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hash/crc32: simplify hasVX checking on s390x

Originally, we use an assembly function that returns a boolean result to
tell whether the machine has vector facility or not. It is now no longer
needed when we can directly use cpu.S390X.HasVX variable. This CL
also removes the last occurence of hasVectorFacility function on s390x.

Change-Id: Id20cb746c21eacac5e13344b362e2d87adfe4317
Reviewed-on: https://go-review.googlesource.com/c/go/+/230337
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Ruixin(Peter) Bao 2020-04-27 15:23:37 -04:00 committed by Michael Munday
parent a7e9e84716
commit 9a3f22be7a
2 changed files with 4 additions and 26 deletions

View File

@ -4,16 +4,16 @@
package crc32
import "internal/cpu"
const (
vxMinLen = 64
vxAlignMask = 15 // align to 16 bytes
)
// hasVectorFacility reports whether the machine has the z/Architecture
// hasVX reports whether the machine has the z/Architecture
// vector facility installed and enabled.
func hasVectorFacility() bool
var hasVX = hasVectorFacility()
var hasVX = cpu.S390X.HasVX
// vectorizedCastagnoli implements CRC32 using vector instructions.
// It is defined in crc32_s390x.s.

View File

@ -61,28 +61,6 @@ DATA ·crcclecons+88(SB)/8, $0x0000000105ec76f0 // P'(x) << 1
GLOBL ·crcclecons(SB),RODATA, $144
// func hasVectorFacility() bool
TEXT ·hasVectorFacility(SB),NOSPLIT,$24-1
MOVD $x-24(SP), R1
XC $24, 0(R1), 0(R1) // clear the storage
MOVD $2, R0 // R0 is the number of double words stored -1
WORD $0xB2B01000 // STFLE 0(R1)
XOR R0, R0 // reset the value of R0
MOVBZ z-8(SP), R1
AND $0x40, R1
BEQ novector
vectorinstalled:
// check if the vector instruction has been enabled
VLEIB $0, $0xF, V16
VLGVB $0, V16, R1
CMPBNE R1, $0xF, novector
MOVB $1, ret+0(FP) // have vx
RET
novector:
MOVB $0, ret+0(FP) // no vx
RET
// The CRC-32 function(s) use these calling conventions:
//
// Parameters: