[Mesa-dev] [PATCH 2/2] radeonsi: implement TGSI_OPCODE_BFI (v2)

[Tom Stellard]

On Sun, Mar 15, 2015 at 07:59:52PM +0100, Marek Olšák wrote:
> From: Marek Olšák <marek.olsak at amd.com>
> 
> v2: Don't use the intrinsics, the shader backend can recognize these
>     patterns and generates optimal code automatically.

Reviewed-by: Tom Stellard <thomas.stellard at amd.com>

> ---
>  .../drivers/radeon/radeon_setup_tgsi_llvm.c        | 34 ++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
> index 0034b56..d89e2b4 100644
> --- a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
> +++ b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
> @@ -1234,6 +1234,39 @@ build_tgsi_intrinsic_nomem(
>  	build_tgsi_intrinsic(action, bld_base, emit_data, LLVMReadNoneAttribute);
>  }
>  
> +static void emit_bfi(const struct lp_build_tgsi_action * action,
> +		     struct lp_build_tgsi_context * bld_base,
> +		     struct lp_build_emit_data * emit_data)
> +{
> +	struct gallivm_state *gallivm = bld_base->base.gallivm;
> +	LLVMBuilderRef builder = gallivm->builder;
> +	LLVMValueRef bfi_args[3];
> +
> +	// Calculate the bitmask: (((1 << src3) - 1) << src2
> +	bfi_args[0] = LLVMBuildShl(builder,
> +				   LLVMBuildSub(builder,
> +						LLVMBuildShl(builder,
> +							     bld_base->int_bld.one,
> +							     emit_data->args[3], ""),
> +						bld_base->int_bld.one, ""),
> +				   emit_data->args[2], "");
> +
> +	bfi_args[1] = LLVMBuildShl(builder, emit_data->args[1],
> +				   emit_data->args[2], "");
> +
> +	bfi_args[2] = emit_data->args[0];
> +
> +	/* Calculate:
> +	 *   (arg0 & arg1) | (~arg0 & arg2) = arg2 ^ (arg0 & (arg1 ^ arg2)
> +	 * Use the right-hand side, which the LLVM backend can convert to V_BFI.
> +	 */
> +	emit_data->output[emit_data->chan] =
> +		LLVMBuildXor(builder, bfi_args[2],
> +			LLVMBuildAnd(builder, bfi_args[0],
> +				LLVMBuildXor(builder, bfi_args[1], bfi_args[2],
> +					     ""), ""), "");
> +}
> +
>  /* this is ffs in C */
>  static void emit_lsb(const struct lp_build_tgsi_action * action,
>  		     struct lp_build_tgsi_context * bld_base,
> @@ -1381,6 +1414,7 @@ void radeon_llvm_context_init(struct radeon_llvm_context * ctx)
>  	bld_base->op_actions[TGSI_OPCODE_ABS].intr_name = "fabs";
>  	bld_base->op_actions[TGSI_OPCODE_AND].emit = emit_and;
>  	bld_base->op_actions[TGSI_OPCODE_ARL].emit = emit_arl;
> +	bld_base->op_actions[TGSI_OPCODE_BFI].emit = emit_bfi;
>  	bld_base->op_actions[TGSI_OPCODE_BGNLOOP].emit = bgnloop_emit;
>  	bld_base->op_actions[TGSI_OPCODE_BREV].emit = build_tgsi_intrinsic_nomem;
>  	bld_base->op_actions[TGSI_OPCODE_BREV].intr_name = "llvm.AMDGPU.brev";
> -- 
> 2.1.0
> 
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev