ref: a3bce47d15d25fc3bca79ee50fca3fd4df538d5b
dir: /lib/math/ftrap-impl+plan9-x64.s/
TEXT math$fptrap(SB),$0 SUBQ $4,SP WAIT STMXCSR (SP) MOVL (SP),AX ANDL $~0x1f80,AX TESTB DI,DI JNZ .apply ORL $0x1f80,AX .apply: MOVL AX,(SP) LDMXCSR (SP) ADDQ $4,SP RET