[PATCH v3 22/29] target/arm: Improve vector REV

Richard Henderson posted 29 patches 4 years, 7 months ago
Maintainers: Andrzej Zaborowski <balrogg@gmail.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, Richard Henderson <richard.henderson@linaro.org>, Alistair Francis <Alistair.Francis@wdc.com>, Eduardo Habkost <ehabkost@redhat.com>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, Jiaxun Yang <jiaxun.yang@flygoat.com>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, Cornelia Huck <cohuck@redhat.com>, Aurelien Jarno <aurelien@aurel32.net>, Thomas Huth <thuth@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Palmer Dabbelt <palmer@dabbelt.com>
[PATCH v3 22/29] target/arm: Improve vector REV
Posted by Richard Henderson 4 years, 7 months ago
We can eliminate the requirement for a zero-extended output,
because the following store will ignore any garbage high bits.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 304fd3d370..1a40e49db7 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -12444,12 +12444,10 @@ static void handle_rev(DisasContext *s, int opcode, bool u,
             read_vec_element(s, tcg_tmp, rn, i, grp_size);
             switch (grp_size) {
             case MO_16:
-                tcg_gen_bswap16_i64(tcg_tmp, tcg_tmp,
-                                    TCG_BSWAP_IZ | TCG_BSWAP_OZ);
+                tcg_gen_bswap16_i64(tcg_tmp, tcg_tmp, TCG_BSWAP_IZ);
                 break;
             case MO_32:
-                tcg_gen_bswap32_i64(tcg_tmp, tcg_tmp,
-                                    TCG_BSWAP_IZ | TCG_BSWAP_OZ);
+                tcg_gen_bswap32_i64(tcg_tmp, tcg_tmp, TCG_BSWAP_IZ);
                 break;
             case MO_64:
                 tcg_gen_bswap64_i64(tcg_tmp, tcg_tmp);
-- 
2.25.1