[mlir][vector] rephrased description

More carefully worded description. Added constructor to options.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D92664

Author: aartbik

mlir/include/mlir/Conversion/Passes.td

@@ -394,9 +394,10 @@ def ConvertVectorToLLVM : Pass<"convert-vector-to-llvm", "ModuleOp"> {
 
     Convert operations from the vector dialect into the LLVM IR dialect
     operations. The lowering pass provides several options to control
-    the kind of optimizations that are allowed. It also provides options
-    that augment the architectural-neutral vector dialect with
-    architectural-specific dialects (AVX512, Neon, etc.).
+    the kinds of optimizations that are allowed. It also provides options
+    that enable the use of one or more architectural-specific dialects
+    (AVX512, Neon, SVE, etc.) in combination with the architectural-neutral
+    vector dialect lowering.
 
   }];
   let constructor = "mlir::createConvertVectorToLLVMPass()";
@@ -411,7 +412,8 @@ def ConvertVectorToLLVM : Pass<"convert-vector-to-llvm", "ModuleOp"> {
 	   "faster code">,
     Option<"enableAVX512", "enable-avx512",
            "bool", /*default=*/"false",
-           "Augments the vector dialect with the AVX512 dialect during lowering">
+           "Enables the use of AVX512 dialect while lowering the vector "
+	   "dialect.">
   ];
 }
 

mlir/include/mlir/Conversion/VectorToLLVM/ConvertVectorToLLVM.h

@@ -21,9 +21,10 @@ class OperationPass;
 /// This should kept in sync with VectorToLLVM options defined for the
 /// ConvertVectorToLLVM pass in include/mlir/Conversion/Passes.td
 struct LowerVectorToLLVMOptions {
-  bool reassociateFPReductions = false;
-  bool enableIndexOptimizations = true;
-  bool enableAVX512 = false;
+  LowerVectorToLLVMOptions()
+      : reassociateFPReductions(false), enableIndexOptimizations(true),
+        enableAVX512(false) {}
+
   LowerVectorToLLVMOptions &setReassociateFPReductions(bool b) {
     reassociateFPReductions = b;
     return *this;
@@ -36,6 +37,10 @@ struct LowerVectorToLLVMOptions {
     enableAVX512 = b;
     return *this;
   }
+
+  bool reassociateFPReductions;
+  bool enableIndexOptimizations;
+  bool enableAVX512;
 };
 
 /// Collect a set of patterns to convert from Vector contractions to LLVM Matrix