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author | Richard Henderson <rth@twiddle.net> | 2015-09-14 14:39:47 +0100 |
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committer | Peter Maydell <peter.maydell@linaro.org> | 2015-09-14 14:39:47 +0100 |
commit | 6c2c63d3a02c79e9035ca0370cc549d0f938a4dd (patch) | |
tree | bf0c399acd5825ea9a92ea9a1a265668765e9770 /target-arm | |
parent | 78bcaa3e37afbd0c5316634f917c13487384b6ca (diff) | |
download | qemu-6c2c63d3a02c79e9035ca0370cc549d0f938a4dd.zip qemu-6c2c63d3a02c79e9035ca0370cc549d0f938a4dd.tar.gz qemu-6c2c63d3a02c79e9035ca0370cc549d0f938a4dd.tar.bz2 |
target-arm: Introduce DisasCompare
Split arm_gen_test_cc into 3 functions, so that it can be reused
for non-branch TCG comparisons.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-id: 1441909103-24666-3-git-send-email-rth@twiddle.net
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target-arm')
-rw-r--r-- | target-arm/translate.c | 115 | ||||
-rw-r--r-- | target-arm/translate.h | 9 |
2 files changed, 78 insertions, 46 deletions
diff --git a/target-arm/translate.c b/target-arm/translate.c index f1b7c16..7d2e984 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -738,81 +738,104 @@ static void gen_thumb2_parallel_addsub(int op1, int op2, TCGv_i32 a, TCGv_i32 b) #undef PAS_OP /* - * generate a conditional branch based on ARM condition code cc. + * Generate a conditional based on ARM condition code cc. * This is common between ARM and Aarch64 targets. */ -void arm_gen_test_cc(int cc, TCGLabel *label) +void arm_test_cc(DisasCompare *cmp, int cc) { - TCGv_i32 tmp; - TCGLabel *inv; + TCGv_i32 value; + TCGCond cond; + bool global = true; switch (cc) { case 0: /* eq: Z */ - tcg_gen_brcondi_i32(TCG_COND_EQ, cpu_ZF, 0, label); - break; case 1: /* ne: !Z */ - tcg_gen_brcondi_i32(TCG_COND_NE, cpu_ZF, 0, label); + cond = TCG_COND_EQ; + value = cpu_ZF; break; + case 2: /* cs: C */ - tcg_gen_brcondi_i32(TCG_COND_NE, cpu_CF, 0, label); - break; case 3: /* cc: !C */ - tcg_gen_brcondi_i32(TCG_COND_EQ, cpu_CF, 0, label); + cond = TCG_COND_NE; + value = cpu_CF; break; + case 4: /* mi: N */ - tcg_gen_brcondi_i32(TCG_COND_LT, cpu_NF, 0, label); - break; case 5: /* pl: !N */ - tcg_gen_brcondi_i32(TCG_COND_GE, cpu_NF, 0, label); + cond = TCG_COND_LT; + value = cpu_NF; break; + case 6: /* vs: V */ - tcg_gen_brcondi_i32(TCG_COND_LT, cpu_VF, 0, label); - break; case 7: /* vc: !V */ - tcg_gen_brcondi_i32(TCG_COND_GE, cpu_VF, 0, label); + cond = TCG_COND_LT; + value = cpu_VF; break; + case 8: /* hi: C && !Z */ - inv = gen_new_label(); - tcg_gen_brcondi_i32(TCG_COND_EQ, cpu_CF, 0, inv); - tcg_gen_brcondi_i32(TCG_COND_NE, cpu_ZF, 0, label); - gen_set_label(inv); - break; - case 9: /* ls: !C || Z */ - tcg_gen_brcondi_i32(TCG_COND_EQ, cpu_CF, 0, label); - tcg_gen_brcondi_i32(TCG_COND_EQ, cpu_ZF, 0, label); + case 9: /* ls: !C || Z -> !(C && !Z) */ + cond = TCG_COND_NE; + value = tcg_temp_new_i32(); + global = false; + /* CF is 1 for C, so -CF is an all-bits-set mask for C; + ZF is non-zero for !Z; so AND the two subexpressions. */ + tcg_gen_neg_i32(value, cpu_CF); + tcg_gen_and_i32(value, value, cpu_ZF); break; + case 10: /* ge: N == V -> N ^ V == 0 */ - tmp = tcg_temp_new_i32(); - tcg_gen_xor_i32(tmp, cpu_VF, cpu_NF); - tcg_gen_brcondi_i32(TCG_COND_GE, tmp, 0, label); - tcg_temp_free_i32(tmp); - break; case 11: /* lt: N != V -> N ^ V != 0 */ - tmp = tcg_temp_new_i32(); - tcg_gen_xor_i32(tmp, cpu_VF, cpu_NF); - tcg_gen_brcondi_i32(TCG_COND_LT, tmp, 0, label); - tcg_temp_free_i32(tmp); + /* Since we're only interested in the sign bit, == 0 is >= 0. */ + cond = TCG_COND_GE; + value = tcg_temp_new_i32(); + global = false; + tcg_gen_xor_i32(value, cpu_VF, cpu_NF); break; + case 12: /* gt: !Z && N == V */ - inv = gen_new_label(); - tcg_gen_brcondi_i32(TCG_COND_EQ, cpu_ZF, 0, inv); - tmp = tcg_temp_new_i32(); - tcg_gen_xor_i32(tmp, cpu_VF, cpu_NF); - tcg_gen_brcondi_i32(TCG_COND_GE, tmp, 0, label); - tcg_temp_free_i32(tmp); - gen_set_label(inv); - break; case 13: /* le: Z || N != V */ - tcg_gen_brcondi_i32(TCG_COND_EQ, cpu_ZF, 0, label); - tmp = tcg_temp_new_i32(); - tcg_gen_xor_i32(tmp, cpu_VF, cpu_NF); - tcg_gen_brcondi_i32(TCG_COND_LT, tmp, 0, label); - tcg_temp_free_i32(tmp); + cond = TCG_COND_NE; + value = tcg_temp_new_i32(); + global = false; + /* (N == V) is equal to the sign bit of ~(NF ^ VF). Propagate + * the sign bit then AND with ZF to yield the result. */ + tcg_gen_xor_i32(value, cpu_VF, cpu_NF); + tcg_gen_sari_i32(value, value, 31); + tcg_gen_andc_i32(value, cpu_ZF, value); break; + default: fprintf(stderr, "Bad condition code 0x%x\n", cc); abort(); } + + if (cc & 1) { + cond = tcg_invert_cond(cond); + } + + cmp->cond = cond; + cmp->value = value; + cmp->value_global = global; +} + +void arm_free_cc(DisasCompare *cmp) +{ + if (!cmp->value_global) { + tcg_temp_free_i32(cmp->value); + } +} + +void arm_jump_cc(DisasCompare *cmp, TCGLabel *label) +{ + tcg_gen_brcondi_i32(cmp->cond, cmp->value, 0, label); +} + +void arm_gen_test_cc(int cc, TCGLabel *label) +{ + DisasCompare cmp; + arm_test_cc(&cmp, cc); + arm_jump_cc(&cmp, label); + arm_free_cc(&cmp); } static const uint8_t table_logic_cc[16] = { diff --git a/target-arm/translate.h b/target-arm/translate.h index a30a1db..b8fe37a 100644 --- a/target-arm/translate.h +++ b/target-arm/translate.h @@ -63,6 +63,12 @@ typedef struct DisasContext { TCGv_i64 tmp_a64[TMP_A64_MAX]; } DisasContext; +typedef struct DisasCompare { + TCGCond cond; + TCGv_i32 value; + bool value_global; +} DisasCompare; + /* Share the TCG temporaries common between 32 and 64 bit modes. */ extern TCGv_ptr cpu_env; extern TCGv_i32 cpu_NF, cpu_ZF, cpu_CF, cpu_VF; @@ -144,6 +150,9 @@ static inline void aarch64_cpu_dump_state(CPUState *cs, FILE *f, } #endif +void arm_test_cc(DisasCompare *cmp, int cc); +void arm_free_cc(DisasCompare *cmp); +void arm_jump_cc(DisasCompare *cmp, TCGLabel *label); void arm_gen_test_cc(int cc, TCGLabel *label); #endif /* TARGET_ARM_TRANSLATE_H */ |