On Thu, 2017-11-09 at 03:58 +0100, srol...@vmware.com wrote: > From: Roland Scheidegger <srol...@vmware.com> > > r600 used the clamped version for rcp, whereas both evergreen and cayman > used the ieee version. I don't know why that discrepancy exists (it does so > since day 1) but there does not seem to be a valid reason for this, so make > it consistent. This seems now safer than before the previous commit (using > the mystery dx10 clamp). > Note that rsq still uses clamped version (as before even though the table > may have suggested otherwise for evergreen) for r600/eg, but not for cayman.
just layman's opinion here. Does TGSI not mandate specific behaviour
wrt nans and infinities for this OP?
> I just don't feel lucky enough to change this (it should also be noted r600
> supports sqrt natively, which is always ieee, therefore might not really see
> rsqrt with glsl often presumably).
why would that be? isn't RECIPSQRT_IEEE(x) still optimization over
RECIP_IEEE(SQRT(x))?
Jan
> Compile tested only...
> ---
> src/gallium/drivers/r600/r600_shader.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/src/gallium/drivers/r600/r600_shader.c
> b/src/gallium/drivers/r600/r600_shader.c
> index 6a755bb3fd..628c33787e 100644
> --- a/src/gallium/drivers/r600/r600_shader.c
> +++ b/src/gallium/drivers/r600/r600_shader.c
> @@ -8830,11 +8830,7 @@ static const struct r600_shader_tgsi_instruction
> r600_shader_tgsi_instruction[]
> [TGSI_OPCODE_MOV] = { ALU_OP1_MOV, tgsi_op2},
> [TGSI_OPCODE_LIT] = { ALU_OP0_NOP, tgsi_lit},
>
> - /* XXX:
> - * For state trackers other than OpenGL, we'll want to use
> - * _RECIP_IEEE instead.
> - */
> - [TGSI_OPCODE_RCP] = { ALU_OP1_RECIP_CLAMPED,
> tgsi_trans_srcx_replicate},
> + [TGSI_OPCODE_RCP] = { ALU_OP1_RECIP_IEEE,
> tgsi_trans_srcx_replicate},
>
> [TGSI_OPCODE_RSQ] = { ALU_OP0_NOP, tgsi_rsq},
> [TGSI_OPCODE_EXP] = { ALU_OP0_NOP, tgsi_exp},
> @@ -9034,7 +9030,7 @@ static const struct r600_shader_tgsi_instruction
> eg_shader_tgsi_instruction[] =
> [TGSI_OPCODE_MOV] = { ALU_OP1_MOV, tgsi_op2},
> [TGSI_OPCODE_LIT] = { ALU_OP0_NOP, tgsi_lit},
> [TGSI_OPCODE_RCP] = { ALU_OP1_RECIP_IEEE,
> tgsi_trans_srcx_replicate},
> - [TGSI_OPCODE_RSQ] = { ALU_OP1_RECIPSQRT_IEEE, tgsi_rsq},
> + [TGSI_OPCODE_RSQ] = { ALU_OP0_NOP, tgsi_rsq},
> [TGSI_OPCODE_EXP] = { ALU_OP0_NOP, tgsi_exp},
> [TGSI_OPCODE_LOG] = { ALU_OP0_NOP, tgsi_log},
> [TGSI_OPCODE_MUL] = { ALU_OP2_MUL_IEEE, tgsi_op2},
signature.asc
Description: This is a digitally signed message part
_______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
