ref: a8079f496c4c0438c761e1afdf2e05b7617b75c5
dir: /sys/src/libc/386/getfcr.s/
TEXT setfcr(SB), $4 MOVL p+0(FP),AX XORB $0x3f,AX MOVW AX, 0(SP) WAIT FLDCW 0(SP) MOVW 0(SP), AX RET TEXT getfcr(SB), $4 MOVW AX, 0(SP) WAIT FSTCW 0(SP) MOVW 0(SP), AX XORB $0x3f,AX RET TEXT getfsr(SB), $0 WAIT FSTSW AX RET TEXT setfsr(SB), $0 WAIT FCLEX RET