poly1305: use x/sys/cpu for s390x feature detection
Use the recently added CPU feature detection API rather than custom
assembly. This will need to be updated to use 'internal/cpu' when
the package is revendored into std.
Change-Id: Ia99c51c7409fe4fabcd88fdf5ff19772c1ca2257
Reviewed-on: https://go-review.googlesource.com/c/164382
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/poly1305/sum_s390x.go b/poly1305/sum_s390x.go
index 7a266ce..ec99e07 100644
--- a/poly1305/sum_s390x.go
+++ b/poly1305/sum_s390x.go
@@ -6,16 +6,9 @@
package poly1305
-// hasVectorFacility reports whether the machine supports
-// the vector facility (vx).
-func hasVectorFacility() bool
-
-// hasVMSLFacility reports whether the machine supports
-// Vector Multiply Sum Logical (VMSL).
-func hasVMSLFacility() bool
-
-var hasVX = hasVectorFacility()
-var hasVMSL = hasVMSLFacility()
+import (
+ "golang.org/x/sys/cpu"
+)
// poly1305vx is an assembly implementation of Poly1305 that uses vector
// instructions. It must only be called if the vector facility (vx) is
@@ -33,12 +26,12 @@
// 16-byte result into out. Authenticating two different messages with the same
// key allows an attacker to forge messages at will.
func Sum(out *[16]byte, m []byte, key *[32]byte) {
- if hasVX {
+ if cpu.S390X.HasVX {
var mPtr *byte
if len(m) > 0 {
mPtr = &m[0]
}
- if hasVMSL && len(m) > 256 {
+ if cpu.S390X.HasVXE && len(m) > 256 {
poly1305vmsl(out, mPtr, uint64(len(m)), key)
} else {
poly1305vx(out, mPtr, uint64(len(m)), key)
diff --git a/poly1305/sum_s390x.s b/poly1305/sum_s390x.s
index 356c07a..ca5a309 100644
--- a/poly1305/sum_s390x.s
+++ b/poly1305/sum_s390x.s
@@ -376,25 +376,3 @@
MOVD $0, R3
BR multiply
-
-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
diff --git a/poly1305/sum_vmsl_s390x.s b/poly1305/sum_vmsl_s390x.s
index e548020..e60bbc1 100644
--- a/poly1305/sum_vmsl_s390x.s
+++ b/poly1305/sum_vmsl_s390x.s
@@ -907,25 +907,3 @@
MULTIPLY(H0_0, H1_0, H2_0, H0_1, H1_1, H2_1, R_0, R_1, R_2, R5_1, R5_2, M0, M1, M2, M3, M4, M5, T_0, T_1, T_2, T_3, T_4, T_5, T_6, T_7, T_8, T_9)
REDUCE2(H0_0, H1_0, H2_0, M0, M1, M2, M3, M4, T_9, T_10, H0_1, M5)
BR next
-
-TEXT ·hasVMSLFacility(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 $0x01, R1
- BEQ novmsl
-
-vectorinstalled:
- // check if the vector instruction has been enabled
- VLEIB $0, $0xF, V16
- VLGVB $0, V16, R1
- CMPBNE R1, $0xF, novmsl
- MOVB $1, ret+0(FP) // have vx
- RET
-
-novmsl:
- MOVB $0, ret+0(FP) // no vx
- RET
