[AMDGPU][MC][GFX9] Added s_dcache_discard* instructions

[dp]

Summary

See bug 36838: https://bugs.llvm.org/show_bug.cgi?id=36838

[artem.tamazov]

LGTM.

lib/Target/AMDGPU/SMInstructions.td

class SM_Store_Pseudo <string opName, dag ins, string asmOps, list<dag> pattern = []>
   RegisterClass BaseClass;
   RegisterClass SrcClass;
   let mayLoad = 0;
   let mayStore = 1;
   let has_glc = 1;
   let ScalarStore = 1;
 }
 
+class SM_Discard_Pseudo <string opName, dag ins, bit isImm>
+  : SM_Pseudo<opName, (outs), ins, " $sbase, $offset"> {
+  let mayLoad = 0;
+  let mayStore = 0;
+  let has_glc = 0;
+  let has_sdst = 0;
+  let ScalarStore = 0;
+  let hasSideEffects = 1;
+  let offset_is_imm = isImm;
+  let PseudoInstr = opName # !if(isImm, "_IMM", "_SGPR");
+}
+
 multiclass SM_Pseudo_Loads<string opName,
                            RegisterClass baseClass,
                            RegisterClass dstClass> {
   def _IMM  : SM_Load_Pseudo <opName,
                               (outs dstClass:$sdst),
                               (ins baseClass:$sbase, i32imm:$offset, i1imm:$glc),
                               " $sdst, $sbase, $offset$glc", []> {
     let offset_is_imm = 1;
def _SGPR  : SM_Store_Pseudo <opName,
     (ins srcClass:$sdata, baseClass:$sbase, SReg_32:$soff, i1imm:$glc),
     " $sdata, $sbase, $offset$glc", []> {
     let BaseClass = baseClass;
     let SrcClass = srcClass;
     let PseudoInstr = opName # "_SGPR";
   }
 }
 
+multiclass SM_Pseudo_Discards<string opName> {
+  def _IMM  : SM_Discard_Pseudo <opName, (ins SReg_64:$sbase, smrd_offset_20:$offset), 1>;
+  def _SGPR : SM_Discard_Pseudo <opName, (ins SReg_64:$sbase, SReg_32:$offset), 0>;
+}
+
 class SM_Time_Pseudo<string opName, SDPatternOperator node> : SM_Pseudo<
   opName, (outs SReg_64_XEXEC:$sdst), (ins),
   " $sdst", [(set i64:$sdst, (node))]> {
   let hasSideEffects = 1;
   let mayStore = 0;
   let mayLoad = 1;
   let has_sbase = 0;
   let has_offset = 0;

 defm S_ATOMIC_AND_X2              : SM_Pseudo_Atomics <"s_atomic_and_x2", SReg_64, SReg_64_XEXEC>;
 defm S_ATOMIC_OR_X2               : SM_Pseudo_Atomics <"s_atomic_or_x2", SReg_64, SReg_64_XEXEC>;
 defm S_ATOMIC_XOR_X2              : SM_Pseudo_Atomics <"s_atomic_xor_x2", SReg_64, SReg_64_XEXEC>;
 defm S_ATOMIC_INC_X2              : SM_Pseudo_Atomics <"s_atomic_inc_x2", SReg_64, SReg_64_XEXEC>;
 defm S_ATOMIC_DEC_X2              : SM_Pseudo_Atomics <"s_atomic_dec_x2", SReg_64, SReg_64_XEXEC>;
 
 } // let SubtargetPredicate = HasScalarAtomics
 
+let SubtargetPredicate = isGFX9 in {
+defm S_DCACHE_DISCARD    : SM_Pseudo_Discards <"s_dcache_discard">;
+defm S_DCACHE_DISCARD_X2 : SM_Pseudo_Discards <"s_dcache_discard_x2">;
+}
+
 //===----------------------------------------------------------------------===//
 // Scalar Memory Patterns
 //===----------------------------------------------------------------------===//
 
 
 def smrd_load : PatFrag <(ops node:$ptr), (load node:$ptr), [{
   auto Ld = cast<LoadSDNode>(N);
   return Ld->getAlignment() >= 4  &&

 defm S_ATOMIC_SMAX_X2             : SM_Real_Atomics_vi <0xa6, "S_ATOMIC_SMAX_X2">;
 defm S_ATOMIC_UMAX_X2             : SM_Real_Atomics_vi <0xa7, "S_ATOMIC_UMAX_X2">;
 defm S_ATOMIC_AND_X2              : SM_Real_Atomics_vi <0xa8, "S_ATOMIC_AND_X2">;
 defm S_ATOMIC_OR_X2               : SM_Real_Atomics_vi <0xa9, "S_ATOMIC_OR_X2">;
 defm S_ATOMIC_XOR_X2              : SM_Real_Atomics_vi <0xaa, "S_ATOMIC_XOR_X2">;
 defm S_ATOMIC_INC_X2              : SM_Real_Atomics_vi <0xab, "S_ATOMIC_INC_X2">;
 defm S_ATOMIC_DEC_X2              : SM_Real_Atomics_vi <0xac, "S_ATOMIC_DEC_X2">;
 
+multiclass SM_Real_Discard_vi<bits<8> op, string ps> {
+  def _IMM_vi  : SMEM_Real_vi <op, !cast<SM_Discard_Pseudo>(ps#_IMM)>;
+  def _SGPR_vi : SMEM_Real_vi <op, !cast<SM_Discard_Pseudo>(ps#_SGPR)>;
+}
+
+defm S_DCACHE_DISCARD    : SM_Real_Discard_vi <0x28, "S_DCACHE_DISCARD">;
+defm S_DCACHE_DISCARD_X2 : SM_Real_Discard_vi <0x29, "S_DCACHE_DISCARD_X2">;
+
 //===----------------------------------------------------------------------===//
 // CI
 //===----------------------------------------------------------------------===//
 
 def smrd_literal_offset : NamedOperandU32<"SMRDLiteralOffset",
                                           NamedMatchClass<"SMRDLiteralOffset">> {
   let OperandType = "OPERAND_IMMEDIATE";
 }

test/MC/AMDGPU/smem.s

 // GFX9: s_scratch_store_dwordx2 s[2:3], s[4:5], s101 glc ; encoding: [0x82,0x00,0x59,0xc0,0x65,0x00,0x00,0x00]
 // NOSICIVI: error
 
 s_scratch_store_dwordx4 s[4:7], s[4:5], s0 glc
 // GFX9: s_scratch_store_dwordx4 s[4:7], s[4:5], s0 glc ; encoding: [0x02,0x01,0x5d,0xc0,0x00,0x00,0x00,0x00]
 // NOSICIVI: error
 
 //===----------------------------------------------------------------------===//
+// s_dcache_discard instructions
+//===----------------------------------------------------------------------===//
+
+s_dcache_discard s[2:3], s0
+// GFX9:     s_dcache_discard s[2:3], s0 ; encoding: [0x01,0x00,0xa0,0xc0,0x00,0x00,0x00,0x00]
+// NOSICIVI: error: instruction not supported on this GPU
+
+s_dcache_discard s[2:3], 0x0
+// GFX9:     s_dcache_discard s[2:3], 0x0 ; encoding: [0x01,0x00,0xa2,0xc0,0x00,0x00,0x00,0x00]
+// NOSICIVI: error: instruction not supported on this GPU
+
+s_dcache_discard_x2 s[2:3], s101
+// GFX9:     s_dcache_discard_x2 s[2:3], s101 ; encoding: [0x01,0x00,0xa4,0xc0,0x65,0x00,0x00,0x00]
+// NOSICIVI: error: instruction not supported on this GPU
+
+s_dcache_discard_x2 s[2:3], 0x0
+// GFX9:     s_dcache_discard_x2 s[2:3], 0x0 ; encoding: [0x01,0x00,0xa6,0xc0,0x00,0x00,0x00,0x00]
+// NOSICIVI: error: instruction not supported on this GPU
+
+//===----------------------------------------------------------------------===//
 // s_atomic instructions
 //===----------------------------------------------------------------------===//
 
 s_atomic_add s5, s[2:3], s101
 // GFX9:     s_atomic_add s5, s[2:3], s101 ; encoding: [0x41,0x01,0x08,0xc2,0x65,0x00,0x00,0x00]
 // NOSICIVI: error:
 
 s_atomic_add s5, s[2:3], 0x0

test/MC/Disassembler/AMDGPU/smem_gfx9.txt

 
 # GFX9: s_scratch_store_dwordx2 s[2:3], s[4:5], s101 glc ; encoding: [0x82,0x00,0x59,0xc0,0x65,0x00,0x00,0x00]
 0x82,0x00,0x59,0xc0,0x65,0x00,0x00,0x00
 
 # GFX9: s_scratch_store_dwordx4 s[4:7], s[4:5], s0 glc ; encoding: [0x02,0x01,0x5d,0xc0,0x00,0x00,0x00,0x00]
 0x02,0x01,0x5d,0xc0,0x00,0x00,0x00,0x00
 
 #===------------------------------------------------------------------------===#
+# s_dcache_discard
+#===------------------------------------------------------------------------===#
+
+# GFX9: s_dcache_discard s[100:101], s0 ; encoding: [0x32,0x00,0xa0,0xc0,0x00,0x00,0x00,0x00]
+0x32,0x00,0xa0,0xc0,0x00,0x00,0x00,0x00
+
+# GFX9: s_dcache_discard s[2:3], 0x0 ; encoding: [0x01,0x00,0xa2,0xc0,0x00,0x00,0x00,0x00]
+0x01,0x00,0xa2,0xc0,0x00,0x00,0x00,0x00
+
+# GFX9: s_dcache_discard_x2 s[2:3], s101 ; encoding: [0x01,0x00,0xa4,0xc0,0x65,0x00,0x00,0x00]
+0x01,0x00,0xa4,0xc0,0x65,0x00,0x00,0x00
+
+# GFX9: s_dcache_discard_x2 s[2:3], 0x0 ; encoding: [0x01,0x00,0xa6,0xc0,0x00,0x00,0x00,0x00]
+0x01,0x00,0xa6,0xc0,0x00,0x00,0x00,0x00
+
+#===------------------------------------------------------------------------===#
 # s_atomic
 #===------------------------------------------------------------------------===#
 
 # GFX9: s_atomic_add s5, s[2:3], s101    ; encoding: [0x41,0x01,0x08,0xc2,0x65,0x00,0x00,0x00]
 0x41,0x01,0x08,0xc2,0x65,0x00,0x00,0x00
 
 # GFX9: s_atomic_add_x2 s[10:11], s[2:3], s101    ; encoding: [0x81,0x02,0x88,0xc2,0x65,0x00,0x00,0x00]
 0x81,0x02,0x88,0xc2,0x65,0x00,0x00,0x00