From: Francisco Jerez Date: Wed, 4 Feb 2015 16:24:47 +0000 (+0200) Subject: i965: Handle F16TO32/F32TO16 with dword src/dst consistently on both back-ends. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6c07279e5ad67d925b99ff9e0345dcaeffc37283;p=mesa.git i965: Handle F16TO32/F32TO16 with dword src/dst consistently on both back-ends. Due to the way it's implemented in hardware, the F16TO32/F32TO16 instructions require the source/destination register to be of some 16-bit type in Align1 mode, while they require it to be some 32-bit type in Align16 mode (and as an undocumented feature the high 16 bits of the destination register are zeroed out in the case of the F32TO16 instruction on Gen7). Make their behaviour consistent so you can specify a 32 bit register type as source or destination and get predictable results in the most significant bits no matter what access mode is being used. Reviewed-by: Matt Turner --- diff --git a/src/mesa/drivers/dri/i965/brw_eu_emit.c b/src/mesa/drivers/dri/i965/brw_eu_emit.c index d9e01fdd9bd..1d6fd673de1 100644 --- a/src/mesa/drivers/dri/i965/brw_eu_emit.c +++ b/src/mesa/drivers/dri/i965/brw_eu_emit.c @@ -1155,13 +1155,14 @@ brw_F32TO16(struct brw_compile *p, struct brw_reg dst, struct brw_reg src) * an undocumented feature. */ const bool needs_zero_fill = (dst.type == BRW_REGISTER_TYPE_UD && - brw->gen >= 8); + (!align16 || brw->gen >= 8)); brw_inst *inst; if (align16) { assert(dst.type == BRW_REGISTER_TYPE_UD); } else { - assert(dst.type == BRW_REGISTER_TYPE_W || + assert(dst.type == BRW_REGISTER_TYPE_UD || + dst.type == BRW_REGISTER_TYPE_W || dst.type == BRW_REGISTER_TYPE_UW || dst.type == BRW_REGISTER_TYPE_HF); } @@ -1199,6 +1200,15 @@ brw_F16TO32(struct brw_compile *p, struct brw_reg dst, struct brw_reg src) if (align16) { assert(src.type == BRW_REGISTER_TYPE_UD); } else { + /* From the Ivybridge PRM, Vol4, Part3, Section 6.26 f16to32: + * + * Because this instruction does not have a 16-bit floating-point + * type, the source data type must be Word (W). The destination type + * must be F (Float). + */ + if (src.type == BRW_REGISTER_TYPE_UD) + src = spread(retype(src, BRW_REGISTER_TYPE_W), 2); + assert(src.type == BRW_REGISTER_TYPE_W || src.type == BRW_REGISTER_TYPE_UW || src.type == BRW_REGISTER_TYPE_HF);