From 51244859e368d9270a1f2f84aec6e97fbc1f5fac Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Wed, 30 Nov 2016 14:00:28 -0800 Subject: [PATCH] vc4: Avoid false scheduling dependencies for LOAD_IMMs. Noticed in shaders with branching, where we ended up scheduling delay slots near the start of a block for the uniforms reset setup. total instructions in shared programs: 93970 -> 93951 (-0.02%) instructions in affected programs: 3117 -> 3098 (-0.61%) 3DMMES performance +0.423087% +/- 0.133521% (n=9,10) --- src/gallium/drivers/vc4/vc4_qpu_schedule.c | 5 +++++ src/gallium/drivers/vc4/vc4_qpu_validate.c | 4 ++++ 2 files changed, 9 insertions(+) diff --git a/src/gallium/drivers/vc4/vc4_qpu_schedule.c b/src/gallium/drivers/vc4/vc4_qpu_schedule.c index 878cdf95d96..4b2cb9dbd37 100644 --- a/src/gallium/drivers/vc4/vc4_qpu_schedule.c +++ b/src/gallium/drivers/vc4/vc4_qpu_schedule.c @@ -477,6 +477,11 @@ reads_too_soon_after_write(struct choose_scoreboard *scoreboard, uint64_t inst) uint32_t raddr_a = QPU_GET_FIELD(inst, QPU_RADDR_A); uint32_t raddr_b = QPU_GET_FIELD(inst, QPU_RADDR_B); uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG); + + /* Full immediate loads don't read any registers. */ + if (sig == QPU_SIG_LOAD_IMM) + return false; + uint32_t src_muxes[] = { QPU_GET_FIELD(inst, QPU_ADD_A), QPU_GET_FIELD(inst, QPU_ADD_B), diff --git a/src/gallium/drivers/vc4/vc4_qpu_validate.c b/src/gallium/drivers/vc4/vc4_qpu_validate.c index f18ba0364d0..08dd6e5df2e 100644 --- a/src/gallium/drivers/vc4/vc4_qpu_validate.c +++ b/src/gallium/drivers/vc4/vc4_qpu_validate.c @@ -58,6 +58,10 @@ _reads_reg(uint64_t inst, uint32_t r, bool ignore_a, bool ignore_b) if (QPU_GET_FIELD(inst, QPU_SIG) == QPU_SIG_BRANCH) return false; + /* Load immediates don't read any registers. */ + if (QPU_GET_FIELD(inst, QPU_SIG) == QPU_SIG_LOAD_IMM) + return false; + for (int i = 0; i < ARRAY_SIZE(src_regs); i++) { if (!ignore_a && src_regs[i].mux == QPU_MUX_A && -- 2.30.2