<div dir="ltr">Reviewed-by: Jason Ekstrand <<a href="mailto:jason@jlekstrand.net">jason@jlekstrand.net</a>> </div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Feb 12, 2019 at 5:57 AM Iago Toral Quiroga <<a href="mailto:itoral@igalia.com">itoral@igalia.com</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">NIR already has these and correctly considers exact/inexact qualification, whereas the backend doesn't and can apply the optimizations where it shouldn't. This happened to be the case in a handful of Tomb Raider shaders, where NIR would skip the optimizations because of a precise qualification but the backend would then (incorrectly) apply them anyway. Besides this, considering that we are not emitting much math in the backend these days it is unlikely that these optimizations are useful in general. A shader-db run confirms that MAD and LRP optimizations, for example, were only being triggered in cases where NIR would skip them due to precise requirements, so in the near future we might want to remove more of these, but for now we just remove the ones that are not completely correct. Suggested-by: Jason Ekstrand <<a href="mailto:jason@jlekstrand.net" target="_blank">jason@jlekstrand.net</a>> --- src/intel/compiler/brw_fs.cpp | 39 +---------------------------------- 1 file changed, 1 insertion(+), 38 deletions(-) diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp index 0f04e577de3..873a1dd8196 100644 --- a/src/intel/compiler/brw_fs.cpp +++ b/src/intel/compiler/brw_fs.cpp @@ -2547,15 +2547,6 @@ fs_visitor::opt_algebraic() break; } - /* a * 0.0 = 0.0 */ - if (inst->src[1].is_zero()) { - inst->opcode = BRW_OPCODE_MOV; - inst->src[0] = inst->src[1]; - inst->src[1] = reg_undef; - progress = true; - break; - } - if (inst->src[0].file == IMM) { assert(inst->src[0].type == BRW_REGISTER_TYPE_F); inst->opcode = BRW_OPCODE_MOV; @@ -2569,14 +2560,6 @@ fs_visitor::opt_algebraic() if (inst->src[1].file != IMM) continue; - /* a + 0.0 = a */ - if (inst->src[1].is_zero()) { - inst->opcode = BRW_OPCODE_MOV; - inst->src[1] = reg_undef; - progress = true; - break; - } - if (inst->src[0].file == IMM) { assert(inst->src[0].type == BRW_REGISTER_TYPE_F); inst->opcode = BRW_OPCODE_MOV; @@ -2595,16 +2578,6 @@ fs_visitor::opt_algebraic() break; } break; - case BRW_OPCODE_LRP: - if (inst->src[1].equals(inst->src[2])) { - inst->opcode = BRW_OPCODE_MOV; - inst->src[0] = inst->src[1]; - inst->src[1] = reg_undef; - inst->src[2] = reg_undef; - progress = true; - break; - } - break; case BRW_OPCODE_CMP: if ((inst->conditional_mod == BRW_CONDITIONAL_Z || inst->conditional_mod == BRW_CONDITIONAL_NZ) && @@ -2682,17 +2655,7 @@ fs_visitor::opt_algebraic() } break; case BRW_OPCODE_MAD: - if (inst->src[1].is_zero() || inst->src[2].is_zero()) { - inst->opcode = BRW_OPCODE_MOV; - inst->src[1] = reg_undef; - inst->src[2] = reg_undef; - progress = true; - } else if (inst->src[0].is_zero()) { - inst->opcode = BRW_OPCODE_MUL; - inst->src[0] = inst->src[2]; - inst->src[2] = reg_undef; - progress = true; - } else if (inst->src[1].is_one()) { + if (inst->src[1].is_one()) { inst->opcode = BRW_OPCODE_ADD; inst->src[1] = inst->src[2]; inst->src[2] = reg_undef; -- 2.17.1 _______________________________________________ mesa-dev mailing list <a href="mailto:mesa-dev@lists.freedesktop.org" target="_blank">mesa-dev@lists.freedesktop.org</a> <a href="https://lists.freedesktop.org/mailman/listinfo/mesa-dev" rel="noreferrer" target="_blank">https://lists.freedesktop.org/mailman/listinfo/mesa-dev</a></blockquote></div>