Am Donnerstag, den 09.08.2018, 17:10 +0200 schrieb Roland Scheidegger: > This is incorrect for umsb. Hmm, according to the TGSI doc all of those operations including UMSB are supposed to return -1 if no bits are set [1], for me that implies that their return type should be signed.
[1] http://gallium.readthedocs.io/en/latest/tgsi.html#opcode-UMSB > If you really want to move so the dst type is signed, you need to add > it to infer_src_type so the src args are unsigned. I see the control flow now, so I guess I actually should add these three cases to infer_dst_type, and also add the proper src type for umsb. > FWIW I'd like to think that all 3 of these always operate on unsigned > data (even if they might return signed data), imho they are a lot > more easier to understand that way (I mean the signed msb you have to > look up what the hell it actually does, bit operations on unsigned > data are just easier to understand). But of course it doesn't really > make a difference, so I can live with the other 2 if the src type > indicates signed. GLSL bitCount and findLSB are both operating on both types, and I assume that these are actually translated to these two TGSI instructions, so the src type should not be set, thanks for the pointers, Gert > > Roland > > > Am 09.08.2018 um 10:43 schrieb Gert Wollny: > > The GLSL functions findLSB, findMSB, and countBits always return > > a signed integer type. Let the according TGSI operations reflect > > this. > > > > Signed-off-by: Gert Wollny <gert.wol...@collabora.com> > > --- > > src/gallium/auxiliary/tgsi/tgsi_info.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/src/gallium/auxiliary/tgsi/tgsi_info.c > > b/src/gallium/auxiliary/tgsi/tgsi_info.c > > index bbe1a21e43..a8c2bbe663 100644 > > --- a/src/gallium/auxiliary/tgsi/tgsi_info.c > > +++ b/src/gallium/auxiliary/tgsi/tgsi_info.c > > @@ -150,9 +150,6 @@ tgsi_opcode_infer_type(enum tgsi_opcode opcode) > > case TGSI_OPCODE_UBFE: > > case TGSI_OPCODE_BFI: > > case TGSI_OPCODE_BREV: > > - case TGSI_OPCODE_POPC: > > - case TGSI_OPCODE_LSB: > > - case TGSI_OPCODE_UMSB: > > case TGSI_OPCODE_IMG2HND: > > case TGSI_OPCODE_SAMP2HND: > > return TGSI_TYPE_UNSIGNED; > > @@ -188,6 +185,9 @@ tgsi_opcode_infer_type(enum tgsi_opcode opcode) > > case TGSI_OPCODE_U64SGE: > > case TGSI_OPCODE_I64SLT: > > case TGSI_OPCODE_I64SGE: > > + case TGSI_OPCODE_LSB: > > + case TGSI_OPCODE_POPC: > > + case TGSI_OPCODE_UMSB: > > return TGSI_TYPE_SIGNED; > > case TGSI_OPCODE_DADD: > > case TGSI_OPCODE_DABS: > > > > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
