KonstantinSeurer
/
mesa
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

pan/va: Lower BLEND to call blend shaders 

Do this as late as possible.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15223>
This commit is contained in:
Alyssa Rosenzweig 2022-03-17 11:47:47 -04:00 committed by Marge Bot
parent cb76cc1f1d
commit f31208f778
1 changed files with 54 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
src/panfrost/bifrost/valhall/va_pack.c
View File

@ -24,6 +24,7 @@
#include "va_compiler.h"
#include "valhall.h"
#include "valhall_enums.h"
#include "bi_builder.h"
/* This file contains the final passes of the compiler. Running after
* scheduling and RA, the IR is now finalized, so we need to emit it to actual
@ -902,6 +903,55 @@ va_lower_branch_target(bi_context *ctx, bi_block *start, bi_instr *I)
I->branch_offset = offset;
}
/*
* Late lowering to insert blend shader calls after BLEND instructions. Required
* to support blend shaders, so this pass may be omitted if it is known that
* blend shaders are never used.
*
* This lowering runs late because it introduces control flow changes without
* modifying the control flow graph. It hardcodes registers, meaning running
* after RA makes sense. Finally, it hardcodes a manually sized instruction
* sequence, requiring it to run after scheduling.
*
* As it is Valhall specific, running it as a pre-pack lowering is sensible.
*/
static void
va_lower_blend(bi_context *ctx)
{
bool last_blend = true;
/* Link register (ABI between fragment and blend shaders) */
bi_index lr = bi_register(48);
/* Program counter for *next* instruction */
bi_index pc = bi_fau(BIR_FAU_PROGRAM_COUNTER, false);
bi_foreach_instr_global_rev(ctx, I) {
if (I->op != BI_OPCODE_BLEND)
continue;
bi_builder b = bi_init_builder(ctx, bi_after_instr(I));
unsigned prolog_length = 2 * 8;
if (last_blend)
bi_iadd_imm_i32_to(&b, lr, va_zero_lut(), 0);
else
bi_iadd_imm_i32_to(&b, lr, pc, prolog_length - 8);
bi_branchzi(&b, va_zero_lut(), I->src[3], BI_CMPF_EQ);
/* For fixed function: skip the prologue, or return */
if (last_blend)
I->flow = 0x7 | 0x8; /* .return */
else
I->branch_offset = prolog_length;
/* Iterate backwards makes the last BLEND easy to identify */
last_blend = false;
}
}
void
bi_pack_valhall(bi_context *ctx, struct util_dynarray *emission)
{
@ -909,6 +959,10 @@ bi_pack_valhall(bi_context *ctx, struct util_dynarray *emission)
va_validate(stderr, ctx);
/* Late lowering */
if (ctx->stage == MESA_SHADER_FRAGMENT && !ctx->inputs->is_blend)
va_lower_blend(ctx);
bi_foreach_block(ctx, block) {
bi_foreach_instr_in_block(block, I) {
if (I->op == BI_OPCODE_BRANCHZ_I16)