The first and last hunks are needed to pass on the shader_info to the
middle hunk, which needs it so that it can test if the compute shader
has a derivative group.
On Fri, 31 May 2019 at 18:38, Marek Olšák <mar...@gmail.com> wrote:
>
> The first and last hunks look like they shouldn't be there. Other than that:
>
> Reviewed-by: Marek Olšák <marek.ol...@amd.com>
>
> Marek
>
> On Fri, May 31, 2019 at 11:53 AM Rhys Perry <pendingchao...@gmail.com> wrote:
>>
>> Otherwise LLVM can sink them and their texture coordinate calculations
>> into divergent branches.
>>
>> v2: simplify the conditions on which the intrinsic is marked as convergent
>> v3: only mark as convergent in FS and CS with derivative groups
>>
>> Cc: <mesa-sta...@lists.freedesktop.org>
>> Signed-off-by: Rhys Perry <pendingchao...@gmail.com>
>> ---
>> src/amd/common/ac_nir_to_llvm.c | 18 ++++++++++++++++++
>> 1 file changed, 18 insertions(+)
>>
>> diff --git a/src/amd/common/ac_nir_to_llvm.c
>> b/src/amd/common/ac_nir_to_llvm.c
>> index 265e3b636c4..9e9fade7227 100644
>> --- a/src/amd/common/ac_nir_to_llvm.c
>> +++ b/src/amd/common/ac_nir_to_llvm.c
>> @@ -38,6 +38,7 @@ struct ac_nir_context {
>> struct ac_shader_abi *abi;
>>
>> gl_shader_stage stage;
>> + shader_info *info;
>>
>> LLVMValueRef *ssa_defs;
>>
>> @@ -1394,6 +1395,22 @@ static LLVMValueRef build_tex_intrinsic(struct
>> ac_nir_context *ctx,
>> }
>>
>> args->attributes = AC_FUNC_ATTR_READNONE;
>> + bool cs_derivs = ctx->stage == MESA_SHADER_COMPUTE &&
>> + ctx->info->cs.derivative_group !=
>> DERIVATIVE_GROUP_NONE;
>> + if (ctx->stage == MESA_SHADER_FRAGMENT || cs_derivs) {
>> + /* Prevent texture instructions with implicit derivatives
>> from being
>> + * sinked into branches. */
>> + switch (instr->op) {
>> + case nir_texop_tex:
>> + case nir_texop_txb:
>> + case nir_texop_lod:
>> + args->attributes |= AC_FUNC_ATTR_CONVERGENT;
>> + break;
>> + default:
>> + break;
>> + }
>> + }
>> +
>> return ac_build_image_opcode(&ctx->ac, args);
>> }
>>
>> @@ -4350,6 +4367,7 @@ void ac_nir_translate(struct ac_llvm_context *ac,
>> struct ac_shader_abi *abi,
>> ctx.abi = abi;
>>
>> ctx.stage = nir->info.stage;
>> + ctx.info = &nir->info;
>>
>> ctx.main_function =
>> LLVMGetBasicBlockParent(LLVMGetInsertBlock(ctx.ac.builder));
>>
>> --
>> 2.21.0
>>
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