[Mesa-dev] [PATCH] ac/nir_to_llvm: fix interpolateAt* for arrays

[Timothy Arceri]

Ping!

On 10/1/19 4:59 pm, Timothy Arceri wrote:
> This builds on the recent interpolate fix by Rhys ee8488ea3b99.
> 
> This doesn't handle arrays of structs but I've got a feeling those
> might be broken even for radeonsi tgsi (we currently have no tests).
> 
> This fixes the arb_gpu_shader5 interpolateAt* tests that contain
> arrays.
> 
> Fixes: ee8488ea3b99 ("ac/nir,radv,radeonsi/nir: use correct indices for interpolation intrinsics")
> ---
>   src/amd/common/ac_nir_to_llvm.c | 80 +++++++++++++++++++++++++--------
>   1 file changed, 61 insertions(+), 19 deletions(-)
> 
> diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
> index 5023b96f92..00011a439d 100644
> --- a/src/amd/common/ac_nir_to_llvm.c
> +++ b/src/amd/common/ac_nir_to_llvm.c
> @@ -2830,15 +2830,16 @@ static LLVMValueRef visit_interp(struct ac_nir_context *ctx,
>   				 const nir_intrinsic_instr *instr)
>   {
>   	LLVMValueRef result[4];
> -	LLVMValueRef interp_param, attr_number;
> +	LLVMValueRef interp_param;
>   	unsigned location;
>   	unsigned chan;
>   	LLVMValueRef src_c0 = NULL;
>   	LLVMValueRef src_c1 = NULL;
>   	LLVMValueRef src0 = NULL;
>   
> -	nir_variable *var = nir_deref_instr_get_variable(nir_instr_as_deref(instr->src[0].ssa->parent_instr));
> -	int input_index = ctx->abi->fs_input_attr_indices[var->data.location - VARYING_SLOT_VAR0];
> +	nir_deref_instr *deref_instr = nir_instr_as_deref(instr->src[0].ssa->parent_instr);
> +	nir_variable *var = nir_deref_instr_get_variable(deref_instr);
> +	int input_base = ctx->abi->fs_input_attr_indices[var->data.location - VARYING_SLOT_VAR0];
>   	switch (instr->intrinsic) {
>   	case nir_intrinsic_interp_deref_at_centroid:
>   		location = INTERP_CENTROID;
> @@ -2868,7 +2869,6 @@ static LLVMValueRef visit_interp(struct ac_nir_context *ctx,
>   		src_c1 = LLVMBuildFSub(ctx->ac.builder, src_c1, halfval, "");
>   	}
>   	interp_param = ctx->abi->lookup_interp_param(ctx->abi, var->data.interpolation, location);
> -	attr_number = LLVMConstInt(ctx->ac.i32, input_index, false);
>   
>   	if (location == INTERP_CENTER) {
>   		LLVMValueRef ij_out[2];
> @@ -2906,26 +2906,68 @@ static LLVMValueRef visit_interp(struct ac_nir_context *ctx,
>   
>   	}
>   
> +	LLVMValueRef array_idx = ctx->ac.i32_0;
> +	while(deref_instr->deref_type != nir_deref_type_var) {
> +		if (deref_instr->deref_type == nir_deref_type_array) {
> +			unsigned array_size = glsl_get_aoa_size(deref_instr->type);
> +			if (!array_size)
> +				array_size = 1;
> +
> +			LLVMValueRef offset;
> +			nir_const_value *const_value = nir_src_as_const_value(deref_instr->arr.index);
> +			if (const_value) {
> +				offset = LLVMConstInt(ctx->ac.i32, array_size * const_value->u32[0], false);
> +			} else {
> +				LLVMValueRef indirect = get_src(ctx, deref_instr->arr.index);
> +
> +				offset = LLVMBuildMul(ctx->ac.builder, indirect,
> +						      LLVMConstInt(ctx->ac.i32, array_size, false), "");
> +			}
> +
> +			array_idx = LLVMBuildAdd(ctx->ac.builder, array_idx, offset, "");
> +			deref_instr = nir_src_as_deref(deref_instr->parent);
> +		} else if (deref_instr->deref_type == nir_deref_type_struct) {
> +			/* TODO: Probably need to do more here to support arrays of structs etc */
> +			deref_instr = nir_src_as_deref(deref_instr->parent);
> +		} else {
> +			unreachable("Unsupported deref type");
> +		}
> +
> +	}
> +
> +	unsigned input_array_size = glsl_get_aoa_size(var->type);
> +	if (!input_array_size)
> +		input_array_size = 1;
> +
>   	for (chan = 0; chan < 4; chan++) {
> +		LLVMValueRef gather = LLVMGetUndef(LLVMVectorType(ctx->ac.f32, input_array_size));
>   		LLVMValueRef llvm_chan = LLVMConstInt(ctx->ac.i32, chan, false);
>   
> -		if (interp_param) {
> -			interp_param = LLVMBuildBitCast(ctx->ac.builder,
> +		for (unsigned idx = 0; idx < input_array_size; ++idx) {
> +			LLVMValueRef v, attr_number;
> +
> +			attr_number = LLVMConstInt(ctx->ac.i32, input_base + idx, false);
> +			if (interp_param) {
> +				interp_param = LLVMBuildBitCast(ctx->ac.builder,
>   							interp_param, ctx->ac.v2f32, "");
> -			LLVMValueRef i = LLVMBuildExtractElement(
> -				ctx->ac.builder, interp_param, ctx->ac.i32_0, "");
> -			LLVMValueRef j = LLVMBuildExtractElement(
> -				ctx->ac.builder, interp_param, ctx->ac.i32_1, "");
> -
> -			result[chan] = ac_build_fs_interp(&ctx->ac,
> -							  llvm_chan, attr_number,
> -							  ctx->abi->prim_mask, i, j);
> -		} else {
> -			result[chan] = ac_build_fs_interp_mov(&ctx->ac,
> -							      LLVMConstInt(ctx->ac.i32, 2, false),
> -							      llvm_chan, attr_number,
> -							      ctx->abi->prim_mask);
> +				LLVMValueRef i = LLVMBuildExtractElement(
> +					ctx->ac.builder, interp_param, ctx->ac.i32_0, "");
> +				LLVMValueRef j = LLVMBuildExtractElement(
> +					ctx->ac.builder, interp_param, ctx->ac.i32_1, "");
> +
> +				v = ac_build_fs_interp(&ctx->ac, llvm_chan, attr_number,
> +						       ctx->abi->prim_mask, i, j);
> +			} else {
> +				v = ac_build_fs_interp_mov(&ctx->ac, LLVMConstInt(ctx->ac.i32, 2, false),
> +							   llvm_chan, attr_number, ctx->abi->prim_mask);
> +			}
> +
> +			gather = LLVMBuildInsertElement(ctx->ac.builder, gather, v,
> +							LLVMConstInt(ctx->ac.i32, idx, false), "");
>   		}
> +
> +		result[chan] = LLVMBuildExtractElement(ctx->ac.builder, gather, array_idx, "");
> +
>   	}
>   	return ac_build_varying_gather_values(&ctx->ac, result, instr->num_components,
>   					      var->data.location_frac);
>