From 1f5a3391bbf8bb5f2bef047ddfcf08e6aa5f5794 Mon Sep 17 00:00:00 2001 From: Iago Toral Quiroga Date: Mon, 15 May 2023 10:02:10 +0200 Subject: [PATCH] broadcom/compiler: only assign rf0 as last resort in V3D 7.x MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit So we can use it for ldunif(a) and avoid generating ldunif(a)rf which can't be paired with conditional instructions. shader-db (pi5): total instructions in shared programs: 11357802 -> 11338883 (-0.17%) instructions in affected programs: 7117889 -> 7098970 (-0.27%) helped: 24264 HURT: 17574 Instructions are helped. total uniforms in shared programs: 3857808 -> 3857815 (<.01%) uniforms in affected programs: 92 -> 99 (7.61%) helped: 0 HURT: 1 total max-temps in shared programs: 2230904 -> 2230199 (-0.03%) max-temps in affected programs: 52309 -> 51604 (-1.35%) helped: 1219 HURT: 725 Max-temps are helped. total sfu-stalls in shared programs: 15021 -> 15236 (1.43%) sfu-stalls in affected programs: 6848 -> 7063 (3.14%) helped: 1866 HURT: 1704 Inconclusive result total inst-and-stalls in shared programs: 11372823 -> 11354119 (-0.16%) inst-and-stalls in affected programs: 7149177 -> 7130473 (-0.26%) helped: 24315 HURT: 17561 Inst-and-stalls are helped. total nops in shared programs: 273624 -> 273711 (0.03%) nops in affected programs: 31562 -> 31649 (0.28%) helped: 1619 HURT: 1854 Inconclusive result (value mean confidence interval includes 0). Reviewed-by: Alejandro Piñeiro Part-of: --- src/broadcom/compiler/vir_register_allocate.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/src/broadcom/compiler/vir_register_allocate.c b/src/broadcom/compiler/vir_register_allocate.c index a3780a949a5..081376c0f08 100644 --- a/src/broadcom/compiler/vir_register_allocate.c +++ b/src/broadcom/compiler/vir_register_allocate.c @@ -950,6 +950,11 @@ v3d_ra_select_rf(struct v3d_ra_select_callback_data *v3d_ra, for (int i = 0; i < PHYS_COUNT; i++) { int phys_off = (v3d_ra->next_phys + i) % PHYS_COUNT; + + /* Try to keep rf0 available for ldunif in 7.x (see above). */ + if (v3d_ra->devinfo->ver >= 71 && phys_off == 0) + continue; + int phys = v3d_ra->phys_index + phys_off; if (BITSET_TEST(regs, phys)) { @@ -959,6 +964,14 @@ v3d_ra_select_rf(struct v3d_ra_select_callback_data *v3d_ra, } } + /* If we couldn't allocate, do try to assign rf0 if it is available. */ + if (v3d_ra->devinfo->ver >= 71 && + BITSET_TEST(regs, v3d_ra->phys_index)) { + v3d_ra->next_phys = 1; + *out = v3d_ra->phys_index; + return true; + } + return false; }