From: Ruixin(Peter) Bao <ruixin.bao@ibm.com>
Date: Mon, 27 Apr 2020 19:23:37 +0000 (-0400)
Subject: hash/crc32: simplify hasVX checking on s390x
X-Git-Tag: go1.15beta1~340
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=9a3f22be7a3a28bd8f33a86925e2b05f2314ead2;p=gostls13.git

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>
---

diff --git a/src/hash/crc32/crc32_s390x.go b/src/hash/crc32/crc32_s390x.go
index d13000d058..3a98bd8799 100644
--- a/src/hash/crc32/crc32_s390x.go
+++ b/src/hash/crc32/crc32_s390x.go
@@ -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.
diff --git a/src/hash/crc32/crc32_s390x.s b/src/hash/crc32/crc32_s390x.s
index 63aa609db2..a168fad277 100644
--- a/src/hash/crc32/crc32_s390x.s
+++ b/src/hash/crc32/crc32_s390x.s
@@ -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: