Commit cab48881 authored by Miodrag Dinic's avatar Miodrag Dinic Committed by Yongbok Kim
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target/mips: fix msa copy_[s|u]_df rd = 0 corner case 



This patch fixes the msa copy_[s|u]_df instruction emulation when
the destination register rd is zero. Without this patch the zero
register would get clobbered, which should never happen because it
is supposed to be hardwired to 0.

Fix this corner case by explicitly checking rd = 0 and effectively
making these instructions emulation no-op in that case.

Signed-off-by: default avatarMiodrag Dinic <miodrag.dinic@imgtec.com>
Reviewed-by: default avatarAurelien Jarno <aurelien@aurel32.net>
Acked-by: default avatarAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: default avatarYongbok Kim <yongbok.kim@imgtec.com>
parent b5ed2e11

target/mips/translate.c

+6 −2
Original line number Diff line number Diff line
@@ -18712,10 +18712,14 @@ static void gen_msa_elm_df(CPUMIPSState *env, DisasContext *ctx, uint32_t df, 
#endif

        switch (MASK_MSA_ELM(ctx->opcode)) {

        case OPC_COPY_S_df:

            if (likely(wd != 0)) {

                gen_helper_msa_copy_s_df(cpu_env, tdf, twd, tws, tn);

            }

            break;

        case OPC_COPY_U_df:

            if (likely(wd != 0)) {

                gen_helper_msa_copy_u_df(cpu_env, tdf, twd, tws, tn);

            }

            break;

        case OPC_INSERT_df:

            gen_helper_msa_insert_df(cpu_env, tdf, twd, tws, tn);