Make single precision floating point arithmetic actually work -- I think

it never did -- and fix an obvious missing line. Floating point emulation
on Book-E still needs some work but this gets it basically functional on
soft-FPU systems (hard FPU for Book-E is not yet implemented).

MFC after:	1 week

sys/powerpc/fpu/fpu_emu.c

@@ -606,9 +606,11 @@ fpu_execute(struct trapframe *tf, struct fpemu *fe, union instr *insn)
 			rb = instr.i_a.i_frb;
 			rc = instr.i_a.i_frc;
 
-			type = FTYPE_SNG;
-			if (instr.i_any.i_opcd & 0x4)
-				type = FTYPE_DBL;
+			/*
+			 * All arithmetic operations work on registers, which
+			 * are stored as doubles.
+			 */
+			type = FTYPE_DBL;
 			switch ((unsigned int)instr.i_a.i_xo) {
 			case	OPC59_FDIVS:
 				FPU_EMU_EVCNT_INCR(fdiv);
@@ -725,6 +727,13 @@ fpu_execute(struct trapframe *tf, struct fpemu *fe, union instr *insn)
 				return (NOTFPU);
 				break;
 			}
+
+			/* If the instruction was single precision, round */
+			if (!(instr.i_any.i_opcd & 0x4)) {
+				fpu_implode(fe, fp, FTYPE_SNG, 
+					(u_int *)&fs->fpreg[rt]);
+				fpu_explode(fe, fp = &fe->fe_f1, FTYPE_SNG, rt);
+			}
 		}
 	} else {
 		return (NOTFPU);

sys/powerpc/fpu/fpu_explode.c

@@ -235,6 +235,7 @@ fpu_explode(struct fpemu *fe, struct fpn *fp, int type, int reg)
 		s = fpu_dtof(fp, s, space[1]);
 		break;
 
+	default:
 		panic("fpu_explode");
 		panic("fpu_explode: invalid type %d", type);
 	}