agx: Optimize out empty else blocks

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11023>
This commit is contained in:
Alyssa Rosenzweig
2021-05-23 22:51:21 -04:00
committed by Alyssa Rosenzweig
parent cf43206e76
commit 11705488ed

View File

@@ -1,6 +1,7 @@
/*
* Copyright (C) 2021 Alyssa Rosenzweig <alyssa@rosenzweig.io>
* Copyright (C) 2020 Collabora Ltd.
* Copyright © 2016 Broadcom
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
@@ -754,12 +755,18 @@ emit_cf_list(agx_context *ctx, struct exec_list *list);
* ...
* pop_exec
*
* This is not usually optimal, but it's a start.
* If the else is empty, we can omit the else_icmp. This is not usually
* optimal, but it's a start.
*/
static void
emit_if(agx_context *ctx, nir_if *nif)
{
nir_block *nir_else_block = nir_if_first_else_block(nif);
bool empty_else_block =
(nir_else_block == nir_if_last_else_block(nif) &&
exec_list_is_empty(&nir_else_block->instr_list));
agx_builder _b = agx_init_builder(ctx, agx_after_block(ctx->current_block));
agx_index cond = agx_src_index(&nif->condition);
@@ -769,10 +776,13 @@ emit_if(agx_context *ctx, nir_if *nif)
/* Emit the two subblocks. */
emit_cf_list(ctx, &nif->then_list);
_b.cursor = agx_after_block(ctx->current_block);
agx_else_icmp(&_b, cond, agx_zero(), 1, AGX_ICOND_UEQ, false);
if (!empty_else_block) {
_b.cursor = agx_after_block(ctx->current_block);
agx_else_icmp(&_b, cond, agx_zero(), 1, AGX_ICOND_UEQ, false);
emit_cf_list(ctx, &nif->else_list);
}
emit_cf_list(ctx, &nif->else_list);
_b.cursor = agx_after_block(ctx->current_block);
agx_pop_exec(&_b, 1);
ctx->loop_nesting--;