[RFA] Add sh4a to sh-sim (2nd iteration)
Michael Snyder
msnyder@redhat.com
Thu Jan 8 22:02:00 GMT 2004
Joern Rennecke wrote:
>> (expand_ppi_code): Flatten loop for simplicity, tweak for 12-bit
>> instead of 8-bit table (some insns are ambiguous to 8 bits).
>
>
> You are converting iteration into recursion - I don't see
> what is flat about deep recursion.
Just the code structure -- it's one "loop" shallower.
It's also more consistant with the other expand_opcode
function, in which all the recursions are explicit.
And it's not that deep -- upper limit, 12 levels;
in practice never that many.
>>--- gencode.c 7 Jan 2004 21:38:26 -0000
>>***************
>>*** 1,4 ****
>>! /* Simulator/Opcode generator for the Hitachi Super-H architecture.
>>
>> Written by Steve Chamberlain of Cygnus Support.
>> sac@cygnus.com
>>--- 1,5 ----
>>! /* Simulator/Opcode generator for the Renesas
>>! (formerly Hitachi) Super-H architecture.
>>
>> Written by Steve Chamberlain of Cygnus Support.
>> sac@cygnus.com
>
>
> That should be Renesas (formerly Hitachi) / SuperH Inc SuperH architecture.
OK.
>>+ /* sh4a */
>>+ { "", "", "ftrv <FV_N>", "1111vv0111111101",
>>+ "if (FPSCR_PR)",
>>+ " RAISE_EXCEPTION (SIGILL);",
>>+ "else",
>>+ "{",
>>+ " /* FIXME not implemented. */",
>>+ " printf (\"ftrv xmtrx, FV%d\\n\", v1);",
>>+ "}",
>>+ },
>
>
> ftrv is an sh4 instruction.
OK.
>> { "n", "n", "ldc.l @<REG_N>+,DBR", "0100nnnn11110110",
>> "MA (1);",
>> "DBR = RLAT (R[n]);",
>> "R[n] += 4;",
>> "/* FIXME: user mode */",
>> },
>>! { "n", "n", "ldc.l @<REG_N>+,DBR", "0100nnnn11110110",
>>! "if (SR_MD)",
>>! "{ /* priv mode */",
>>! " MA (1);",
>>! " DBR = RLAT (R[n]);",
>>! " R[n] += 4;",
>>! "}",
>>! "else",
>>! " RAISE_EXCEPTION (SIGILL); /* user mode */",
>>! },
>
>
> Why do you keep the old "ldc.l @<REG_N>+,DBR" version around?
Good question. Assume that I will delete it, unles I say otherwise.
>>! { "", "mn", "mul.l <REG_M>,<REG_N>", "0000nnnnmmmm0111",
>>! "MACL = ((int) R[n]) * ((int) R[m]);",
>> },
>
>
> The #if 0 was left there as a reminder that the casts to int are not fully
> portable. The casts should be replaced with the SEXT32 macro.
OK, I'll either put them back or do the replacement.
If I put them back, I'll add this as a comment.
>>! { "", "n", "movx.w @<REG_xy>,<DSP_XY>", "111100xyXY0001??",
>> "DSP_R (m) = RSWAT (R[n]) << 16;",
>>! "if (iword & 3)",
>>! " {",
>>! " iword &= 0xfd53; goto top;",
>>! " }",
>>! },
>
>
> I think I understand the way the new move instructions were added a bit
> better now.
> The implementation could be made faster by having the movx/nopy
> patterns separate, but I suppose speed is not such an issue for sh-dsp
> simulation, seeing that we don't have time-intensive testcases that
> use dsp move instructions.
Shall we commit it as is for now, and save speed improvements
for a later round?
>
>
>>*************** op ppi_tab[] =
>>*** 1379,1385 ****
>> "COMPUTE_OVERFLOW;",
>> "greater_equal = 0;",
>> },
>>! { "","", "pmuls Se,Sf,Dg", "0100eeffxxyygguu",
>> "res = (DSP_R (e) >> 16) * (DSP_R (f) >> 16) * 2;",
>> "if (res == 0x80000000)",
>> " res = 0x7fffffff;",
>>--- 1581,1587 ----
>> "COMPUTE_OVERFLOW;",
>> "greater_equal = 0;",
>> },
>>! { "","", "pmuls Se,Sf,Dg", "0100eeff0000gguu",
>> "res = (DSP_R (e) >> 16) * (DSP_R (f) >> 16) * 2;",
>> "if (res == 0x80000000)",
>> " res = 0x7fffffff;",
>
>
> According to the sh2-dsp manual that is still at the Renesas web site,
> the xx / yy fields are still present in the pmuls instruction.
Hmm, well, are they used for anything? I think I took them out to
resolve a conflict with another insn (but I don't remember for sure).
Since there's no corresponding register parameter, and the code
does not use them -- is there any harm? If the other patterns
are not used now, they probably will be someday.
>> printf ("ppi_insn (iword)\n");
>> printf (" int iword;\n");
>> printf ("{\n");
>>+ printf (" /* 'ee' = [x0, x1, y0, a1] (FIXME [x0, x1, a1, m1]) */\n");
>> printf (" static char e_tab[] = { 8, 9, 10, 5};\n");
>>+ printf (" /* 'ff' = [y0, y1, x0, a1] (FIXME [y0, y1, a1, m1]) */\n");
>> printf (" static char f_tab[] = {10, 11, 8, 5};\n");
>>+ printf (" /* 'xx'(?) = [x0, x1, a0, a1] */\n");
>> printf (" static char x_tab[] = { 8, 9, 7, 5};\n");
>>+ printf (" /* 'yy'(?) = [y0, y1, m0, m1] */\n");
>> printf (" static char y_tab[] = {10, 11, 12, 14};\n");
>>+ printf (" /* 'gg' = [m0, m1, a0, a1] */\n");
>> printf (" static char g_tab[] = {12, 14, 7, 5};\n");
>>+ printf (" /* 'uu' = [x0, y0, a0, a1] (FIXME [m1, x1, a0, a1]) */\n");
>> printf (" static char u_tab[] = { 8, 10, 7, 5};\n");
>
>
> What are these FIXMEs supposed to mean?
I did this work 4 months ago. Probably I thought the
comment was wrong, and that the actual set of registers
was as shown. Your second opinion would be appreciated.
More information about the Gdb-patches
mailing list