[Mesa-dev] [PATCH] r600g: Why all this fiddling with tgsi_helper_copy?

[Jerome Glisse]

2010/12/13 Christian König <deathsimple at vodafone.de>:
> tgsi_helper_copy is used on several occasions to copy a temporary result
> into the real destination register to emulate writemasks for OP3 and
> reduction operations. According to R600 ISA that's unnecessary.
>

What in R600 ISA makes you think so (page) ? write mask is bit 4
SQ_ALU_WORD1_OP2 but bit 4 of SQ_ALU_WORD1_OP3 is in SRC2_SEL field.

Cheers,
Jerome