From 29541ec53175120f916a0ab74e5d82308aa9ef47 Mon Sep 17 00:00:00 2001 From: Iago Toral Quiroga Date: Mon, 4 Jan 2016 16:02:47 +0100 Subject: nir/lower_double_ops: lower floor() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit At least i965 hardware does not have native support for floor on doubles. v2 (Sam): - Improve the lowering pass to remove one bcsel (Jason) Signed-off-by: Samuel Iglesias Gonsálvez Reviewed-by: Jason Ekstrand --- src/compiler/nir/nir.h | 1 + src/compiler/nir/nir_lower_double_ops.c | 25 +++++++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 4a49d6e1ac8..809e83b7d12 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -2418,6 +2418,7 @@ typedef enum { nir_lower_dsqrt = (1 << 1), nir_lower_drsq = (1 << 2), nir_lower_dtrunc = (1 << 3), + nir_lower_dfloor = (1 << 4), } nir_lower_doubles_options; void nir_lower_doubles(nir_shader *shader, nir_lower_doubles_options options); diff --git a/src/compiler/nir/nir_lower_double_ops.c b/src/compiler/nir/nir_lower_double_ops.c index e8ae884d12c..1370ddf9266 100644 --- a/src/compiler/nir/nir_lower_double_ops.c +++ b/src/compiler/nir/nir_lower_double_ops.c @@ -351,6 +351,23 @@ lower_trunc(nir_builder *b, nir_ssa_def *src) nir_iand(b, mask_hi, src_hi)))); } +static nir_ssa_def * +lower_floor(nir_builder *b, nir_ssa_def *src) +{ + /* + * For x >= 0, floor(x) = trunc(x) + * For x < 0, + * - if x is integer, floor(x) = x + * - otherwise, floor(x) = trunc(x) - 1 + */ + nir_ssa_def *tr = nir_ftrunc(b, src); + nir_ssa_def *positive = nir_fge(b, src, nir_imm_double(b, 0.0)); + return nir_bcsel(b, + nir_ior(b, positive, nir_feq(b, src, tr)), + tr, + nir_fsub(b, tr, nir_imm_double(b, 1.0))); +} + static void lower_doubles_instr(nir_alu_instr *instr, nir_lower_doubles_options options) { @@ -379,6 +396,11 @@ lower_doubles_instr(nir_alu_instr *instr, nir_lower_doubles_options options) return; break; + case nir_op_ffloor: + if (!(options & nir_lower_dfloor)) + return; + break; + default: return; } @@ -405,6 +427,9 @@ lower_doubles_instr(nir_alu_instr *instr, nir_lower_doubles_options options) case nir_op_ftrunc: result = lower_trunc(&bld, src); break; + case nir_op_ffloor: + result = lower_floor(&bld, src); + break; default: unreachable("unhandled opcode"); } -- cgit v1.2.3