모두의 코드
VZEROUPPER (Intel x86/64 assembly instruction)
VZEROUPPER
Zero Upper Bits of YMM Registers
참고 사항
아래 표를 해석하는 방법은 x86-64 명령어 레퍼런스 읽는 법 글을 참조하시기 바랍니다.
Opcode/ | Op/ | 64/32 bit | CPUID | Description |
|---|---|---|---|---|
| NP | V/V | AVX | Zero upper 128 bits of all YMM registers. |
Instruction Operand Encoding
Op/En | Operand 1 | Operand 2 | Operand 3 | Operand 4 |
|---|---|---|---|---|
NP | NA | NA | NA | NA |
Description
The instruction zeros the bits in position 128 and higher of all YMM registers. The lower 128-bits of the registers (the corresponding XMM registers) are unmodified.
This instruction is recommended when transitioning between AVX and legacy SSE code - it will eliminate perfor-mance penalties caused by false dependencies.
Note: VEX.vvvv is reserved and must be 1111b otherwise instructions will #UD. In Compatibility and legacy 32-bit mode only the lower 8 registers are modified.
Operation
VZEROUPPER
IF (64-bit mode)
YMM0[VLMAX-1:128] <- 0
YMM1[VLMAX-1:128] <- 0
YMM2[VLMAX-1:128] <- 0
YMM3[VLMAX-1:128] <- 0
YMM4[VLMAX-1:128] <- 0
YMM5[VLMAX-1:128] <- 0
YMM6[VLMAX-1:128] <- 0
YMM7[VLMAX-1:128] <- 0
YMM8[VLMAX-1:128] <- 0
YMM9[VLMAX-1:128] <- 0
YMM10[VLMAX-1:128] <- 0
YMM11[VLMAX-1:128] <- 0
YMM12[VLMAX-1:128] <- 0
YMM13[VLMAX-1:128] <- 0
YMM14[VLMAX-1:128] <- 0
YMM15[VLMAX-1:128] <- 0
ELSE
YMM0[VLMAX-1:128] <- 0
YMM1[VLMAX-1:128] <- 0
YMM2[VLMAX-1:128] <- 0
YMM3[VLMAX-1:128] <- 0
YMM4[VLMAX-1:128] <- 0
YMM5[VLMAX-1:128] <- 0
YMM6[VLMAX-1:128] <- 0
YMM7[VLMAX-1:128] <- 0
YMM8-15: unmodified
FI
Intel C/C++ Compiler Intrinsic Equivalent
VZEROUPPER : _mm256_zeroupper()
SIMD Floating-Point Exceptions
None.
Other Exceptions
See Exceptions Type 8.
댓글을 불러오는 중입니다..