From c92fb60007f9c73a4c174f5f4cbce57fbc5118f4 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Mon, 11 Jun 2018 23:21:57 -0700 Subject: [PATCH] intel/fs/gen12: Implement gl_FrontFacing on gen12+. The bit moved on gen12 in order to prepare for dual-SIMD8 dispatch. This implementation isn't an entirely complete as it only works on SIMD8 and SIMD16 and not dual-SIMD8. Reviewed-by: Kenneth Graunke --- src/intel/compiler/brw_fs.cpp | 8 +++++++- src/intel/compiler/brw_fs_nir.cpp | 19 ++++++++++++++++++- 2 files changed, 25 insertions(+), 2 deletions(-) diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp index 86cd5b96986..46f5fca9a62 100644 --- a/src/intel/compiler/brw_fs.cpp +++ b/src/intel/compiler/brw_fs.cpp @@ -1326,7 +1326,13 @@ fs_visitor::emit_frontfacing_interpolation() { fs_reg *reg = new(this->mem_ctx) fs_reg(vgrf(glsl_type::bool_type)); - if (devinfo->gen >= 6) { + if (devinfo->gen >= 12) { + fs_reg g1 = fs_reg(retype(brw_vec1_grf(1, 1), BRW_REGISTER_TYPE_W)); + + fs_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_W); + bld.ASR(tmp, g1, brw_imm_d(15)); + bld.NOT(*reg, tmp); + } else if (devinfo->gen >= 6) { /* Bit 15 of g0.0 is 0 if the polygon is front facing. We want to create * a boolean result from this (~0/true or 0/false). * diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp index 6a9a2548b6c..709aeacf38f 100644 --- a/src/intel/compiler/brw_fs_nir.cpp +++ b/src/intel/compiler/brw_fs_nir.cpp @@ -580,7 +580,24 @@ fs_visitor::optimize_frontfacing_ternary(nir_alu_instr *instr, fs_reg tmp = vgrf(glsl_type::int_type); - if (devinfo->gen >= 6) { + if (devinfo->gen >= 12) { + /* Bit 15 of g1.1 is 0 if the polygon is front facing. */ + fs_reg g1 = fs_reg(retype(brw_vec1_grf(1, 1), BRW_REGISTER_TYPE_W)); + + /* For (gl_FrontFacing ? 1.0 : -1.0), emit: + * + * or(8) tmp.1<2>W g0.0<0,1,0>W 0x00003f80W + * and(8) dst<1>D tmp<8,8,1>D 0xbf800000D + * + * and negate the result for (gl_FrontFacing ? -1.0 : 1.0). + */ + bld.OR(subscript(tmp, BRW_REGISTER_TYPE_W, 1), + g1, brw_imm_uw(0x3f80)); + + if (value1 == -1.0f) + bld.MOV(tmp, negate(tmp)); + + } else if (devinfo->gen >= 6) { /* Bit 15 of g0.0 is 0 if the polygon is front facing. */ fs_reg g0 = fs_reg(retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_W)); -- 2.30.2