#include "brw_fs.h"
#include "brw_cfg.h"
+#include "util/half_float.h"
using namespace brw;
*/
exec_list *uses;
- /** The immediate value. We currently only handle floats. */
- float val;
+ /** The immediate value */
+ union {
+ char bytes[8];
+ double df;
+ int64_t d64;
+ float f;
+ int32_t d;
+ int16_t w;
+ };
+ uint8_t size;
+
+ /** When promoting half-float we need to account for certain restrictions */
+ bool is_half_float;
/**
* The GRF register and subregister number where we've decided to store the
};
static struct imm *
-find_imm(struct table *table, float val)
+find_imm(struct table *table, void *data, uint8_t size)
{
for (int i = 0; i < table->len; i++) {
- if (table->imm[i].val == val) {
+ if (table->imm[i].size == size &&
+ !memcmp(table->imm[i].bytes, data, size)) {
return &table->imm[i];
}
}
return a->first_use_ip - b->first_use_ip;
}
+static bool
+get_constant_value(const struct gen_device_info *devinfo,
+ const fs_inst *inst, uint32_t src_idx,
+ void *out, brw_reg_type *out_type)
+{
+ const bool can_do_source_mods = inst->can_do_source_mods(devinfo);
+ const fs_reg *src = &inst->src[src_idx];
+
+ *out_type = src->type;
+
+ switch (*out_type) {
+ case BRW_REGISTER_TYPE_DF: {
+ double val = !can_do_source_mods ? src->df : fabs(src->df);
+ memcpy(out, &val, 8);
+ break;
+ }
+ case BRW_REGISTER_TYPE_F: {
+ float val = !can_do_source_mods ? src->f : fabsf(src->f);
+ memcpy(out, &val, 4);
+ break;
+ }
+ case BRW_REGISTER_TYPE_HF: {
+ uint16_t val = src->d & 0xffffu;
+ if (can_do_source_mods)
+ val = _mesa_float_to_half(fabsf(_mesa_half_to_float(val)));
+ memcpy(out, &val, 2);
+ break;
+ }
+ case BRW_REGISTER_TYPE_Q: {
+ int64_t val = !can_do_source_mods ? src->d64 : abs(src->d64);
+ memcpy(out, &val, 8);
+ break;
+ }
+ case BRW_REGISTER_TYPE_UQ:
+ memcpy(out, &src->u64, 8);
+ break;
+ case BRW_REGISTER_TYPE_D: {
+ int32_t val = !can_do_source_mods ? src->d : abs(src->d);
+ memcpy(out, &val, 4);
+ break;
+ }
+ case BRW_REGISTER_TYPE_UD:
+ memcpy(out, &src->ud, 4);
+ break;
+ case BRW_REGISTER_TYPE_W: {
+ int16_t val = src->d & 0xffffu;
+ if (can_do_source_mods)
+ val = abs(val);
+ memcpy(out, &val, 2);
+ break;
+ }
+ case BRW_REGISTER_TYPE_UW:
+ memcpy(out, &src->ud, 2);
+ break;
+ default:
+ return false;
+ };
+
+ return true;
+}
+
+static struct brw_reg
+build_imm_reg_for_copy(struct imm *imm)
+{
+ switch (imm->size) {
+ case 8:
+ return brw_imm_d(imm->d64);
+ case 4:
+ return brw_imm_d(imm->d);
+ case 2:
+ return brw_imm_w(imm->w);
+ default:
+ unreachable("not implemented");
+ }
+}
+
+static inline uint32_t
+get_alignment_for_imm(const struct imm *imm)
+{
+ if (imm->is_half_float)
+ return 4; /* At least MAD seems to require this */
+ else
+ return imm->size;
+}
+
+static bool
+needs_negate(const struct fs_reg *reg, const struct imm *imm)
+{
+ switch (reg->type) {
+ case BRW_REGISTER_TYPE_DF:
+ return signbit(reg->df) != signbit(imm->df);
+ case BRW_REGISTER_TYPE_F:
+ return signbit(reg->f) != signbit(imm->f);
+ case BRW_REGISTER_TYPE_Q:
+ return (reg->d64 < 0) != (imm->d64 < 0);
+ case BRW_REGISTER_TYPE_D:
+ return (reg->d < 0) != (imm->d < 0);
+ case BRW_REGISTER_TYPE_HF:
+ return (reg->d & 0x8000u) != (imm->w & 0x8000u);
+ case BRW_REGISTER_TYPE_W:
+ return ((reg->d & 0xffffu) < 0) != (imm->w < 0);
+ case BRW_REGISTER_TYPE_UQ:
+ case BRW_REGISTER_TYPE_UD:
+ case BRW_REGISTER_TYPE_UW:
+ return false;
+ default:
+ unreachable("not implemented");
+ };
+}
+
bool
fs_visitor::opt_combine_constants()
{
continue;
for (int i = 0; i < inst->sources; i++) {
- if (inst->src[i].file != IMM ||
- inst->src[i].type != BRW_REGISTER_TYPE_F)
+ if (inst->src[i].file != IMM)
+ continue;
+
+ char data[8];
+ brw_reg_type type;
+ if (!get_constant_value(devinfo, inst, i, data, &type))
continue;
- float val = !inst->can_do_source_mods(devinfo) ? inst->src[i].f :
- fabs(inst->src[i].f);
- struct imm *imm = find_imm(&table, val);
+ uint8_t size = type_sz(type);
+
+ struct imm *imm = find_imm(&table, data, size);
if (imm) {
bblock_t *intersection = cfg_t::intersect(block, imm->block);
imm->uses_by_coissue += could_coissue(devinfo, inst);
imm->must_promote = imm->must_promote || must_promote_imm(devinfo, inst);
imm->last_use_ip = ip;
+ if (type == BRW_REGISTER_TYPE_HF)
+ imm->is_half_float = true;
} else {
imm = new_imm(&table, const_ctx);
imm->block = block;
imm->inst = inst;
imm->uses = new(const_ctx) exec_list();
imm->uses->push_tail(link(const_ctx, &inst->src[i]));
- imm->val = val;
+ memcpy(imm->bytes, data, size);
+ imm->size = size;
+ imm->is_half_float = type == BRW_REGISTER_TYPE_HF;
imm->uses_by_coissue = could_coissue(devinfo, inst);
imm->must_promote = must_promote_imm(devinfo, inst);
imm->first_use_ip = ip;
*/
exec_node *n = (imm->inst ? imm->inst :
imm->block->last_non_control_flow_inst()->next);
- const fs_builder ibld = bld.at(imm->block, n).exec_all().group(1, 0);
- ibld.MOV(reg, brw_imm_f(imm->val));
- imm->nr = reg.nr;
- imm->subreg_offset = reg.offset;
+ /* From the BDW and CHV PRM, 3D Media GPGPU, Special Restrictions:
+ *
+ * "In Align16 mode, the channel selects and channel enables apply to a
+ * pair of half-floats, because these parameters are defined for DWord
+ * elements ONLY. This is applicable when both source and destination
+ * are half-floats."
+ *
+ * This means that Align16 instructions that use promoted HF immediates
+ * and use a <0,1,0>:HF region would read 2 HF slots instead of
+ * replicating the single one we want. To avoid this, we always populate
+ * both HF slots within a DWord with the constant.
+ */
+ const uint32_t width = devinfo->gen == 8 && imm->is_half_float ? 2 : 1;
+ const fs_builder ibld = bld.at(imm->block, n).exec_all().group(width, 0);
+
+ /* Put the immediate in an offset aligned to its size. Some instructions
+ * seem to have additional alignment requirements, so account for that
+ * too.
+ */
+ reg.offset = ALIGN(reg.offset, get_alignment_for_imm(imm));
- reg.offset += sizeof(float);
- if (reg.offset == 8 * sizeof(float)) {
+ /* Ensure we have enough space in the register to copy the immediate */
+ struct brw_reg imm_reg = build_imm_reg_for_copy(imm);
+ if (reg.offset + type_sz(imm_reg.type) * width > REG_SIZE) {
reg.nr = alloc.allocate(1);
reg.offset = 0;
}
+
+ ibld.MOV(retype(reg, imm_reg.type), imm_reg);
+ imm->nr = reg.nr;
+ imm->subreg_offset = reg.offset;
+
+ reg.offset += imm->size * width;
}
promoted_constants = table.len;
for (int i = 0; i < table.len; i++) {
foreach_list_typed(reg_link, link, link, table.imm[i].uses) {
fs_reg *reg = link->reg;
- assert((isnan(reg->f) && isnan(table.imm[i].val)) ||
- fabsf(reg->f) == fabs(table.imm[i].val));
+#ifdef DEBUG
+ switch (reg->type) {
+ case BRW_REGISTER_TYPE_DF:
+ assert((isnan(reg->df) && isnan(table.imm[i].df)) ||
+ (fabs(reg->df) == fabs(table.imm[i].df)));
+ break;
+ case BRW_REGISTER_TYPE_F:
+ assert((isnan(reg->f) && isnan(table.imm[i].f)) ||
+ (fabsf(reg->f) == fabsf(table.imm[i].f)));
+ break;
+ case BRW_REGISTER_TYPE_HF:
+ assert((isnan(_mesa_half_to_float(reg->d & 0xffffu)) &&
+ isnan(_mesa_half_to_float(table.imm[i].w))) ||
+ (fabsf(_mesa_half_to_float(reg->d & 0xffffu)) ==
+ fabsf(_mesa_half_to_float(table.imm[i].w))));
+ break;
+ case BRW_REGISTER_TYPE_Q:
+ assert(abs(reg->d64) == abs(table.imm[i].d64));
+ break;
+ case BRW_REGISTER_TYPE_UQ:
+ assert(reg->d64 == table.imm[i].d64);
+ break;
+ case BRW_REGISTER_TYPE_D:
+ assert(abs(reg->d) == abs(table.imm[i].d));
+ break;
+ case BRW_REGISTER_TYPE_UD:
+ assert(reg->d == table.imm[i].d);
+ break;
+ case BRW_REGISTER_TYPE_W:
+ assert(abs((int16_t) (reg->d & 0xffff)) == table.imm[i].w);
+ break;
+ case BRW_REGISTER_TYPE_UW:
+ assert((reg->ud & 0xffffu) == (uint16_t) table.imm[i].w);
+ break;
+ default:
+ break;
+ }
+#endif
reg->file = VGRF;
reg->offset = table.imm[i].subreg_offset;
reg->stride = 0;
- reg->negate = signbit(reg->f) != signbit(table.imm[i].val);
+ reg->negate = needs_negate(reg, &table.imm[i]);
reg->nr = table.imm[i].nr;
}
}
for (int i = 0; i < table.len; i++) {
struct imm *imm = &table.imm[i];
- printf("%.3fF - block %3d, reg %3d sub %2d, Uses: (%2d, %2d), "
- "IP: %4d to %4d, length %4d\n",
- imm->val,
+ printf("0x%016" PRIx64 " - block %3d, reg %3d sub %2d, "
+ "Uses: (%2d, %2d), IP: %4d to %4d, length %4d\n",
+ (uint64_t)(imm->d & BITFIELD64_MASK(imm->size * 8)),
imm->block->num,
imm->nr,
imm->subreg_offset,