r600/sfn: Fix scheduling with limited channel availability

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20141>

src/gallium/drivers/r600/sfn/sfn_instr.h

@@ -136,7 +136,7 @@ public:
    const InstrList& dependend_instr() { return m_dependend_instr; }
 
    virtual AluInstr *as_alu() { return nullptr; }
-   virtual uint8_t allowed_dest_chan_mask() const { return 0; }
+   virtual uint8_t allowed_src_chan_mask() const { return 0; }
 
 protected:
    const InstrList& required_instr() const { return m_required_instr; }

src/gallium/drivers/r600/sfn/sfn_instr_alu.cpp

@@ -465,15 +465,16 @@ AluInstr::set_sources(SrcValues src)
    }
 }
 
+uint8_t AluInstr::allowed_src_chan_mask() const
+{
+   return 0xf;
+}
+
 uint8_t
 AluInstr::allowed_dest_chan_mask() const
 {
-   if (alu_slots() != 1) {
-      if (has_alu_flag(alu_is_cayman_trans)) {
+   if (alu_slots() != 1 && has_alu_flag(alu_is_cayman_trans)) {
          return (1 << alu_slots()) - 1;
-      } else {
-         return 0;
-      }
    }
    return 0xf;
 }

src/gallium/drivers/r600/sfn/sfn_instr_alu.h

@@ -179,7 +179,8 @@ public:
 
    AluInstr *as_alu() override { return this; }
 
-   uint8_t allowed_dest_chan_mask() const override;
+   uint8_t allowed_src_chan_mask() const override;
+   uint8_t allowed_dest_chan_mask() const;
 
 private:
    friend class AluGroup;

src/gallium/drivers/r600/sfn/sfn_instr_alugroup.cpp

@@ -202,8 +202,14 @@ AluGroup::add_vec_instructions(AluInstr *instr)
       if (dest && (dest->pin() == pin_free || dest->pin() == pin_group)) {
 
          int free_mask = 0xf;
+         for (auto p : dest->parents()) {
+            auto alu = p->as_alu();
+            if (alu)
+               free_mask &= alu->allowed_dest_chan_mask();
+         }
+
          for (auto u : dest->uses()) {
-            free_mask &= u->allowed_dest_chan_mask();
+            free_mask &= u->allowed_src_chan_mask();
             if (!free_mask)
                return false;
          }

src/gallium/drivers/r600/sfn/sfn_instr_export.cpp

@@ -161,7 +161,7 @@ ExportInstr::from_string_impl(std::istream& is, ValueFactory& vf)
 }
 
 uint8_t
-ExportInstr::allowed_dest_chan_mask() const
+ExportInstr::allowed_src_chan_mask() const
 {
    return value().free_chan_mask();
 }

src/gallium/drivers/r600/sfn/sfn_instr_export.h

@@ -77,7 +77,7 @@ public:
    static Instr::Pointer from_string(std::istream& is, ValueFactory& vf);
    static Instr::Pointer last_from_string(std::istream& is, ValueFactory& vf);
 
-   uint8_t allowed_dest_chan_mask() const override;
+   uint8_t allowed_src_chan_mask() const override;
 
 private:
    static ExportInstr::Pointer from_string_impl(std::istream& is, ValueFactory& vf);

src/gallium/drivers/r600/sfn/sfn_instr_tex.cpp

@@ -423,7 +423,7 @@ TexInstr::replace_source(PRegister old_src, PVirtualValue new_src)
 }
 
 uint8_t
-TexInstr::allowed_dest_chan_mask() const
+TexInstr::allowed_src_chan_mask() const
 {
    return m_src.free_chan_mask();
 }

src/gallium/drivers/r600/sfn/sfn_instr_tex.h

@@ -153,7 +153,7 @@ public:
 
    bool replace_source(PRegister old_src, PVirtualValue new_src) override;
 
-   uint8_t allowed_dest_chan_mask() const override;
+   uint8_t allowed_src_chan_mask() const override;
 
 private:
    bool do_ready() const override;