<html dir="ltr"><head></head><body style="text-align:left; direction:ltr;"><div>On Fri, 2019-01-18 at 12:13 +0100, Iago Toral wrote:</div><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex"><div>On Thu, 2019-01-17 at 17:12 -0600, Jason Ekstrand wrote:</div><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex"><div dir="ltr"><div>This patch doesn't really do what the commit message says. What it really does is implement float -> 8-bit converions for *any* size float.<br></div><div><br></div><div class="gmail_quote"><div dir="ltr">On Tue, Jan 15, 2019 at 7:55 AM Iago Toral Quiroga <<a href="mailto:itoral@igalia.com">itoral@igalia.com</a>> wrote:<br></div><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex">These are not directly supported in hardware and brw_nir_lower_conversions<br>
should have taken care of that before we get here. Also, while we are<br>
at it, make sure 64-bit integer to 8-bit are also properly split by<br>
the same lowering pass, since they have the same hardware restrictions.<br></blockquote><div><br></div><div>Now that we have a lowering pass, having separate cases just so one of them can assert seems silly. If anything, we should just do</div><div><br></div><div>if (result.type == BRW_REGISTER_TYPE_B ||</div><div> result.type == BRW_REGISTER_TYPE_UB ||</div><div> result.type == BRW_REGISTER_TYPE_HF)</div><div> assert(type_sz(op[0].type) < 8) /* brw_nir_lower_conversions */</div><div><br></div><div>and have it all in one big case. The only special case we need is for booleans where we need to negate them and fall through.</div></div></div></blockquote><div><br></div><div>There are more cases, since the inverse conversions of these are not supported either. I guess I'll just add this as well:</div><div><br></div><div>if (op[0].type == BRW_REGISTER_TYPE_B ||</div><div> op[0].type == BRW_REGISTER_TYPE_UB ||</div><div> op[0].type == BRW_REGISTER_TYPE_HF)</div><div> assert(type_sz(result.type) < 8); /* brw_nir_lower_conversions */</div></blockquote><div><br></div><div>Oh, and there is also the rounding opcodes for f16 destinations (plus the big comment about brw_F32TO16 that comes with their fallthrough)... I think we might want to keep the three f2f16* opcodes as a separate block and do as you suggest for the remaining ones if that is okay.</div><div><br></div><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex"><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex"><div dir="ltr"><div class="gmail_quote"><div>--Jason<br></div><div> </div><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex">
---<br>
src/intel/compiler/brw_fs_nir.cpp | 6 ++++--<br>
1 file changed, 4 insertions(+), 2 deletions(-)<br>
<br>
diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp<br>
index cf546b8ff09..e454578d99b 100644<br>
--- a/src/intel/compiler/brw_fs_nir.cpp<br>
+++ b/src/intel/compiler/brw_fs_nir.cpp<br>
@@ -786,6 +786,10 @@ fs_visitor::nir_emit_alu(const fs_builder &bld, nir_alu_instr *instr)<br>
case nir_op_f2f16:<br>
case nir_op_i2f16:<br>
case nir_op_u2f16:<br>
+ case nir_op_i2i8:<br>
+ case nir_op_u2u8:<br>
+ case nir_op_f2i8:<br>
+ case nir_op_f2u8:<br>
assert(type_sz(op[0].type) < 8); /* brw_nir_lower_conversions */<br>
inst = bld.MOV(result, op[0]);<br>
inst->saturate = instr->dest.saturate;<br>
@@ -824,8 +828,6 @@ fs_visitor::nir_emit_alu(const fs_builder &bld, nir_alu_instr *instr)<br>
case nir_op_u2u32:<br>
case nir_op_i2i16:<br>
case nir_op_u2u16:<br>
- case nir_op_i2i8:<br>
- case nir_op_u2u8:<br>
inst = bld.MOV(result, op[0]);<br>
inst->saturate = instr->dest.saturate;<br>
break;<br>
</blockquote></div></div></blockquote>
</blockquote></body></html>