[PULL 19/20] target/riscv: Add MAX_INSN_LEN and insn_len

Richard Henderson posted 20 patches 2 years, 7 months ago
Maintainers: Richard Henderson <richard.henderson@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, Riku Voipio <riku.voipio@iki.fi>, Laurent Vivier <laurent@vivier.eu>, Peter Xu <peterx@redhat.com>, David Hildenbrand <david@redhat.com>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, Peter Maydell <peter.maydell@linaro.org>, Michael Rolnik <mrolnik@gmail.com>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Taylor Simpson <tsimpson@quicinc.com>, Eduardo Habkost <eduardo@habkost.net>, Song Gao <gaosong@loongson.cn>, Xiaojuan Yang <yangxiaojuan@loongson.cn>, Aurelien Jarno <aurelien@aurel32.net>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, Chris Wulff <crwulff@gmail.com>, Marek Vasut <marex@denx.de>, Stafford Horne <shorne@gmail.com>, "Cédric Le Goater" <clg@kaod.org>, Daniel Henrique Barboza <danielhb413@gmail.com>, David Gibson <david@gibson.dropbear.id.au>, Greg Kurz <groug@kaod.org>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, Cornelia Huck <cohuck@redhat.com>, Thomas Huth <thuth@redhat.com>, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, Artyom Tarasenko <atar4qemu@gmail.com>, Bastian Koppelmann <kbastian@mail.uni-paderborn.de>, Max Filippov <jcmvbkbc@gmail.com>, "Alex Bennée" <alex.bennee@linaro.org>
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[PULL 19/20] target/riscv: Add MAX_INSN_LEN and insn_len
Posted by Richard Henderson 2 years, 7 months ago
These will be useful in properly ending the TB.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/riscv/translate.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 38666ddc91..a719aa6e63 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -1022,6 +1022,14 @@ static uint32_t opcode_at(DisasContextBase *dcbase, target_ulong pc)
 /* Include decoders for factored-out extensions */
 #include "decode-XVentanaCondOps.c.inc"
 
+/* The specification allows for longer insns, but not supported by qemu. */
+#define MAX_INSN_LEN  4
+
+static inline int insn_len(uint16_t first_word)
+{
+    return (first_word & 3) == 3 ? 4 : 2;
+}
+
 static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode)
 {
     /*
@@ -1037,7 +1045,7 @@ static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode)
     };
 
     /* Check for compressed insn */
-    if (extract16(opcode, 0, 2) != 3) {
+    if (insn_len(opcode) == 2) {
         if (!has_ext(ctx, RVC)) {
             gen_exception_illegal(ctx);
         } else {
-- 
2.34.1