diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp index b6e5ed6a72b..72190f3312c 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp @@ -250,6 +250,57 @@ emit_system_values_block(nir_block *block, void *void_visitor) *reg = *v->emit_cs_work_group_id_setup(); break; + case nir_intrinsic_load_helper_invocation: + assert(v->stage == MESA_SHADER_FRAGMENT); + reg = &v->nir_system_values[SYSTEM_VALUE_HELPER_INVOCATION]; + if (reg->file == BAD_FILE) { + const fs_builder abld = + v->bld.annotate("gl_HelperInvocation", NULL); + + /* On Gen6+ (gl_HelperInvocation is only exposed on Gen7+) the + * pixel mask is in g1.7 of the thread payload. + * + * We move the per-channel pixel enable bit to the low bit of each + * channel by shifting the byte containing the pixel mask by the + * vector immediate 0x76543210UV. + * + * The region of <1,8,0> reads only 1 byte (the pixel masks for + * subspans 0 and 1) in SIMD8 and an additional byte (the pixel + * masks for 2 and 3) in SIMD16. + */ + fs_reg shifted = abld.vgrf(BRW_REGISTER_TYPE_UW, 1); + abld.SHR(shifted, + stride(byte_offset(retype(brw_vec1_grf(1, 0), + BRW_REGISTER_TYPE_UB), 28), + 1, 8, 0), + brw_imm_uv(0x76543210)); + + /* A set bit in the pixel mask means the channel is enabled, but + * that is the opposite of gl_HelperInvocation so we need to invert + * the mask. + * + * The negate source-modifier bit of logical instructions on Gen8+ + * performs 1's complement negation, so we can use that instead of + * a NOT instruction. + */ + fs_reg inverted = negate(shifted); + if (v->devinfo->gen < 8) { + inverted = abld.vgrf(BRW_REGISTER_TYPE_UW); + abld.NOT(inverted, shifted); + } + + /* We then resolve the 0/1 result to 0/~0 boolean values by ANDing + * with 1 and negating. + */ + fs_reg anded = abld.vgrf(BRW_REGISTER_TYPE_UD, 1); + abld.AND(anded, inverted, brw_imm_uw(1)); + + fs_reg dst = abld.vgrf(BRW_REGISTER_TYPE_D, 1); + abld.MOV(dst, negate(retype(anded, BRW_REGISTER_TYPE_D))); + *reg = dst; + } + break; + default: break; } @@ -1776,6 +1827,7 @@ fs_visitor::nir_emit_fs_intrinsic(const fs_builder &bld, break; } + case nir_intrinsic_load_helper_invocation: case nir_intrinsic_load_sample_mask_in: case nir_intrinsic_load_sample_id: { gl_system_value sv = nir_system_value_from_intrinsic(instr->intrinsic); |