[flang-commits] [flang] [mlir] [RFC][mlir] Conditional support for fast-math attributes. (PR #125620)

[Slava Zakharin via flang-commits]

================
@@ -22,31 +22,60 @@ def ArithFastMathInterface : OpInterface<"ArithFastMathInterface"> {
 
   let cppNamespace = "::mlir::arith";
 
-  let methods = [
-    InterfaceMethod<
-      /*desc=*/        "Returns a FastMathFlagsAttr attribute for the operation",
-      /*returnType=*/  "FastMathFlagsAttr",
-      /*methodName=*/  "getFastMathFlagsAttr",
-      /*args=*/        (ins),
-      /*methodBody=*/  [{}],
-      /*defaultImpl=*/ [{
+  let methods =
+      [InterfaceMethod<
+           /*desc=*/"Returns a FastMathFlagsAttr attribute for the operation",
+           /*returnType=*/"FastMathFlagsAttr",
+           /*methodName=*/"getFastMathFlagsAttr",
+           /*args=*/(ins),
+           /*methodBody=*/[{}],
+           /*defaultImpl=*/[{
         ConcreteOp op = cast<ConcreteOp>(this->getOperation());
         return op.getFastmathAttr();
-      }]
-      >,
-    StaticInterfaceMethod<
-      /*desc=*/        [{Returns the name of the FastMathFlagsAttr attribute
+      }]>,
+       StaticInterfaceMethod<
+           /*desc=*/[{Returns the name of the FastMathFlagsAttr attribute
                          for the operation}],
-      /*returnType=*/  "StringRef",
-      /*methodName=*/  "getFastMathAttrName",
-      /*args=*/        (ins),
-      /*methodBody=*/  [{}],
-      /*defaultImpl=*/ [{
+           /*returnType=*/"StringRef",
+           /*methodName=*/"getFastMathAttrName",
+           /*args=*/(ins),
+           /*methodBody=*/[{}],
+           /*defaultImpl=*/[{
         return "fastmath";
-      }]
-      >
+      }]>,
+       InterfaceMethod<
+           /*desc=*/[{Returns true iff FastMathFlagsAttr attribute
+                         is applicable to the operation that supports
+                         ArithFastMathInterface. If it returns false,
+                         then the FastMathFlagsAttr of the operation
+                         must be nullptr or have 'none' value}],
+           /*returnType=*/"bool",
+           /*methodName=*/"isArithFastMathApplicable",
----------------
vzakhari wrote:

Its intention is to tell whether fast-math flags are applicable.  It is used in the verified code below, but it may also be used by the passes/builders the create new operations supporting `ArithFastMathInterface`, e.g. see its usage in `FIRBuilder.cpp` file above.

https://github.com/llvm/llvm-project/pull/125620