diff options
Diffstat (limited to 'target/ppc/translate.c')
| -rw-r--r-- | target/ppc/translate.c | 52 |
1 files changed, 37 insertions, 15 deletions
diff --git a/target/ppc/translate.c b/target/ppc/translate.c index aaafa3a..d3aaa64 100644 --- a/target/ppc/translate.c +++ b/target/ppc/translate.c @@ -3747,22 +3747,44 @@ static void gen_bcond(DisasContext *ctx, int type) if ((bo & 0x4) == 0) { /* Decrement and test CTR */ TCGv temp = tcg_temp_new(); - if (unlikely(type == BCOND_CTR)) { - gen_inval_exception(ctx, POWERPC_EXCP_INVAL_INVAL); - tcg_temp_free(temp); - tcg_temp_free(target); - return; - } - tcg_gen_subi_tl(cpu_ctr, cpu_ctr, 1); - if (NARROW_MODE(ctx)) { - tcg_gen_ext32u_tl(temp, cpu_ctr); - } else { - tcg_gen_mov_tl(temp, cpu_ctr); - } - if (bo & 0x2) { - tcg_gen_brcondi_tl(TCG_COND_NE, temp, 0, l1); + + if (type == BCOND_CTR) { + /* + * All ISAs up to v3 describe this form of bcctr as invalid but + * some processors, ie. 64-bit server processors compliant with + * arch 2.x, do implement a "test and decrement" logic instead, + * as described in their respective UMs. + */ + if (unlikely(!(ctx->insns_flags & PPC_SEGMENT_64B))) { + gen_inval_exception(ctx, POWERPC_EXCP_INVAL_INVAL); + tcg_temp_free(temp); + tcg_temp_free(target); + return; + } + + if (NARROW_MODE(ctx)) { + tcg_gen_ext32u_tl(temp, cpu_ctr); + } else { + tcg_gen_mov_tl(temp, cpu_ctr); + } + if (bo & 0x2) { + tcg_gen_brcondi_tl(TCG_COND_NE, temp, 0, l1); + } else { + tcg_gen_brcondi_tl(TCG_COND_EQ, temp, 0, l1); + } + tcg_gen_subi_tl(cpu_ctr, cpu_ctr, 1); } else { - tcg_gen_brcondi_tl(TCG_COND_EQ, temp, 0, l1); + tcg_gen_subi_tl(cpu_ctr, cpu_ctr, 1); + if (NARROW_MODE(ctx)) { + tcg_gen_ext32u_tl(temp, cpu_ctr); + } else { + tcg_gen_mov_tl(temp, cpu_ctr); + } + if (bo & 0x2) { + tcg_gen_brcondi_tl(TCG_COND_NE, temp, 0, l1); + } else { + tcg_gen_brcondi_tl(TCG_COND_EQ, temp, 0, l1); + } } tcg_temp_free(temp); } |