R600/SI: Fix definition for s_cselect_b32

[arsenm]

Summary

These were directly using the old base instruction
class, and specifying the wrong register classes
for operands. The operands can be the other special
inputs besides SGPRs. The op name was also being
directly used for the asm string, so this was printed
without any operands.

[arsenm]

r221921

lib/Target/R600/SIInstrInfo.td

   opName#" $dst, $src0, $src1", pattern
 >;
 
+class SOP2_SELECT_32 <bits<7> op, string opName, list<dag> pattern> : SOP2 <
+  op, (outs SReg_32:$dst), (ins SSrc_32:$src0, SSrc_32:$src1, SCCReg:$scc),
+  opName#" $dst, $src0, $src1 [$scc]", pattern
+>;
+
 class SOP2_64 <bits<7> op, string opName, list<dag> pattern> : SOP2 <
   op, (outs SReg_64:$dst), (ins SSrc_64:$src0, SSrc_64:$src1),
   opName#" $dst, $src0, $src1", pattern

lib/Target/R600/SIInstructions.td

   [(set i32:$dst, (AMDGPUumax i32:$src0, i32:$src1))]
 >;
 
-def S_CSELECT_B32 : SOP2 <
-  0x0000000a, (outs SReg_32:$dst),
-  (ins SReg_32:$src0, SReg_32:$src1, SCCReg:$scc), "S_CSELECT_B32",
+def S_CSELECT_B32 : SOP2_SELECT_32 <
+  0x0000000a, "S_CSELECT_B32",
   []
 >;