpp:251) ==10298== by 0xAAD5216: fs_visitor::opt_cse() (brw_fs_cse.cpp:361) ==10298== by 0xAAC8AAD: fs_visitor::optimize() (brw_fs.cpp:5401) ==10298== by 0xAACB9DC: fs_visitor::run_fs(bool) (brw_fs.cpp:5803) ==10298== by 0xAACC38B: brw_compile_fs (brw_fs.cpp:6029) ==10298== by 0xAA39796: brw_codegen_wm_prog (brw_wm.c:137) ==10298== by 0xAA3B068: brw_fs_precompile (brw_wm.c:637) This patch adds an explicit padding and initializes it to zero. Signed-off-by: Samuel Iglesias Gonsálvez <[email protected]> --- This patch replaces the following one: [PATCH 2/2] i965: check each field separately in backend_end::equals() src/mesa/drivers/dri/i965/brw_reg.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/src/mesa/drivers/dri/i965/brw_reg.h b/src/mesa/drivers/dri/i965/brw_reg.h index 3b76d7d..ebb7f29 100644 --- a/src/mesa/drivers/dri/i965/brw_reg.h +++ b/src/mesa/drivers/dri/i965/brw_reg.h @@ -243,6 +243,9 @@ struct brw_reg { unsigned subnr:5; /* :1 in align16 */ unsigned nr:16; + /* IMPORTANT: adjust padding bits if you add new fields */ + unsigned padding:32; + union { struct { unsigned swizzle:8; /* src only, align16 only */ @@ -337,7 +340,7 @@ brw_reg(enum brw_reg_file file, reg.pad0 = 0; reg.subnr = subnr * type_sz(type); reg.nr = nr; - + reg.padding = 0; /* Initialize all union's bits to zero before setting them. */ reg.df = 0; -- 2.5.0 _______________________________________________ mesa-dev mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-dev
