From 10037ce52320df38d1cc652f4d1be78053b11ed8 Mon Sep 17 00:00:00 2001 From: Alyssa Rosenzweig Date: Sat, 28 Sep 2019 12:13:52 -0400 Subject: [PATCH] pan/midgard: Tightly pack 32-bit constants If we can reuse constant slots from other instructions, we would like to do so to include more instructions per bundle. Signed-off-by: Alyssa Rosenzweig --- src/panfrost/midgard/midgard_schedule.c | 129 ++++++++++++++++++++++++++++---- 1 file changed, 113 insertions(+), 16 deletions(-) diff --git a/src/panfrost/midgard/midgard_schedule.c b/src/panfrost/midgard/midgard_schedule.c index d09726b..7ed36a5 100644 --- a/src/panfrost/midgard/midgard_schedule.c +++ b/src/panfrost/midgard/midgard_schedule.c @@ -370,26 +370,123 @@ mir_adjust_constants(midgard_instruction *ins, if (!ins->has_constants) return true; - /* TODO: Deduplicate; permit multiple constants within a bundle */ - - if (destructive && !pred->constant_count) { - if (ins->alu.reg_mode == midgard_reg_mode_16) { - /* TODO: Fix packing XXX */ - uint16_t *bundles = (uint16_t *) pred->constants; - uint32_t *constants = (uint32_t *) ins->constants; - - /* Copy them wholesale */ - for (unsigned i = 0; i < 4; ++i) - bundles[i] = constants[i]; - } else { - memcpy(pred->constants, ins->constants, 16); - } + if (ins->alu.reg_mode == midgard_reg_mode_16) { + /* TODO: 16-bit constant combining */ + if (pred->constant_count) + return false; + + uint16_t *bundles = (uint16_t *) pred->constants; + uint32_t *constants = (uint32_t *) ins->constants; + + /* Copy them wholesale */ + for (unsigned i = 0; i < 4; ++i) + bundles[i] = constants[i]; pred->constant_count = 16; - return true; + } else { + /* Pack 32-bit constants */ + uint32_t *bundles = (uint32_t *) pred->constants; + uint32_t *constants = (uint32_t *) ins->constants; + unsigned r_constant = SSA_FIXED_REGISTER(REGISTER_CONSTANT); + unsigned mask = mir_mask_of_read_components(ins, r_constant); + + /* First, check if it fits */ + unsigned count = DIV_ROUND_UP(pred->constant_count, sizeof(uint32_t)); + unsigned existing_count = count; + + for (unsigned i = 0; i < 4; ++i) { + if (!(mask & (1 << i))) + continue; + + bool ok = false; + + /* Look for existing constant */ + for (unsigned j = 0; j < existing_count; ++j) { + if (bundles[j] == constants[i]) { + ok = true; + break; + } + } + + if (ok) + continue; + + /* If the constant is new, check ourselves */ + for (unsigned j = 0; j < i; ++j) { + if (constants[j] == constants[i]) { + ok = true; + break; + } + } + + if (ok) + continue; + + /* Otherwise, this is a new constant */ + count++; + } + + /* Check if we have space */ + if (count > 4) + return false; + + /* If non-destructive, we're done */ + if (!destructive) + return true; + + /* If destructive, let's copy in the new constants and adjust + * swizzles to pack it in. */ + + uint32_t indices[4] = { 0 }; + + /* Reset count */ + count = existing_count; + + for (unsigned i = 0; i < 4; ++i) { + if (!(mask & (1 << i))) + continue; + + uint32_t cons = constants[i]; + bool constant_found = false; + + /* Search for the constant */ + for (unsigned j = 0; j < count; ++j) { + if (bundles[j] != cons) + continue; + + /* We found it, reuse */ + indices[i] = j; + constant_found = true; + break; + } + + if (constant_found) + continue; + + /* We didn't find it, so allocate it */ + unsigned idx = count++; + + /* We have space, copy it in! */ + bundles[idx] = cons; + indices[i] = idx; + } + + pred->constant_count = count * sizeof(uint32_t); + + /* Cool, we have it in. So use indices as a + * swizzle */ + + unsigned swizzle = SWIZZLE_FROM_ARRAY(indices); + + if (ins->src[0] == r_constant) + ins->alu.src1 = vector_alu_apply_swizzle(ins->alu.src1, swizzle); + + if (ins->src[1] == r_constant) + ins->alu.src2 = vector_alu_apply_swizzle(ins->alu.src2, swizzle); + } - return !pred->constant_count; + return true; } static midgard_instruction * -- 2.7.4