[Mesa-dev] [PATCH 12/24] radeonsi: set readnone on reads from read-only memory

[Constantine Kharlamov]

On 26.02.2017 02:58, Marek Olšák wrote:
> From: Marek Olšák <marek.olsak at amd.com>
> 
> ---
>  src/amd/common/ac_llvm_build.c           | 11 +++++++++--
>  src/amd/common/ac_llvm_build.h           |  3 ++-
>  src/gallium/drivers/radeonsi/si_shader.c | 20 ++++++++++----------
>  3 files changed, 21 insertions(+), 13 deletions(-)
> 
> diff --git a/src/amd/common/ac_llvm_build.c b/src/amd/common/ac_llvm_build.c
> index 42965b6..f0ab9cb 100644
> --- a/src/amd/common/ac_llvm_build.c
> +++ b/src/amd/common/ac_llvm_build.c
> @@ -612,21 +612,22 @@ ac_build_tbuffer_store_dwords(struct ac_llvm_context *ctx,
>  
>  LLVMValueRef
>  ac_build_buffer_load(struct ac_llvm_context *ctx,
>  		     LLVMValueRef rsrc,
>  		     int num_channels,
>  		     LLVMValueRef vindex,
>  		     LLVMValueRef voffset,
>  		     LLVMValueRef soffset,
>  		     unsigned inst_offset,
>  		     unsigned glc,
> -		     unsigned slc)
> +		     unsigned slc,
> +		     bool readonly_memory)
>  {
>  	unsigned func = CLAMP(num_channels, 1, 3) - 1;
>  
>  	if (HAVE_LLVM >= 0x309) {
>  		LLVMValueRef args[] = {
>  			LLVMBuildBitCast(ctx->builder, rsrc, ctx->v4i32, ""),
>  			vindex ? vindex : LLVMConstInt(ctx->i32, 0, 0),
>  			LLVMConstInt(ctx->i32, inst_offset, 0),
>  			LLVMConstInt(ctx->i1, glc, 0),
>  			LLVMConstInt(ctx->i1, slc, 0)
> @@ -644,21 +645,27 @@ ac_build_buffer_load(struct ac_llvm_context *ctx,
>  
>  		if (soffset) {
>  			args[2] = LLVMBuildAdd(ctx->builder, args[2], soffset,
>  			                       "");
>  		}
>  
>  		snprintf(name, sizeof(name), "llvm.amdgcn.buffer.load.%s",
>  		         type_names[func]);
>  
>  		return ac_emit_llvm_intrinsic(ctx, name, types[func], args,
> -					      ARRAY_SIZE(args), AC_FUNC_ATTR_READONLY);
> +					      ARRAY_SIZE(args),
> +					      /* READNONE means writes can't
> +					       * affect it, while READONLY means
> +					       * that writes can affect it. */
> +					      readonly_memory ?
> +						      AC_FUNC_ATTR_READNONE :
> +						      AC_FUNC_ATTR_READONLY);

You probably swapped the arguments, i.e. when "readonly_memory == true",
you're passing AC_FUNC_ATTR_READNONE instead of AC_FUNC_ATTR_READONLY.