From 9626ea497de8af5580ee3af76df79ad8083c5922 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Tue, 26 Jun 2018 18:30:09 -0700 Subject: [PATCH] i965/vec4: Properly handle sign(-abs(x)) This is achived by copying the sign(abs(x)) optimization from the FS backend. On Gen7 an earlier platforms, this fixes new piglit tests: - glsl-1.10/execution/vs-sign-neg-abs.shader_test - glsl-1.10/execution/vs-sign-sat-neg-abs.shader_test Signed-off-by: Ian Romanick Cc: mesa-stable@lists.freedesktop.org Reviewed-by: Caio Marcelo de Oliveira Filho --- src/intel/compiler/brw_vec4_nir.cpp | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/src/intel/compiler/brw_vec4_nir.cpp b/src/intel/compiler/brw_vec4_nir.cpp index b77fa5fa821..4c3a2d2e10a 100644 --- a/src/intel/compiler/brw_vec4_nir.cpp +++ b/src/intel/compiler/brw_vec4_nir.cpp @@ -1805,7 +1805,23 @@ vec4_visitor::nir_emit_alu(nir_alu_instr *instr) unreachable("not reached: should have been lowered"); case nir_op_fsign: - if (type_sz(op[0].type) < 8) { + if (op[0].abs) { + /* Straightforward since the source can be assumed to be either + * strictly >= 0 or strictly <= 0 depending on the setting of the + * negate flag. + */ + inst = emit(MOV(dst, op[0])); + inst->conditional_mod = BRW_CONDITIONAL_NZ; + + inst = (op[0].negate) + ? emit(MOV(dst, brw_imm_f(-1.0f))) + : emit(MOV(dst, brw_imm_f(1.0f))); + inst->predicate = BRW_PREDICATE_NORMAL; + + if (instr->dest.saturate) + inst->saturate = true; + + } else if (type_sz(op[0].type) < 8) { /* AND(val, 0x80000000) gives the sign bit. * * Predicated OR ORs 1.0 (0x3f800000) with the sign bit if val is not -- 2.30.2