On 16 September 2016 at 14:16, Jason Ekstrand <ja...@jlekstrand.net> wrote: > Previously, we were saving off the last nir_block in a vtn_block before > moving on so that we could find the nir_block again when it came time to > handle phi sources. Unfortunately, NIR's control flow modification code is > inconsistent when it comes to how it splits blocks so the block pointer we > saved off may point to a block somewhere else in the shader by the time we > get around to handling phi sources. In order to get around this, we insert > a nop instruction and use that as the logical end of our block. Since the > control flow manipulation code respects instructions, the nop will keeps > its place like any other instruction and we can easily find the end of our > block when we need it. > > Signed-off-by: Jason Ekstrand <ja...@jlekstrand.net>
I'm not sure I'm good enough to review it, but this makes sense after I looked through it. It also fixes vkQuake on radv. Tested-by: Dave Airlie <airl...@redhat.com> Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=97233 Dave. > --- > src/compiler/spirv/vtn_cfg.c | 6 ++++-- > src/compiler/spirv/vtn_private.h | 4 ++-- > 2 files changed, 6 insertions(+), 4 deletions(-) > > diff --git a/src/compiler/spirv/vtn_cfg.c b/src/compiler/spirv/vtn_cfg.c > index d9096f4..599ed69 100644 > --- a/src/compiler/spirv/vtn_cfg.c > +++ b/src/compiler/spirv/vtn_cfg.c > @@ -518,7 +518,7 @@ vtn_handle_phi_second_pass(struct vtn_builder *b, SpvOp > opcode, > struct vtn_block *pred = > vtn_value(b, w[i + 1], vtn_value_type_block)->block; > > - b->nb.cursor = nir_after_block_before_jump(pred->end_block); > + b->nb.cursor = nir_after_instr(&pred->end_nop->instr); > > vtn_local_store(b, src, nir_deref_var_create(b, phi_var)); > } > @@ -576,7 +576,9 @@ vtn_emit_cf_list(struct vtn_builder *b, struct list_head > *cf_list, > > vtn_foreach_instruction(b, block_start, block_end, handler); > > - block->end_block = nir_cursor_current_block(b->nb.cursor); > + block->end_nop = nir_intrinsic_instr_create(b->nb.shader, > + nir_intrinsic_nop); > + nir_builder_instr_insert(&b->nb, &block->end_nop->instr); > > if ((*block->branch & SpvOpCodeMask) == SpvOpReturnValue) { > struct vtn_ssa_value *src = vtn_ssa_value(b, block->branch[1]); > diff --git a/src/compiler/spirv/vtn_private.h > b/src/compiler/spirv/vtn_private.h > index 7f5444e..6f34f09 100644 > --- a/src/compiler/spirv/vtn_private.h > +++ b/src/compiler/spirv/vtn_private.h > @@ -149,8 +149,8 @@ struct vtn_block { > /** Points to the switch case started by this block (if any) */ > struct vtn_case *switch_case; > > - /** The last block in this SPIR-V block. */ > - nir_block *end_block; > + /** Every block ends in a nop intrinsic so that we can find it again */ > + nir_intrinsic_instr *end_nop; > }; > > struct vtn_function { > -- > 2.5.0.400.gff86faf > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
