[mlir][llvm] Add fastmathFlags to SelectOp

[Mogball]

Summary

select has fastmath flags, which were missing from the LLVM dialect op
definition.

[ftynse]

Could you check if the translation works in the opposite direction, too?

[gysit]

LGTM, the import fastmath tests are in /llvm-project/mlir/test/Target/LLVMIR/Import/fastmath.ll

[Mogball]

Yep thanks for the suggestion

[Mogball]

add import test

[Mogball]

rebase

mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td

string mlirBuilder = [{
     $res = $_builder.create<LLVM::ShuffleVectorOp>(
       $_location, $v1, $v2, mask);
   }];
 }
 
 // Misc operations.
 def LLVM_SelectOp
     : LLVM_Op<"select",
-          [Pure, AllTypesMatch<["trueValue", "falseValue", "res"]>]>,
+          [Pure, AllTypesMatch<["trueValue", "falseValue", "res"]>,
+           DeclareOpInterfaceMethods<FastmathFlagsInterface>]>,
       LLVM_Builder<
           "$res = builder.CreateSelect($condition, $trueValue, $falseValue);"> {
   let arguments = (ins LLVM_ScalarOrVectorOf<I1>:$condition,
-                   LLVM_Type:$trueValue, LLVM_Type:$falseValue);
+                   LLVM_Type:$trueValue, LLVM_Type:$falseValue,
+                   DefaultValuedAttr<LLVM_FastmathFlagsAttr,
+                                     "{}">:$fastmathFlags);
   let results = (outs LLVM_Type:$res);
   let assemblyFormat = "operands attr-dict `:` type($condition) `,` type($res)";
   string llvmInstName = "Select";
   string mlirBuilder = [{
-    $res = $_builder.create<LLVM::SelectOp>(
+    auto op = $_builder.create<LLVM::SelectOp>(
       $_location, $_resultType, $condition, $trueValue, $falseValue);
+    moduleImport.setFastmathFlagsAttr(inst, op);
+    $res = op;
   }];
 }
 def LLVM_FreezeOp : LLVM_Op<"freeze", [SameOperandsAndResultType]> {
   let arguments = (ins LLVM_Type:$val);
   let results = (outs LLVM_Type:$res);
   let builders = [LLVM_OneResultOpBuilder];
   let assemblyFormat = "$val attr-dict `:` type($val)";
   string llvmInstName = "Freeze";

mlir/test/Target/LLVMIR/Import/fastmath.ll

 ; RUN: mlir-translate -import-llvm -split-input-file %s | FileCheck %s
 
 ; CHECK-LABEL: @fastmath_inst
-define void @fastmath_inst(float %arg1, float %arg2) {
+define void @fastmath_inst(float %arg1, float %arg2, i1 %arg3) {
   ; CHECK: llvm.fadd %{{.*}}, %{{.*}}  {fastmathFlags = #llvm.fastmath<nnan, ninf>} : f32
   %1 = fadd nnan ninf float %arg1, %arg2
   ; CHECK: llvm.fsub %{{.*}}, %{{.*}}  {fastmathFlags = #llvm.fastmath<nsz>} : f32
   %2 = fsub nsz float %arg1, %arg2
   ; CHECK: llvm.fmul %{{.*}}, %{{.*}}  {fastmathFlags = #llvm.fastmath<arcp, contract>} : f32
   %3 = fmul arcp contract float %arg1, %arg2
   ; CHECK: llvm.fdiv %{{.*}}, %{{.*}}  {fastmathFlags = #llvm.fastmath<afn, reassoc>} : f32
   %4 = fdiv afn reassoc float %arg1, %arg2
   ; CHECK: llvm.fneg %{{.*}}  {fastmathFlags = #llvm.fastmath<fast>} : f32
   %5 = fneg fast float %arg1
+  ; CHECK: llvm.select %{{.*}}, %{{.*}}, %{{.*}} {fastmathFlags = #llvm.fastmath<contract>} : i1, f32
+  %6 = select contract i1 %arg3, float %arg1, float %arg2
   ret void
 }
 
 ; // -----
 
 ; CHECK-LABEL: @fastmath_fcmp
 define void @fastmath_fcmp(float %arg1, float %arg2) {
   ; CHECK:  llvm.fcmp "oge" %{{.*}}, %{{.*}} {fastmathFlags = #llvm.fastmath<nsz>} : f32

mlir/test/Target/LLVMIR/llvmir.mlir

 // CHECK: call afn float @llvm.powi.f32.i32(float {{.*}}, i32 {{.*}})
   %20 = "llvm.intr.powi"(%arg0, %exp) {fastmathFlags = #llvm.fastmath<afn>} : (f32, i32) -> f32
 
 // CHECK: call nnan float @llvm.vector.reduce.fmax.v2f32(<2 x float> {{.*}})
 // CHECK: call nnan float @llvm.vector.reduce.fmin.v2f32(<2 x float> {{.*}})
   %21 = llvm.intr.vector.reduce.fmax(%arg1) {fastmathFlags = #llvm.fastmath<nnan>} : (vector<2xf32>) -> f32
   %22 = llvm.intr.vector.reduce.fmin(%arg1) {fastmathFlags = #llvm.fastmath<nnan>} : (vector<2xf32>) -> f32
 
+
+  %23 = llvm.mlir.constant(true) : i1
+// CHECK: select contract i1
+  %24 = llvm.select %23, %arg0, %20 {fastmathFlags = #llvm.fastmath<contract>} : i1, f32
   llvm.return
 }
 
 // -----
 
 // CHECK-LABEL: @switch_args
 llvm.func @switch_args(%arg0: i32) -> i32 {
   %0 = llvm.mlir.constant(5 : i32) : i32