for (unsigned reg = 0; reg < 2; reg++)
constrained[p.atom_of_reg(reg)] = true;
+ /* At Intel Broadwell PRM, vol 07, section "Instruction Set Reference",
+ * subsection "EUISA Instructions", Send Message (page 990):
+ *
+ * "r127 must not be used for return address when there is a src and
+ * dest overlap in send instruction."
+ *
+ * Register allocation ensures that, so don't move 127 around to avoid
+ * breaking that property.
+ */
+ if (v->devinfo->gen >= 8)
+ constrained[p.atom_of_reg(127)] = true;
+
foreach_block_and_inst(block, fs_inst, inst, v->cfg) {
/* Assume that anything referenced via fixed GRFs is baked into the
* hardware's fixed-function logic and may be unsafe to move around.
constrained[p.atom_of_reg(reg_of(inst->src[i]))] = true;
}
+ /* Preserve the original allocation of VGRFs used by the barycentric
+ * source of the LINTERP instruction on Gen6, since pair-aligned
+ * barycentrics allow the PLN instruction to be used.
+ */
+ if (v->devinfo->has_pln && v->devinfo->gen <= 6 &&
+ inst->opcode == FS_OPCODE_LINTERP)
+ constrained[p.atom_of_reg(reg_of(inst->src[0]))] = true;
+
/* The location of the Gen7 MRF hack registers is hard-coded in the
* rest of the compiler back-end. Don't attempt to move them around.
*/
if (v->devinfo->gen >= 7) {
assert(inst->dst.file != MRF);
- for (int i = 0; i < v->implied_mrf_writes(inst); i++) {
+ for (unsigned i = 0; i < inst->implied_mrf_writes(); i++) {
const unsigned reg = GEN7_MRF_HACK_START + inst->base_mrf + i;
constrained[p.atom_of_reg(reg)] = true;
}
}
/**
- * Estimate the number of GRF bank conflict cycles incurred by an instruction.
+ * Return whether the instruction incurs GRF bank conflict cycles.
*
- * Note that this neglects conflict cycles prior to register allocation
- * because we don't know which bank each VGRF is going to end up aligned to.
+ * Note that this is only accurate after register allocation because otherwise
+ * we don't know which bank each VGRF is going to end up aligned to.
*/
-unsigned
-fs_visitor::bank_conflict_cycles(const fs_inst *inst) const
+bool
+has_bank_conflict(const gen_device_info *devinfo, const fs_inst *inst)
{
- if (grf_used && inst->is_3src(devinfo) &&
- is_grf(inst->src[1]) && is_grf(inst->src[2]) &&
- bank_of(reg_of(inst->src[1])) == bank_of(reg_of(inst->src[2])) &&
- !is_conflict_optimized_out(devinfo, inst)) {
- return DIV_ROUND_UP(inst->dst.component_size(inst->exec_size), REG_SIZE);
- } else {
- return 0;
- }
+ return inst->is_3src(devinfo) &&
+ is_grf(inst->src[1]) && is_grf(inst->src[2]) &&
+ bank_of(reg_of(inst->src[1])) == bank_of(reg_of(inst->src[2])) &&
+ !is_conflict_optimized_out(devinfo, inst);
}