[flang] Propagate fastmath flags to matmul_transpose. (#122842)

Author: vzakhari

flang/lib/Optimizer/HLFIR/IR/HLFIROps.cpp

@@ -1197,7 +1197,8 @@ hlfir::MatmulOp::canonicalize(MatmulOp matmulOp,
       mlir::Location loc = matmulOp.getLoc();
       mlir::Type resultTy = matmulOp.getResult().getType();
       auto matmulTransposeOp = rewriter.create<hlfir::MatmulTransposeOp>(
-          loc, resultTy, transposeOp.getArray(), matmulOp.getRhs());
+          loc, resultTy, transposeOp.getArray(), matmulOp.getRhs(),
+          matmulOp.getFastmathAttr());
 
       // we don't need to remove any hlfir.destroy because it will be needed for
       // the new intrinsic result anyway

flang/test/HLFIR/mul_transpose.f90

@@ -24,7 +24,7 @@ subroutine mul_transpose(a, b, res)
 ! CHECK-BASE-NEXT:      hlfir.destroy %[[MATMUL_RES]]
 ! CHECK-BASE-NEXT:      hlfir.destroy %[[TRANSPOSE_RES]]
 
-! CHECK-CANONICAL-NEXT: %[[CHAIN_RES:.*]] = hlfir.matmul_transpose %[[A_DECL]]#0 %[[B_DECL]]#0 : (!fir.ref<!fir.array<2x1xf32>>, !fir.ref<!fir.array<2x2xf32>>) -> !hlfir.expr<1x2xf32>
+! CHECK-CANONICAL-NEXT: %[[CHAIN_RES:.*]] = hlfir.matmul_transpose %[[A_DECL]]#0 %[[B_DECL]]#0 {fastmath = #arith.fastmath<contract>} : (!fir.ref<!fir.array<2x1xf32>>, !fir.ref<!fir.array<2x2xf32>>) -> !hlfir.expr<1x2xf32>
 ! CHECK-CANONICAL-NEXT: hlfir.assign %[[CHAIN_RES]] to %[[RES_DECL]]#0 : !hlfir.expr<1x2xf32>, !fir.ref<!fir.array<1x2xf32>>
 ! CHECK-CANONICAL-NEXT: hlfir.destroy %[[CHAIN_RES]]