cmd/asm: fix bug about VMOV instruction (move register to vector element) on ARM64

This change fixes index error when encoding VMOV instruction which pattern is
VMOV Rn, V.<T>[index]. For example VMOV R1, V1.S[1] is assembled as VMOV R1, V1.S[0]

Fixes #24400
Change-Id: I82b5edc8af4e06862bc4692b119697c6bb7dc3fb
Reviewed-on: https://go-review.googlesource.com/101297
Reviewed-by: Cherry Zhang <cherryyz@google.com>

diff --git a/src/cmd/asm/internal/asm/testdata/arm64.s b/src/cmd/asm/internal/asm/testdata/arm64.s
index c53023e6304b05a072e9e378a27df31ba547beaa..4b364c458bbee8069a3761745b35230c01d2d29b 100644 (file)
--- a/src/cmd/asm/internal/asm/testdata/arm64.s
+++ b/src/cmd/asm/internal/asm/testdata/arm64.s
@@ -230,6 +230,7 @@ TEXT        foo(SB), DUPOK|NOSPLIT, $-8
        VMOV    V0.D[0], R11          // 0b3c084e
        VMOV    V0.D[1], R11          // 0b3c184e
        VMOV    R20, V1.S[0]          // 811e044e
+       VMOV    R20, V1.S[1]          // 811e0c4e
        VMOV    R1, V9.H4             // 290c020e
        VMOV    R22, V11.D2           // cb0e084e
        VMOV    V2.B16, V4.B16        // 441ca24e

diff --git a/src/cmd/internal/obj/arm64/asm7.go b/src/cmd/internal/obj/arm64/asm7.go
index 7b940dd58cef54db4ca84faed5ee9b427294b712..a948d1243de34a782fd3cfdb6d1cc19c985fbd66 100644 (file)
--- a/src/cmd/internal/obj/arm64/asm7.go
+++ b/src/cmd/internal/obj/arm64/asm7.go
@@ -3563,7 +3563,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
                rt := int(p.To.Reg)
                imm5 := 0
                o1 = 1<<30 | 7<<25 | 7<<10
-               index := int(p.From.Index)
+               index := int(p.To.Index)
                switch (p.To.Reg >> 5) & 15 {
                case ARNG_B:
                        c.checkindex(p, index, 15)