[Mesa-dev] [PATCH] r600/sb: use safe math optimizatiosn when TGSI contains precise operations

[Roland Scheidegger]

I suppose ideally it would only affect instruction chains which have a
precise modifier somewhere. But it's better than just ignoring it
completely.

Reviewed-by: Roland Scheidegger <sroland at vmware.com>


Am 14.09.2018 um 16:56 schrieb Gert Wollny:
> Fixes:
>   dEQP-GLES3.functional.shaders.invariance.highp.common_subexpression_3
>   dEQP-GLES3.functional.shaders.invariance.mediump.common_subexpression_3
>   dEQP-GLES3.functional.shaders.invariance.lowp.common_subexpression_3
> 
> Signed-off-by: Gert Wollny <gw.fossdev at gmail.com>
> ---
>  src/gallium/drivers/r600/r600_asm.h          | 1 +
>  src/gallium/drivers/r600/r600_shader.c       | 3 +++
>  src/gallium/drivers/r600/sb/sb_bc_parser.cpp | 2 +-
>  3 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/src/gallium/drivers/r600/r600_asm.h b/src/gallium/drivers/r600/r600_asm.h
> index 5841044bf8..ca9280a7a8 100644
> --- a/src/gallium/drivers/r600/r600_asm.h
> +++ b/src/gallium/drivers/r600/r600_asm.h
> @@ -277,6 +277,7 @@ struct r600_bytecode {
>  	struct r600_bytecode_output pending_outputs[5];
>  	int n_pending_outputs;
>  	boolean			need_wait_ack; /* emit a pending WAIT_ACK prior to control flow */
> +	boolean			precise;
>  };
>  
>  /* eg_asm.c */
> diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
> index 2229dc8fab..408939d110 100644
> --- a/src/gallium/drivers/r600/r600_shader.c
> +++ b/src/gallium/drivers/r600/r600_shader.c
> @@ -3879,6 +3879,9 @@ static int r600_shader_from_tgsi(struct r600_context *rctx,
>  				ctx.inst_info = &eg_shader_tgsi_instruction[opcode];
>  			else
>  				ctx.inst_info = &r600_shader_tgsi_instruction[opcode];
> +
> +			ctx.bc->precise |= ctx.parse.FullToken.FullInstruction.Instruction.Precise;
> +
>  			r = ctx.inst_info->process(&ctx);
>  			if (r)
>  				goto out_err;
> diff --git a/src/gallium/drivers/r600/sb/sb_bc_parser.cpp b/src/gallium/drivers/r600/sb/sb_bc_parser.cpp
> index a7b828268b..eafc1cb8ec 100644
> --- a/src/gallium/drivers/r600/sb/sb_bc_parser.cpp
> +++ b/src/gallium/drivers/r600/sb/sb_bc_parser.cpp
> @@ -75,7 +75,7 @@ int bc_parser::decode() {
>  	}
>  
>  	sh = new shader(ctx, t, bc->debug_id);
> -	sh->safe_math = sb_context::safe_math || (t == TARGET_COMPUTE);
> +	sh->safe_math = sb_context::safe_math || (t == TARGET_COMPUTE || bc->precise);
>  
>  	int r = decode_shader();
>  
>