[Mesa-dev] [PATCH] gallivm/tgsi: fix src modifier fetching with non-float types.
Roland Scheidegger
sroland at vmware.com
Fri Feb 15 07:49:20 PST 2013
Allowing that looks very odd to me, and it seems no API does that.
FWIW the MOV with negation can't work like that (not in a consistent way
at least) since for ordinary temps etc. we don't know the type (hence
arguements are considered floats).
I think if you'd really want to do something like that you should just
use explicit negation rather than rely on modifiers. Negation on
unsigned numbers is imho a abuse (granted a well defined one and not
that rare) which should rather be explicit.
Roland
Am 15.02.2013 16:32, schrieb Jose Fonseca:
> I think that we should probably allow signed everywhere.
>
> The operation and result may be unsigned, but the arguments may need to be negated to become unsigned.
>
> Imagine:
>
> int a = -1;
>
> unsigned b = 10 / (unsigned)-a;
>
> That is
>
> MOV TEMP[0], INT IMM{-1}
> UDIV TEMP[1], UINT IMM{10}, -TEMP[0]
>
>
> Jose
>
> ----- Original Message -----
>> From: Roland Scheidegger <sroland at vmware.com>
>>
>> Need to take the type into account. Also, if we want to allow
>> mov's with modifiers we need to pick a type (assume float).
>>
>> v2: don't allow all modifiers on all type, in particular don't allow
>> absolute on non-float types and don't allow negate on unsigned.
>> Also treat UADD as signed (despite the name) since it is used
>> for handling both signed and unsigned integer arguments and otherwise
>> modifiers don't work.
>> Also add tgsi docs clarifying this.
>> ---
>> src/gallium/auxiliary/gallivm/lp_bld_tgsi.c | 36
>> +++++++++++++++++++++++++--
>> src/gallium/auxiliary/tgsi/tgsi_exec.c | 2 +-
>> src/gallium/auxiliary/tgsi/tgsi_info.c | 6 +++--
>> src/gallium/docs/source/tgsi.rst | 15 +++++++++++
>> 4 files changed, 54 insertions(+), 5 deletions(-)
>>
>> diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.c
>> b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.c
>> index a4fea7d..b97c766 100644
>> --- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.c
>> +++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.c
>> @@ -311,11 +311,43 @@ lp_build_emit_fetch(
>> }
>>
>> if (reg->Register.Absolute) {
>> - res = lp_build_emit_llvm_unary(bld_base, TGSI_OPCODE_ABS, res);
>> + switch (stype) {
>> + case TGSI_TYPE_FLOAT:
>> + case TGSI_TYPE_DOUBLE:
>> + case TGSI_TYPE_UNTYPED:
>> + /* modifiers on movs assume data is float */
>> + res = lp_build_emit_llvm_unary(bld_base, TGSI_OPCODE_ABS, res);
>> + break;
>> + case TGSI_TYPE_UNSIGNED:
>> + case TGSI_TYPE_SIGNED:
>> + case TGSI_TYPE_VOID:
>> + default:
>> + /* abs modifier is only legal on floating point types */
>> + assert(0);
>> + break;
>> + }
>> }
>>
>> if (reg->Register.Negate) {
>> - res = lp_build_negate( &bld_base->base, res );
>> + switch (stype) {
>> + case TGSI_TYPE_FLOAT:
>> + case TGSI_TYPE_UNTYPED:
>> + /* modifiers on movs assume data is float */
>> + res = lp_build_negate( &bld_base->base, res );
>> + break;
>> + case TGSI_TYPE_DOUBLE:
>> + /* no double build context */
>> + assert(0);
>> + break;
>> + case TGSI_TYPE_SIGNED:
>> + res = lp_build_negate( &bld_base->int_bld, res );
>> + break;
>> + case TGSI_TYPE_UNSIGNED:
>> + case TGSI_TYPE_VOID:
>> + default:
>> + assert(0);
>> + break;
>> + }
>> }
>>
>> /*
>> diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.c
>> b/src/gallium/auxiliary/tgsi/tgsi_exec.c
>> index 03f1942..1099d06 100644
>> --- a/src/gallium/auxiliary/tgsi/tgsi_exec.c
>> +++ b/src/gallium/auxiliary/tgsi/tgsi_exec.c
>> @@ -4150,7 +4150,7 @@ exec_instruction(
>> break;
>>
>> case TGSI_OPCODE_UADD:
>> - exec_vector_binary(mach, inst, micro_uadd, TGSI_EXEC_DATA_UINT,
>> TGSI_EXEC_DATA_UINT);
>> + exec_vector_binary(mach, inst, micro_uadd, TGSI_EXEC_DATA_INT,
>> TGSI_EXEC_DATA_INT);
>> break;
>>
>> case TGSI_OPCODE_UDIV:
>> diff --git a/src/gallium/auxiliary/tgsi/tgsi_info.c
>> b/src/gallium/auxiliary/tgsi/tgsi_info.c
>> index f289ebc..9c6fdfc 100644
>> --- a/src/gallium/auxiliary/tgsi/tgsi_info.c
>> +++ b/src/gallium/auxiliary/tgsi/tgsi_info.c
>> @@ -277,9 +277,9 @@ tgsi_opcode_infer_src_type( uint opcode )
>> case TGSI_OPCODE_AND:
>> case TGSI_OPCODE_OR:
>> case TGSI_OPCODE_XOR:
>> + /* XXX some src args may be signed for SAD ? */
>> case TGSI_OPCODE_SAD:
>> case TGSI_OPCODE_U2F:
>> - case TGSI_OPCODE_UADD:
>> case TGSI_OPCODE_UDIV:
>> case TGSI_OPCODE_UMOD:
>> case TGSI_OPCODE_UMAD:
>> @@ -310,6 +310,8 @@ tgsi_opcode_infer_src_type( uint opcode )
>> case TGSI_OPCODE_IABS:
>> case TGSI_OPCODE_ISSG:
>> case TGSI_OPCODE_UARL:
>> + /* UADD is both signed and unsigned require signed for working modifiers
>> */
>> + case TGSI_OPCODE_UADD:
>> return TGSI_TYPE_SIGNED;
>> default:
>> return TGSI_TYPE_FLOAT;
>> @@ -331,7 +333,6 @@ tgsi_opcode_infer_dst_type( uint opcode )
>> case TGSI_OPCODE_OR:
>> case TGSI_OPCODE_XOR:
>> case TGSI_OPCODE_SAD:
>> - case TGSI_OPCODE_UADD:
>> case TGSI_OPCODE_UDIV:
>> case TGSI_OPCODE_UMOD:
>> case TGSI_OPCODE_UMAD:
>> @@ -362,6 +363,7 @@ tgsi_opcode_infer_dst_type( uint opcode )
>> case TGSI_OPCODE_ARR:
>> case TGSI_OPCODE_IABS:
>> case TGSI_OPCODE_ISSG:
>> + case TGSI_OPCODE_UADD:
>> return TGSI_TYPE_SIGNED;
>> default:
>> return TGSI_TYPE_FLOAT;
>> diff --git a/src/gallium/docs/source/tgsi.rst
>> b/src/gallium/docs/source/tgsi.rst
>> index dd4c773..d9a7fe9 100644
>> --- a/src/gallium/docs/source/tgsi.rst
>> +++ b/src/gallium/docs/source/tgsi.rst
>> @@ -23,6 +23,21 @@ When an instruction has a scalar result, the result is
>> usually copied into
>> each of the components of *dst*. When this happens, the result is said to be
>> *replicated* to *dst*. :opcode:`RCP` is one such instruction.
>>
>> +Modifiers
>> +^^^^^^^^^^^^^^^
>> +
>> +TGSI supports modifiers on inputs (as well as saturate modifier on
>> instructions).
>> +
>> +For inputs which have a floating point type, both absolute value and
>> negation
>> +modifiers are supported (with absolute value being applied first).
>> +TGSI_OPCODE_MOV is considered to have float input type for applying
>> modifiers.
>> +
>> +For inputs which have signed type only the negate modifier is supported.
>> This
>> +includes instructions which are otherwise ignorant if the type is signed or
>> +unsigned, such as TGSI_OPCODE_UADD.
>> +
>> +For inputs with unsigned type no modifiers are allowed.
>> +
>> Instruction Set
>> ---------------
>>
>> --
>> 1.7.9.5
>>
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