On Wed, Jun 13, 2018 at 6:14 PM, Kenneth Graunke <kenn...@whitecape.org> wrote:
> The UBO push analysis pass incorrectly assumed that all values would fit > within a 32B chunk, and only recorded a bit for the 32B chunk containing > the starting offset. > > For example, if a UBO contained the following, tightly packed: > > vec4 a; // [0, 16) > float b; // [16, 20) > vec4 c; // [20, 36) > > then, c would start at offset 20 / 32 = 0 and end at 36 / 32 = 1, > which means that we ought to record two 32B chunks in the bitfield. > > Similarly, dvec4s would suffer from the same problem. > > v2: Rewrite the accounting, my calculations were wrong. > > Reviewed-by: Rafael Antognolli <rafael.antogno...@intel.com> [v1] > --- > src/intel/compiler/brw_nir_analyze_ubo_ranges.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/src/intel/compiler/brw_nir_analyze_ubo_ranges.c > b/src/intel/compiler/brw_nir_analyze_ubo_ranges.c > index d58fe3dd2e3..31026ca65ba 100644 > --- a/src/intel/compiler/brw_nir_analyze_ubo_ranges.c > +++ b/src/intel/compiler/brw_nir_analyze_ubo_ranges.c > @@ -141,10 +141,17 @@ analyze_ubos_block(struct ubo_analysis_state *state, > nir_block *block) > if (offset >= 64) > continue; > This should take end into account, not just offset. > + /* The value might span multiple 32-byte chunks. */ > + const int bytes = nir_intrinsic_dest_components(intrin) * > + (nir_dest_bit_size(intrin->dest) / 8); > + const int start = ROUND_DOWN_TO(offset_const->u32[0], 32); > + const int end = ALIGN(offset_const->u32[0] + bytes, 32); > You could probably use / and DIV_ROUND_UP here too. I'm not sure which is better TBH. --Jason > + const int chunks = (end - start) / 32; > + > /* TODO: should we count uses in loops as higher benefit? */ > > struct ubo_block_info *info = get_block_info(state, block); > - info->offsets |= 1ull << offset; > + info->offsets |= ((1ull << chunks) - 1) << offset; > info->uses[offset]++; > } > } > -- > 2.17.0 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/mesa-dev >
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