diff options
author | Eric Anholt <eric@anholt.net> | 2010-01-18 15:12:40 -0800 |
---|---|---|
committer | Eric Anholt <eric@anholt.net> | 2010-01-19 11:31:23 -0800 |
commit | fb4901593c9495714d3f54920a28c271852e2112 (patch) | |
tree | 697c6c525f9340f136459c93f06c823034fadc22 /src/mesa/drivers/dri/i965/brw_vs_emit.c | |
parent | 62a96f74c9a1fd07301d349e4181a7212fc7d45c (diff) |
i965: Upload as many VS constants as possible through the push constants.
The pull constants require sending out to an overworked shared unit
and waiting for a response, while push constants are nicely loaded in
for us at thread dispatch time. By putting things we access in every
VS invocation there, ETQW performance improved by 2.5% +/- 1.6% (n=6).
Diffstat (limited to 'src/mesa/drivers/dri/i965/brw_vs_emit.c')
-rw-r--r-- | src/mesa/drivers/dri/i965/brw_vs_emit.c | 49 |
1 files changed, 45 insertions, 4 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_vs_emit.c b/src/mesa/drivers/dri/i965/brw_vs_emit.c index 7a252dde6c..52cc04fee8 100644 --- a/src/mesa/drivers/dri/i965/brw_vs_emit.c +++ b/src/mesa/drivers/dri/i965/brw_vs_emit.c @@ -104,9 +104,47 @@ static void brw_vs_alloc_regs( struct brw_vs_compile *c ) /* Vertex program parameters from curbe: */ if (c->vp->use_const_buffer) { - /* get constants from a real constant buffer */ - c->prog_data.curb_read_length = 0; - c->prog_data.nr_params = 4; /* XXX 0 causes a bug elsewhere... */ + int max_constant = BRW_MAX_GRF - 20 - c->vp->program.Base.NumTemporaries; + int constant = 0; + + /* We've got more constants than we can load with the push + * mechanism. This is often correlated with reladdr loads where + * we should probably be using a pull mechanism anyway to avoid + * excessive reading. However, the pull mechanism is slow in + * general. So, we try to allocate as many non-reladdr-loaded + * constants through the push buffer as we can before giving up. + */ + memset(c->constant_map, -1, c->vp->program.Base.Parameters->NumParameters); + for (i = 0; + i < c->vp->program.Base.NumInstructions && constant < max_constant; + i++) { + struct prog_instruction *inst = &c->vp->program.Base.Instructions[i]; + int arg; + + for (arg = 0; arg < 3 && constant < max_constant; arg++) { + if ((inst->SrcReg[arg].File != PROGRAM_STATE_VAR && + inst->SrcReg[arg].File != PROGRAM_CONSTANT && + inst->SrcReg[arg].File != PROGRAM_UNIFORM && + inst->SrcReg[arg].File != PROGRAM_ENV_PARAM && + inst->SrcReg[arg].File != PROGRAM_LOCAL_PARAM) || + inst->SrcReg[arg].RelAddr) + continue; + + if (c->constant_map[inst->SrcReg[arg].Index] == -1) { + c->constant_map[inst->SrcReg[arg].Index] = constant++; + } + } + } + + for (i = 0; i < constant; i++) { + c->regs[PROGRAM_STATE_VAR][i] = stride( brw_vec4_grf(reg+i/2, + (i%2) * 4), + 0, 4, 1); + } + reg += (constant + 1) / 2; + c->prog_data.curb_read_length = reg - 1; + /* XXX 0 causes a bug elsewhere... */ + c->prog_data.nr_params = MAX2(constant * 4, 4); } else { /* use a section of the GRF for constants */ @@ -955,7 +993,10 @@ get_src_reg( struct brw_vs_compile *c, case PROGRAM_ENV_PARAM: case PROGRAM_LOCAL_PARAM: if (c->vp->use_const_buffer) { - if (relAddr) + if (!relAddr && c->constant_map[index] != -1) { + assert(c->regs[PROGRAM_STATE_VAR][c->constant_map[index]].nr != 0); + return c->regs[PROGRAM_STATE_VAR][c->constant_map[index]]; + } else if (relAddr) return get_reladdr_constant(c, inst, argIndex); else return get_constant(c, inst, argIndex); |