[RFC,v4,19/29] Hexagon (target/hexagon) generator phase 3 - C preprocessor for decode tree

Run the C preprocessor across the instruction definition and encoding
files to expand macros and prepare the iset.py file.  The resulting
fill contains python data structures used to build the decode tree.

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
---
 target/hexagon/gen_dectree_import.c | 191 ++++++++++++++++++++++++++++++++++++
 1 file changed, 191 insertions(+)
 create mode 100644 target/hexagon/gen_dectree_import.c

On 9/28/20 7:28 PM, Taylor Simpson wrote:
> Run the C preprocessor across the instruction definition and encoding
> files to expand macros and prepare the iset.py file.  The resulting
> fill contains python data structures used to build the decode tree.
> 
> Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
> ---
>  target/hexagon/gen_dectree_import.c | 191 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 191 insertions(+)
>  create mode 100644 target/hexagon/gen_dectree_import.c
> 
> diff --git a/target/hexagon/gen_dectree_import.c b/target/hexagon/gen_dectree_import.c
> new file mode 100644
> index 0000000..237726e
> --- /dev/null
> +++ b/target/hexagon/gen_dectree_import.c
> @@ -0,0 +1,191 @@
> +/*
> + *  Copyright(c) 2019-2020 Qualcomm Innovation Center, Inc. All Rights Reserved.
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or
> + *  (at your option) any later version.
> + *
> + *  This program is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + *  GNU General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License
> + *  along with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +/*
> + * This program generates the encodings file that is processed by
> + * the dectree.py script to produce the decoding tree.  We use the C
> + * preprocessor to manipulate the files imported from the Hexagon
> + * architecture library.
> + */
> +#include "qemu/osdep.h"
> +#include "opcodes.h"
> +
> +#define STRINGIZE(X)    #X
> +
> +const char *opcode_names[] = {

Richard will probably ask to use "const char *const opcode_names[]".

> +#define OPCODE(IID) STRINGIZE(IID)
> +#include "opcodes_def_generated.h"
> +    NULL
> +#undef OPCODE
> +};
> +
> +const char *opcode_syntax[XX_LAST_OPCODE];
> +
> +/*
> + * Process the instruction definitions
> + *     Scalar core instructions have the following form
> + *         Q6INSN(A2_add,"Rd32=add(Rs32,Rt32)",ATTRIBS(),
> + *         "Add 32-bit registers",
> + *         { RdV=RsV+RtV;})
> + */
> +void opcode_init(void)
> +{
> +#define Q6INSN(TAG, BEH, ATTRIBS, DESCR, SEM) \
> +   opcode_syntax[TAG] = BEH;
> +#define EXTINSN(TAG, BEH, ATTRIBS, DESCR, SEM) \
> +   opcode_syntax[TAG] = BEH;
> +#include "imported/allidefs.def"
> +#undef Q6INSN
> +#undef EXTINSN
> +}
> +
> +const char *opcode_rregs[] = {

Ditto '*const'.

> +#define REGINFO(TAG, REGINFO, RREGS, WREGS) RREGS,
> +#define IMMINFO(TAG, SIGN, SIZE, SHAMT, SIGN2, SIZE2, SHAMT2)  /* nothing */
> +#include "op_regs_generated.h"
> +    NULL
> +#undef REGINFO
> +#undef IMMINFO
> +};
> +
> +const char *opcode_wregs[] = {

Ditto '*const'.

> +#define REGINFO(TAG, REGINFO, RREGS, WREGS) WREGS,
> +#define IMMINFO(TAG, SIGN, SIZE, SHAMT, SIGN2, SIZE2, SHAMT2)  /* nothing */
> +#include "op_regs_generated.h"
> +    NULL
> +#undef REGINFO
> +#undef IMMINFO
> +};
> +
> +opcode_encoding_t opcode_encodings[] = {

'const'.

> +#define DEF_ENC32(TAG, ENCSTR) \
> +    [TAG] = { .encoding = ENCSTR },
> +#define DEF_ENC_SUBINSN(TAG, CLASS, ENCSTR) \
> +    [TAG] = { .encoding = ENCSTR, .enc_class = CLASS },
> +#define DEF_EXT_ENC(TAG, CLASS, ENCSTR) \
> +    [TAG] = { .encoding = ENCSTR, .enc_class = CLASS },
> +#include "imported/encode.def"
> +#undef DEF_ENC32
> +#undef DEF_ENC_SUBINSN
> +#undef DEF_EXT_ENC
> +};
> +
> +static const char * const opcode_enc_class_names[XX_LAST_ENC_CLASS] = {
> +    "NORMAL",
> +    "16BIT",
> +    "SUBINSN_A",
> +    "SUBINSN_L1",
> +    "SUBINSN_L2",
> +    "SUBINSN_S1",
> +    "SUBINSN_S2",
> +    "EXT_noext",
> +    "EXT_mmvec",
> +};
> +
> +static const char *get_opcode_enc(int opcode)
> +{
> +    const char *tmp = opcode_encodings[opcode].encoding;
> +    if (tmp == NULL) {
> +        tmp = "MISSING ENCODING";
> +    }
> +    return tmp;
> +}
> +
> +static const char *get_opcode_enc_class(int opcode)
> +{
> +    return opcode_enc_class_names[opcode_encodings[opcode].enc_class];
> +}
> +
> +static void gen_iset_table(FILE *out)
> +{
> +    int i;
> +
> +    fprintf(out, "iset = {\n");
> +    for (i = 0; i < XX_LAST_OPCODE; i++) {
> +        fprintf(out, "\t\'%s\' : {\n", opcode_names[i]);
> +        fprintf(out, "\t\t\'tag\' : \'%s\',\n", opcode_names[i]);
> +        fprintf(out, "\t\t\'syntax\' : \'%s\',\n", opcode_syntax[i]);
> +        fprintf(out, "\t\t\'rregs\' : \'%s\',\n", opcode_rregs[i]);
> +        fprintf(out, "\t\t\'wregs\' : \'%s\',\n", opcode_wregs[i]);
> +        fprintf(out, "\t\t\'enc\' : \'%s\',\n", get_opcode_enc(i));
> +        fprintf(out, "\t\t\'enc_class\' : \'%s\',\n", get_opcode_enc_class(i));
> +        fprintf(out, "\t},\n");
> +    }
> +    fprintf(out, "};\n\n");
> +}
> +
> +static void gen_tags_list(FILE *out)
> +{
> +    int i;
> +
> +    fprintf(out, "tags = [\n");
> +    for (i = 0; i < XX_LAST_OPCODE; i++) {
> +        fprintf(out, "\t\'%s\',\n", opcode_names[i]);
> +    }
> +    fprintf(out, "];\n\n");
> +}
> +
> +static void gen_enc_ext_spaces_table(FILE *out)
> +{
> +    fprintf(out, "enc_ext_spaces = {\n");
> +#define DEF_EXT_SPACE(SPACEID, ENCSTR) \
> +    fprintf(out, "\t\'%s\' : \'%s\',\n", #SPACEID, ENCSTR);
> +#include "imported/encode.def"
> +#undef DEF_EXT_SPACE
> +    fprintf(out, "};\n\n");
> +}
> +
> +static void gen_subinsn_groupings_table(FILE *out)
> +{
> +    fprintf(out, "subinsn_groupings = {\n");
> +#define DEF_PACKED32(TAG, TYPEA, TYPEB, ENCSTR) \
> +    do { \
> +        fprintf(out, "\t\'%s\' : {\n", #TAG); \
> +        fprintf(out, "\t\t\'name\' : \'%s\',\n", #TAG); \
> +        fprintf(out, "\t\t\'class_a\' : \'%s\',\n", #TYPEA); \
> +        fprintf(out, "\t\t\'class_b\' : \'%s\',\n", #TYPEB); \
> +        fprintf(out, "\t\t\'enc\' : \'%s\',\n", ENCSTR); \
> +        fprintf(out, "\t},\n"); \
> +    } while (0);
> +#include "imported/encode.def"
> +#undef DEF_PACKED32
> +    fprintf(out, "};\n\n");
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +    FILE *outfile;
> +
> +    if (argc != 2) {
> +        fprintf(stderr, "Usage: gen_dectree_import ouptputfile\n");
> +        return -1;

Again, 'return 1;'?

> +    }
> +    outfile = fopen(argv[1], "w");
> +    if (outfile == NULL) {
> +        fprintf(stderr, "Cannot open %s for writing\n", argv[1]);
> +        return -1;

Ditto.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> +    }
> +
> +    opcode_init();
> +    gen_iset_table(outfile);
> +    gen_tags_list(outfile);
> +    gen_enc_ext_spaces_table(outfile);
> +    gen_subinsn_groupings_table(outfile);
> +
> +    fclose(outfile);
> +    return 0;
> +}
>

On 9/29/20 6:37 AM, Philippe Mathieu-Daudé wrote:
> On 9/28/20 7:28 PM, Taylor Simpson wrote:
>> Run the C preprocessor across the instruction definition and encoding
>> files to expand macros and prepare the iset.py file.  The resulting
>> fill contains python data structures used to build the decode tree.
>>
>> Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
>> ---
>>  target/hexagon/gen_dectree_import.c | 191 ++++++++++++++++++++++++++++++++++++
>>  1 file changed, 191 insertions(+)
>>  create mode 100644 target/hexagon/gen_dectree_import.c
>>
>> diff --git a/target/hexagon/gen_dectree_import.c b/target/hexagon/gen_dectree_import.c
>> new file mode 100644
>> index 0000000..237726e
>> --- /dev/null
>> +++ b/target/hexagon/gen_dectree_import.c
>> @@ -0,0 +1,191 @@
>> +/*
>> + *  Copyright(c) 2019-2020 Qualcomm Innovation Center, Inc. All Rights Reserved.
>> + *
>> + *  This program is free software; you can redistribute it and/or modify
>> + *  it under the terms of the GNU General Public License as published by
>> + *  the Free Software Foundation; either version 2 of the License, or
>> + *  (at your option) any later version.
>> + *
>> + *  This program is distributed in the hope that it will be useful,
>> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + *  GNU General Public License for more details.
>> + *
>> + *  You should have received a copy of the GNU General Public License
>> + *  along with this program; if not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +/*
>> + * This program generates the encodings file that is processed by
>> + * the dectree.py script to produce the decoding tree.  We use the C
>> + * preprocessor to manipulate the files imported from the Hexagon
>> + * architecture library.
>> + */
>> +#include "qemu/osdep.h"
>> +#include "opcodes.h"
>> +
>> +#define STRINGIZE(X)    #X
>> +
>> +const char *opcode_names[] = {
> 
> Richard will probably ask to use "const char *const opcode_names[]".

It is good practice, even if this is a generator and so doesn't actually impact
the qemu executable itself.  ;-)


>> +const char *opcode_syntax[XX_LAST_OPCODE];
>> +
>> +/*
>> + * Process the instruction definitions
>> + *     Scalar core instructions have the following form
>> + *         Q6INSN(A2_add,"Rd32=add(Rs32,Rt32)",ATTRIBS(),
>> + *         "Add 32-bit registers",
>> + *         { RdV=RsV+RtV;})
>> + */
>> +void opcode_init(void)
>> +{
>> +#define Q6INSN(TAG, BEH, ATTRIBS, DESCR, SEM) \
>> +   opcode_syntax[TAG] = BEH;
>> +#define EXTINSN(TAG, BEH, ATTRIBS, DESCR, SEM) \
>> +   opcode_syntax[TAG] = BEH;
>> +#include "imported/allidefs.def"
>> +#undef Q6INSN
>> +#undef EXTINSN
>> +}

What is it that about this case that can't be initialized at compile time?


r~

> -----Original Message-----
> From: Richard Henderson <richard.henderson@linaro.org>
> Sent: Thursday, October 1, 2020 1:54 PM
> To: Philippe Mathieu-Daudé <f4bug@amsat.org>; Taylor Simpson
> <tsimpson@quicinc.com>; qemu-devel@nongnu.org
> Cc: laurent@vivier.eu; riku.voipio@iki.fi; aleksandar.m.mail@gmail.com;
> ale@rev.ng
> Subject: Re: [RFC PATCH v4 19/29] Hexagon (target/hexagon) generator
> phase 3 - C preprocessor for decode tree
>
> >> +void opcode_init(void)
> >> +{
> >> +#define Q6INSN(TAG, BEH, ATTRIBS, DESCR, SEM) \
> >> +   opcode_syntax[TAG] = BEH;
> >> +#define EXTINSN(TAG, BEH, ATTRIBS, DESCR, SEM) \
> >> +   opcode_syntax[TAG] = BEH;
> >> +#include "imported/allidefs.def"
> >> +#undef Q6INSN
> >> +#undef EXTINSN
> >> +}
>
> What is it that about this case that can't be initialized at compile time?

Several of the Q6INSN's in the imported directory have a ; after them - bleh.  Here's an example.
    Q6INSN(L2_loadw_locked,"Rd32=memw_locked(Rs32)", ATTRIBS(A_LOAD,A_RESTRICT_SLOT0ONLY), "Load word with lock",
    { fEA_REG(RsV); fLOAD_LOCKED(1,4,u,EA,RdV) });
So, if I do this, there are syntax errors.
    const char * const opcode_syntax[XX_LAST_OPCODE] = {
    #define Q6INSN(TAG, BEH, ATTRIBS, DESCR, SEM) \
       [TAG] = BEH,
    #define EXTINSN(TAG, BEH, ATTRIBS, DESCR, SEM) \
       [TAG] = BEH,
    #include "imported/allidefs.def"
    #undef Q6INSN
    #undef EXTINSN
    };

I'll remove the extra ;'s from the imported files and make the change in this file.

Taylor