[libcxx] [lld] [libc] [lldb] [clang] [flang] [compiler-rt] [clang-tools-extra] [llvm] [AMDGPU][GFX12] VOP encoding and codegen - add support for v_cvt fp8/… (PR #78414)

[Ivan Kosarev via cfe-commits]

================
@@ -626,11 +629,82 @@ class Cvt_PK_F32_F8_Pat<SDPatternOperator node, int index,
          (inst_e32 $src))
 >;
 
-foreach Index = [0, -1] in {
-  def : Cvt_PK_F32_F8_Pat<int_amdgcn_cvt_pk_f32_fp8, Index,
-                          V_CVT_PK_F32_FP8_e32, V_CVT_PK_F32_FP8_sdwa>;
-  def : Cvt_PK_F32_F8_Pat<int_amdgcn_cvt_pk_f32_bf8, Index,
-                          V_CVT_PK_F32_BF8_e32, V_CVT_PK_F32_BF8_sdwa>;
+let SubtargetPredicate = isGFX9Only in {
+  foreach Index = [0, -1] in {
+    def : Cvt_PK_F32_F8_Pat<int_amdgcn_cvt_pk_f32_fp8, Index,
+                            V_CVT_PK_F32_FP8_e32, V_CVT_PK_F32_FP8_sdwa>;
+    def : Cvt_PK_F32_F8_Pat<int_amdgcn_cvt_pk_f32_bf8, Index,
+                            V_CVT_PK_F32_BF8_e32, V_CVT_PK_F32_BF8_sdwa>;
+  }
+}
+
+
+// Similar to VOPProfile_Base_CVT_F32_F8, but for VOP3 instructions.
+def VOPProfile_Base_CVT_PK_F32_F8_OpSel : VOPProfileI2F <v2f32, i32> {
+  let InsVOP3OpSel = (ins Src0Mod:$src0_modifiers, Src0RC64:$src0,
+                          clampmod:$clamp, omod:$omod, op_sel0:$op_sel);
+
+  let HasOpSel = 1;
+  let HasExtVOP3DPP = 0;
+}
+
+def VOPProfile_Base_CVT_F32_F8_OpSel : VOPProfile<[f32, i32, i32, untyped]> {
+  let InsVOP3OpSel = (ins Src0Mod:$src0_modifiers, Src0RC64:$src0,
+                          Src1Mod:$src1_modifiers, Src1RC64:$src1,
+                          clampmod:$clamp, omod:$omod, op_sel0:$op_sel);
+  let AsmVOP3OpSel = !subst(", $src1_modifiers", "", getAsmVOP3OpSel<2, 0, 0, 1, 1, 0>.ret);
+
+  let HasOpSel = 1;
+  let HasExtDPP = 1;
+  let HasExtVOP3DPP = 1;
+
+  let Src1VOP3DPP = Src1RC64;
+  let AsmVOP3DPP8 = getAsmVOP3DPP8<AsmVOP3OpSel>.ret;
+  let AsmVOP3DPP16 = getAsmVOP3DPP16<AsmVOP3OpSel>.ret;
+}
+
+let SubtargetPredicate = isGFX12Plus, mayRaiseFPException = 0,
+    SchedRW = [WriteFloatCvt] in {
+  defm V_CVT_F32_FP8_OP_SEL    : VOP1Inst<"v_cvt_f32_fp8_op_sel", VOPProfile_Base_CVT_F32_F8_OpSel>;
+  defm V_CVT_F32_BF8_OP_SEL    : VOP1Inst<"v_cvt_f32_bf8_op_sel", VOPProfile_Base_CVT_F32_F8_OpSel>;
+  defm V_CVT_PK_F32_FP8_OP_SEL : VOP1Inst<"v_cvt_pk_f32_fp8_op_sel", VOPProfile_Base_CVT_PK_F32_F8_OpSel>;
+  defm V_CVT_PK_F32_BF8_OP_SEL : VOP1Inst<"v_cvt_pk_f32_bf8_op_sel", VOPProfile_Base_CVT_PK_F32_F8_OpSel>;
+}
+
+class Cvt_F32_F8_Pat_OpSel<SDPatternOperator node, bits<2> index,
+    VOP1_Pseudo inst_e32, VOP3_Pseudo inst_e64> : GCNPat<
+    (f32 (node i32:$src, index)),
+    !if (index,
+         (inst_e64 !if(index{0}, SRCMODS.OP_SEL_0, SRCMODS.OP_SEL_1), $src,
+                   !if(index{1}, SRCMODS.OP_SEL_0, SRCMODS.OP_SEL_1), (i32 0),
----------------
kosarev wrote:

Why do we expect `SRCMODS.OP_SEL_1` for dropped index bits? Is there any test coverage for these cases?

https://github.com/llvm/llvm-project/pull/78414