Call 'wreduce' after mul2dsp to avoid unextend()

techlibs/xilinx/synth_xilinx.cc

@@ -346,6 +346,7 @@ struct SynthXilinxPass : public ScriptPass
 						"-D DSP_A_MINWIDTH=2 -D DSP_B_MINWIDTH=2 " // Blocks Nx1 multipliers
 						"-D DSP_Y_MINWIDTH=9 " // UG901 suggests small multiplies are those 4x4 and smaller
 						"-D DSP_SIGNEDONLY=1 -D DSP_NAME=$__MUL25X18");
+				run("wreduce t:$add");
 				run("xilinx_dsp");
 				run("chtype -set $mul t:$__soft_mul");
 			}