From: Philippe Mathieu-Daudé <f4bug@amsat.org>
Simply call the generic gen_lsa() helper, taking care
to substract 1 to the shift field.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
target/mips/tcg/nanomips32.decode | 8 ++++++++
target/mips/tcg/nanomips_translate.c | 12 ++++++++++++
target/mips/tcg/nanomips_translate.c.inc | 9 ---------
3 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/target/mips/tcg/nanomips32.decode b/target/mips/tcg/nanomips32.decode
index 9cecf1e13d..11bf5cd6c4 100644
--- a/target/mips/tcg/nanomips32.decode
+++ b/target/mips/tcg/nanomips32.decode
@@ -6,3 +6,11 @@
#
# Reference: nanoMIPS32 Instruction Set Technical Reference Manual
# (Document Number: MD01247)
+
+&r rs rt rd sa
+
+%lsa_u2 9:2 !function=minus_1
+
+@lsa ...... rt:5 rs:5 rd:5 .. --- ... ... &r sa=%lsa_u2
+
+LSA 001000 ..... ..... ..... .. ... 001 111 @lsa
diff --git a/target/mips/tcg/nanomips_translate.c b/target/mips/tcg/nanomips_translate.c
index c148c13ed9..9a6db4a828 100644
--- a/target/mips/tcg/nanomips_translate.c
+++ b/target/mips/tcg/nanomips_translate.c
@@ -9,6 +9,18 @@
#include "qemu/osdep.h"
#include "translate.h"
+static inline int minus_1(DisasContext *ctx, int x)
+{
+ return x - 1;
+}
+
/* Include the auto-generated decoders. */
#include "decode-nanomips16.c.inc"
#include "decode-nanomips32.c.inc"
+
+static bool trans_LSA(DisasContext *ctx, arg_r *a)
+{
+ gen_lsa(ctx, a->rd, a->rt, a->rs, a->sa);
+
+ return true;
+}
diff --git a/target/mips/tcg/nanomips_translate.c.inc b/target/mips/tcg/nanomips_translate.c.inc
index e401b92bfd..0e012ab3d0 100644
--- a/target/mips/tcg/nanomips_translate.c.inc
+++ b/target/mips/tcg/nanomips_translate.c.inc
@@ -399,7 +399,6 @@ enum {
/* POOL32A7 instruction pool */
enum {
NM_P_LSX = 0x00,
- NM_LSA = 0x01,
NM_EXTW = 0x03,
NM_POOL32AXF = 0x07,
};
@@ -3625,14 +3624,6 @@ static int decode_nanomips_32_48_opc(CPUMIPSState *env, DisasContext *ctx)
case NM_P_LSX:
gen_p_lsx(ctx, rd, rs, rt);
break;
- case NM_LSA:
- /*
- * In nanoMIPS, the shift field directly encodes the shift
- * amount, meaning that the supported shift values are in
- * the range 0 to 3 (instead of 1 to 4 in MIPSR6).
- */
- gen_lsa(ctx, rd, rt, rs, extract32(ctx->opcode, 9, 2) - 1);
- break;
case NM_EXTW:
gen_ext(ctx, 32, rd, rs, rt, extract32(ctx->opcode, 6, 5));
break;
--
2.45.2
On 11/11/24 14:44, Philippe Mathieu-Daudé wrote:
> From: Philippe Mathieu-Daudé <f4bug@amsat.org>
>
> Simply call the generic gen_lsa() helper, taking care
> to substract 1 to the shift field.
>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
> target/mips/tcg/nanomips32.decode | 8 ++++++++
> target/mips/tcg/nanomips_translate.c | 12 ++++++++++++
> target/mips/tcg/nanomips_translate.c.inc | 9 ---------
> 3 files changed, 20 insertions(+), 9 deletions(-)
>
> diff --git a/target/mips/tcg/nanomips32.decode b/target/mips/tcg/nanomips32.decode
> index 9cecf1e13d..11bf5cd6c4 100644
> --- a/target/mips/tcg/nanomips32.decode
> +++ b/target/mips/tcg/nanomips32.decode
> @@ -6,3 +6,11 @@
> #
> # Reference: nanoMIPS32 Instruction Set Technical Reference Manual
> # (Document Number: MD01247)
> +
> +&r rs rt rd sa
> +
> +%lsa_u2 9:2 !function=minus_1
> +
> +@lsa ...... rt:5 rs:5 rd:5 .. --- ... ... &r sa=%lsa_u2
> +
> +LSA 001000 ..... ..... ..... .. ... 001 111 @lsa
> diff --git a/target/mips/tcg/nanomips_translate.c b/target/mips/tcg/nanomips_translate.c
> index c148c13ed9..9a6db4a828 100644
> --- a/target/mips/tcg/nanomips_translate.c
> +++ b/target/mips/tcg/nanomips_translate.c
> @@ -9,6 +9,18 @@
> #include "qemu/osdep.h"
> #include "translate.h"
>
> +static inline int minus_1(DisasContext *ctx, int x)
> +{
> + return x - 1;
> +}
> +
> /* Include the auto-generated decoders. */
> #include "decode-nanomips16.c.inc"
> #include "decode-nanomips32.c.inc"
> +
> +static bool trans_LSA(DisasContext *ctx, arg_r *a)
> +{
> + gen_lsa(ctx, a->rd, a->rt, a->rs, a->sa);
I think decoding shift-amount - 1 is misleading.
Surely it would be better for other callers to pass extract(...) + 1?
r~
On 12/11/24 14:30, Richard Henderson wrote:
> On 11/11/24 14:44, Philippe Mathieu-Daudé wrote:
>> From: Philippe Mathieu-Daudé <f4bug@amsat.org>
>>
>> Simply call the generic gen_lsa() helper, taking care
>> to substract 1 to the shift field.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>> target/mips/tcg/nanomips32.decode | 8 ++++++++
>> target/mips/tcg/nanomips_translate.c | 12 ++++++++++++
>> target/mips/tcg/nanomips_translate.c.inc | 9 ---------
>> 3 files changed, 20 insertions(+), 9 deletions(-)
>> diff --git a/target/mips/tcg/nanomips_translate.c
>> b/target/mips/tcg/nanomips_translate.c
>> index c148c13ed9..9a6db4a828 100644
>> --- a/target/mips/tcg/nanomips_translate.c
>> +++ b/target/mips/tcg/nanomips_translate.c
>> @@ -9,6 +9,18 @@
>> #include "qemu/osdep.h"
>> #include "translate.h"
>> +static inline int minus_1(DisasContext *ctx, int x)
>> +{
>> + return x - 1;
>> +}
>> +
>> /* Include the auto-generated decoders. */
>> #include "decode-nanomips16.c.inc"
>> #include "decode-nanomips32.c.inc"
>> +
>> +static bool trans_LSA(DisasContext *ctx, arg_r *a)
>> +{
>> + gen_lsa(ctx, a->rd, a->rt, a->rs, a->sa);
>
> I think decoding shift-amount - 1 is misleading.
Yeah I thought the same while rebasing ...
> Surely it would be better for other callers to pass extract(...) + 1?
... but was too lazy to do the changes :p
>
>
> r~
>
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