From 6ffbfc760da14fc710a05438b9fd9eff034128da Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Thu, 15 Sep 2016 21:12:34 -0700 Subject: [PATCH] nir/spirv/cfg: Use a nop intrinsic for tagging the ends of blocks 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. This fixes a bug triggered by a couple of vkQuake shaders. Signed-off-by: Jason Ekstrand Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97233 Cc: "12.0" Tested-by: Dave Airlie Reviewed-by: Kenneth Graunke --- 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 1c8c4f8e108..62b9056990e 100644 --- a/src/compiler/spirv/vtn_cfg.c +++ b/src/compiler/spirv/vtn_cfg.c @@ -531,7 +531,7 @@ 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)); } @@ -589,7 +589,9 @@ 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 7f5444ee875..6f34f09ebd2 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 { -- 2.30.2