cmd/internal/obj/loong64: fixed operand assignment error for BFPT/BFPF instructions

The BFPT correspond to BCNEZ instruction of LoongArch64 which structure
is:
	| op-p1 | offs[15:0] | op-p2 | cj | offs[20:16] |
The register REG_FCC0 should be assigned to the source operand cj which named rj here.

Change-Id: I696d0a46028924da1cd7e240fbb40a1913f1a757
Reviewed-on: https://go-review.googlesource.com/c/go/+/565620
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Qiqi Huang <huangqiqi@loongson.cn>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: sophie zhao <zhaoxiaolin@loongson.cn>

diff --git a/src/cmd/internal/obj/loong64/asm.go b/src/cmd/internal/obj/loong64/asm.go
index 6d2176764564d5e9e205867f55826adc569d4bb2..749db66421717cec2514136f958862a8ac7f5e8a 100644 (file)
--- a/src/cmd/internal/obj/loong64/asm.go
+++ b/src/cmd/internal/obj/loong64/asm.go
@@ -1373,7 +1373,7 @@ func (c *ctxt0) asmout(p *obj.Prog, o *Optab, out []uint32) {
                        width = 21
                        // FCC0 is the implicit source operand, now that we
                        // don't register-allocate from the FCC bank.
-                       rd = REG_FCC0
+                       rj = REG_FCC0
                case ABEQ, ABNE:
                        if rd == 0 || rd == REGZERO || rj == REGZERO {
                                // BEQZ/BNEZ can be encoded with 21-bit offsets.