[Mesa-dev] [PATCH 08/19] gallium/radeon: clean up emit_declaration for temporaries

[Tom Stellard]

On Tue, Aug 09, 2016 at 12:36:37PM +0200, Nicolai Hähnle wrote:
> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
> 
> In the alloca'd array case, no longer create redundant and unused allocas
> for the individual elements; create getelementptrs instead.

Reviewed-by: Tom Stellard <thomas.stellard at amd.com>
> ---
>  .../drivers/radeon/radeon_setup_tgsi_llvm.c        | 27 ++++++++++++++--------
>  1 file changed, 18 insertions(+), 9 deletions(-)
> 
> diff --git a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
> index d75311e..41f24d3 100644
> --- a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
> +++ b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
> @@ -408,81 +408,90 @@ static LLVMValueRef si_build_alloca_undef(struct gallivm_state *gallivm,
>  	LLVMValueRef ptr = lp_build_alloca(gallivm, type, name);
>  	LLVMBuildStore(gallivm->builder, LLVMGetUndef(type), ptr);
>  	return ptr;
>  }
>  
>  static void emit_declaration(struct lp_build_tgsi_context *bld_base,
>  			     const struct tgsi_full_declaration *decl)
>  {
>  	struct radeon_llvm_context *ctx = radeon_llvm_context(bld_base);
>  	LLVMBuilderRef builder = bld_base->base.gallivm->builder;
> -	unsigned first, last, i, idx;
> +	unsigned first, last, i;
>  	switch(decl->Declaration.File) {
>  	case TGSI_FILE_ADDRESS:
>  	{
>  		 unsigned idx;
>  		for (idx = decl->Range.First; idx <= decl->Range.Last; idx++) {
>  			unsigned chan;
>  			for (chan = 0; chan < TGSI_NUM_CHANNELS; chan++) {
>  				 ctx->soa.addr[idx][chan] = si_build_alloca_undef(
>  					&ctx->gallivm,
>  					ctx->soa.bld_base.uint_bld.elem_type, "");
>  			}
>  		}
>  		break;
>  	}
>  
>  	case TGSI_FILE_TEMPORARY:
>  	{
> +		LLVMValueRef array_alloca = NULL;
>  		unsigned decl_size;
>  		first = decl->Range.First;
>  		last = decl->Range.Last;
>  		decl_size = 4 * ((last - first) + 1);
>  		if (decl->Declaration.Array) {
>  			unsigned id = decl->Array.ArrayID - 1;
>  			if (!ctx->arrays) {
>  				int size = bld_base->info->array_max[TGSI_FILE_TEMPORARY];
>  				ctx->arrays = CALLOC(size, sizeof(ctx->arrays[0]));
> -			for (i = 0; i < size; ++i) {
> -				assert(!ctx->arrays[i].alloca);}
>  			}
>  
>  			ctx->arrays[id].range = decl->Range;
>  
>  			/* If the array is more than 16 elements (each element
>  			 * is 32-bits), then store it in a vector.  Storing the
>  			 * array in a vector will causes the compiler to store
>  			 * the array in registers and access it using indirect
>  			 * addressing.  16 is number of vector elements that
>  			 * LLVM will store in a register.
>  			 * FIXME: We shouldn't need to do this.  LLVM should be
>  			 * smart enough to promote allocas int registers when
>  			 * profitable.
>  			 */
>  			if (decl_size > 16) {
> -				ctx->arrays[id].alloca = LLVMBuildAlloca(builder,
> +				array_alloca = LLVMBuildAlloca(builder,
>  					LLVMArrayType(bld_base->base.vec_type, decl_size),"array");
> +				ctx->arrays[id].alloca = array_alloca;
>  			}
>  		}
> -		first = decl->Range.First;
> -		last = decl->Range.Last;
> +
>  		if (!ctx->temps_count) {
>  			ctx->temps_count = bld_base->info->file_max[TGSI_FILE_TEMPORARY] + 1;
>  			ctx->temps = MALLOC(TGSI_NUM_CHANNELS * ctx->temps_count * sizeof(LLVMValueRef));
>  		}
> -		for (idx = first; idx <= last; idx++) {
> -			for (i = 0; i < TGSI_NUM_CHANNELS; i++) {
> -				ctx->temps[idx * TGSI_NUM_CHANNELS + i] =
> +		if (!array_alloca) {
> +			for (i = 0; i < decl_size; ++i) {
> +				ctx->temps[first * TGSI_NUM_CHANNELS + i] =
>  					si_build_alloca_undef(bld_base->base.gallivm,
>  							      bld_base->base.vec_type,
>  							      "temp");
>  			}
> +		} else {
> +			LLVMValueRef idxs[2] = {
> +				bld_base->uint_bld.zero,
> +				NULL
> +			};
> +			for (i = 0; i < decl_size; ++i) {
> +				idxs[1] = lp_build_const_int32(bld_base->base.gallivm, i);
> +				ctx->temps[first * TGSI_NUM_CHANNELS + i] =
> +					LLVMBuildGEP(builder, array_alloca, idxs, 2, "temp");
> +			}
>  		}
>  		break;
>  	}
>  	case TGSI_FILE_INPUT:
>  	{
>  		unsigned idx;
>  		for (idx = decl->Range.First; idx <= decl->Range.Last; idx++) {
>  			if (ctx->load_input)
>  				ctx->load_input(ctx, idx, decl);
>  		}
> -- 
> 2.7.4
> 
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev