cmd/internal/obj/arm64: disable AL and NV for some condition operation instructions
According to the armv8-a reference manual, conditions AL and NV are not allowed
for instructions CINC, CINV, CNEG, CSET and CSETM. This CL adds this check and
the corresponding test cases.
Change-Id: Icb496b7b13a353f41491f2de4d939a5cd88abb04
Reviewed-on: https://go-review.googlesource.com/c/go/+/317912
Reviewed-by: eric fang <eric.fang@arm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Trust: eric fang <eric.fang@arm.com>
Run-TryBot: eric fang <eric.fang@arm.com>
TryBot-Result: Go Bot <gobot@golang.org>
diff --git a/src/cmd/asm/internal/asm/testdata/arm64error.s b/src/cmd/asm/internal/asm/testdata/arm64error.s
index 66fc910..cf57179 100644
--- a/src/cmd/asm/internal/asm/testdata/arm64error.s
+++ b/src/cmd/asm/internal/asm/testdata/arm64error.s
@@ -52,6 +52,16 @@
NEGSW R7@>2, R5 // ERROR "unsupported shift operator"
CINC CS, R2, R3, R4 // ERROR "illegal combination"
CSEL LT, R1, R2 // ERROR "illegal combination"
+ CINC AL, R2, R3 // ERROR "invalid condition"
+ CINC NV, R2, R3 // ERROR "invalid condition"
+ CINVW AL, R2, R3 // ERROR "invalid condition"
+ CINV NV, R2, R3 // ERROR "invalid condition"
+ CNEG AL, R2, R3 // ERROR "invalid condition"
+ CNEGW NV, R2, R3 // ERROR "invalid condition"
+ CSET AL, R2 // ERROR "invalid condition"
+ CSET NV, R2 // ERROR "invalid condition"
+ CSETMW AL, R2 // ERROR "invalid condition"
+ CSETM NV, R2 // ERROR "invalid condition"
LDP.P 8(R2), (R2, R3) // ERROR "constrained unpredictable behavior"
LDP.W 8(R3), (R2, R3) // ERROR "constrained unpredictable behavior"
LDP (R1), (R2, R2) // ERROR "constrained unpredictable behavior"
diff --git a/src/cmd/internal/obj/arm64/asm7.go b/src/cmd/internal/obj/arm64/asm7.go
index 575436d..b8c3cd9 100644
--- a/src/cmd/internal/obj/arm64/asm7.go
+++ b/src/cmd/internal/obj/arm64/asm7.go
@@ -3536,27 +3536,25 @@
o1 = c.oprrr(p, p.As)
cond := int(p.From.Reg)
- if cond < COND_EQ || cond > COND_NV {
+ // AL and NV are not allowed for CINC/CINV/CNEG/CSET/CSETM instructions
+ if cond < COND_EQ || cond > COND_NV || (cond == COND_AL || cond == COND_NV) && p.From3Type() == obj.TYPE_NONE {
c.ctxt.Diag("invalid condition: %v", p)
} else {
cond -= COND_EQ
}
r := int(p.Reg)
- var rf int
- if r != 0 {
- if p.From3Type() == obj.TYPE_NONE {
- /* CINC/CINV/CNEG */
- rf = r
- cond ^= 1
- } else {
- rf = int(p.GetFrom3().Reg) /* CSEL */
+ var rf int = r
+ if p.From3Type() == obj.TYPE_NONE {
+ /* CINC/CINV/CNEG or CSET/CSETM*/
+ if r == 0 {
+ /* CSET/CSETM */
+ rf = REGZERO
+ r = rf
}
- } else {
- /* CSET */
- rf = REGZERO
- r = rf
cond ^= 1
+ } else {
+ rf = int(p.GetFrom3().Reg) /* CSEL */
}
rt := int(p.To.Reg)
