From 2b0a39e51e64ae501192b18233bddcc81c098312 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sun, 13 Jun 2021 16:17:03 -0700 Subject: [PATCH] target/arm: Improve REV32 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit For the sf version, we are performing two 32-bit bswaps in either half of the register. This is equivalent to performing one 64-bit bswap followed by a rotate. For the non-sf version, we can remove TCG_BSWAP_IZ and the preceding zero-extension. Reviewed-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- target/arm/translate-a64.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index f2641a37ba..304fd3d370 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -5430,22 +5430,13 @@ static void handle_rev32(DisasContext *s, unsigned int sf, unsigned int rn, unsigned int rd) { TCGv_i64 tcg_rd = cpu_reg(s, rd); + TCGv_i64 tcg_rn = cpu_reg(s, rn); if (sf) { - TCGv_i64 tcg_tmp = tcg_temp_new_i64(); - TCGv_i64 tcg_rn = read_cpu_reg(s, rn, sf); - - /* bswap32_i64 requires zero high word */ - tcg_gen_ext32u_i64(tcg_tmp, tcg_rn); - tcg_gen_bswap32_i64(tcg_rd, tcg_tmp, TCG_BSWAP_IZ | TCG_BSWAP_OZ); - tcg_gen_shri_i64(tcg_tmp, tcg_rn, 32); - tcg_gen_bswap32_i64(tcg_tmp, tcg_tmp, TCG_BSWAP_IZ | TCG_BSWAP_OZ); - tcg_gen_concat32_i64(tcg_rd, tcg_rd, tcg_tmp); - - tcg_temp_free_i64(tcg_tmp); + tcg_gen_bswap64_i64(tcg_rd, tcg_rn); + tcg_gen_rotri_i64(tcg_rd, tcg_rd, 32); } else { - tcg_gen_ext32u_i64(tcg_rd, cpu_reg(s, rn)); - tcg_gen_bswap32_i64(tcg_rd, tcg_rd, TCG_BSWAP_IZ | TCG_BSWAP_OZ); + tcg_gen_bswap32_i64(tcg_rd, tcg_rn, TCG_BSWAP_OZ); } }