Implement set[n]bc[r] instructions

This implements the setbc, setnbc, setbcr and setnbcr instructions.
Because the insn_type_t type already has 64 elements, this uses the
existing OP_SETB for the new instructions, and has execute1 compute
different results depending on bits 6-9 of the instruction.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

execute1.vhdl

@@ -836,15 +836,28 @@ begin
 		end if;
                 misc_result <= mfcr_result;
             when "110" =>
+                -- setb and set[n]bc[r]
+                setb_result := (others => '0');
+                if e_in.insn(9) = '0' then
                     -- setb
                     bfa := insn_bfa(e_in.insn);
                     crbit := to_integer(unsigned(bfa)) * 4;
-                setb_result := (others => '0');
                     if cr_in(31 - crbit) = '1' then
                         setb_result := (others => '1');
                     elsif cr_in(30 - crbit) = '1' then
                         setb_result(0) := '1';
                     end if;
+                else
+                    -- set[n]bc[r]
+                    crbit := to_integer(unsigned(insn_bi(e_in.insn)));
+                    if (cr_in(31 - crbit) xor e_in.insn(6)) = '1' then
+                        if e_in.insn(7) = '0' then
+                            setb_result(0) := '1';
+                        else
+                            setb_result := (others => '1');
+                        end if;
+                    end if;
+                end if;
                 misc_result <= setb_result;
             when others =>
                 misc_result <= (others => '0');

predecode.vhdl

@@ -336,6 +336,10 @@ architecture behaviour of predecoder is
         2#0_00101_11010#  =>  INSN_prtyd,
         2#0_00100_11010#  =>  INSN_prtyw,
         2#0_00100_00000#  =>  INSN_setb,
+        2#0_01100_00000#  =>  INSN_setb, -- setbc
+        2#0_01101_00000#  =>  INSN_setb, -- setbcr
+        2#0_01110_00000#  =>  INSN_setb, -- setnbc
+        2#0_01111_00000#  =>  INSN_setb, -- setnbcr
         2#0_01111_10010#  =>  INSN_slbia,
         2#0_00000_11011#  =>  INSN_sld,
         2#0_00000_11000#  =>  INSN_slw,