[Mesa-dev] [PATCH] ac/nir: Use an array instead of hashtable for SSA defs.

[Timothy Arceri]

On 10/04/18 18:17, Timothy Arceri wrote:
> 
> 
> On 10/04/18 17:33, Bas Nieuwenhuizen wrote:
>> Saves about 2% of compile time for F1 2017, as well as reduce code
>> size of an optimized libvulkan_radeon.so by about 1 KiB.
>>
>> This still keeps the hashtable, as we also stored blocks in there.
>> ---
>>   src/amd/common/ac_nir_to_llvm.c | 22 +++++++++++++---------
>>   1 file changed, 13 insertions(+), 9 deletions(-)
>>
>> diff --git a/src/amd/common/ac_nir_to_llvm.c 
>> b/src/amd/common/ac_nir_to_llvm.c
>> index 053c19808f..7c2bd5c0cc 100644
>> --- a/src/amd/common/ac_nir_to_llvm.c
>> +++ b/src/amd/common/ac_nir_to_llvm.c
>> @@ -38,6 +38,8 @@ struct ac_nir_context {
>>       gl_shader_stage stage;
>> +    LLVMValueRef *ssa_defs;
>> +
>>       struct hash_table *defs;
>>       struct hash_table *phis;
>>       struct hash_table *vars;
>> @@ -87,8 +89,7 @@ static LLVMTypeRef get_def_type(struct 
>> ac_nir_context *ctx,
>>   static LLVMValueRef get_src(struct ac_nir_context *nir, nir_src src)
>>   {
>>       assert(src.is_ssa);
>> -    struct hash_entry *entry = _mesa_hash_table_search(nir->defs, 
>> src.ssa);
>> -    return (LLVMValueRef)entry->data;
>> +    return nir->ssa_defs[src.ssa->index];
>>   }
>>   static LLVMValueRef
>> @@ -1028,8 +1029,7 @@ static void visit_alu(struct ac_nir_context 
>> *ctx, const nir_alu_instr *instr)
>>       if (result) {
>>           assert(instr->dest.dest.is_ssa);
>>           result = ac_to_integer(&ctx->ac, result);
>> -        _mesa_hash_table_insert(ctx->defs, &instr->dest.dest.ssa,
>> -                                result);
>> +        ctx->ssa_defs[instr->dest.dest.ssa.index] = result;
>>       }
>>   }
>> @@ -1062,7 +1062,7 @@ static void visit_load_const(struct 
>> ac_nir_context *ctx,
>>       } else
>>           value = values[0];
>> -    _mesa_hash_table_insert(ctx->defs, &instr->def, value);
>> +    ctx->ssa_defs[instr->def.index] = value;
>>   }
>>   static LLVMValueRef
>> @@ -3095,7 +3095,7 @@ static void visit_intrinsic(struct 
>> ac_nir_context *ctx,
>>           break;
>>       }
>>       if (result) {
>> -        _mesa_hash_table_insert(ctx->defs, &instr->dest.ssa, result);
>> +        ctx->ssa_defs[instr->dest.ssa.index] = result;
>>       }
>>   }
>> @@ -3596,7 +3596,7 @@ write_result:
>>       if (result) {
>>           assert(instr->dest.is_ssa);
>>           result = ac_to_integer(&ctx->ac, result);
>> -        _mesa_hash_table_insert(ctx->defs, &instr->dest.ssa, result);
>> +        ctx->ssa_defs[instr->dest.ssa.index] = result;
>>       }
>>   }
>> @@ -3606,7 +3606,7 @@ static void visit_phi(struct ac_nir_context 
>> *ctx, nir_phi_instr *instr)
>>       LLVMTypeRef type = get_def_type(ctx, &instr->dest.ssa);
>>       LLVMValueRef result = LLVMBuildPhi(ctx->ac.builder, type, "");
>> -    _mesa_hash_table_insert(ctx->defs, &instr->dest.ssa, result);
>> +    ctx->ssa_defs[instr->dest.ssa.index] = result;
>>       _mesa_hash_table_insert(ctx->phis, instr, result);
>>   }
>> @@ -3644,7 +3644,7 @@ static void visit_ssa_undef(struct 
>> ac_nir_context *ctx,
>>       else {
>>           undef = LLVMGetUndef(LLVMVectorType(type, num_components));
>>       }
>> -    _mesa_hash_table_insert(ctx->defs, &instr->def, undef);
>> +    ctx->ssa_defs[instr->def.index] = undef;
>>   }
>>   static void visit_jump(struct ac_llvm_context *ctx,
>> @@ -3927,6 +3927,9 @@ void ac_nir_translate(struct ac_llvm_context 
>> *ac, struct ac_shader_abi *abi,
>>       func = (struct nir_function *)exec_list_get_head(&nir->functions);
>> +    nir_index_ssa_defs(func->impl);
>> +    ctx.ssa_defs = calloc(func->impl->ssa_alloc, sizeof(LLVMValueRef));
> 
> You don't seem to allocate enough memory here?

blah never mind my bad.