[RISC-V] Integer min/max intrinsics (#114687)

* Intrinsify integer min/max

* Implement integer min/max

* Cleanup assert

* Fix windows build

* Add tests

* Different VNFunc for unsigned

* Min/Max is commutative

* Different intrinsic name for unsigned

Author: tomeksowi

src/coreclr/jit/codegenriscv64.cpp

@@ -4718,6 +4718,18 @@ void CodeGen::genIntrinsic(GenTreeIntrinsic* treeNode)
         case NI_System_Math_MaxNumber:
             instr = is4 ? INS_fmax_s : INS_fmax_d;
             break;
+        case NI_System_Math_Min:
+            instr = INS_min;
+            break;
+        case NI_System_Math_MinUnsigned:
+            instr = INS_minu;
+            break;
+        case NI_System_Math_Max:
+            instr = INS_max;
+            break;
+        case NI_System_Math_MaxUnsigned:
+            instr = INS_maxu;
+            break;
         case NI_PRIMITIVE_LeadingZeroCount:
             instr = is4 ? INS_clzw : INS_clz;
             break;

src/coreclr/jit/emitriscv64.cpp

@@ -826,7 +826,8 @@ void emitter::emitIns_R_R_R(
     if ((INS_add <= ins && ins <= INS_and) || (INS_mul <= ins && ins <= INS_remuw) ||
         (INS_addw <= ins && ins <= INS_sraw) || (INS_fadd_s <= ins && ins <= INS_fmax_s) ||
         (INS_fadd_d <= ins && ins <= INS_fmax_d) || (INS_feq_s <= ins && ins <= INS_fle_s) ||
-        (INS_feq_d <= ins && ins <= INS_fle_d) || (INS_lr_w <= ins && ins <= INS_amomaxu_d))
+        (INS_feq_d <= ins && ins <= INS_fle_d) || (INS_lr_w <= ins && ins <= INS_amomaxu_d) ||
+        (INS_min <= ins && ins <= INS_maxu))
     {
 #ifdef DEBUG
         switch (ins)
@@ -913,6 +914,11 @@ void emitter::emitIns_R_R_R(
             case INS_amominu_d:
             case INS_amomaxu_w:
             case INS_amomaxu_d:
+
+            case INS_min:
+            case INS_minu:
+            case INS_max:
+            case INS_maxu:
                 break;
             default:
                 NYI_RISCV64("illegal ins within emitIns_R_R_R!");
@@ -4070,6 +4076,15 @@ void emitter::emitDispInsName(
                             return emitDispIllegalInstruction(code);
                     }
                     return;
+                case 0b0000101:
+                {
+                    if ((opcode3 >> 2) != 1) // clmul[h] unsupported
+                        return emitDispIllegalInstruction(code);
+
+                    static const char names[][5] = {"min ", "minu", "max ", "maxu"};
+                    printf("%s           %s, %s, %s\n", names[opcode3 & 0b11], rd, rs1, rs2);
+                    return;
+                }
                 default:
                     return emitDispIllegalInstruction(code);
             }

src/coreclr/jit/gentree.cpp

@@ -5404,10 +5404,12 @@ unsigned Compiler::gtSetEvalOrder(GenTree* tree)
                         case NI_System_Math_MaxMagnitude:
                         case NI_System_Math_MaxMagnitudeNumber:
                         case NI_System_Math_MaxNumber:
+                        case NI_System_Math_MaxUnsigned:
                         case NI_System_Math_Min:
                         case NI_System_Math_MinMagnitude:
                         case NI_System_Math_MinMagnitudeNumber:
                         case NI_System_Math_MinNumber:
+                        case NI_System_Math_MinUnsigned:
                         case NI_System_Math_Pow:
                         case NI_System_Math_Round:
                         case NI_System_Math_Sin:
@@ -5759,10 +5761,12 @@ unsigned Compiler::gtSetEvalOrder(GenTree* tree)
                     case NI_System_Math_MaxMagnitude:
                     case NI_System_Math_MaxMagnitudeNumber:
                     case NI_System_Math_MaxNumber:
+                    case NI_System_Math_MaxUnsigned:
                     case NI_System_Math_Min:
                     case NI_System_Math_MinMagnitude:
                     case NI_System_Math_MinMagnitudeNumber:
                     case NI_System_Math_MinNumber:
+                    case NI_System_Math_MinUnsigned:
                     {
                         level++;
                         break;
@@ -12758,6 +12762,9 @@ void Compiler::gtDispTree(GenTree*                    tree,
                 case NI_System_Math_MaxNumber:
                     printf(" maxNumber");
                     break;
+                case NI_System_Math_MaxUnsigned:
+                    printf(" maxUnsigned");
+                    break;
                 case NI_System_Math_Min:
                     printf(" min");
                     break;
@@ -12770,6 +12777,9 @@ void Compiler::gtDispTree(GenTree*                    tree,
                 case NI_System_Math_MinNumber:
                     printf(" minNumber");
                     break;
+                case NI_System_Math_MinUnsigned:
+                    printf(" minUnsigned");
+                    break;
                 case NI_System_Math_Pow:
                     printf(" pow");
                     break;