Expand the delay characterization.

 * Add more comments in the `samples.textproto`.
 * Aligned the various bit widths, to make it clearer.

 * Unalias a number of operands;
   * Inverted ops (IE `kNand` from `kAnd`, `kNor` from `kOr`)
   * Comparison operators (IE `kUGt`, `kULt`, `kUGe`)
   * Subtraction and addition (`kSub` from `kAdd`)
   * Unsigned verse signed multiply (IE `kSMul` from `kUMul`)

 * Expand samples;
   * More values for `kNot` (4bit -> 256bit)
   * More values for simple ops like `kAnd` (& `kNand`), `kOr` (& `kNor`) and `kXor`.

PiperOrigin-RevId: 589704971

xls/delay_model/op_models.textproto

@@ -50,7 +50,16 @@ op_models {
     }
   }
 }
-op_models { op: "kNand" estimator { alias_op: "kAnd" } }
+op_models {
+  op: "kNand"
+  estimator {
+    regression {
+      expressions {
+        factor { source: OPERAND_COUNT }
+      }
+    }
+  }
+}
 op_models {
   op: "kOr"
   estimator {
@@ -61,7 +70,16 @@ op_models {
     }
   }
 }
-op_models { op: "kNor" estimator { alias_op: "kOr" } }
+op_models {
+  op: "kNor"
+  estimator {
+    regression {
+      expressions {
+        factor { source: OPERAND_COUNT }
+      }
+    }
+  }
+}
 op_models {
   op: "kXor"
   estimator {
@@ -138,7 +156,19 @@ op_models {
     }
   }
 }
-op_models { op: "kSub" estimator { alias_op: "kAdd" } }
+op_models {
+  op: "kSub"
+  estimator {
+    regression {
+      expressions {
+        factor {
+          source: OPERAND_BIT_COUNT
+          operand_number: 0
+        }
+      }
+    }
+  }
+}
 
 op_models {
   op: "kNeg"
@@ -193,6 +223,8 @@ op_models {
     }
   }
 }
+
+# Multiplier operators
 op_models {
   op: "kUMul"
   estimator {
@@ -218,8 +250,31 @@ op_models {
     }
   }
 }
-
-op_models { op: "kSMul" estimator { alias_op: "kUMul" } }
+op_models {
+  op: "kSMul"
+  estimator {
+    regression {
+      expressions {
+        factor {
+          source: RESULT_BIT_COUNT
+        }
+      }
+    }
+  }
+  specializations {
+    kind: OPERANDS_IDENTICAL
+    estimator {
+      regression {
+        expressions {
+          factor {
+            source: OPERAND_BIT_COUNT
+            operand_number: 0
+          }
+        }
+      }
+    }
+  }
+}
 
 op_models {
   op: "kUMulp"
@@ -246,8 +301,31 @@ op_models {
     }
   }
 }
-
-op_models { op: "kSMulp" estimator { alias_op: "kUMulp" } }
+op_models {
+  op: "kSMulp"
+  estimator {
+    regression {
+      expressions {
+        factor {
+          source: RESULT_BIT_COUNT
+        }
+      }
+    }
+  }
+  specializations {
+    kind: OPERANDS_IDENTICAL
+    estimator {
+      regression {
+        expressions {
+          factor {
+            source: OPERAND_BIT_COUNT
+            operand_number: 0
+          }
+        }
+      }
+    }
+  }
+}
 
 op_models {
   op: "kUDiv"
@@ -364,13 +442,40 @@ op_models {
     }
   }
 }
-op_models { op: "kSLt" estimator { alias_op: "kSLe" } }
-op_models { op: "kSGe" estimator { alias_op: "kSLe" } }
-op_models { op: "kSGt" estimator { alias_op: "kSLe" } }
+op_models {
+  op: "kSLt"
+  estimator {
+    regression {
+      expressions {
+        factor { source: OPERAND_BIT_COUNT operand_number: 0 }
+      }
+    }
+  }
+}
+op_models {
+  op: "kSGe"
+  estimator {
+    regression {
+      expressions {
+        factor { source: OPERAND_BIT_COUNT operand_number: 0 }
+      }
+    }
+  }
+}
+op_models {
+  op: "kSGt"
+  estimator {
+    regression {
+      expressions {
+        factor { source: OPERAND_BIT_COUNT operand_number: 0 }
+      }
+    }
+  }
+}
 op_models { op: "kULe" estimator { alias_op: "kSLe" } }
-op_models { op: "kULt" estimator { alias_op: "kSLe" } }
-op_models { op: "kUGe" estimator { alias_op: "kSLe" } }
-op_models { op: "kUGt" estimator { alias_op: "kSLe" } }
+op_models { op: "kULt" estimator { alias_op: "kSLt" } }
+op_models { op: "kUGe" estimator { alias_op: "kSGe" } }
+op_models { op: "kUGt" estimator { alias_op: "kSGt" } }
 
 op_models {
   op: "kEq"