From 97f8ec321b73975bf6a3ed997c10381942e9f19e Mon Sep 17 00:00:00 2001 From: Neil Roberts Date: Tue, 7 Jul 2020 15:49:27 +0200 Subject: [PATCH] v3d/compiler: Lower geometry output store base into offset src When generating the VPM write instruction for geometry shader outputs, emit_store_output_gs ends up adding the base and offset arguments together with an ADD instruction. The addition was done at the VIR level after scheduling so it always ends up right next to the corresponding stvpm instruction. Most of the time the offset is constant but nothing does any constant folding at the VIR level. This patch makes it instead fold the addition into the offset at the NIR level in v3d_nir_lower_io so that the NIR-level constant folding can get rid of the addition most of the time. v2: Use nir_iadd_imm to simplify the code. (Eric Anholt) Reviewed-by: Iago Toral Quiroga Part-of: --- src/broadcom/compiler/nir_to_vir.c | 8 +++++--- src/broadcom/compiler/v3d_nir_lower_io.c | 13 ++++++++++--- 2 files changed, 15 insertions(+), 6 deletions(-) diff --git a/src/broadcom/compiler/nir_to_vir.c b/src/broadcom/compiler/nir_to_vir.c index 8f568d4779a..671f3dbd2ab 100644 --- a/src/broadcom/compiler/nir_to_vir.c +++ b/src/broadcom/compiler/nir_to_vir.c @@ -2014,10 +2014,12 @@ emit_store_output_gs(struct v3d_compile *c, nir_intrinsic_instr *instr) { assert(instr->num_components == 1); + struct qreg offset = ntq_get_src(c, instr->src[1], 0); + uint32_t base_offset = nir_intrinsic_base(instr); - struct qreg src_offset = ntq_get_src(c, instr->src[1], 0); - struct qreg offset = - vir_ADD(c, vir_uniform_ui(c, base_offset), src_offset); + + if (base_offset) + offset = vir_ADD(c, vir_uniform_ui(c, base_offset), offset); /* Usually, for VS or FS, we only emit outputs once at program end so * our VPM writes are never in non-uniform control flow, but this diff --git a/src/broadcom/compiler/v3d_nir_lower_io.c b/src/broadcom/compiler/v3d_nir_lower_io.c index 2d3d307ef2f..d35061d33a1 100644 --- a/src/broadcom/compiler/v3d_nir_lower_io.c +++ b/src/broadcom/compiler/v3d_nir_lower_io.c @@ -81,10 +81,17 @@ v3d_nir_store_output(nir_builder *b, int base, nir_ssa_def *offset, intr->num_components = 1; intr->src[0] = nir_src_for_ssa(chan); - if (offset) - intr->src[1] = nir_src_for_ssa(offset); - else + if (offset) { + /* When generating the VIR instruction, the base and the offset + * are just going to get added together with an ADD instruction + * so we might as well do the add here at the NIR level instead + * and let the constant folding do its magic. + */ + intr->src[1] = nir_src_for_ssa(nir_iadd_imm(b, offset, base)); + base = 0; + } else { intr->src[1] = nir_src_for_ssa(nir_imm_int(b, 0)); + } nir_intrinsic_set_base(intr, base); nir_intrinsic_set_write_mask(intr, 0x1); -- 2.30.2